Publicaciones
2004 |
J.M. Montagna, O.A. Iribarren, A.R. Vecchietti Synthesis of biotechnological processes using generalized disjunctive programming (Artículo de revista) Industrial and Engineering Chemistry Research, 43 (15), pp. 4220-4232, 2004, (cited By 9). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Montagna20044220, title = {Synthesis of biotechnological processes using generalized disjunctive programming}, author = { J.M. Montagna and O.A. Iribarren and A.R. Vecchietti}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-3242658966&partnerID=40&md5=215ca8693101651cce9ac5bd231a45e5}, year = {2004}, date = {2004-01-01}, journal = {Industrial and Engineering Chemistry Research}, volume = {43}, number = {15}, pages = {4220-4232}, abstract = {This article presents a model for the synthesis of a biotechnological process in which a set of biotechnological products must be elaborated. For each of these products, there is a set of hosts that can be used for production. According to the host selected for each product, there is a different set of stages involved in the process. Furthermore, to carry out the task involved at a particular stage, there are different units that can be selected. Depending on the kind of equipment used, different performances can be obtained in terms of the stage yield, dimension required by the unit, processing time, etc. A generalized disjunctive programming model is formulated to solve this problem. This problem is transformed into an MINLP using either a big-M or convex hull reformulation. Both alternatives are solved, and their performances are evaluated.}, note = {cited By 9}, keywords = {}, pubstate = {published}, tppubtype = {article} } This article presents a model for the synthesis of a biotechnological process in which a set of biotechnological products must be elaborated. For each of these products, there is a set of hosts that can be used for production. According to the host selected for each product, there is a different set of stages involved in the process. Furthermore, to carry out the task involved at a particular stage, there are different units that can be selected. Depending on the kind of equipment used, different performances can be obtained in terms of the stage yield, dimension required by the unit, processing time, etc. A generalized disjunctive programming model is formulated to solve this problem. This problem is transformed into an MINLP using either a big-M or convex hull reformulation. Both alternatives are solved, and their performances are evaluated. |
O.A. Iribarren, J.M. Montagna, A.R. Vecchietti, B. Andrews, J.A. Asenjo, J.M. Pinto Optimal process synthesis for the production of multiple recombinant proteins (Artículo de revista) Biotechnology Progress, 20 (4), pp. 1032-1043, 2004, (cited By 8). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Iribarren20041032, title = {Optimal process synthesis for the production of multiple recombinant proteins}, author = { O.A. Iribarren and J.M. Montagna and A.R. Vecchietti and B. Andrews and J.A. Asenjo and J.M. Pinto}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-4043173342&partnerID=40&md5=54744e8b510538cbbe553a048d6e2481}, doi = {10.1021/bp034330+}, year = {2004}, date = {2004-01-01}, journal = {Biotechnology Progress}, volume = {20}, number = {4}, pages = {1032-1043}, abstract = {This paper presents a novel solution strategy for the synthesis of multiproduct and multihost protein production processes. There are several possible hosts that may express each of the products, and different downstream processing separation and purification tasks are needed, which in part depend on the host selection. Moreover, alternative unit operations may be available for some of these separation tasks. Finally, these processing units may be arranged in different configurations. A single mixed-integer optimization model represents the different decisions involved in synthesizing a plant for producing multiple proteins. The mathematical model optimizes the profit of the multiproduct plant and allows the decisions to be made simultaneously, namely, the choice of hosts, downstream operations, the configuration and size of units, as well as their scheduling. An example is solved for a plant that must produce four proteins for which there are alternative hosts for their expression (Escherichia coli, Chinese hamster ovary cells, and yeast that, depending on the product, may express it as an extracellular or intracellular protein) that require 15 stages with choices of unit operations as well as in or out of phase operations. Given the very large quantity of novel recombinant proteins for a number of novel therapeutic uses presently being approved or "in the pipeline", multiproduct and multihost recombinant protein production plants have recently been or are being built for the manufacture of these products. The strategy presented in this paper is of crucial value for the optimal utilization of such plants.