Publicaciones
2000 |
J.M. Montagna, A.R. Vecchietti, O.A. Iribarren, J.M. Pinto, J.A. Asenjo Optimal design of protein production plants with time and size factor process models (Artículo de revista) Biotechnology Progress, 16 (2), pp. 228-237, 2000, (cited By 40). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Montagna2000228, title = {Optimal design of protein production plants with time and size factor process models}, author = { J.M. Montagna and A.R. Vecchietti and O.A. Iribarren and J.M. Pinto and J.A. Asenjo}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0034059846&partnerID=40&md5=8f8f4e1d0f683640016fc5ebce8be472}, doi = {10.1021/bp990145d}, year = {2000}, date = {2000-01-01}, journal = {Biotechnology Progress}, volume = {16}, number = {2}, pages = {228-237}, abstract = {In this work we propose an optimization model for the design of a biotechnological multiproduct batch plant. A first level of detail posynomial model is constructed for each unit, as well as decisions regarding the structural optimization of the plant. A particular feature of this model is that it contains composite units in which semicontinuous items operate on the material contained by batch items. This occurs in the purification steps, in particular with the microfilters operating between retentate and permeate vessels, and with the homogenizer and ultrafilters operating on the material contained in a batch holding vessel. Also, the unit models rely on batch operating time expressions that depend on both the batch size and the size of semicontinuous items. The model takes into account all of the available options to increase the efficiency of the batch plant design: unit duplication in-phase and out-of-phase and intermediate storage tanks. The resulting mathematical model for the minimization of the plant capital cost is a mixed integer non-linear program (MINLP), which is solved to global optimality with an implementation of the outer approximation/equality relaxation/augmented penalty (OA/ER/AP) method. A plant that produces four recombinant proteins in eight processing stages is used to illustrate the proposed approach. An interesting feature of this example is that it represents an attempt to standardize a plant for the production of both therapeutic and nontherapeutic proteins; the model applied is generic and can thus be applied to any such modular plant. Results indicate that the best solution in terms of minimal capital cost contains no units in parallel and with intermediate storage tank allocation. In this work we propose an optimization model for the design of a biotechnological multiproduct batch plant. A first level of detail posynomial model is constructed for each unit, as well as decisions regarding the structural optimization of the plant. A particular feature of this model is that it contains composite units in which semicontinuous items operate on the material contained by batch items. This occurs in the purification steps, in particular with the microfilters operating between retentate and permeate vessels, and with the homogenizer and ultrafilters operating on the material contained in a batch holding vessel. Also, the unit models rely on batch operating time expressions that depend on both the batch size and the size of semicontinuous items. The model takes into account all of the available options to increase the efficiency of the batch plant design: unit duplication in-phase and out-of-phase and intermediate storage tanks. The resulting mathematical model for the minimization of the plant capital cost is a mixed integer non-linear program (MINLP), which is solved to global optimality with an implementation of the outer approximation/equality relaxation/augmented penalty (OA/ER/AP) method. A plant that produces four recombinant proteins in eight processing stages is used to illustrate the proposed approach. An interesting feature of this example is that it represents an attempt to standardize a plant for the production of both therapeutic and nontherapeutic proteins; the model applied is generic and can thus be applied to any such modular plant. Results indicate that the best solution in terms of minimal capital cost contains no units in parallel and with intermediate storage tank allocation.}, note = {cited By 40}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this work we propose an optimization model for the design of a biotechnological multiproduct batch plant. A first level of detail posynomial model is constructed for each unit, as well as decisions regarding the structural optimization of the plant. A particular feature of this model is that it contains composite units in which semicontinuous items operate on the material contained by batch items. This occurs in the purification steps, in particular with the microfilters operating between retentate and permeate vessels, and with the homogenizer and ultrafilters operating on the material contained in a batch holding vessel. Also, the unit models rely on batch operating time expressions that depend on both the batch size and the size of semicontinuous items. The model takes into account all of the available options to increase the efficiency of the batch plant design: unit duplication in-phase and out-of-phase and intermediate storage tanks. The resulting mathematical model for the minimization of the plant capital cost is a mixed integer non-linear program (MINLP), which is solved to global optimality with an implementation of the outer approximation/equality relaxation/augmented penalty (OA/ER/AP) method. A plant that produces four recombinant proteins in eight processing stages is used to illustrate the proposed approach. An interesting feature of this example is that it represents an attempt to standardize a plant for the production of both therapeutic and nontherapeutic proteins; the model applied is generic and can thus be applied to any such modular plant. Results indicate that the best solution in terms of minimal capital cost contains no units in parallel and with intermediate storage tank allocation. In this work we propose an optimization model for the design of a biotechnological multiproduct batch plant. A first level of detail posynomial model is constructed for each unit, as well as decisions regarding the structural optimization of the plant. A particular feature of this model is that it contains composite units in which semicontinuous items operate on the material contained by batch items. This occurs in the purification steps, in particular with the microfilters operating between retentate and permeate vessels, and with the homogenizer and ultrafilters operating on the material contained in a batch holding vessel. Also, the unit models rely on batch operating time expressions that depend on both the batch size and the size of semicontinuous items. The model takes into account all of the available options to increase the efficiency of the batch plant design: unit duplication in-phase and out-of-phase and intermediate storage tanks. The resulting mathematical model for the minimization of the plant capital cost is a mixed integer non-linear program (MINLP), which is solved to global optimality with an implementation of the outer approximation/equality relaxation/augmented penalty (OA/ER/AP) method. A plant that produces four recombinant proteins in eight processing stages is used to illustrate the proposed approach. An interesting feature of this example is that it represents an attempt to standardize a plant for the production of both therapeutic and nontherapeutic proteins; the model applied is generic and can thus be applied to any such modular plant. Results indicate that the best solution in terms of minimal capital cost contains no units in parallel and with intermediate storage tank allocation. |
J. Espinosa, H.E. Salomone, S. Xu Using conceptual models for the synthesis and design of batch distillations (Artículo de revista) Computer Aided Chemical Engineering, 8 (C), pp. 1033-1038, 2000, (cited By 3). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Espinosa20001033, title = {Using conceptual models for the synthesis and design of batch distillations}, author = { J. Espinosa and H.E. Salomone and S. Xu}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0000880959&partnerID=40&md5=44083dbc79417b257503f6883bbd2b08}, doi = {10.1016/S1570-7946(00)80174-1}, year = {2000}, date = {2000-01-01}, journal = {Computer Aided Chemical Engineering}, volume = {8}, number = {C}, pages = {1033-1038}, abstract = {We present a methodology to estimate the maximum recovery of each component in an azeotropic multicomponent mixture processed at a batch distillation column. Based in the most recent advances in the field of separation feasibility we have adapted an algorithm to predict all the distillation regions for the multicomponent mixture with their corresponding natural and distillation boundaries. The results of the maximum separation problem togheter with those corresponding to conceptual dynamic runs are used to illustrate several important issues related to the synthesis and design of highly non-ideal azeotropic mixtures. © 2000 Elsevier B.V. All rights reserved.}, note = {cited By 3}, keywords = {}, pubstate = {published}, tppubtype = {article} } We present a methodology to estimate the maximum recovery of each component in an azeotropic multicomponent mixture processed at a batch distillation column. Based in the most recent advances in the field of separation feasibility we have adapted an algorithm to predict all the distillation regions for the multicomponent mixture with their corresponding natural and distillation boundaries. The results of the maximum separation problem togheter with those corresponding to conceptual dynamic runs are used to illustrate several important issues related to the synthesis and design of highly non-ideal azeotropic mixtures. © 2000 Elsevier B.V. All rights reserved. |
1999 |
E.C. Martínez Solving batch process scheduling/planning tasks using reinforcement learning (Artículo de revista) Computers and Chemical Engineering, 23 (SUPPL. 1), pp. S527-S530, 1999, (cited By 4). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Martínez1999, title = {Solving batch process scheduling/planning tasks using reinforcement learning}, author = { E.C. Martínez}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77649283071&partnerID=40&md5=5ef9c37642d8d42771165217454433a3}, doi = {10.1016/S0098-1354(99)80130-6}, year = {1999}, date = {1999-01-01}, journal = {Computers and Chemical Engineering}, volume = {23}, number = {SUPPL. 1}, pages = {S527-S530}, abstract = {The complex and dynamic nature of shop-floor environments, coupled with unpredictable market demands, makes batch plant's reactivity a crucial management issue. In this work, reinforcement learning and a repair-based search strategy are integrated together in a learning problem-solver for scheduling/planning tasks. The overaIl design of the learning algorithm is based on a state-space search perspective in which the associated optimization problem is solved by starting in some initial infeasible solution and then proceeding to progressively repair intermediate solutions until a feasible one is found. A key component to accelerate search in the state space is learning an evaluation function that accumulates context-dependent knowledge about the goodness of applying a smaIl set of repair operators so that future (re)scheduling and (re)planning problems can be solved with less effort. A demonstrative example is used to illustrate the importance of improving plant reactivity by learning to repair infeasible plans and schedules. © 1999 Elsevier Science Ltd.}, note = {cited By 4}, keywords = {}, pubstate = {published}, tppubtype = {article} } The complex and dynamic nature of shop-floor environments, coupled with unpredictable market demands, makes batch plant's reactivity a crucial management issue. In this work, reinforcement learning and a repair-based search strategy are integrated together in a learning problem-solver for scheduling/planning tasks. The overaIl design of the learning algorithm is based on a state-space search perspective in which the associated optimization problem is solved by starting in some initial infeasible solution and then proceeding to progressively repair intermediate solutions until a feasible one is found. A key component to accelerate search in the state space is learning an evaluation function that accumulates context-dependent knowledge about the goodness of applying a smaIl set of repair operators so that future (re)scheduling and (re)planning problems can be solved with less effort. A demonstrative example is used to illustrate the importance of improving plant reactivity by learning to repair infeasible plans and schedules. © 1999 Elsevier Science Ltd. |
E.C. Martínez Project-oriented management of batch plants. Information system design (Artículo de revista) Computers and Chemical Engineering, 23 (SUPPL. 1), pp. S711-S714, 1999, (cited By 2). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Martínez1999b, title = {Project-oriented management of batch plants. Information system design}, author = { E.C. Martínez}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-4244082353&partnerID=40&md5=dcee938e38871f46355ec7677243eede}, doi = {10.1016/S0098-1354(99)80174-4}, year = {1999}, date = {1999-01-01}, journal = {Computers and Chemical Engineering}, volume = {23}, number = {SUPPL. 1}, pages = {S711-S714}, abstract = {Intense competition and rapid environmental changes are revealing severe limitations in the effectiveness of the hierarchical and functional-oriented management system currently used by the vast majority of batchmanufacturing industries. A project-oriented enterprise model of batch plants is proposed here. Each project is seen as an autonomous, temporary entity within the management system, in which different types of expertise are combined to achieve a concrete goal or deliverable (e.g. completing a given order, product development, maintenance program, etc.). The cornerstone for successfully implementing this type of project-based organization is the design of an information system backbone that favors a decentralized, yet effective decision structure. To achieve this, an integrated design approach which combines a systems perspective describing the organizational complexity resulting from the multifunctional nature of projects with an analytical viewpoint emphasizing the structure of product recipes, equipment capabilities and human competencies (skills and knowledge) that are required for batch plant management is proposed. This integration is crucial to the establishment and widespread accessibility of enterprise memory, namely accumulation, adaptation and use of best practice. It is argued here that these capabilities need to be built-in as part of the information system design. A prototype implementation of the proposed design in Project 98™ is conceptually discussed. © 1999 Elsevier Science Ltd.}, note = {cited By 2}, keywords = {}, pubstate = {published}, tppubtype = {article} } Intense competition and rapid environmental changes are revealing severe limitations in the effectiveness of the hierarchical and functional-oriented management system currently used by the vast majority of batchmanufacturing industries. A project-oriented enterprise model of batch plants is proposed here. Each project is seen as an autonomous, temporary entity within the management system, in which different types of expertise are combined to achieve a concrete goal or deliverable (e.g. completing a given order, product development, maintenance program, etc.). The cornerstone for successfully implementing this type of project-based organization is the design of an information system backbone that favors a decentralized, yet effective decision structure. To achieve this, an integrated design approach which combines a systems perspective describing the organizational complexity resulting from the multifunctional nature of projects with an analytical viewpoint emphasizing the structure of product recipes, equipment capabilities and human competencies (skills and knowledge) that are required for batch plant management is proposed. This integration is crucial to the establishment and widespread accessibility of enterprise memory, namely accumulation, adaptation and use of best practice. It is argued here that these capabilities need to be built-in as part of the information system design. A prototype implementation of the proposed design in Project 98™ is conceptually discussed. © 1999 Elsevier Science Ltd. |
A. Lozano, O.J. Chiotti Modeling the supervising control of a multipurpose batch plant operated by activity (Artículo de revista) Computers and Chemical Engineering, 23 (SUPPL. 1), pp. S187-S190, 1999, (cited By 2). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Lozano1999, title = {Modeling the supervising control of a multipurpose batch plant operated by activity}, author = { A. Lozano and O.J. Chiotti}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-25944456647&partnerID=40&md5=9601dd030dafafe4da6728c5aa5c98a7}, doi = {10.1016/S0098-1354(99)80046-5}, year = {1999}, date = {1999-01-01}, journal = {Computers and Chemical Engineering}, volume = {23}, number = {SUPPL. 1}, pages = {S187-S190}, abstract = {The aim of this work is to present a model to represent the supervisory contra! structure organized by activities of an order driven multipurpose batch plant. In this control structure each activity of the plant has its own supervisory control and all of them are coordinated by a supervisory control structure at the level of orders. In this work we present a framework to represent the supervising control of an order driven multipurpose batch plant operated by activities. The framework is based on a strategy that uses Petri nets to describe and analyze the supervising control. This strategy permits to automate the modeling of the supervising control. Based on this framework we developed a supervising control support system (SCSS) of an order driven multipurpose batch plant operated by activities. © 1999 Elsevier Science Ltd.}, note = {cited By 2}, keywords = {}, pubstate = {published}, tppubtype = {article} } The aim of this work is to present a model to represent the supervisory contra! structure organized by activities of an order driven multipurpose batch plant. In this control structure each activity of the plant has its own supervisory control and all of them are coordinated by a supervisory control structure at the level of orders. In this work we present a framework to represent the supervising control of an order driven multipurpose batch plant operated by activities. The framework is based on a strategy that uses Petri nets to describe and analyze the supervising control. This strategy permits to automate the modeling of the supervising control. Based on this framework we developed a supervising control support system (SCSS) of an order driven multipurpose batch plant operated by activities. © 1999 Elsevier Science Ltd. |
S. Gonnet, O.J. Chiotti Modeling of the supervisory control system of a multipurpose batch plant (Artículo de revista) Computers and Chemical Engineering, 23 (4-5), pp. 611-622, 1999, (cited By 5). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Gonnet1999611, title = {Modeling of the supervisory control system of a multipurpose batch plant}, author = { S. Gonnet and O.J. Chiotti}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0033134748&partnerID=40&md5=be6996a9b4e4a28eb574a5659b4d8061}, doi = {10.1016/S0098-1354(98)00297-X}, year = {1999}, date = {1999-01-01}, journal = {Computers and Chemical Engineering}, volume = {23}, number = {4-5}, pages = {611-622}, abstract = {A supervisory control of a multipurpose batch plant supervises that the plant is operated according to the schedule of production orders set by the scheduling module. The supervisory control depends on the plant topology, which is not defined a priori but generated while scheduling the production orders. This requires that the supervisory control system be able to generate the control structure after the generation of plant topologies. In the first part of this work we present a framework to represent the supervisory control of an order driven multipurpose batch plant. The framework is based on a strategy that uses Petri nets to describe and analyze the supervisory control of a process. This strategy permits the automation of the modeling of the supervisory control. Based on this framework we developed a supervisory control support system (SCSS) of an order driven multipurpose batch plant. In the second part of this work we present a description of an object oriented analysis and design of this SCSS. A supervisory control of a multipurpose batch plant supervises that the plant is operated according to the schedule of production orders set by the scheduling module. The supervisory control depends on the plant topology, which is not defined a priori but generated while scheduling the production orders. This requires that the supervisory control system be able to generate the control structure after the generation of plant topologies. In the first part of this work we present a framework to represent the supervisory control of an order driven multipurpose batch plant. The framework is based on a strategy that uses Petri nets to describe and analyze the supervisory control of a process. This strategy permits the automation of the modeling of the supervisory control. Based on this framework we developed a supervisory control support system (SCSS) of an order driven multipurpose batch plant. In the second part of this work we present a description of an object oriented analysis and design of this SCSS.}, note = {cited By 5}, keywords = {}, pubstate = {published}, tppubtype = {article} } A supervisory control of a multipurpose batch plant supervises that the plant is operated according to the schedule of production orders set by the scheduling module. The supervisory control depends on the plant topology, which is not defined a priori but generated while scheduling the production orders. This requires that the supervisory control system be able to generate the control structure after the generation of plant topologies. In the first part of this work we present a framework to represent the supervisory control of an order driven multipurpose batch plant. The framework is based on a strategy that uses Petri nets to describe and analyze the supervisory control of a process. This strategy permits the automation of the modeling of the supervisory control. Based on this framework we developed a supervisory control support system (SCSS) of an order driven multipurpose batch plant. In the second part of this work we present a description of an object oriented analysis and design of this SCSS. A supervisory control of a multipurpose batch plant supervises that the plant is operated according to the schedule of production orders set by the scheduling module. The supervisory control depends on the plant topology, which is not defined a priori but generated while scheduling the production orders. This requires that the supervisory control system be able to generate the control structure after the generation of plant topologies. In the first part of this work we present a framework to represent the supervisory control of an order driven multipurpose batch plant. The framework is based on a strategy that uses Petri nets to describe and analyze the supervisory control of a process. This strategy permits the automation of the modeling of the supervisory control. Based on this framework we developed a supervisory control support system (SCSS) of an order driven multipurpose batch plant. In the second part of this work we present a description of an object oriented analysis and design of this SCSS. |
A.R. Vecchietti, I.E. Grossmann LOGMIP: A disjunctive 0-1 non-linear optimizer for process system models (Artículo de revista) Computers and Chemical Engineering, 23 (4-5), pp. 555-565, 1999, (cited By 38). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Vecchietti1999555, title = {LOGMIP: A disjunctive 0-1 non-linear optimizer for process system models}, author = { A.R. Vecchietti and I.E. Grossmann}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0033134714&partnerID=40&md5=656004ec1ad5e5ff8bf312b2be2eb2c0}, doi = {10.1016/S0098-1354(98)00293-2}, year = {1999}, date = {1999-01-01}, journal = {Computers and Chemical Engineering}, volume = {23}, number = {4-5}, pages = {555-565}, abstract = {Discrete-continuous non-linear optimization models are frequently used to formulate problems in process system engineering. Major modeling alternatives and solution algorithms include generalized disjunctive programming and mixed integer non-linear programming (MINLP). Both have advantages and drawbacks depending on the problem they are dealing with. In this work, we describe the theory behind LOGMIP, a new computer code for disjunctive programming and MINLP. We discuss a hybrid modeling framework that combines both approaches, allowing binary variables and disjunctions for expressing discrete choices. An extension of the logic-based outer approximation (OA) algorithm has been implemented to solve the proposed hybrid model. Computational experience is reported on several examples, which are solved using disjunctive, MINLP and hybrid formulations. Discrete-continuous non-linear optimization models are frequently used to formulate problems in process system engineering. Major modeling alternatives and solution algorithms include generalized disjunctive programming and mixed integer non-linear programming (MINLP). Both have advantages and drawbacks depending on the problem they are dealing with. In this work, we describe the theory behind LOGMIP, a new computer code for disjunctive programming and MINLP. We discuss a hybrid modeling framework that combines both approaches, allowing binary variables and disjunctions for expressing discrete choices. An extension of the logic-based outer approximation (OA) algorithm has been implemented to solve the proposed hybrid model. Computational experience is reported on several examples, which are solved using disjunctive, MINLP and hybrid formulations.}, note = {cited By 38}, keywords = {}, pubstate = {published}, tppubtype = {article} } Discrete-continuous non-linear optimization models are frequently used to formulate problems in process system engineering. Major modeling alternatives and solution algorithms include generalized disjunctive programming and mixed integer non-linear programming (MINLP). Both have advantages and drawbacks depending on the problem they are dealing with. In this work, we describe the theory behind LOGMIP, a new computer code for disjunctive programming and MINLP. We discuss a hybrid modeling framework that combines both approaches, allowing binary variables and disjunctions for expressing discrete choices. An extension of the logic-based outer approximation (OA) algorithm has been implemented to solve the proposed hybrid model. Computational experience is reported on several examples, which are solved using disjunctive, MINLP and hybrid formulations. Discrete-continuous non-linear optimization models are frequently used to formulate problems in process system engineering. Major modeling alternatives and solution algorithms include generalized disjunctive programming and mixed integer non-linear programming (MINLP). Both have advantages and drawbacks depending on the problem they are dealing with. In this work, we describe the theory behind LOGMIP, a new computer code for disjunctive programming and MINLP. We discuss a hybrid modeling framework that combines both approaches, allowing binary variables and disjunctions for expressing discrete choices. An extension of the logic-based outer approximation (OA) algorithm has been implemented to solve the proposed hybrid model. Computational experience is reported on several examples, which are solved using disjunctive, MINLP and hybrid formulations. |
J. Espinosa, H.E. Salomone Minimum reflux for batch distillations of ideal and nonideal mixtures at constant reflux (Artículo de revista) Industrial and Engineering Chemistry Research, 38 (7), pp. 2732-2746, 1999, (cited By 10). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Espinosa19992732, title = {Minimum reflux for batch distillations of ideal and nonideal mixtures at constant reflux}, author = { J. Espinosa and H.E. Salomone}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0032765207&partnerID=40&md5=0a4003fea416b38d71b89096440faabc}, year = {1999}, date = {1999-01-01}, journal = {Industrial and Engineering Chemistry Research}, volume = {38}, number = {7}, pages = {2732-2746}, abstract = {This paper presents a short-cut procedure for estimating the instantaneous separation performance in batch-columns Having an infinite number of stages that it is applicable to nonideal mixtures with any number of components. The model allows the estimation of the instantaneous top composition without resorting to stage-by-stage computation and therefore can be used both as a method for rapid simulation of the batch operation and as a procedure for calculating the minimum-energy demand. A key aspect of the method is the determination of the different regimes that can be found during the operation of batch columns. Each one of the different regimes is controlled by a pinch that determines the geometry of the internal profiles. For systems with constant relative volatilities, the presented approach is compared with the use of the Underwood equation to determine the instantaneous separation column performance. We show that both methods are equivalent. This analysis also gives an interpretation of the application of the Underwood equation in the context of batch rectification. Finally, we analyze the application of the model to highly nonideal mixtures with azeotropes and distillation boundaries and briefly discuss the modifications that have to be introduced to extend the method. © 1999 American Chemical Society.}, note = {cited By 10}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents a short-cut procedure for estimating the instantaneous separation performance in batch-columns Having an infinite number of stages that it is applicable to nonideal mixtures with any number of components. The model allows the estimation of the instantaneous top composition without resorting to stage-by-stage computation and therefore can be used both as a method for rapid simulation of the batch operation and as a procedure for calculating the minimum-energy demand. A key aspect of the method is the determination of the different regimes that can be found during the operation of batch columns. Each one of the different regimes is controlled by a pinch that determines the geometry of the internal profiles. For systems with constant relative volatilities, the presented approach is compared with the use of the Underwood equation to determine the instantaneous separation column performance. We show that both methods are equivalent. This analysis also gives an interpretation of the application of the Underwood equation in the context of batch rectification. Finally, we analyze the application of the model to highly nonideal mixtures with azeotropes and distillation boundaries and briefly discuss the modifications that have to be introduced to extend the method. © 1999 American Chemical Society. |
G. Stephanopoulos, S. Ali, A. Linninger, H.E. Salomone Batch Process Development: From Reactions To Manufacturing Systems (Artículo de revista) Computers and Chemical Engineering, 23 (SUPPL. 1), pp. S975-S984, 1999, (cited By 6). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Stephanopoulos1999, title = {Batch Process Development: From Reactions To Manufacturing Systems}, author = { G. Stephanopoulos and S. Ali and A. Linninger and H.E. Salomone}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-4243267299&partnerID=40&md5=a57454cacbb3da8e217ccbd2e1a95031}, doi = {10.1016/S0098-1354(99)80232-4}, year = {1999}, date = {1999-01-01}, journal = {Computers and Chemical Engineering}, volume = {23}, number = {SUPPL. 1}, pages = {S975-S984}, abstract = {Development of batch processes is quite different from that practiced for continuous processes. Highly desired short development cycles, the multitude of products under development and the continuous adaptation of existing products, the broad range of scientific knowledge and engineering expertise that must be brought together, are some of the features that call for different development paradigms. In this paper we examine the nature of batch process development, its phases and the needs for each phase, the requisite knowledge, and its current weaknesses. We also discuss certain methodological approaches that have evolved over the last few years with emphasis on the work carried out by the authors, and outline needed approaches for further progress in this important field. © 1999 Elsevier Science Ltd.}, note = {cited By 6}, keywords = {}, pubstate = {published}, tppubtype = {article} } Development of batch processes is quite different from that practiced for continuous processes. Highly desired short development cycles, the multitude of products under development and the continuous adaptation of existing products, the broad range of scientific knowledge and engineering expertise that must be brought together, are some of the features that call for different development paradigms. In this paper we examine the nature of batch process development, its phases and the needs for each phase, the requisite knowledge, and its current weaknesses. We also discuss certain methodological approaches that have evolved over the last few years with emphasis on the work carried out by the authors, and outline needed approaches for further progress in this important field. © 1999 Elsevier Science Ltd. |
J. Espinosa, P.A. Aguirre, T. Frey, J. Stichlmair Analysis of finishing reactive distillation columns (Artículo de revista) Industrial and Engineering Chemistry Research, 38 (1), pp. 187-196, 1999, (cited By 7). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Espinosa1999187, title = {Analysis of finishing reactive distillation columns}, author = { J. Espinosa and P.A. Aguirre and T. Frey and J. Stichlmair}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0033067826&partnerID=40&md5=6f51a891ed81242337244b076fb5dbb7}, year = {1999}, date = {1999-01-01}, journal = {Industrial and Engineering Chemistry Research}, volume = {38}, number = {1}, pages = {187-196}, abstract = {In this paper, a novel method to deal with the design and the synthesis of finishing reactive distillation columns with one reactive core, two rectifying sections, and one stripping section is presented. The attention of our work is concentrated on three subjects: (i) the feasibility of a given separation at both finite and total reflux operation; (ii) the minimum energy demand operation; (iii) the distribution of the reaction between the reactor and the finishing reactive column. The design problem presents the same grade of difficulty as that found in the design of conventional extractive columns. A geometric based method is used to explain key features of reactive distillation. Here, the relation between the reaction yield and the distillate flow rate plays a role similar to that of the entrainer flow in extractive distillation. Hence, special attention is given to the behavior of the profiles inside the rectifying section below the reactive core. The methodology is illustrated using the well-known MTBE case study. In this paper, a novel method to deal with the design and the synthesis of finishing reactive distillation columns with one reactive core, two rectifying sections, and one stripping section is presented. The attention of our work is concentrated on three subjects: (i) the feasibility of a given separation at both finite and total reflux operation; (ii) the minimum energy demand operation; (iii) the distribution of the reaction between the reactor and the finishing reactive column. The design problem presents the same grade of difficulty as that found in the design of conventional extractive columns. A geometric based method is used to explain key features of reactive distillation. Here, the relation between the reaction yield and the distillate flow rate plays a role similar to that of the entrainer flow in extractive distillation. Hence, special attention is given to the behavior of the profiles inside the rectifying section below the reactive core. The methodology is illustrated using the well-known MTBE case study.}, note = {cited By 7}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, a novel method to deal with the design and the synthesis of finishing reactive distillation columns with one reactive core, two rectifying sections, and one stripping section is presented. The attention of our work is concentrated on three subjects: (i) the feasibility of a given separation at both finite and total reflux operation; (ii) the minimum energy demand operation; (iii) the distribution of the reaction between the reactor and the finishing reactive column. The design problem presents the same grade of difficulty as that found in the design of conventional extractive columns. A geometric based method is used to explain key features of reactive distillation. Here, the relation between the reaction yield and the distillate flow rate plays a role similar to that of the entrainer flow in extractive distillation. Hence, special attention is given to the behavior of the profiles inside the rectifying section below the reactive core. The methodology is illustrated using the well-known MTBE case study. In this paper, a novel method to deal with the design and the synthesis of finishing reactive distillation columns with one reactive core, two rectifying sections, and one stripping section is presented. The attention of our work is concentrated on three subjects: (i) the feasibility of a given separation at both finite and total reflux operation; (ii) the minimum energy demand operation; (iii) the distribution of the reaction between the reactor and the finishing reactive column. The design problem presents the same grade of difficulty as that found in the design of conventional extractive columns. A geometric based method is used to explain key features of reactive distillation. Here, the relation between the reaction yield and the distillate flow rate plays a role similar to that of the entrainer flow in extractive distillation. Hence, special attention is given to the behavior of the profiles inside the rectifying section below the reactive core. The methodology is illustrated using the well-known MTBE case study. |
1998 |