}, note = {cited By 8}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents a novel solution strategy for the synthesis of multiproduct and multihost protein production processes. There are several possible hosts that may express each of the products, and different downstream processing separation and purification tasks are needed, which in part depend on the host selection. Moreover, alternative unit operations may be available for some of these separation tasks. Finally, these processing units may be arranged in different configurations. A single mixed-integer optimization model represents the different decisions involved in synthesizing a plant for producing multiple proteins. The mathematical model optimizes the profit of the multiproduct plant and allows the decisions to be made simultaneously, namely, the choice of hosts, downstream operations, the configuration and size of units, as well as their scheduling. An example is solved for a plant that must produce four proteins for which there are alternative hosts for their expression (Escherichia coli, Chinese hamster ovary cells, and yeast that, depending on the product, may express it as an extracellular or intracellular protein) that require 15 stages with choices of unit operations as well as in or out of phase operations. Given the very large quantity of novel recombinant proteins for a number of novel therapeutic uses presently being approved or "in the pipeline", multiproduct and multihost recombinant protein production plants have recently been or are being built for the manufacture of these products. The strategy presented in this paper is of crucial value for the optimal utilization of such plants. |
J. Espinosa, H.E. Salomone, O.A. Iribarren Computer-Aided Conceptual Design of Batch Distillation Systems (Artículo de revista) Industrial and Engineering Chemistry Research, 43 (7), pp. 1723-1733, 2004, (cited By 8). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Espinosa20041723, title = {Computer-Aided Conceptual Design of Batch Distillation Systems}, author = { J. Espinosa and H.E. Salomone and O.A. Iribarren}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-1842457049&partnerID=40&md5=01b90b22a80159a4c3e4d7a7c224af27}, year = {2004}, date = {2004-01-01}, journal = {Industrial and Engineering Chemistry Research}, volume = {43}, number = {7}, pages = {1723-1733}, abstract = {During the past decade, several authors worked in the development of methods to cope with different steps of the design and synthesis of batch distillation systems. Among these methods, the conceptual design is based both on the thermodynamic analysis of residue curve maps and on the behavior of composition profiles in batch columns operating at limiting operating conditions, i.e., infinite number of stages and total reflux. In this work, we apply the conceptual design approach to design the recovery of 2-propanol from a mixture containing water by using cyclohexane as entrainer. All the computations were performed through an integration of these methods in a software tool for conceptual design.}, note = {cited By 8}, keywords = {}, pubstate = {published}, tppubtype = {article} } During the past decade, several authors worked in the development of methods to cope with different steps of the design and synthesis of batch distillation systems. Among these methods, the conceptual design is based both on the thermodynamic analysis of residue curve maps and on the behavior of composition profiles in batch columns operating at limiting operating conditions, i.e., infinite number of stages and total reflux. In this work, we apply the conceptual design approach to design the recovery of 2-propanol from a mixture containing water by using cyclohexane as entrainer. All the computations were performed through an integration of these methods in a software tool for conceptual design. |
I.E. Grossmann, P.A. Aguirre, M. Barttfeld Optimal synthesis of complex distillation columns using rigorous models (Artículo de revista) Computer Aided Chemical Engineering, 18 (C), pp. 53-74, 2004, (cited By 4). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Grossmann200453, title = {Optimal synthesis of complex distillation columns using rigorous models}, author = { I.E. Grossmann and P.A. Aguirre and M. Barttfeld}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77955641874&partnerID=40&md5=d60ab0fd9ffe682f7baddc42cde272c6}, doi = {10.1016/S1570-7946(04)80083-X}, year = {2004}, date = {2004-01-01}, journal = {Computer Aided Chemical Engineering}, volume = {18}, number = {C}, pages = {53-74}, abstract = {The synthesis of complex distillation columns has remained a major challenge since the pioneering work by Sargent and Gaminibanadara that was reported in 1976. In this paper we first provide a review of recent work for the optimal design of distillation of individual columns using tray-by-tray models. We examine the impact of different representations and models, NLP, MINLP and GDP, as well as the importance of appropriate initialization schemes. We next provide a review of the synthesis of complex column configurations for zeotropic mixtures and discuss different superstructure representations as well as decomposition schemes for tackling these problems. Finally, we briefly discuss extensions for handling azeotropic mixtures, reactive distillation columns and integration in process flowsheets. Numerical examples are presented to demonstrate that effective computational strategies are emerging that are based on disjunctive programming models that are coupled with thermodynamic initialization models and integrated through hierarchical decomposition techniques. © 2004 Elsevier B.V. All rights reserved.