E.C. Martínez, G.A. Pérez A project-oriented production model of batch plants (Artículo de revista) Computers and Chemical Engineering, 22 (3), pp. 391-414, 1998, (cited By 3). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Martínez1998391, title = {A project-oriented production model of batch plants}, author = { E.C. Martínez and G.A. Pérez}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0031676667&partnerID=40&md5=7369a99979192548cf170606d4f1c71b}, year = {1998}, date = {1998-01-01}, journal = {Computers and Chemical Engineering}, volume = {22}, number = {3}, pages = {391-414}, abstract = {This paper presents a project-oriented framework for interactive analysis of the feasible plans and schedules that can provide an effective/efficient flow of orders within a batch process. The proposed approach is based on a hierarchical project-oriented production model that integrates production planning with short-term scheduling and resource leveling. At the highest layer of the hierarchy, the use of aggregate activities and their milestone dates is aimed to emphasize a management perspective of the production model. As a core element of the model a process task network is used. Each node of this network is expanded further into sub-tasks and their detailed schedules. Efficiency in resource's usage during short-term scheduling is improved by changing process task durations. The implementation of the project-oriented production planning methodology has been based on the existing literature in project management (Leachman, 1982, Leachman, 1983; Hackman and Leachman, 1989), but many alternative techniques can be used for specific layers (sub-problems) of the proposed hierarchy. An attractive feature of the project oriented approach is that descentralized decision making is favored. Conflicts between management objectives and shop-floor decisions are solved iteratively in a two-tier scheme. Simple examples are considered to illustrate the potentials and advantages of the project-oriented approach. © 1998 Elsevier Science Ltd. All rights reserved.}, note = {cited By 3}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents a project-oriented framework for interactive analysis of the feasible plans and schedules that can provide an effective/efficient flow of orders within a batch process. The proposed approach is based on a hierarchical project-oriented production model that integrates production planning with short-term scheduling and resource leveling. At the highest layer of the hierarchy, the use of aggregate activities and their milestone dates is aimed to emphasize a management perspective of the production model. As a core element of the model a process task network is used. Each node of this network is expanded further into sub-tasks and their detailed schedules. Efficiency in resource's usage during short-term scheduling is improved by changing process task durations. The implementation of the project-oriented production planning methodology has been based on the existing literature in project management (Leachman, 1982, Leachman, 1983; Hackman and Leachman, 1989), but many alternative techniques can be used for specific layers (sub-problems) of the proposed hierarchy. An attractive feature of the project oriented approach is that descentralized decision making is favored. Conflicts between management objectives and shop-floor decisions are solved iteratively in a two-tier scheme. Simple examples are considered to illustrate the potentials and advantages of the project-oriented approach. © 1998 Elsevier Science Ltd. All rights reserved. |
E.C. Martínez Learning to control the performance of batch processes (Artículo de revista) Chemical Engineering Research and Design, 76 (A6), pp. 711-722, 1998, (cited By 1). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Martinez1998711, title = {Learning to control the performance of batch processes}, author = { E.C. Martínez}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0032172553&partnerID=40&md5=fea9036498d814447485f86a89a6ed54}, doi = {10.1205/026387698525414}, year = {1998}, date = {1998-01-01}, journal = {Chemical Engineering Research and Design}, volume = {76}, number = {A6}, pages = {711-722}, abstract = {The current shift in chemical industry interest away from high throughput production towards small amounts of high value added products has increased the industry's awareness of the issues associated with product and process performance. This fact poses a unique set of challenging control problems characterized by their 'ill-definedness', high process nonlinearities and imperfect modelling. In this work, a novel methodology is proposed for incremental learning of a control policy that can continuously improve product quality and operating performance. The new concept introduced here is the notion of a performance function that implicitly includes end-product quality constraints as a process goal and operational preferences which describe different modes of operation. Since plant information is often scarce and expensive to obtain, it is proposed that the performance function be learned by integrating together batch-to-batch data, intra-run measurements and a predictive process model. A new framework for this integration, called coarse code generalization, is proposed which revolves around the generation of an artificial set of batch runs using a hybrid process model. In this model, learning biases are incorporated through background knowledge that expresses run outcome sensitivities with respect to states and actions. Artificial batch runs provide an augmented data set which is used for inductive learning of the performance function. With a minimum amount of information on process performance available, a first approximation to the performance function is constructed and an optimization program is used to define a near-optimal control policy. As more plant data become available, the performance function refinement procedure permits also an increasing refinement of the learned control policy. Recipe changes that increase process performance can then be implemented on-line. A semi-batch reactor where an autocatalytic reaction takes place is used to present and test the methodology. Results obtained demonstrate that the methodology can cope successfully with the problems of both imperfect modelling and scarce information which are typical of the industrial environment. Also, coarse code generalization for performance control proves to be an ideal means of integrating inductive learning with first-principles models and other types of domain knowledge. The current shift in chemical industry interest away from high throughout production towards small amounts of high value added products has increased the industry's awareness of the issues associated with product and process performance. This fact poses a unique set of challenging control problems characterized by their `ill-definedness', high process nonlinearities and imperfect modelling. In this work, a novel methodology is proposed for incremental learning of a control policy that can continuously improve product quality and operating performance. The new concept introduced here is the notion of a performance function that implicitly includes end-product quality constraints as a process goal and operational preferences which describe different modes of operation. Since plant information is often scarce and expensive to obtain, it is proposed that the performance function be learned by integrating together batch-to-batch data, intra-run measurements and a predictive process model. A new framework for this integration, called coarse code generalization, is proposed which revolves around the generation of an artificial set of batch runs using a hybrid process model. In this model, learning biases are incorporated through background knowledge that expresses run outcome sensitivities with respect to states and actions. Artificial batch runs provide an augmented data set which is used for inductive learning of the performance function. With a minimum amount of information on process performance available, a first approximation to the performance function is constructed and an optimization program is used to define a near-optimal control policy. As more plant data become available, the performance function refinement procedure permits also an increasing refinement of the learned control policy. Recipe changes that increase process performance can then be implemented on-line. A semi-batch reactor where an autocatalytic reaction takes place is used to present and test the methodology. Results obtained demonstrate that the methodology can cope successfully with the problems of both imperfect modelling and scarce information which are typical of the industrial environment. Also, coarse code generalization for performance control proves to be an ideal means of integrating inductive learning with first-principles models and other types of domain knowledge.}, note = {cited By 1}, keywords = {}, pubstate = {published}, tppubtype = {article} } The current shift in chemical industry interest away from high throughput production towards small amounts of high value added products has increased the industry's awareness of the issues associated with product and process performance. This fact poses a unique set of challenging control problems characterized by their 'ill-definedness', high process nonlinearities and imperfect modelling. In this work, a novel methodology is proposed for incremental learning of a control policy that can continuously improve product quality and operating performance. The new concept introduced here is the notion of a performance function that implicitly includes end-product quality constraints as a process goal and operational preferences which describe different modes of operation. Since plant information is often scarce and expensive to obtain, it is proposed that the performance function be learned by integrating together batch-to-batch data, intra-run measurements and a predictive process model. A new framework for this integration, called coarse code generalization, is proposed which revolves around the generation of an artificial set of batch runs using a hybrid process model. In this model, learning biases are incorporated through background knowledge that expresses run outcome sensitivities with respect to states and actions. Artificial batch runs provide an augmented data set which is used for inductive learning of the performance function. With a minimum amount of information on process performance available, a first approximation to the performance function is constructed and an optimization program is used to define a near-optimal control policy. As more plant data become available, the performance function refinement procedure permits also an increasing refinement of the learned control policy. Recipe changes that increase process performance can then be implemented on-line. A semi-batch reactor where an autocatalytic reaction takes place is used to present and test the methodology. Results obtained demonstrate that the methodology can cope successfully with the problems of both imperfect modelling and scarce information which are typical of the industrial environment. Also, coarse code generalization for performance control proves to be an ideal means of integrating inductive learning with first-principles models and other types of domain knowledge. The current shift in chemical industry interest away from high throughout production towards small amounts of high value added products has increased the industry's awareness of the issues associated with product and process performance. This fact poses a unique set of challenging control problems characterized by their `ill-definedness', high process nonlinearities and imperfect modelling. In this work, a novel methodology is proposed for incremental learning of a control policy that can continuously improve product quality and operating performance. The new concept introduced here is the notion of a performance function that implicitly includes end-product quality constraints as a process goal and operational preferences which describe different modes of operation. Since plant information is often scarce and expensive to obtain, it is proposed that the performance function be learned by integrating together batch-to-batch data, intra-run measurements and a predictive process model. A new framework for this integration, called coarse code generalization, is proposed which revolves around the generation of an artificial set of batch runs using a hybrid process model. In this model, learning biases are incorporated through background knowledge that expresses run outcome sensitivities with respect to states and actions. Artificial batch runs provide an augmented data set which is used for inductive learning of the performance function. With a minimum amount of information on process performance available, a first approximation to the performance function is constructed and an optimization program is used to define a near-optimal control policy. As more plant data become available, the performance function refinement procedure permits also an increasing refinement of the learned control policy. Recipe changes that increase process performance can then be implemented on-line. A semi-batch reactor where an autocatalytic reaction takes place is used to present and test the methodology. Results obtained demonstrate that the methodology can cope successfully with the problems of both imperfect modelling and scarce information which are typical of the industrial environment. Also, coarse code generalization for performance control proves to be an ideal means of integrating inductive learning with first-principles models and other types of domain knowledge. |
E.C. Martínez, J.A. Wilson A hybrid neural network-first principles approach to batch unit optimisation (Artículo de revista) Computers and Chemical Engineering, 22 (SUPPL.1), pp. S893-S896, 1998, (cited By 4). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Martinez1998, title = {A hybrid neural network-first principles approach to batch unit optimisation}, author = { E.C. Martínez and J.A. Wilson}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-3142736855&partnerID=40&md5=e138d1ef83d0c4d3d9e88285c79b05a3}, year = {1998}, date = {1998-01-01}, journal = {Computers and Chemical Engineering}, volume = {22}, number = {SUPPL.1}, pages = {S893-S896}, abstract = {Achieving an optimal operation of batch processes is a difficult problem due to issues such as imperfect modelling, scarcity of information and delayed access to key measurements of process states. In this paper, a hybrid approach for batch process optimisation that integrates together inductive learning (neural networks) and first principles knowledge is proposed. The latter is expressed as derivative constraints that impose learning bias for inductive modelling and generalisation. The result of such integration is a value function that is incrementally learned, and later used to implement a nearoptimal control policy that is geared to guarantee product quality and to improve process performance. Artificial batch runs are simulated by means of a predictive process model to help constrain and speed up the learning procedure for the value function. The efficacy of the proposed methodology is demonstrated using a semi-batch autocalytic reactor. © 1998 Elsevier Science Ltd: All rights reserved.}, note = {cited By 4}, keywords = {}, pubstate = {published}, tppubtype = {article} } Achieving an optimal operation of batch processes is a difficult problem due to issues such as imperfect modelling, scarcity of information and delayed access to key measurements of process states. In this paper, a hybrid approach for batch process optimisation that integrates together inductive learning (neural networks) and first principles knowledge is proposed. The latter is expressed as derivative constraints that impose learning bias for inductive modelling and generalisation. The result of such integration is a value function that is incrementally learned, and later used to implement a nearoptimal control policy that is geared to guarantee product quality and to improve process performance. Artificial batch runs are simulated by means of a predictive process model to help constrain and speed up the learning procedure for the value function. The efficacy of the proposed methodology is demonstrated using a semi-batch autocalytic reactor. © 1998 Elsevier Science Ltd: All rights reserved. |
M.R. Galli, J. Cerdá A designer-controlled framework for the synthesis of heat exchanger networks involving non-isothermal mixers and multiple units over split streams (Artículo de revista) Computers and Chemical Engineering, 22 (SUPPL.1), pp. S813-S816, 1998, (cited By 8). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Galli1998, title = {A designer-controlled framework for the synthesis of heat exchanger networks involving non-isothermal mixers and multiple units over split streams}, author = { M.R. Galli and J. Cerdá}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0031814211&partnerID=40&md5=670dad167622b83a7a9ae1fb5e444ae7}, year = {1998}, date = {1998-01-01}, journal = {Computers and Chemical Engineering}, volume = {22}, number = {SUPPL.1}, pages = {S813-S816}, abstract = {A general MINLP algorithmic approach to the optimal synthesis of heat exchanger networks reaching specified topology targets is presented. The approach regards the network structure as composed of two types of primary components: individual units and parallel arrangements of heat matches, all connected in series over each process stream. Proper sets of decision variables are introduced to stand for the existence and relative location of (a) the primary components in the network and (b) the individual units within each parallel arrangement. In this manner, the designer can gain control on the network structure synthesis task by specifying some desired topological features. Nonlinearities are just confined to parallel sub-structures involving non-isothermal mixers and/or multiple units in series over a split stream. Topology targets normally lowering the problem size are taken into account from the beginning to compute both the least utility usage and the minimum number of units. Application of the new synthesis method to the widely known 4SP2 example problem provides an optimal network configuration not reported before. © 1998 Elsevier Science Ltd. All rights reserved.}, note = {cited By 8}, keywords = {}, pubstate = {published}, tppubtype = {article} } A general MINLP algorithmic approach to the optimal synthesis of heat exchanger networks reaching specified topology targets is presented. The approach regards the network structure as composed of two types of primary components: individual units and parallel arrangements of heat matches, all connected in series over each process stream. Proper sets of decision variables are introduced to stand for the existence and relative location of (a) the primary components in the network and (b) the individual units within each parallel arrangement. In this manner, the designer can gain control on the network structure synthesis task by specifying some desired topological features. Nonlinearities are just confined to parallel sub-structures involving non-isothermal mixers and/or multiple units in series over a split stream. Topology targets normally lowering the problem size are taken into account from the beginning to compute both the least utility usage and the minimum number of units. Application of the new synthesis method to the widely known 4SP2 example problem provides an optimal network configuration not reported before. © 1998 Elsevier Science Ltd. All rights reserved. |
M.R. Galli, J. Cerdá A user-controlled framework for the synthesis of heat exchanger networks involving non-isothermal mixers (Artículo de revista) Latin American Applied Research, 28 (1-2), pp. 57-62, 1998, (cited By 1). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Galli199857, title = {A user-controlled framework for the synthesis of heat exchanger networks involving non-isothermal mixers}, author = { M.R. Galli and J. Cerdá}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0032413623&partnerID=40&md5=8a9180c5fc5a652e2990ecc8d7ab09fd}, year = {1998}, date = {1998-01-01}, journal = {Latin American Applied Research}, volume = {28}, number = {1-2}, pages = {57-62}, abstract = {A MINLP mathematical formulation for the optimal synthesis of heat exchanger networks under topology constraints is presented. The proposed approach regards stream splitters and non-isothermal mixers as additional network constituents. By defining the interconnections between the network equipment items through structural variables, the approach admits the specification of different types of topology targets by the user. They are taken into account from the beginning to determine both the least utility usage and the minimum number of units. Non-isothermal mixers are handled at the expense of including a small set of nonlinear restrictions. A couple of examples has successfully been solved in a short CPU time. The optimal solution to the isothermal-mixing MILP formulation was always selected as the starting point for the search.}, note = {cited By 1}, keywords = {}, pubstate = {published}, tppubtype = {article} } A MINLP mathematical formulation for the optimal synthesis of heat exchanger networks under topology constraints is presented. The proposed approach regards stream splitters and non-isothermal mixers as additional network constituents. By defining the interconnections between the network equipment items through structural variables, the approach admits the specification of different types of topology targets by the user. They are taken into account from the beginning to determine both the least utility usage and the minimum number of units. Non-isothermal mixers are handled at the expense of including a small set of nonlinear restrictions. A couple of examples has successfully been solved in a short CPU time. The optimal solution to the isothermal-mixing MILP formulation was always selected as the starting point for the search. |