}, note = {cited By 4}, keywords = {}, pubstate = {published}, tppubtype = {article} } The synthesis of complex distillation columns has remained a major challenge since the pioneering work by Sargent and Gaminibanadara that was reported in 1976. In this paper we first provide a review of recent work for the optimal design of distillation of individual columns using tray-by-tray models. We examine the impact of different representations and models, NLP, MINLP and GDP, as well as the importance of appropriate initialization schemes. We next provide a review of the synthesis of complex column configurations for zeotropic mixtures and discuss different superstructure representations as well as decomposition schemes for tackling these problems. Finally, we briefly discuss extensions for handling azeotropic mixtures, reactive distillation columns and integration in process flowsheets. Numerical examples are presented to demonstrate that effective computational strategies are emerging that are based on disjunctive programming models that are coupled with thermodynamic initialization models and integrated through hierarchical decomposition techniques. © 2004 Elsevier B.V. All rights reserved. |
M. Barttfeld, P.A. Aguirre, I.E. Grossmann A decomposition method for synthesizing complex column configurations using tray-by-tray GDP models (Artículo de revista) Computers and Chemical Engineering, 28 (11), pp. 2165-2188, 2004, (cited By 24). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Barttfeld20042165, title = {A decomposition method for synthesizing complex column configurations using tray-by-tray GDP models}, author = { M. Barttfeld and P.A. Aguirre and I.E. Grossmann}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-4143094617&partnerID=40&md5=0f7f3647351a4c14afad625ca6dd5118}, doi = {10.1016/j.compchemeng.2004.03.006}, year = {2004}, date = {2004-01-01}, journal = {Computers and Chemical Engineering}, volume = {28}, number = {11}, pages = {2165-2188}, abstract = {This paper describes an optimization procedure for the synthesis of complex distillation configurations. A superstructure based on the Reversible Distillation Sequence Model (RDSM) is proposed embedding all possible alternative designs using tray-by-tray models. Generalize disjunctive programming (GDP) is used to model the superstructure. Each column section of the superstructure is modeled using rigorous MESH equations. Due to the large size and complexity of the formulation, as well as the great difficulty in coverging the corresponding equations, a decomposition solution strategy is proposed where discrete decisions are decomposed into two hierarchical levels within an iterative procedure. In the first level, the column sections are selected yielding a candidate configuration. In the second level, the feed location and the number of trays of the selected sections are optimized. A preprocessing phase including thermodynamic information is considered to provide a good starting point to the algorithm in order to improve the convergence and robustness of the method. Examples are presented for zeotropic and azeotropic multicomponent mixtures to illustrate the performance of the proposed method. Non-trivial configurations are obtained involving modest solution times. © 2004 Elsevier Ltd. All rights reserved.}, note = {cited By 24}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper describes an optimization procedure for the synthesis of complex distillation configurations. A superstructure based on the Reversible Distillation Sequence Model (RDSM) is proposed embedding all possible alternative designs using tray-by-tray models. Generalize disjunctive programming (GDP) is used to model the superstructure. Each column section of the superstructure is modeled using rigorous MESH equations. Due to the large size and complexity of the formulation, as well as the great difficulty in coverging the corresponding equations, a decomposition solution strategy is proposed where discrete decisions are decomposed into two hierarchical levels within an iterative procedure. In the first level, the column sections are selected yielding a candidate configuration. In the second level, the feed location and the number of trays of the selected sections are optimized. A preprocessing phase including thermodynamic information is considered to provide a good starting point to the algorithm in order to improve the convergence and robustness of the method. Examples are presented for zeotropic and azeotropic multicomponent mixtures to illustrate the performance of the proposed method. Non-trivial configurations are obtained involving modest solution times. © 2004 Elsevier Ltd. All rights reserved. |
S.F. Mussati, P.A. Aguirre, N.J. Scenna A rigorous, mixed-integer, nonlineal programming model (MINLP) for synthesis and optimal operation of cogeneration seawater desalination plants (Artículo de revista) Desalination, 166 (1-3), pp. 339-345, 2004, (cited By 9). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Mussati2004339, title = {A rigorous, mixed-integer, nonlineal programming model (MINLP) for synthesis and optimal operation of cogeneration seawater desalination plants}, author = { S.F. Mussati and P.A. Aguirre and N.J. Scenna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-7544246299&partnerID=40&md5=b0e85c86ebc7be8dd82de86af443a9f4}, doi = {10.1016/j.desal.2004.06.088}, year = {2004}, date = {2004-01-01}, journal = {Desalination}, volume = {166}, number = {1-3}, pages = {339-345}, abstract = {This paper presents a rigorous mixed-integer nonlinear programming (MINLP) model for optimal synthesis and design of dual-purpose seawater desalination plants. The proposed superstructure considers more alternative configurations than the model recently proposed by Mussati et al. [1] and all process equipment is modelled in a rigorous way. The MINLP model introduces binary variables in order to select equipment for the cogeneration plant. The detailed model for the MSF desalter developed by Mussati et al. [2] was considered. The MSF mathematical model involves the real-physical constraints for the evaporation process. Nonlinear equations are used to model all plant equipment rigorously in terms of chemico-physical properties (enthalpies, entropies, vapor pressure) and design equations (efficiencies, NEA, BPE, heat transfer coefficients, momentum balances, among others). The proposed model is not only useful for synthesis, but also for analyzing different design alternatives. The model has been implemented in a general algebraic modelling system [4]. Several study cases were successfully solved by applying the MINLP model. A case study is presented in order to illustrate the model's capabilities. © 2004 Elsevier B.V. All rights reserved.}, note = {cited By 9}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents a rigorous mixed-integer nonlinear programming (MINLP) model for optimal synthesis and design of dual-purpose seawater desalination plants. The proposed superstructure considers more alternative configurations than the model recently proposed by Mussati et al. [1] and all process equipment is modelled in a rigorous way. The MINLP model introduces binary variables in order to select equipment for the cogeneration plant. The detailed model for the MSF desalter developed by Mussati et al. [2] was considered. The MSF mathematical model involves the real-physical constraints for the evaporation process. Nonlinear equations are used to model all plant equipment rigorously in terms of chemico-physical properties (enthalpies, entropies, vapor pressure) and design equations (efficiencies, NEA, BPE, heat transfer coefficients, momentum balances, among others). The proposed model is not only useful for synthesis, but also for analyzing different design alternatives. The model has been implemented in a general algebraic modelling system [4]. Several study cases were successfully solved by applying the MINLP model. A case study is presented in order to illustrate the model's capabilities. © 2004 Elsevier B.V. All rights reserved. |
S.F. Mussati, M.G. Marcovecchio, P.A. Aguirre, N.J. Scenna A new global optimization algorithm for process design: Its application to thermal desalination processes (Artículo de revista) Desalination, 166 (1-3), pp. 129-140, 2004, (cited By 3). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Mussati2004129, title = {A new global optimization algorithm for process design: Its application to thermal desalination processes}, author = { S.F. Mussati and M.G. Marcovecchio and P.A. Aguirre and N.J. Scenna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-7544234154&partnerID=40&md5=49a066d7c03bef798ccc9ca7c0bb7060}, doi = {10.1016/j.desal.2004.06.067}, year = {2004}, date = {2004-01-01}, journal = {Desalination}, volume = {166}, number = {1-3}, pages = {129-140}, abstract = {A new deterministic algorithm [1] to solve a nonconvex, nonlinear optimization problem (a desalination process model) to global optimality is presented. The algorithm optimization was applied to the simplified model developed previously by Mussati et al. [2,3]. The objective was to determine the optimal process design and operating conditions for a given water production. Although the model for the desaltor was derived from a simplified hypothesis, it considers all the most important aspects of the process. The model takes into account the evaporator geometric design (height, length and width of stages), number of tubes in the pre-heater, boiling point elevation, among other. The resulting mathematical model contains inherently nonlinear and nonconvex constraints. The proposed iterative algorithm is deterministic, and it attains finite ε-convergence to the global optimum through the successive subdivision of the original region and the subsequent solution of nonconvex optimization problems. A bound reduction technique is performed in order to accelerate the algorithm convergence. The global optimal solutions obtained by the algorithm provide preliminary designs for the process. Moreover, these solutions are used as a starting point to solve more complex models efficiently [3]. Different case studies are presented and discussed in order to illustrate the methodology and computational performance. © 2004 Elsevier B.V. All rights reserved.