M.R. Galli, J. Cerdá Synthesis of structural-constrained heat exchanger networks -II split networks (Artículo de revista) Computers and Chemical Engineering, 22 (7-8), pp. 1017-1035, 1998, (cited By 11). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Galli19981017, title = {Synthesis of structural-constrained heat exchanger networks -II split networks}, author = { M.R. Galli and J. Cerdá}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0032551503&partnerID=40&md5=55fef9d638535113f02997ab7c8ad5ee}, year = {1998}, date = {1998-01-01}, journal = {Computers and Chemical Engineering}, volume = {22}, number = {7-8}, pages = {1017-1035}, abstract = {To tackle constrained HENS problems featuring split networks as the best design options, the MILP framework introduced in Part I has been generalized in such a way that the new formulation remains linear. Parallel arrangements were considered by allowing multiple preceding and succeeding units for each potential heat match. The proposed approach allows the design engineer to specify the feasible predecessors and successors for every unit as well as the heat exchangers with which it can be arranged in parallel. Such topology constraints on the network design are considered from the beginning. To this purpose, new structural conditions have been incorporated into the MILP problem formulation so as to generate the larger solution space resulting from using stream splitting. Moreover, additional sets of restrictions are also included to define the common exit temperature of a hot/cold process streams coming from a set of parallel units. Similar to Yee and Grossmann (1990), the mathematical formulation assumes (a) isothermal mixers, (b) a single exchanger over a split stream and (c) no stream by-pass. The generalized MILP framework is the basis of a targetting algorithmic method that accounts for all topology conditions from the start to sequentially determine (a) the constrained utility usage target; (b) the stream pseudo-pinch temperatures to decompose the problem into smaller independent subproblems and (c) the network designs at the level of structure one-by-one going from the top to the bottom network. Four example problems involving five to seven process streams were succesfully solved in a reasonable CPU time. © 1998 Elsevier Science Ltd. All rights reserved.}, note = {cited By 11}, keywords = {}, pubstate = {published}, tppubtype = {article} } To tackle constrained HENS problems featuring split networks as the best design options, the MILP framework introduced in Part I has been generalized in such a way that the new formulation remains linear. Parallel arrangements were considered by allowing multiple preceding and succeeding units for each potential heat match. The proposed approach allows the design engineer to specify the feasible predecessors and successors for every unit as well as the heat exchangers with which it can be arranged in parallel. Such topology constraints on the network design are considered from the beginning. To this purpose, new structural conditions have been incorporated into the MILP problem formulation so as to generate the larger solution space resulting from using stream splitting. Moreover, additional sets of restrictions are also included to define the common exit temperature of a hot/cold process streams coming from a set of parallel units. Similar to Yee and Grossmann (1990), the mathematical formulation assumes (a) isothermal mixers, (b) a single exchanger over a split stream and (c) no stream by-pass. The generalized MILP framework is the basis of a targetting algorithmic method that accounts for all topology conditions from the start to sequentially determine (a) the constrained utility usage target; (b) the stream pseudo-pinch temperatures to decompose the problem into smaller independent subproblems and (c) the network designs at the level of structure one-by-one going from the top to the bottom network. Four example problems involving five to seven process streams were succesfully solved in a reasonable CPU time. © 1998 Elsevier Science Ltd. All rights reserved. |
M.R. Galli, J. Cerdá Synthesis of structural-constrained heat exchanger networks - I. Series networks (Artículo de revista) Computers and Chemical Engineering, 22 (7-8), pp. 819-839, 1998, (cited By 13). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Galli1998819, title = {Synthesis of structural-constrained heat exchanger networks - I. Series networks}, author = { M.R. Galli and J. Cerdá}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0032551504&partnerID=40&md5=540117906d79767cab658d5772634102}, doi = {10.1016/S0098-1354(98)00028-3}, year = {1998}, date = {1998-01-01}, journal = {Computers and Chemical Engineering}, volume = {22}, number = {7-8}, pages = {819-839}, abstract = {In this two-part paper, a MILP sequential synthesis approach based on a new network representation is proposed to facilitate the involvement of the process engineer in the synthesis of series and split heat exchanger networlks. The network configuration is defined by choosing the neighboring units for every performed heat match. In this way, the structural conditions specified by the designer to simplify the network complexity can be considered from the beginning by properly restraining the set of feasible neighbors for each potential unit. Such topology constraints usually have a great impact on the problem feasible space, thus preventing from achieving the least utility usage. Consequently, a net heat flow across the pinch normally arises and the notion of pseudo-pinch point becomes worthwhile. The proposed network representation allows to develop a MILP framework to sequentially determine (a) the structural-constrained utility usage target to be achieved by the sought design; (b) the stream pseudo-pinch temperatures and (c) the solution space within which any configuration stands for a network satisfying the design specifications and the constrained utility target. In this way, a realistic network design featuring the lowest number of units can be found and no further modifications to meet the topology conditions will be required. To reduce the size of the MILP network design problem, a decomposition strategy is applied so as to independently find the network configurations at both sides of the stream pseudo-pinch temperatures. Series networks are only considered in Part 1. Several examples have successfully been solved in a short CPU time. In this two-part paper, a MILP sequential synthesis approach based on a new network representation is proposed to facilitate the involvement of the process engineer in the synthesis of series and split heat exchanger networks. The network configuration is defined by choosing the neighboring units for every performed heat match. In this way, the structural conditions specified by the designer to simplify the network complexity can be considered from the beginning by properly restraining the set of feasible neighbors for each potential unit. Such topology constraints usually have a great impact on the problem feasible space, thus preventing from achieving the least utility usage. Consequently, a net heat flow across the pinch normally arises and the notion of pseudo-pinch point becomes worthwhile. The proposed network representation allows to develop a MILP framework to sequentially determine (a) the structural-constrained utility usage target to be achieved by the sought design; (b) the stream pseudo-pinch temperatures and (c) the solution space within which any configuration stands for a network satisfying the design specifications and the constrained utility target. In this way, a realistic network design featuring the lowest number of units can be found and no further modifications to meet the topology conditions will be required. To reduce the size of the MILP network design problem, a decomposition strategy is applied so as to independently find the network configurations at both sides of the stream pseudo-pinch temperatures. Series networks are only considered in Part I. Several examples have successfully been solved in a short CPU time.}, note = {cited By 13}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this two-part paper, a MILP sequential synthesis approach based on a new network representation is proposed to facilitate the involvement of the process engineer in the synthesis of series and split heat exchanger networlks. The network configuration is defined by choosing the neighboring units for every performed heat match. In this way, the structural conditions specified by the designer to simplify the network complexity can be considered from the beginning by properly restraining the set of feasible neighbors for each potential unit. Such topology constraints usually have a great impact on the problem feasible space, thus preventing from achieving the least utility usage. Consequently, a net heat flow across the pinch normally arises and the notion of pseudo-pinch point becomes worthwhile. The proposed network representation allows to develop a MILP framework to sequentially determine (a) the structural-constrained utility usage target to be achieved by the sought design; (b) the stream pseudo-pinch temperatures and (c) the solution space within which any configuration stands for a network satisfying the design specifications and the constrained utility target. In this way, a realistic network design featuring the lowest number of units can be found and no further modifications to meet the topology conditions will be required. To reduce the size of the MILP network design problem, a decomposition strategy is applied so as to independently find the network configurations at both sides of the stream pseudo-pinch temperatures. Series networks are only considered in Part 1. Several examples have successfully been solved in a short CPU time. In this two-part paper, a MILP sequential synthesis approach based on a new network representation is proposed to facilitate the involvement of the process engineer in the synthesis of series and split heat exchanger networks. The network configuration is defined by choosing the neighboring units for every performed heat match. In this way, the structural conditions specified by the designer to simplify the network complexity can be considered from the beginning by properly restraining the set of feasible neighbors for each potential unit. Such topology constraints usually have a great impact on the problem feasible space, thus preventing from achieving the least utility usage. Consequently, a net heat flow across the pinch normally arises and the notion of pseudo-pinch point becomes worthwhile. The proposed network representation allows to develop a MILP framework to sequentially determine (a) the structural-constrained utility usage target to be achieved by the sought design; (b) the stream pseudo-pinch temperatures and (c) the solution space within which any configuration stands for a network satisfying the design specifications and the constrained utility target. In this way, a realistic network design featuring the lowest number of units can be found and no further modifications to meet the topology conditions will be required. To reduce the size of the MILP network design problem, a decomposition strategy is applied so as to independently find the network configurations at both sides of the stream pseudo-pinch temperatures. Series networks are only considered in Part I. Several examples have successfully been solved in a short CPU time. |
M.R. Galli, J. Gerdá A customized MILP approach to the synthesis of heat recovery networks reaching specified topology targets (Artículo de revista) Industrial and Engineering Chemistry Research, 37 (6), pp. 2479-2495, 1998, (cited By 10). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Galli19982479, title = {A customized MILP approach to the synthesis of heat recovery networks reaching specified topology targets}, author = { M.R. Galli and J. Gerdá}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0032104443&partnerID=40&md5=b27079234991c8718debd56e980e9d08}, year = {1998}, date = {1998-01-01}, journal = {Industrial and Engineering Chemistry Research}, volume = {37}, number = {6}, pages = {2479-2495}, abstract = {A mathematical representation of a heat-exchanger network structure that explicitly accounts for the relative location of heat-transfer units, splitters, and mixers is presented. It is the basis of a mixed-integer linear programming sequential approach to the synthesis of heat-exchanger networks that allows the designer to specify beforehand some desired topology features as further design targets. Such structural information stands for additional problem data to be considered in the problem formulation, thus enhancing the involvement of the design engineer in the synthesis task. The topology constraints are expressed in terms of (i) the equipment items (heat exchangers, splitters, and mixers) that could be incorporated into the network, (ii) the feasible neighbors for every potential unit, and (iii) the heat matches, if any, with which a heat exchanger can be accomplished in parallel over any process stream. Moreover, the number and types of splitters being arranged over either a particular stream or the whole network can also be restrained. The new approach has been successfully applied to the solution of five example problems at each of which a wide variety of structural design restrictions were specified. A mathematical representation of a heat-exchanger network structure that explicitly accounts for the relative location of heat-transfer units, splitters, and mixers is presented. It is the basis of a mixed-integer linear programming sequential approach to the synthesis of heat-exchanger networks that allows the designer to specify beforehand some desired topology features as further design targets. Such structural information stands for additional problem data to be considered in the problem formulation, thus enhancing the involvement of the design engineer in the synthesis task. The topology constraints are expressed in terms of (i) the equipment items (heat exchangers, splitters, and mixers) that could be incorporated into the network, (ii) the feasible neighbors for every potential unit, and (iii) the heat matches, if any, with which a heat exchanger can be accomplished in parallel over any process stream. Moreover, the number and types of splitters being arranged over either a particular stream or the whole network can also be restrained. The new approach has been successfully applied to the solution of five example problems at each of which a wide variety of structural design restrictions were specified.}, note = {cited By 10}, keywords = {}, pubstate = {published}, tppubtype = {article} } A mathematical representation of a heat-exchanger network structure that explicitly accounts for the relative location of heat-transfer units, splitters, and mixers is presented. It is the basis of a mixed-integer linear programming sequential approach to the synthesis of heat-exchanger networks that allows the designer to specify beforehand some desired topology features as further design targets. Such structural information stands for additional problem data to be considered in the problem formulation, thus enhancing the involvement of the design engineer in the synthesis task. The topology constraints are expressed in terms of (i) the equipment items (heat exchangers, splitters, and mixers) that could be incorporated into the network, (ii) the feasible neighbors for every potential unit, and (iii) the heat matches, if any, with which a heat exchanger can be accomplished in parallel over any process stream. Moreover, the number and types of splitters being arranged over either a particular stream or the whole network can also be restrained. The new approach has been successfully applied to the solution of five example problems at each of which a wide variety of structural design restrictions were specified. A mathematical representation of a heat-exchanger network structure that explicitly accounts for the relative location of heat-transfer units, splitters, and mixers is presented. It is the basis of a mixed-integer linear programming sequential approach to the synthesis of heat-exchanger networks that allows the designer to specify beforehand some desired topology features as further design targets. Such structural information stands for additional problem data to be considered in the problem formulation, thus enhancing the involvement of the design engineer in the synthesis task. The topology constraints are expressed in terms of (i) the equipment items (heat exchangers, splitters, and mixers) that could be incorporated into the network, (ii) the feasible neighbors for every potential unit, and (iii) the heat matches, if any, with which a heat exchanger can be accomplished in parallel over any process stream. Moreover, the number and types of splitters being arranged over either a particular stream or the whole network can also be restrained. The new approach has been successfully applied to the solution of five example problems at each of which a wide variety of structural design restrictions were specified. |
G.S. Mannarino, G.P. Henning, H.P. Leone Multiview enterprise models for process industries (Artículo de revista) Latin American Applied Research, 28 (1-2), pp. 25-30, 1998, (cited By 0). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Mannarino199825, title = {Multiview enterprise models for process industries}, author = { G.S. Mannarino and G.P. Henning and H.P. Leone}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0032445290&partnerID=40&md5=1317afc3d817d0f791d954490f03e835}, year = {1998}, date = {1998-01-01}, journal = {Latin American Applied Research}, volume = {28}, number = {1-2}, pages = {25-30}, abstract = {Nowadays, corporations undertake activities that require having a complete understanding of the production enterprise (Lindheim et al., 1996). Models provide appropriate means for describing organizations. However, the relevant aspects of a system depend on the problem being faced, the activity being carried out, the objectives that are pursued, etc. The complexity inherent to production environments makes the definition of a unique model infeasible. The modeling of a production organization requires a modeling language. This paper presents a set of basic modeling constructs, assigns them a semantic content and introduces the appropriate relationships to link them. They are exemplified by addressing a real world case study.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } Nowadays, corporations undertake activities that require having a complete understanding of the production enterprise (Lindheim et al., 1996). Models provide appropriate means for describing organizations. However, the relevant aspects of a system depend on the problem being faced, the activity being carried out, the objectives that are pursued, etc. The complexity inherent to production environments makes the definition of a unique model infeasible. The modeling of a production organization requires a modeling language. This paper presents a set of basic modeling constructs, assigns them a semantic content and introduces the appropriate relationships to link them. They are exemplified by addressing a real world case study. |
O.J. Chiotti, J.M. Montagna A global approach for the provision of bar pieces in a metallurgic firm (Artículo de revista) Mathematical and Computer Modelling, 28 (9), pp. 73-89, 1998, (cited By 2). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Chiotti199873, title = {A global approach for the provision of bar pieces in a metallurgic firm}, author = { O.J. Chiotti and J.M. Montagna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0032211688&partnerID=40&md5=7fa7dc69edaeadda5339e647bcc38bec}, doi = {10.1016/S0895-7177(98)00146-0}, year = {1998}, date = {1998-01-01}, journal = {Mathematical and Computer Modelling}, volume = {28}, number = {9}, pages = {73-89}, abstract = {Until now, several algorithms have been presented for the cutting stock problem. They are all focused on a unitary task, without taking into account the relationships between the different activities involved in the process considered. The purpose of this paper is to present a global approach where all the activities included in the provision of bar pieces to the assembly department are considered. The paper analyses all of the meaningful tasks involved in the process, taking into account the global performance, often resorting to heuristic criteria and to the knowledge of the operating conditions of the plant. Mathematically using not too complex elements solutions have been reached which allow efficient exploitation of the bars used with reasonable computing times. The solution thus obtained makes it possible to achieve different goals. Not only is there a significant decrease of loss due to bar cutting, but also an efficient processing of the bars has been achieved, reducing delays, and operation times, obtaining a better use of the storage, adequate displacement of the containers storing the bars, etc.}, note = {cited By 2}, keywords = {}, pubstate = {published}, tppubtype = {article} } Until now, several algorithms have been presented for the cutting stock problem. They are all focused on a unitary task, without taking into account the relationships between the different activities involved in the process considered. The purpose of this paper is to present a global approach where all the activities included in the provision of bar pieces to the assembly department are considered. The paper analyses all of the meaningful tasks involved in the process, taking into account the global performance, often resorting to heuristic criteria and to the knowledge of the operating conditions of the plant. Mathematically using not too complex elements solutions have been reached which allow efficient exploitation of the bars used with reasonable computing times. The solution thus obtained makes it possible to achieve different goals. Not only is there a significant decrease of loss due to bar cutting, but also an efficient processing of the bars has been achieved, reducing delays, and operation times, obtaining a better use of the storage, adequate displacement of the containers storing the bars, etc. |
J. Ramos, L. Bearzotti, E. Milani, F. Woscoff, M. Gorsky, C.M. Carletti, M.R. Galli, O.J. Chiotti Decision support systems generator for industrial companies Module I: Product design support system (Artículo de revista) Computers and Industrial Engineering, 35 (1-2), pp. 303-306, 1998, (cited By 1). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Ramos1998303, title = {Decision support systems generator for industrial companies Module I: Product design support system}, author = { J. Ramos and L. Bearzotti and E. Milani and F. Woscoff and M. Gorsky and C.M. Carletti and M.R. Galli and O.J. Chiotti}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0032183041&partnerID=40&md5=6b2c6983584711c21c304d7161b2aa60}, year = {1998}, date = {1998-01-01}, journal = {Computers and Industrial Engineering}, volume = {35}, number = {1-2}, pages = {303-306}, abstract = {In this work we present the architecture of a product design support system. This system is part of a global decision support system generator that the GIDSATD is developing (Rico et al., 1997). In first place, we describe the strategy utilized to organize the product information. In second place, we present an object oriented analysis and design of the product design support system module. © 1998 Elsevier Science Ltd. All rights reserved.}, note = {cited By 1}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this work we present the architecture of a product design support system. This system is part of a global decision support system generator that the GIDSATD is developing (Rico et al., 1997). In first place, we describe the strategy utilized to organize the product information. In second place, we present an object oriented analysis and design of the product design support system module. © 1998 Elsevier Science Ltd. All rights reserved. |
M.L. Caliusco, P. Villarreal, A. Toffolo, M.L. Taverna, O.J. Chiotti Decision support systems generator for industrial companies Module IV: Forecasting support system (Artículo de revista) Computers and Industrial Engineering, 35 (1-2), pp. 315-318, 1998, (cited By 2). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Caliusco1998315, title = {Decision support systems generator for industrial companies Module IV: Forecasting support system}, author = { M.L. Caliusco and P. Villarreal and A. Toffolo and M.L. Taverna and O.J. Chiotti}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0032183699&partnerID=40&md5=7eb9e8e715e805a2414b9aefdc180dd3}, year = {1998}, date = {1998-01-01}, journal = {Computers and Industrial Engineering}, volume = {35}, number = {1-2}, pages = {315-318}, abstract = {In this work we present the architecture of a forecasting support system. This system is a part of a global decision support system generator that the GIDSATD is developing (Rico et al., 1997). First, we briefly describe the forecasting support system model base conformation, then we present an object oriented analysis and design of the forecasting support system. © 1998 Elsevier Science Ltd. All rights reserved.}, note = {cited By 2}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this work we present the architecture of a forecasting support system. This system is a part of a global decision support system generator that the GIDSATD is developing (Rico et al., 1997). First, we briefly describe the forecasting support system model base conformation, then we present an object oriented analysis and design of the forecasting support system. © 1998 Elsevier Science Ltd. All rights reserved. |
P. Rossi, C. Diaz, P. Fruttero, C. Vittori, M. Rico, O.J. Chiotti Decision support systems generator for industrial companies Module III: Scheduling support system (Artículo de revista) Computers and Industrial Engineering, 35 (1-2), pp. 311-314, 1998, (cited By 4). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Rossi1998311, title = {Decision support systems generator for industrial companies Module III: Scheduling support system}, author = { P. Rossi and C. Diaz and P. Fruttero and C. Vittori and M. Rico and O.J. Chiotti}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0032183946&partnerID=40&md5=88ec6acacd14f1c55cff73119c82d3bc}, year = {1998}, date = {1998-01-01}, journal = {Computers and Industrial Engineering}, volume = {35}, number = {1-2}, pages = {311-314}, abstract = {In this work we present a description of a module to support the scheduling of production orders. This system is part of a global decision support system generator that the GIDSATD is developing (Rico et al., 1997). First, we briefly describe the designed architecture to manage the information required for scheduling. Second, we present an object oriented analysis and design of the scheduling support subsystem generator. Finally, we describe a particular scheduling algorithm included in the model base. © 1998 Elsevier Science Ltd. All rights reserved.}, note = {cited By 4}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this work we present a description of a module to support the scheduling of production orders. This system is part of a global decision support system generator that the GIDSATD is developing (Rico et al., 1997). First, we briefly describe the designed architecture to manage the information required for scheduling. Second, we present an object oriented analysis and design of the scheduling support subsystem generator. Finally, we describe a particular scheduling algorithm included in the model base. © 1998 Elsevier Science Ltd. All rights reserved. |
G. Castro, L. Gregoret, W. Delfabro, O.J. Chiotti Decision support systems generator for industrial companies Module II: System to support the material management (Artículo de revista) Computers and Industrial Engineering, 35 (1-2), pp. 307-310, 1998, (cited By 2). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Castro1998307, title = {Decision support systems generator for industrial companies Module II: System to support the material management}, author = { G. Castro and L. Gregoret and W. Delfabro and O.J. Chiotti}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0032183079&partnerID=40&md5=66f08ead250044c90006f609acd90741}, year = {1998}, date = {1998-01-01}, journal = {Computers and Industrial Engineering}, volume = {35}, number = {1-2}, pages = {307-310}, abstract = {In this work we present a module to support the material management. This system is part of a global decision support system generator that the GIDSATD is developing (Rico et al., 1997). First, we describe the strategy to generate the information. This strategy is the design base of the system. In second place, we present an object oriented analysis and design of the system to support the material management. © 1998 Elsevier Science Ltd. All rights reserved.}, note = {cited By 2}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this work we present a module to support the material management. This system is part of a global decision support system generator that the GIDSATD is developing (Rico et al., 1997). First, we describe the strategy to generate the information. This strategy is the design base of the system. In second place, we present an object oriented analysis and design of the system to support the material management. © 1998 Elsevier Science Ltd. All rights reserved. |
A.R. Vecchietti, J.M. Montagna Alternatives in the optimal allocation of intermediate storage tank in multiproduct batch plants (Artículo de revista) Computers and Chemical Engineering, 22 (SUPPL.1), pp. S801-S804, 1998, (cited By 10). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Vecchietti1998, title = {Alternatives in the optimal allocation of intermediate storage tank in multiproduct batch plants}, author = { A.R. Vecchietti and J.M. Montagna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0007806982&partnerID=40&md5=101eb7eaa0de0ea154857e5d2b2b3a01}, year = {1998}, date = {1998-01-01}, journal = {Computers and Chemical Engineering}, volume = {22}, number = {SUPPL.1}, pages = {S801-S804}, abstract = {Optimal allocation of intermediate storage tanks is an important issue in a batch plant to reduce its cost. In this work the design of multiproduct batch plant is analyzed. The proposed model considers simultaneously the possibility of having parallel units and intermediate storage tanks. The location of the storage tanks can be variable for each product. The problem is modeled as a MINLP (Mixed Integer Non Linear Program). This approach is compared to the one proposed by Ravemark (1995) where the intermediate storage tank location is the same for every product in the batch plant. Finally the results obtained in the execution of several examples are presented. © 1998 Elsevier Science Ltd. All rights reserved.}, note = {cited By 10}, keywords = {}, pubstate = {published}, tppubtype = {article} } Optimal allocation of intermediate storage tanks is an important issue in a batch plant to reduce its cost. In this work the design of multiproduct batch plant is analyzed. The proposed model considers simultaneously the possibility of having parallel units and intermediate storage tanks. The location of the storage tanks can be variable for each product. The problem is modeled as a MINLP (Mixed Integer Non Linear Program). This approach is compared to the one proposed by Ravemark (1995) where the intermediate storage tank location is the same for every product in the batch plant. Finally the results obtained in the execution of several examples are presented. © 1998 Elsevier Science Ltd. All rights reserved. |
S.D. Zamar, H.E. Salomone, O.A. Iribarren Shortcut method for multiple task batch distillations (Artículo de revista) Industrial and Engineering Chemistry Research, 37 (12), pp. 4801-4807, 1998, (cited By 11). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Zamar19984801, title = {Shortcut method for multiple task batch distillations}, author = { S.D. Zamar and H.E. Salomone and O.A. Iribarren}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0032456118&partnerID=40&md5=b7ac4d0c58b86fc4fa14844ed5ac24ce}, year = {1998}, date = {1998-01-01}, journal = {Industrial and Engineering Chemistry Research}, volume = {37}, number = {12}, pages = {4801-4807}, abstract = {A methodology is presented for the preliminary design of separation networks of batch distillation. Analytical partition functions are derived based on the assumption that the distribution of components in an actual batch distillation can be approximated by the distribution of a batch column at total reflux. This permits computation of mass balances of multiple separation networks (allowing recycle of intermediate cuts) by solving a linear system of equations. Once the composition of the feeds to each separation task is known, the reflux ratios required to perform the tasks can be computed by using a previously developed method that relates the minimum to the actual reflux ratios and number of stages. The validity of the assumption is tested against simulation and the methodology compared with previously reported short-cut approaches. Since no new simplifications are introduced to the model, the reduction in computation effort is achieved with the same overall accuracy. A methodology is presented for the preliminary design of separation networks of batch distillation. Analytical partition functions are derived based on the assumption that the distribution of components in an actual batch distillation can be approximated by the distribution of a batch column at total reflux. This permits computation of mass balances of multiple separation networks (allowing recycle of intermediate cuts) by solving a linear system of equations. Once the composition of the feeds to each separation task is known, the reflux ratios required to perform the tasks can be computed by using a previously developed method that relates the minimum to the actual reflux ratios and number of stages. The validity of the assumption is tested against simulation and the methodology compared with previously reported short-cut approaches. Since no new simplifications are introduced to the model, the reduction in computation effort is achieved with the same overall accuracy.}, note = {cited By 11}, keywords = {}, pubstate = {published}, tppubtype = {article} } A methodology is presented for the preliminary design of separation networks of batch distillation. Analytical partition functions are derived based on the assumption that the distribution of components in an actual batch distillation can be approximated by the distribution of a batch column at total reflux. This permits computation of mass balances of multiple separation networks (allowing recycle of intermediate cuts) by solving a linear system of equations. Once the composition of the feeds to each separation task is known, the reflux ratios required to perform the tasks can be computed by using a previously developed method that relates the minimum to the actual reflux ratios and number of stages. The validity of the assumption is tested against simulation and the methodology compared with previously reported short-cut approaches. Since no new simplifications are introduced to the model, the reduction in computation effort is achieved with the same overall accuracy. A methodology is presented for the preliminary design of separation networks of batch distillation. Analytical partition functions are derived based on the assumption that the distribution of components in an actual batch distillation can be approximated by the distribution of a batch column at total reflux. This permits computation of mass balances of multiple separation networks (allowing recycle of intermediate cuts) by solving a linear system of equations. Once the composition of the feeds to each separation task is known, the reflux ratios required to perform the tasks can be computed by using a previously developed method that relates the minimum to the actual reflux ratios and number of stages. The validity of the assumption is tested against simulation and the methodology compared with previously reported short-cut approaches. Since no new simplifications are introduced to the model, the reduction in computation effort is achieved with the same overall accuracy. |
A.A. Linninger, H.E. Salomone, S.A. Ali, E. Stephanopoulos, G. Stephanopoulos Erratum: Pollution prevention for production systems of energetic materials (Waste Management (1997) 17:2/3 (165-173) PII: S0956053X97100174) (Artículo de revista) Waste Management, 18 (1), pp. 63, 1998, (cited By 0). (Enlaces | BibTeX | Etiquetas: ) @article{Linninger199863, title = {Erratum: Pollution prevention for production systems of energetic materials (Waste Management (1997) 17:2/3 (165-173) PII: S0956053X97100174)}, author = { A.A. Linninger and H.E. Salomone and S.A. Ali and E. Stephanopoulos and G. Stephanopoulos}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0031753424&partnerID=40&md5=addc9f27059d7aacdc55b574250ff19c}, doi = {10.1016/S0956-053X(98)00033-6}, year = {1998}, date = {1998-01-01}, journal = {Waste Management}, volume = {18}, number = {1}, pages = {63}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
S.F. Mussati, P.A. Aguirre, N.J. Scenna Thermodynamic synthesis of cogeneration systems in chemical processes including gas turbines (Artículo de revista) Latin American Applied Research, 28 (4), pp. 243-246, 1998, (cited By 0). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Mussati1998243, title = {Thermodynamic synthesis of cogeneration systems in chemical processes including gas turbines}, author = { S.F. Mussati and P.A. Aguirre and N.J. Scenna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0040095485&partnerID=40&md5=569e0f13bef596be0b3bd9860086549c}, year = {1998}, date = {1998-01-01}, journal = {Latin American Applied Research}, volume = {28}, number = {4}, pages = {243-246}, abstract = {The thermodynamic synthesis procedure presented in previous papers is extended to dual purpose desalination plants including gas turbines, using exhausted gas as a heat source for steam turbine cycles. The new conditions that must be satisfied by the optimal thermodynamic solutions are discussed and the corresponding numerical algorithm is presented. A set of thermodynamically non-ideal optimal solutions is obtained, for each amount of investment determined by the items used (heat transfer areas, turbine efficiencies and capacities, etc.). The assumed structure considers a gas turbine discharging the exhausted gas to a backpressure turbine cycle coupled to a desalination process and to a condensation turbine cycle. It is easy to extend the synthesis procedure to an extraction-condensation turbine system also. The solutions obtained constitute a basis for the designer's selection, of those alternatives that satisfy optimum economical and process functional criteria.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } The thermodynamic synthesis procedure presented in previous papers is extended to dual purpose desalination plants including gas turbines, using exhausted gas as a heat source for steam turbine cycles. The new conditions that must be satisfied by the optimal thermodynamic solutions are discussed and the corresponding numerical algorithm is presented. A set of thermodynamically non-ideal optimal solutions is obtained, for each amount of investment determined by the items used (heat transfer areas, turbine efficiencies and capacities, etc.). The assumed structure considers a gas turbine discharging the exhausted gas to a backpressure turbine cycle coupled to a desalination process and to a condensation turbine cycle. It is easy to extend the synthesis procedure to an extraction-condensation turbine system also. The solutions obtained constitute a basis for the designer's selection, of those alternatives that satisfy optimum economical and process functional criteria. |