}, note = {cited By 3}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new deterministic algorithm [1] to solve a nonconvex, nonlinear optimization problem (a desalination process model) to global optimality is presented. The algorithm optimization was applied to the simplified model developed previously by Mussati et al. [2,3]. The objective was to determine the optimal process design and operating conditions for a given water production. Although the model for the desaltor was derived from a simplified hypothesis, it considers all the most important aspects of the process. The model takes into account the evaporator geometric design (height, length and width of stages), number of tubes in the pre-heater, boiling point elevation, among other. The resulting mathematical model contains inherently nonlinear and nonconvex constraints. The proposed iterative algorithm is deterministic, and it attains finite ε-convergence to the global optimum through the successive subdivision of the original region and the subsequent solution of nonconvex optimization problems. A bound reduction technique is performed in order to accelerate the algorithm convergence. The global optimal solutions obtained by the algorithm provide preliminary designs for the process. Moreover, these solutions are used as a starting point to solve more complex models efficiently [3]. Different case studies are presented and discussed in order to illustrate the methodology and computational performance. © 2004 Elsevier B.V. All rights reserved. |
S.F. Mussati, P.A. Aguirre, N.J. Scenna Improving the efficiency of the MSF once through (MSF-OT) and MSF-mixer (MSF-M) evaporators (Artículo de revista) Desalination, 166 (1-3), pp. 141-151, 2004, (cited By 6). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Mussati2004141, title = {Improving the efficiency of the MSF once through (MSF-OT) and MSF-mixer (MSF-M) evaporators}, author = { S.F. Mussati and P.A. Aguirre and N.J. Scenna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-7544230078&partnerID=40&md5=0f086172877b9b6bc66853d55044d17a}, doi = {10.1016/j.desal.2004.06.068}, year = {2004}, date = {2004-01-01}, journal = {Desalination}, volume = {166}, number = {1-3}, pages = {141-151}, abstract = {During the last decade intensive research and development have been carried out to increase the efficiency of the multi stage flash (MSF) desalination system. Although a great number of reviews have been published on this topic, no relevant improvements on the flow pattern distribution have been achieved to improve the efficiency and/or the economy of the process. A different configuration for the MSF evaporator is presented in this paper. This configuration was obtained by considering a superstructure for the evaporator where, the flow pattern of the streams and the number of stages are variables of the problem. The resulting configuration is characterized by distillate extraction from stages, improving the efficiency of the evaporator. The distillate extraction not only decreases the heat area transfer (investment), but also the seawater feed (pre-treatment costs). In this paper, the influence of the main parameters such as maximum admissible temperature, number of stages, heat consumption, heat transfer area, different modes of recycles (MSF-OT and MSF-M) and the desaltor distillate extraction efficiency are discussed. Finally, the solution obtained in this paper is compared to the solution reported previously in [1]. © 2004 Elsevier B.V. All rights reserved.}, note = {cited By 6}, keywords = {}, pubstate = {published}, tppubtype = {article} } During the last decade intensive research and development have been carried out to increase the efficiency of the multi stage flash (MSF) desalination system. Although a great number of reviews have been published on this topic, no relevant improvements on the flow pattern distribution have been achieved to improve the efficiency and/or the economy of the process. A different configuration for the MSF evaporator is presented in this paper. This configuration was obtained by considering a superstructure for the evaporator where, the flow pattern of the streams and the number of stages are variables of the problem. The resulting configuration is characterized by distillate extraction from stages, improving the efficiency of the evaporator. The distillate extraction not only decreases the heat area transfer (investment), but also the seawater feed (pre-treatment costs). In this paper, the influence of the main parameters such as maximum admissible temperature, number of stages, heat consumption, heat transfer area, different modes of recycles (MSF-OT and MSF-M) and the desaltor distillate extraction efficiency are discussed. Finally, the solution obtained in this paper is compared to the solution reported previously in [1]. © 2004 Elsevier B.V. All rights reserved. |