M.C. Mussati, P.A. Aguirre, N.J. Scenna Modeling of real biological reactors for the treatment of complex substrates. Dynamic simulation (Artículo de revista) Computers and Chemical Engineering, 22 (SUPPL.1), pp. S723-S726, 1998, (cited By 4). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Mussati1998, title = {Modeling of real biological reactors for the treatment of complex substrates. Dynamic simulation}, author = { M.C. Mussati and P.A. Aguirre and N.J. Scenna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0031845057&partnerID=40&md5=621054495a46009720e66fe47b90acf2}, year = {1998}, date = {1998-01-01}, journal = {Computers and Chemical Engineering}, volume = {22}, number = {SUPPL.1}, pages = {S723-S726}, abstract = {A mathematical model for the dynamic simulation of anaerobic bioreactors containing biofilm and degrading complex substrates is presented. The model allows to simulate different reactor configurations: single CSTR, multiple CSTRs and non-ideal reactors. Our simulator was developed on the basis of gPROMS, which allows to study a wide variety of problems such as optimal start-up, design under forced regimen and parameter estimations of the biofilm kinetic from experimental data. The digestion of cattle manure in different reactor configurations was selected as example to show the model and the simulator performances. © 1998 Published by Elsevier Science Ltd. All rights reserved.}, note = {cited By 4}, keywords = {}, pubstate = {published}, tppubtype = {article} } A mathematical model for the dynamic simulation of anaerobic bioreactors containing biofilm and degrading complex substrates is presented. The model allows to simulate different reactor configurations: single CSTR, multiple CSTRs and non-ideal reactors. Our simulator was developed on the basis of gPROMS, which allows to study a wide variety of problems such as optimal start-up, design under forced regimen and parameter estimations of the biofilm kinetic from experimental data. The digestion of cattle manure in different reactor configurations was selected as example to show the model and the simulator performances. © 1998 Published by Elsevier Science Ltd. All rights reserved. |
1997 |
E.C. Martínez, D. Duje, G.A. Pérez On performance modeling of project-oriented production (Artículo de revista) Computers and Industrial Engineering, 32 (3), pp. 509-527, 1997, (cited By 9). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Martínez1997509, title = {On performance modeling of project-oriented production}, author = { E.C. Martínez and D. Duje and G.A. Pérez}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0031189509&partnerID=40&md5=2f3b74fe6616268693d71a161cea32c0}, year = {1997}, date = {1997-01-01}, journal = {Computers and Industrial Engineering}, volume = {32}, number = {3}, pages = {509-527}, abstract = {A methodology has been developed in order to incorporate a performance perspective into production planning. The concept of project-oriented production has been used to emphasize a hierarchical structure for analysis and decision making. Based on a new type of resource workload model, the methodology has been applied to estimate the speed-up of each project for different levels of the resources assigned to it. We introduce the notion of leverage to trade-off resource usage or efficiency with each project duration or makespan. Using leverage we are able to find for each project the optimal level of resources that minimize peak demands through variation of aggregate activity intensities. Project performance has been integrated within production planning using a two-tier iterative scheme. In the upper level, resource leveraging is carried out. In the lower level, feasibility constraints are applied to adjust aggregate activity intensities and project milestones. This process is implemented interactively until a solution consistent with management's objectives is obtained. The most attractive feature of this strategy is that only extreme (early and late) schedules are required. © 1997 Elsevier Science Ltd.}, note = {cited By 9}, keywords = {}, pubstate = {published}, tppubtype = {article} } A methodology has been developed in order to incorporate a performance perspective into production planning. The concept of project-oriented production has been used to emphasize a hierarchical structure for analysis and decision making. Based on a new type of resource workload model, the methodology has been applied to estimate the speed-up of each project for different levels of the resources assigned to it. We introduce the notion of leverage to trade-off resource usage or efficiency with each project duration or makespan. Using leverage we are able to find for each project the optimal level of resources that minimize peak demands through variation of aggregate activity intensities. Project performance has been integrated within production planning using a two-tier iterative scheme. In the upper level, resource leveraging is carried out. In the lower level, feasibility constraints are applied to adjust aggregate activity intensities and project milestones. This process is implemented interactively until a solution consistent with management's objectives is obtained. The most attractive feature of this strategy is that only extreme (early and late) schedules are required. © 1997 Elsevier Science Ltd. |
J.A. Wilson, E.C. Martínez Neuro-fuzzy modeling and control of a batch process involving simultaneous reaction and distillation (Artículo de revista) Computers and Chemical Engineering, 21 (SUPPL.1), pp. S1233-S1238, 1997, (cited By 9). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Wilson1997, title = {Neuro-fuzzy modeling and control of a batch process involving simultaneous reaction and distillation}, author = { J.A. Wilson and E.C. Martínez}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0008612661&partnerID=40&md5=43e8ad48382424c5ca30449524f594fa}, year = {1997}, date = {1997-01-01}, journal = {Computers and Chemical Engineering}, volume = {21}, number = {SUPPL.1}, pages = {S1233-S1238}, abstract = {This paper is concerned with a novel approach to batch process automation using fuzzy modeling and reinforcement learning. The core part of the automation strategy is an autonomous agent that continuously learns to implement control actions that can drive the batch process' state very close to the desired one with near-optimal performance. An efficient algorithm for reinforcement learning called fuzzy Q-Learning is proposed to build the agent (controller). The use of linguistic information to guide the learning process and to implement near-optimal actions provides the means for both knowledge integration and scaling reinforcement learning. The methodology is exemplified using a batch process involving simultaneous reaction and distillation.}, note = {cited By 9}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper is concerned with a novel approach to batch process automation using fuzzy modeling and reinforcement learning. The core part of the automation strategy is an autonomous agent that continuously learns to implement control actions that can drive the batch process' state very close to the desired one with near-optimal performance. An efficient algorithm for reinforcement learning called fuzzy Q-Learning is proposed to build the agent (controller). The use of linguistic information to guide the learning process and to implement near-optimal actions provides the means for both knowledge integration and scaling reinforcement learning. The methodology is exemplified using a batch process involving simultaneous reaction and distillation. |
G.S. Mannarino, G.P. Henning, H.P. Leone Process industry information systems: Modeling support tools (Artículo de revista) Computers and Chemical Engineering, 21 (SUPPL.1), pp. S667-S672, 1997, (cited By 5). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Mannarino1997, title = {Process industry information systems: Modeling support tools}, author = { G.S. Mannarino and G.P. Henning and H.P. Leone}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0013516159&partnerID=40&md5=064467cb32dc69e92080568abb3ed45f}, year = {1997}, date = {1997-01-01}, journal = {Computers and Chemical Engineering}, volume = {21}, number = {SUPPL.1}, pages = {S667-S672}, abstract = {The definition of Integrated Information Systems is not an easy task. In consequence, the development of models is a prerequisite when trying to identify the information requirements of an organization. The complexity inherent to production environments makes the definition of a unique model infeasible. Thus, a three layer architecture is proposed as a framework for building Task, Domain and Dynamic models. Each model focuses on one aspect but all of them are needed to reach an understanding of a particular production domain. This paper introduces a series of primitive constructs that allow the definition of high level classes of models (metamodels). Specifically, it describes in detail the Function-Task Metamodel that is employed to represent the different types of activities that are performed in a Production Enterprise.}, note = {cited By 5}, keywords = {}, pubstate = {published}, tppubtype = {article} } The definition of Integrated Information Systems is not an easy task. In consequence, the development of models is a prerequisite when trying to identify the information requirements of an organization. The complexity inherent to production environments makes the definition of a unique model infeasible. Thus, a three layer architecture is proposed as a framework for building Task, Domain and Dynamic models. Each model focuses on one aspect but all of them are needed to reach an understanding of a particular production domain. This paper introduces a series of primitive constructs that allow the definition of high level classes of models (metamodels). Specifically, it describes in detail the Function-Task Metamodel that is employed to represent the different types of activities that are performed in a Production Enterprise. |
S. Gonnet, O.J. Chiotti Modeling of the supervising control system of a multipurpose batch plant (Artículo de revista) Computers and Chemical Engineering, 21 (SUPPL.1), pp. S691-S696, 1997, (cited By 5). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Gonnet1997, title = {Modeling of the supervising control system of a multipurpose batch plant}, author = { S. Gonnet and O.J. Chiotti}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0039668339&partnerID=40&md5=d5be883f1599aedb2e654dfabda2e7d1}, year = {1997}, date = {1997-01-01}, journal = {Computers and Chemical Engineering}, volume = {21}, number = {SUPPL.1}, pages = {S691-S696}, abstract = {A multipurpose batch plant supervising control supervises that the plant is operated according to the schedule set by the planning and scheduling of production orders module. The supervising control depends on the topology of the plant, which is not defined a priori but generated while scheduling the production orders. This requires that the supervising control system be able to generate the control structure after the generation of plant topologies. This work presents a strategy for the modeling of supervising control tasks for a multipurpose batch plant resorting to Petri nets. The modeling of the batch processing system through Petri nets is a useful tool for the description and analysis of the process, necessary for the design of a supervising control system.The present work uses C/E (Condition/Event) and P/T (Place/Transition) Petri nets to develop the model.}, note = {cited By 5}, keywords = {}, pubstate = {published}, tppubtype = {article} } A multipurpose batch plant supervising control supervises that the plant is operated according to the schedule set by the planning and scheduling of production orders module. The supervising control depends on the topology of the plant, which is not defined a priori but generated while scheduling the production orders. This requires that the supervising control system be able to generate the control structure after the generation of plant topologies. This work presents a strategy for the modeling of supervising control tasks for a multipurpose batch plant resorting to Petri nets. The modeling of the batch processing system through Petri nets is a useful tool for the description and analysis of the process, necessary for the design of a supervising control system.The present work uses C/E (Condition/Event) and P/T (Place/Transition) Petri nets to develop the model. |
M. Rico, O. Yuschak, M.L. Taverna, J.C. Ramos, M.R. Galli, O.J. Chiotti Decision support systems generator for industrial companies (Artículo de revista) Computers and Industrial Engineering, 33 (1-2), pp. 357-360, 1997, (cited By 3). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Rico1997357, title = {Decision support systems generator for industrial companies}, author = { M. Rico and O. Yuschak and M.L. Taverna and J.C. Ramos and M.R. Galli and O.J. Chiotti}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0031248385&partnerID=40&md5=0104f1a62b5b39f87edc333bc739e0d5}, year = {1997}, date = {1997-01-01}, journal = {Computers and Industrial Engineering}, volume = {33}, number = {1-2}, pages = {357-360}, abstract = {This work presents a prototype generator of DSS with adjustment capability to different organizational structures of the company, flexibility to accommodate changes of the products and production processes and to offer support to all the decision points of the organization. © 1997 Elsevier Science Ltd.}, note = {cited By 3}, keywords = {}, pubstate = {published}, tppubtype = {article} } This work presents a prototype generator of DSS with adjustment capability to different organizational structures of the company, flexibility to accommodate changes of the products and production processes and to offer support to all the decision points of the organization. © 1997 Elsevier Science Ltd. |
H.E. Salomone, O.J. Chiotti, O.A. Iribarren Short-Cut Design Procedure for Batch Distillations (Artículo de revista) Industrial and Engineering Chemistry Research, 36 (1), pp. 130-136, 1997, (cited By 29). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Salomone1997130, title = {Short-Cut Design Procedure for Batch Distillations}, author = { H.E. Salomone and O.J. Chiotti and O.A. Iribarren}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0030818968&partnerID=40&md5=955c17a7daf9266fb9d1b766fad0ee22}, year = {1997}, date = {1997-01-01}, journal = {Industrial and Engineering Chemistry Research}, volume = {36}, number = {1}, pages = {130-136}, abstract = {This paper presents a short-cut procedure for the design of batch distillations which is equivalent to the Fenske-Underwood-Gilliland procedure for continuous distillations. Given a separation task, we propose computing the minimum number of stages and minimum reflux ratio required to perform it by batch distillation. These parameters are quite different from the continuous Nmin and Rmin parameters for the same separation task, because of the difference in the form of the material balances (steady state in continuous but integrated differential mass balances in the batch case). We propose that they should be computed as the number of stages and reflux ratio required by hypothetical batch distillation columns that operate at total reflux or have an infinite number of stages, respectively. Then, it is shown that the performance of batch distillations does correlate in Gilliland coordinates constructed with these batch Nmin and Rmin. This produces a quite simple, straightforward method to do preliminary design of batch distillations.}, note = {cited By 29}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents a short-cut procedure for the design of batch distillations which is equivalent to the Fenske-Underwood-Gilliland procedure for continuous distillations. Given a separation task, we propose computing the minimum number of stages and minimum reflux ratio required to perform it by batch distillation. These parameters are quite different from the continuous Nmin and Rmin parameters for the same separation task, because of the difference in the form of the material balances (steady state in continuous but integrated differential mass balances in the batch case). We propose that they should be computed as the number of stages and reflux ratio required by hypothetical batch distillation columns that operate at total reflux or have an infinite number of stages, respectively. Then, it is shown that the performance of batch distillations does correlate in Gilliland coordinates constructed with these batch Nmin and Rmin. This produces a quite simple, straightforward method to do preliminary design of batch distillations. |
S. Gonnet, O.J. Chiotti Modeling of the supervising control system of a multipurpose batch plant using Petri nets [Modelado del sistema de control supervisor de una planta batch multiproposito usando redes de Petri] (Artículo de revista) Informacion Tecnologica, 8 (4), pp. 323-326, 1997, (cited By 0). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Gonnet1997323, title = {Modeling of the supervising control system of a multipurpose batch plant using Petri nets [Modelado del sistema de control supervisor de una planta batch multiproposito usando redes de Petri]}, author = { S. Gonnet and O.J. Chiotti}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0030719837&partnerID=40&md5=a7e3421eeba66d55ea2231f34f801fac}, year = {1997}, date = {1997-01-01}, journal = {Informacion Tecnologica}, volume = {8}, number = {4}, pages = {323-326}, abstract = {This work presents a strategy for the modeling of supervising control tasks for a multipurpose batch plant using Petri nets. Here, the so-called Condition/Event Petri nets are used to develop the model. The article shows that the modeling of the batch processing system by Petri nets is a useful tool for the description and analysis of the process, a necessary step for the design of a supervising control system.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } This work presents a strategy for the modeling of supervising control tasks for a multipurpose batch plant using Petri nets. Here, the so-called Condition/Event Petri nets are used to develop the model. The article shows that the modeling of the batch processing system by Petri nets is a useful tool for the description and analysis of the process, a necessary step for the design of a supervising control system. |
A.R. Vecchietti, I.E. Grossmann LOGMIP: A disjunctive 0-1 nonlinear optimizer for process systems models (Artículo de revista) Computers and Chemical Engineering, 21 (SUPPL.1), pp. S427-S432, 1997, (cited By 13). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Vecchietti1997, title = {LOGMIP: A disjunctive 0-1 nonlinear optimizer for process systems models}, author = { A.R. Vecchietti and I.E. Grossmann}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0004669343&partnerID=40&md5=25fd7092da131a1691a1c5c432851584}, year = {1997}, date = {1997-01-01}, journal = {Computers and Chemical Engineering}, volume = {21}, number = {SUPPL.1}, pages = {S427-S432}, abstract = {Discrete-continuous non-linear optimization models are frequently used to formulate problems in Process System Engineering. Major modeling alternatives and solution algorithms include generalized disjunctive programming and MINLP. Both have advantages and drawbacks depending on the problem they are dealing with. In this work, we describe the theory behind LOGMIP, a new computer code for disjunctive programming and MINLP. We discuss a hybrid modeling framework which combines both approaches, allowing binary variables and disjunctions for expressing discrete choices. An extension of the Logic-Based OA algorithm has been implemented to solve the proposed hybrid model. Computational experience is reported on several examples, which are solved with disjunctive, MINLP and hybrid approaches.}, note = {cited By 13}, keywords = {}, pubstate = {published}, tppubtype = {article} } Discrete-continuous non-linear optimization models are frequently used to formulate problems in Process System Engineering. Major modeling alternatives and solution algorithms include generalized disjunctive programming and MINLP. Both have advantages and drawbacks depending on the problem they are dealing with. In this work, we describe the theory behind LOGMIP, a new computer code for disjunctive programming and MINLP. We discuss a hybrid modeling framework which combines both approaches, allowing binary variables and disjunctions for expressing discrete choices. An extension of the Logic-Based OA algorithm has been implemented to solve the proposed hybrid model. Computational experience is reported on several examples, which are solved with disjunctive, MINLP and hybrid approaches. |
A.A. Linninger, H.E. Salomone, S.A. Ali, E. Stephanopoulos, G. Stephanopoulos Pollution prevention for production systems of energetic materials (Artículo de revista) Waste Management, 17 (2-3), pp. 165-173, 1997, (cited By 3). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Linninger1997165, title = {Pollution prevention for production systems of energetic materials}, author = { A.A. Linninger and H.E. Salomone and S.A. Ali and E. Stephanopoulos and G. Stephanopoulos}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0031410897&partnerID=40&md5=07cb2c7b5741e86cb5857132616df77b}, doi = {10.1016/S0956-053X(97)10017-4}, year = {1997}, date = {1997-01-01}, journal = {Waste Management}, volume = {17}, number = {2-3}, pages = {165-173}, abstract = {The Batch Design-Kit (BDK) environment is a software system for the development of batch manufacturing processes. Given a set of reaction pathways, BDK enables chemists and chemical engineers to investigate possible production routes, refine promising candidates and develop a detailed chemical recipe in an interactive manner. Automatic facility allocation of equipment for these conceptual recipes help determine the feasibility and efficiency of the processing idea at existing manufacturing sites. Material assessment reveals the environmental impact caused by the utilized chemical compounds and process mixtures. Automatic waste treatment synthesis generates efficient treatment strategies for all process wastes and calculates the residuals emitted to the environment. With process analysis based on the facility allocation, material assessment and treatment selection, alternative processing schemes can be ranked and potential problems, such as examination of equipment costs, regulatory compliance and expenditures for waste treatment, can be identified at an early stage of the process development. Through its material-centered design concept, BDK maintains a cause-effect relationship between process mixtures, operations and their economic and environmental performance. In that way, process improvement can be focused specifically on the replacement of offending chemicals and/or the improvement or modification of problematic operations or operation sequences.}, note = {cited By 3}, keywords = {}, pubstate = {published}, tppubtype = {article} } The Batch Design-Kit (BDK) environment is a software system for the development of batch manufacturing processes. Given a set of reaction pathways, BDK enables chemists and chemical engineers to investigate possible production routes, refine promising candidates and develop a detailed chemical recipe in an interactive manner. Automatic facility allocation of equipment for these conceptual recipes help determine the feasibility and efficiency of the processing idea at existing manufacturing sites. Material assessment reveals the environmental impact caused by the utilized chemical compounds and process mixtures. Automatic waste treatment synthesis generates efficient treatment strategies for all process wastes and calculates the residuals emitted to the environment. With process analysis based on the facility allocation, material assessment and treatment selection, alternative processing schemes can be ranked and potential problems, such as examination of equipment costs, regulatory compliance and expenditures for waste treatment, can be identified at an early stage of the process development. Through its material-centered design concept, BDK maintains a cause-effect relationship between process mixtures, operations and their economic and environmental performance. In that way, process improvement can be focused specifically on the replacement of offending chemicals and/or the improvement or modification of problematic operations or operation sequences. |
H.E. Salomone, J.M. Montagna, O.A. Iribarren Simulation approach to the design and operation of multiproduct batch plants (Artículo de revista) Chemical Engineering Research and Design, 75 (A4), pp. 427-437, 1997, (cited By 3). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Salomone1997427, title = {Simulation approach to the design and operation of multiproduct batch plants}, author = { H.E. Salomone and J.M. Montagna and O.A. Iribarren}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0031139510&partnerID=40&md5=5ffe5acfe37ce84931370ddfeba6c383}, doi = {10.1205/026387697523895}, year = {1997}, date = {1997-01-01}, journal = {Chemical Engineering Research and Design}, volume = {75}, number = {A4}, pages = {427-437}, abstract = {This paper presents a strategy for the design of multiproduct batch plants that permits the use of detailed dynamic models to represent the stages involved in the process. The use of base case simulations at the decoupled solution of the modules into which the plant is decomposed yields a strategy that iterates on dynamic simulations and optimization steps. The merits of such a strategy are robustness, reliability, reuse and full exploitation of already developed technologies. The results obtained so far are encouraging. It is possible to handle rigorous models that take into account the tradeoffs among the different decision variables, the stages and the products. This makes it possible to arrive at conclusions and to evaluate alternatives not approached in the past. Different scenarios and applications of this approach are analyzed.}, note = {cited By 3}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents a strategy for the design of multiproduct batch plants that permits the use of detailed dynamic models to represent the stages involved in the process. The use of base case simulations at the decoupled solution of the modules into which the plant is decomposed yields a strategy that iterates on dynamic simulations and optimization steps. The merits of such a strategy are robustness, reliability, reuse and full exploitation of already developed technologies. The results obtained so far are encouraging. It is possible to handle rigorous models that take into account the tradeoffs among the different decision variables, the stages and the products. This makes it possible to arrive at conclusions and to evaluate alternatives not approached in the past. Different scenarios and applications of this approach are analyzed. |
P.A. Aguirre, J. Espinosa, E. Tarifa, N. Scenna Optimal Thermodynamic Approximation to Reversible Distillation by Means of Interheaters and Intercoolers (Artículo de revista) Industrial and Engineering Chemistry Research, 36 (11), pp. 4882-4893, 1997, (cited By 10). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Aguirre19974882, title = {Optimal Thermodynamic Approximation to Reversible Distillation by Means of Interheaters and Intercoolers}, author = { P.A. Aguirre and J. Espinosa and E. Tarifa and N. Scenna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0031270892&partnerID=40&md5=d42f1ade550b96f33646b9e3cf9ee05d}, year = {1997}, date = {1997-01-01}, journal = {Industrial and Engineering Chemistry Research}, volume = {36}, number = {11}, pages = {4882-4893}, abstract = {The purpose of this paper is to deal with the problem of heat and power integration on one side and the problem of minimizing heat exchange areas on the other side, in both conventional and nonconventional distillation columns. We consider the limiting case of columns operating at minimum reflux. The appropriate objective functions that one must consider are the entropy production rate and the total heat exchange area, respectively. This is done by means of optimal placement of a given number of interheaters (IHs) and intercoolers (ICs) in stripping and rectifying sections, respectively. To solve these problems, an appropriate thermodynamic model for both conventional and nonconventional distillative columns is formally presented. This model allows us to formulate an optimization problem involving thermodynamically reversible profiles in stripping and rectifying sections of the columns. Our approach differs from others previously reported in that multiple reversible profiles were identified for each section of the column which give rise to lower and upper bounds for the objective function of the minimization problem. In other words, we obtain two solutions for each column section: the first is a nonoptimal feasible one, and the second is an optimal but not necessarily feasible one. Finally, the comparison of our approach with a method based on pseudobinary reversible profiles is carried out. Optimizing with this curve, solutions will be generated with objective function values between our lower and upper bounds. Therefore, care would be taken in using a pseudobinary pinch point curve for the placement of intermediate heat-exchanger units especially when the difference between our upper and lower bounds for the objective function values is relatively great.}, note = {cited By 10}, keywords = {}, pubstate = {published}, tppubtype = {article} } The purpose of this paper is to deal with the problem of heat and power integration on one side and the problem of minimizing heat exchange areas on the other side, in both conventional and nonconventional distillation columns. We consider the limiting case of columns operating at minimum reflux. The appropriate objective functions that one must consider are the entropy production rate and the total heat exchange area, respectively. This is done by means of optimal placement of a given number of interheaters (IHs) and intercoolers (ICs) in stripping and rectifying sections, respectively. To solve these problems, an appropriate thermodynamic model for both conventional and nonconventional distillative columns is formally presented. This model allows us to formulate an optimization problem involving thermodynamically reversible profiles in stripping and rectifying sections of the columns. Our approach differs from others previously reported in that multiple reversible profiles were identified for each section of the column which give rise to lower and upper bounds for the objective function of the minimization problem. In other words, we obtain two solutions for each column section: the first is a nonoptimal feasible one, and the second is an optimal but not necessarily feasible one. Finally, the comparison of our approach with a method based on pseudobinary reversible profiles is carried out. Optimizing with this curve, solutions will be generated with objective function values between our lower and upper bounds. Therefore, care would be taken in using a pseudobinary pinch point curve for the placement of intermediate heat-exchanger units especially when the difference between our upper and lower bounds for the objective function values is relatively great. |
S.G. Olesen, G.T. Polley, J.M. Montagna A simple methodology for the design of water networks handling single contaminants (Artículo de revista) Chemical Engineering Research and Design, 75 (4), pp. 420-437, 1997, (cited By 81). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Olesen1997420, title = {A simple methodology for the design of water networks handling single contaminants}, author = { S.G. Olesen and G.T. Polley and J.M. Montagna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0031148051&partnerID=40&md5=cf6b4268aa4067d4d9728468951bf56b}, year = {1997}, date = {1997-01-01}, journal = {Chemical Engineering Research and Design}, volume = {75}, number = {4}, pages = {420-437}, abstract = {The procedures introduced by Wang and Smith for the estimation of the minimum water needs for systems involving single contaminants are reviewed. A new network design procedure is then developed. This procedure is demonstrated on problems involving simple direct water re-use, water draw-off and regenerated water re-use. It is shown that in the case of regenerated water re-use, there are cases in which the water target can only be met by splitting operations into two parts. Where this is unacceptable, the Load Table developed in this paper can be used to determine a revised water consumption target.}, note = {cited By 81}, keywords = {}, pubstate = {published}, tppubtype = {article} } The procedures introduced by Wang and Smith for the estimation of the minimum water needs for systems involving single contaminants are reviewed. A new network design procedure is then developed. This procedure is demonstrated on problems involving simple direct water re-use, water draw-off and regenerated water re-use. It is shown that in the case of regenerated water re-use, there are cases in which the water target can only be met by splitting operations into two parts. Where this is unacceptable, the Load Table developed in this paper can be used to determine a revised water consumption target. |
1996 |
H.P. Leone A knowledge-based system for HAZOP studies. The knowledge representation structure (Artículo de revista) Computers and Chemical Engineering, 20 (SUPPL.1), pp. S369-S374, 1996, (cited By 12). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Leone1996, title = {A knowledge-based system for HAZOP studies. The knowledge representation structure}, author = { H.P. Leone}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0029713065&partnerID=40&md5=d33051f746d0f6bbc4e761aac1af927f}, year = {1996}, date = {1996-01-01}, journal = {Computers and Chemical Engineering}, volume = {20}, number = {SUPPL.1}, pages = {S369-S374}, abstract = {The Chemical Process Industry is been forced by the society to improve its standards in safety, environmental effects and product quality. One approach used to address all these aspects in traditional process industries is the HAZOP study (HAzard and OPerability study). But, the application of this technique to a detailed chemical plant design is a complex and time consuming task. These two aspects and the availability of proved technology to develop computational systems able to manage qualitative knowledge, have motivated the construction of SERO, a knowledge-based system for HAZOP studies. The objective of this project is to generate a system aimed at enhancing the knowledge and creative power of the expert team involved in a HAZOP study. One of the main aspects of SERO, that is presented in this paper, is its knowledge representation structure, which has been developed to encode the different kinds of knowledge used in a HAZOP study. The knowledge representation structure of SERO has been designed and constructed using the object oriented paradigm.}, note = {cited By 12}, keywords = {}, pubstate = {published}, tppubtype = {article} } The Chemical Process Industry is been forced by the society to improve its standards in safety, environmental effects and product quality. One approach used to address all these aspects in traditional process industries is the HAZOP study (HAzard and OPerability study). But, the application of this technique to a detailed chemical plant design is a complex and time consuming task. These two aspects and the availability of proved technology to develop computational systems able to manage qualitative knowledge, have motivated the construction of SERO, a knowledge-based system for HAZOP studies. The objective of this project is to generate a system aimed at enhancing the knowledge and creative power of the expert team involved in a HAZOP study. One of the main aspects of SERO, that is presented in this paper, is its knowledge representation structure, which has been developed to encode the different kinds of knowledge used in a HAZOP study. The knowledge representation structure of SERO has been designed and constructed using the object oriented paradigm. |
N. Scenna, H.P. Leone Expert system for operation support in a carbon sulfide plant [Sistema experto para consulta de operadores de una planta de sulfuro de carbono] (Artículo de revista) Informacion Tecnologica, 7 (4), pp. 47-56, 1996, (cited By 0). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Scenna199647, title = {Expert system for operation support in a carbon sulfide plant [Sistema experto para consulta de operadores de una planta de sulfuro de carbono]}, author = { N. Scenna and H.P. Leone}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0029698118&partnerID=40&md5=ad15a85d04c30a7f599074c63c1167b9}, year = {1996}, date = {1996-01-01}, journal = {Informacion Tecnologica}, volume = {7}, number = {4}, pages = {47-56}, abstract = {This paper presents the development of a rule-based Expert System for fault diagnosis and operation support of a Carbon Sulfide production plant, named SECOSU. Plant operators consult SECOSU when they need help in the detection of the possible cause of an abnormal operation condition. The paper reviews the experiences obtained from the development of an information system of this type in an operating plant, and the strategy used for knowledge acquisition from information provided by process engineers and plant operators. The results of this work is a system to support control room operators in the fault diagnosis task which was implemented on a i80386 PC. The system has a knowledge data base comprised by two hundred rules encoding all the elicited process knowledge.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents the development of a rule-based Expert System for fault diagnosis and operation support of a Carbon Sulfide production plant, named SECOSU. Plant operators consult SECOSU when they need help in the detection of the possible cause of an abnormal operation condition. The paper reviews the experiences obtained from the development of an information system of this type in an operating plant, and the strategy used for knowledge acquisition from information provided by process engineers and plant operators. The results of this work is a system to support control room operators in the fault diagnosis task which was implemented on a i80386 PC. The system has a knowledge data base comprised by two hundred rules encoding all the elicited process knowledge. |
O.J. Chiotti, H.E. Salomone, O.A. Iribarren Batch plants with adaptive operating policies (Artículo de revista) Computers and Chemical Engineering, 20 (10), pp. 1241-1256, 1996, (cited By 5). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Chiotti19961241, title = {Batch plants with adaptive operating policies}, author = { O.J. Chiotti and H.E. Salomone and O.A. Iribarren}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0030269047&partnerID=40&md5=5b5eaa4b3e99d8e58179d2cc54eb0f49}, year = {1996}, date = {1996-01-01}, journal = {Computers and Chemical Engineering}, volume = {20}, number = {10}, pages = {1241-1256}, abstract = {The objective of this paper is to develop an approach for the design of batch chemical processes, accounting for adaptive operating policies to cope with varying parameters. The approach is novel in the sense that it traces variations in process parameters, while previous approaches considered variations in size factors or cycle times. A process model explicit on parameters and control variables is used. The approach proposes to partition the operation of the plant in "periods" for which it is possible to assign a set of values for the operating variables in order to adapt to each period occurrence of the varying parameters. Thus, the solution approach is the optimization of a multiperiod formulation. An analysis of the nature of perturbations was made, which led to the proposal of different operating policies, depending on the variations' predictability, time scale and occurrence pattern. A fermentation downstream process is solved as a case study to illustrate the approach, considering variations of a single parameter. Afterwards, we discuss the limitations of the approach and the direction of future work. Considering adaptive operating policies at the design step leads to plants less oversized and with lower operating costs. Copyright © 1996 Elsevier Science Ltd.}, note = {cited By 5}, keywords = {}, pubstate = {published}, tppubtype = {article} } The objective of this paper is to develop an approach for the design of batch chemical processes, accounting for adaptive operating policies to cope with varying parameters. The approach is novel in the sense that it traces variations in process parameters, while previous approaches considered variations in size factors or cycle times. A process model explicit on parameters and control variables is used. The approach proposes to partition the operation of the plant in "periods" for which it is possible to assign a set of values for the operating variables in order to adapt to each period occurrence of the varying parameters. Thus, the solution approach is the optimization of a multiperiod formulation. An analysis of the nature of perturbations was made, which led to the proposal of different operating policies, depending on the variations' predictability, time scale and occurrence pattern. A fermentation downstream process is solved as a case study to illustrate the approach, considering variations of a single parameter. Afterwards, we discuss the limitations of the approach and the direction of future work. Considering adaptive operating policies at the design step leads to plants less oversized and with lower operating costs. Copyright © 1996 Elsevier Science Ltd. |
H.E. Salomone, J.M. Montagna, O.A. Iribarren Performance analysis of fermentation batch processes by decoupled dynamic simulations (Artículo de revista) Process Biochemistry, 31 (1), pp. 47-61, 1996, (cited By 2). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Salomone199647, title = {Performance analysis of fermentation batch processes by decoupled dynamic simulations}, author = { H.E. Salomone and J.M. Montagna and O.A. Iribarren}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0028894441&partnerID=40&md5=38b065386e961ceb997194e88f288953}, year = {1996}, date = {1996-01-01}, journal = {Process Biochemistry}, volume = {31}, number = {1}, pages = {47-61}, abstract = {This paper presents a performance analysis of a typical fermentation batch process by applying the method of Decoupled Dynamic Simulations to integrate the models that describe the behavior of the stages with the overall plant design and optimization. This kind of analysis allows the determination of the optimal value for some decision variables which have an important economic impact on the performance of the process. By implementing a complete case study, typical tradeoff variables are illustrated. A better insight on the trade-off involved and on how the process variables affect different components of the performance index is obtained as a result of the analysis. The simulation of whole batch processes is a formidable task but the Decoupled Dynamic Simulations methodology greatly simplifies the computational burden and makes it affordable.}, note = {cited By 2}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents a performance analysis of a typical fermentation batch process by applying the method of Decoupled Dynamic Simulations to integrate the models that describe the behavior of the stages with the overall plant design and optimization. This kind of analysis allows the determination of the optimal value for some decision variables which have an important economic impact on the performance of the process. By implementing a complete case study, typical tradeoff variables are illustrated. A better insight on the trade-off involved and on how the process variables affect different components of the performance index is obtained as a result of the analysis. The simulation of whole batch processes is a formidable task but the Decoupled Dynamic Simulations methodology greatly simplifies the computational burden and makes it affordable. |
J. Espinosa, P.A. Aguirre, G. Pérez Some Aspects in the Design of Multicomponent Reactive Distillation Columns with a Reacting Core: Mixtures Containing Inerts (Artículo de revista) Industrial and Engineering Chemistry Research, 35 (12), pp. 4537-4549, 1996, (cited By 19). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Espinosa19964537, title = {Some Aspects in the Design of Multicomponent Reactive Distillation Columns with a Reacting Core: Mixtures Containing Inerts}, author = { J. Espinosa and P.A. Aguirre and G. Pérez}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0030414199&partnerID=40&md5=49b7304266dfa2090bb6889940ad39f6}, year = {1996}, date = {1996-01-01}, journal = {Industrial and Engineering Chemistry Research}, volume = {35}, number = {12}, pages = {4537-4549}, abstract = {Some aspects related to the design of reactive distillation columns with a reacting core are addressed in this paper. A set of transformed composition variables proposed in a previous paper is used to develop both the design equations and the reactive residue curve maps for quaternary reacting mixtures. Also, conventional residue curve maps are employed to achieve a better physical and conceptual insight into the relationships between the different constitutive parts of a column with a reacting core. Limitations in product specifications of entirely reactive distillation columns are explained by means of reactive residue curve maps, and a new feasibility criterion of a given separation for reactive columns with a reacting core is also developed on the basis of the two extreme operation conditions of a column. Finally, the behavior of column profiles for both high-conversion and low-conversion cases is analyzed and optimal product specifications are suggested to obtain high purity products. As we concluded in previous works, the inerts have a central role in both the design and synthesis of a reactive distillation column. All the concepts are applied to azeotrope-forming mixtures.}, note = {cited By 19}, keywords = {}, pubstate = {published}, tppubtype = {article} } Some aspects related to the design of reactive distillation columns with a reacting core are addressed in this paper. A set of transformed composition variables proposed in a previous paper is used to develop both the design equations and the reactive residue curve maps for quaternary reacting mixtures. Also, conventional residue curve maps are employed to achieve a better physical and conceptual insight into the relationships between the different constitutive parts of a column with a reacting core. Limitations in product specifications of entirely reactive distillation columns are explained by means of reactive residue curve maps, and a new feasibility criterion of a given separation for reactive columns with a reacting core is also developed on the basis of the two extreme operation conditions of a column. Finally, the behavior of column profiles for both high-conversion and low-conversion cases is analyzed and optimal product specifications are suggested to obtain high purity products. As we concluded in previous works, the inerts have a central role in both the design and synthesis of a reactive distillation column. All the concepts are applied to azeotrope-forming mixtures. |
P.A. Aguirre, J. Espinosa A Robust method to solve mass balances in reversible column sections (Artículo de revista) Industrial and Engineering Chemistry Research, 35 (2), pp. 559-572, 1996, (cited By 9). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Aguirre1996559, title = {A Robust method to solve mass balances in reversible column sections}, author = { P.A. Aguirre and J. Espinosa}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0000527470&partnerID=40&md5=4dedf8778afeb931f63243675ce68ea4}, year = {1996}, date = {1996-01-01}, journal = {Industrial and Engineering Chemistry Research}, volume = {35}, number = {2}, pages = {559-572}, abstract = {Reversible composition profiles in azeotropic and reactive distillation were used as pieces of new methods for the prediction of product composition regions and minimum reflux in single-and multiple-feed columns. A simple and robust algorithm to solve the nonlinear equation system corresponding to mass and energy balances in a reversible distillation column section for highly nonideal mixtures is proposed. If a distillate (bottom) is specified, one additional variable has to be set to calculate a cross section in the rectifying (stripping) part. We initially use the concentration of the component to be eliminated in the section as the variable to be fixed. A former direct successive substitution (DSS) procedure used in a previous paper is here analyzed, and the conditions for convergence are discussed. A damped Newton-Raphson method (DNR) is an alternative also presented. The new algorithm involves an improved direct successive substitution (IDSS) outer loop and a bubble point temperature (BUTE) loop included. By assuming the liquid phase composition at the reversible section, solving BUTE, and using geometric considerations, a related "hypothetical" product composition can be calculated. The difference between the real and the "hypothetical" product composition is used to recompute the liquid phase. This method can be considered robust in view that it does not uses derivative calculations that cause numerical drawbacks in cases that maxima, minima, or turning points are reached. The initialization variables are the liquid mole fractions instead of temperatures and component flow rates, resulting in a more general case-independent method. The geometrical characteristics allow that the algorithm can be initialized in any arbitrary region of the concentration simplex. For constant relative volatility (CRV) mixtures, a small number of iterations are needed despite the start point selected. The convergence was found always satisfactory independently of the start point, even when inversions in volatility order of some components take place. Finally, a variant (secant) of imbedding homotopy continuation is proposed to efficiently trace the complete path of the reversible profile, using the IDSS algorithm as the corrector. This combination becomes necessary when multiple disjoint branches of a product pinch point curve must be computed in highly nonideal mixtures. Other approaches to the problem are mentioned and their results compared.}, note = {cited By 9}, keywords = {}, pubstate = {published}, tppubtype = {article} } Reversible composition profiles in azeotropic and reactive distillation were used as pieces of new methods for the prediction of product composition regions and minimum reflux in single-and multiple-feed columns. A simple and robust algorithm to solve the nonlinear equation system corresponding to mass and energy balances in a reversible distillation column section for highly nonideal mixtures is proposed. If a distillate (bottom) is specified, one additional variable has to be set to calculate a cross section in the rectifying (stripping) part. We initially use the concentration of the component to be eliminated in the section as the variable to be fixed. A former direct successive substitution (DSS) procedure used in a previous paper is here analyzed, and the conditions for convergence are discussed. A damped Newton-Raphson method (DNR) is an alternative also presented. The new algorithm involves an improved direct successive substitution (IDSS) outer loop and a bubble point temperature (BUTE) loop included. By assuming the liquid phase composition at the reversible section, solving BUTE, and using geometric considerations, a related "hypothetical" product composition can be calculated. The difference between the real and the "hypothetical" product composition is used to recompute the liquid phase. This method can be considered robust in view that it does not uses derivative calculations that cause numerical drawbacks in cases that maxima, minima, or turning points are reached. The initialization variables are the liquid mole fractions instead of temperatures and component flow rates, resulting in a more general case-independent method. The geometrical characteristics allow that the algorithm can be initialized in any arbitrary region of the concentration simplex. For constant relative volatility (CRV) mixtures, a small number of iterations are needed despite the start point selected. The convergence was found always satisfactory independently of the start point, even when inversions in volatility order of some components take place. Finally, a variant (secant) of imbedding homotopy continuation is proposed to efficiently trace the complete path of the reversible profile, using the IDSS algorithm as the corrector. This combination becomes necessary when multiple disjoint branches of a product pinch point curve must be computed in highly nonideal mixtures. Other approaches to the problem are mentioned and their results compared. |
1995 |
E. Tarifa, O.J. Chiotti Flexibility vs costs in multiproduct batch plant design: a calculation algorithm (Artículo de revista) Chemical Engineering Research and Design, 73 (A8), pp. 931-940, 1995, (cited By 3). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Tarifa1995931, title = {Flexibility vs costs in multiproduct batch plant design: a calculation algorithm}, author = { E. Tarifa and O.J. Chiotti}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0029407379&partnerID=40&md5=b670142dd1e88546d619cbe95c1a297c}, year = {1995}, date = {1995-01-01}, journal = {Chemical Engineering Research and Design}, volume = {73}, number = {A8}, pages = {931-940}, abstract = {In this work we consider an important problem of multiproduct batch plants which is the uncertainty in process parameter values and in product demands. This context raises the Flexibility problem. It has been defined as the need to size the plant such that this guarantees that all constraints are satisfied for any value of the parameters during the process operation. Therefore, this problem demands consideration of two opposite goals: maximum flexibility vs. minimum cost. It can be approached as a bicriterion optimization problem. Such a problem yields an infinite set of pareto optimal solutions that force only one arbitrary decision to obtain the solution. However, this decision involves a set of factors that should be considered individually. Moreover, it must be borne in mind that it is only the investor who will take this decision. That is why, if the problem requires a subjective decision to be taken, it is important that at least an effort be made to offer an appropriate frame to support the decision. The fuzzy sets are a mathematical tool to represent vagueness in everyday life. There is much evidence nowadays that fuzzy approaches to real problems are often a good alternative to more familiar schemes. Thus, in this work we will use them to approach the problem in the terms formulated above. Then, we present an algorithm based on this strategy.}, note = {cited By 3}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this work we consider an important problem of multiproduct batch plants which is the uncertainty in process parameter values and in product demands. This context raises the Flexibility problem. It has been defined as the need to size the plant such that this guarantees that all constraints are satisfied for any value of the parameters during the process operation. Therefore, this problem demands consideration of two opposite goals: maximum flexibility vs. minimum cost. It can be approached as a bicriterion optimization problem. Such a problem yields an infinite set of pareto optimal solutions that force only one arbitrary decision to obtain the solution. However, this decision involves a set of factors that should be considered individually. Moreover, it must be borne in mind that it is only the investor who will take this decision. That is why, if the problem requires a subjective decision to be taken, it is important that at least an effort be made to offer an appropriate frame to support the decision. The fuzzy sets are a mathematical tool to represent vagueness in everyday life. There is much evidence nowadays that fuzzy approaches to real problems are often a good alternative to more familiar schemes. Thus, in this work we will use them to approach the problem in the terms formulated above. Then, we present an algorithm based on this strategy. |
G. Guilhou, A.R. Vecchietti Optimizing SDH networks (Artículo de revista) Commutation and transmission English ed., 17 (1), pp. 35-42, 1995, (cited By 0). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Guilhou199535, title = {Optimizing SDH networks}, author = { G. Guilhou and A.R. Vecchietti}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0029225476&partnerID=40&md5=faaca199a499d12590683923aec9b91b}, year = {1995}, date = {1995-01-01}, journal = {Commutation and transmission English ed.}, volume = {17}, number = {1}, pages = {35-42}, abstract = {In close cooperation with its customers, Alcatel can help to optimize synchronous transmission networks. Using powerful tools, Alcatel can assist operators in designing the network architectures that meet their needs.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } In close cooperation with its customers, Alcatel can help to optimize synchronous transmission networks. Using powerful tools, Alcatel can assist operators in designing the network architectures that meet their needs. |
J. Espinosa, P.A. Aguirre, G.A. Perez Product composition regions of single-feed reactive distillation columns: Mixtures containing inerts (Artículo de revista) Industrial and Engineering Chemistry Research, 34 (3), pp. 853-861, 1995, (cited By 52). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Espinosa1995853, title = {Product composition regions of single-feed reactive distillation columns: Mixtures containing inerts}, author = { J. Espinosa and P.A. Aguirre and G.A. Perez}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0029271981&partnerID=40&md5=820183e5275b7fe0ea95b8994affd70b}, year = {1995}, date = {1995-01-01}, journal = {Industrial and Engineering Chemistry Research}, volume = {34}, number = {3}, pages = {853-861}, abstract = {This paper presents a method to determine the product composition regions of single-feed reactive distillation columns. A new set of transformed compositions is introduced, and the resulting residue curve maps are studied for two reacting mixtures containing inerts. Due to the geometrical properties of the new composition variables, by using the residue curves it is possible to determine the feasibility of a desired separation from the extreme limiting operating conditions. As in conventional distillation, the generalization of the feasibility criterion gives a method to obtain the complete product composition region attainable in a single-feed reactive distillation column for a given quaternary feed. These concepts are applied to azeotrope-forming mixtures. An interesting behavior is observed for the highly nonideal reacting mixture isobutene-methanol-MTBE-butane. The minimum reflux ratio, for certain splits, corresponds to a finite number of trays in both column sections. The conditions for the occurrence of such a case are given.}, note = {cited By 52}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents a method to determine the product composition regions of single-feed reactive distillation columns. A new set of transformed compositions is introduced, and the resulting residue curve maps are studied for two reacting mixtures containing inerts. Due to the geometrical properties of the new composition variables, by using the residue curves it is possible to determine the feasibility of a desired separation from the extreme limiting operating conditions. As in conventional distillation, the generalization of the feasibility criterion gives a method to obtain the complete product composition region attainable in a single-feed reactive distillation column for a given quaternary feed. These concepts are applied to azeotrope-forming mixtures. An interesting behavior is observed for the highly nonideal reacting mixture isobutene-methanol-MTBE-butane. The minimum reflux ratio, for certain splits, corresponds to a finite number of trays in both column sections. The conditions for the occurrence of such a case are given. |