G. Corsano, P.A. Aguirre, O.A. Iribarren, J.M. Montagna Batch fermentation networks model for optimal synthesis, design, and operation (Artículo de revista) Industrial and Engineering Chemistry Research, 43 (15), pp. 4211-4219, 2004, (cited By 14). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Corsano20044211, title = {Batch fermentation networks model for optimal synthesis, design, and operation}, author = { G. Corsano and P.A. Aguirre and O.A. Iribarren and J.M. Montagna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-3242704963&partnerID=40&md5=d057cf8dcf3700033d8ab53b83bc65ce}, year = {2004}, date = {2004-01-01}, journal = {Industrial and Engineering Chemistry Research}, volume = {43}, number = {15}, pages = {4211-4219}, abstract = {This paper addresses an integral optimization of fermentation processes. The behavior of the fermentors is described by a set of algebraic and differential equations written as finite-difference equations in an equation-oriented environment. Unconventional constraints related to the number of batch items and connections among them, detailed kinetic models and operating costs corresponding to inoculum, and different available substrates are included in the model. The optimal number of units to be used in the process, their optimal operation policy (i.e., connected in series or in parallel working out of phase), as well as the optimal volume and operation of each unit, are determined simultaneously. The model is formulated as a sequence of nonlinear programming (NLP) problems.}, note = {cited By 14}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper addresses an integral optimization of fermentation processes. The behavior of the fermentors is described by a set of algebraic and differential equations written as finite-difference equations in an equation-oriented environment. Unconventional constraints related to the number of batch items and connections among them, detailed kinetic models and operating costs corresponding to inoculum, and different available substrates are included in the model. The optimal number of units to be used in the process, their optimal operation policy (i.e., connected in series or in parallel working out of phase), as well as the optimal volume and operation of each unit, are determined simultaneously. The model is formulated as a sequence of nonlinear programming (NLP) problems. |
M. González, E. González, P.A. Aguirre, G. Corsano Optimal integration of water recycling systems in paper manufacturing processes [Integración Óptima en el Sistema de Reciclado de Aguas en Procesos Papeleros] (Artículo de revista) Informacion Tecnologica, 15 (3), pp. 71-74, 2004, (cited By 0). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{González200471, title = {Optimal integration of water recycling systems in paper manufacturing processes [Integración Óptima en el Sistema de Reciclado de Aguas en Procesos Papeleros]}, author = { M. González and E. González and P.A. Aguirre and G. Corsano}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-3042530941&partnerID=40&md5=cc69d42db2496ff5e56d39937633a514}, year = {2004}, date = {2004-01-01}, journal = {Informacion Tecnologica}, volume = {15}, number = {3}, pages = {71-74}, abstract = {This work proposes a novel non-linear programming model that solves the problem of minimizing fresh water consumption in the paper manufacturing process, as well as reducing waste release. The degree of pollution of the flows to be recycled and the maximum contaminant composition treatable by different equipment units are determined; on the basis of this data, the maximum amount of recycleable residual flow is determined. The problem is modeled mathematically, determining the minimum consumption of fresh water, the maximum flow of waste water, the mass of fiber in suspension which can be recuperated, and the amount of pollutant to be removed in the process. It is concluded that the model used is a powerful generic systematic tool which can be used in any process for the reduction of residues.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } This work proposes a novel non-linear programming model that solves the problem of minimizing fresh water consumption in the paper manufacturing process, as well as reducing waste release. The degree of pollution of the flows to be recycled and the maximum contaminant composition treatable by different equipment units are determined; on the basis of this data, the maximum amount of recycleable residual flow is determined. The problem is modeled mathematically, determining the minimum consumption of fresh water, the maximum flow of waste water, the mass of fiber in suspension which can be recuperated, and the amount of pollutant to be removed in the process. It is concluded that the model used is a powerful generic systematic tool which can be used in any process for the reduction of residues. |
L.I. Ferrario, J.M. Montagna A framework for evaluating difficulties in ERP implementation (Conferencia) 2004, (cited By 0). (Resumen | Enlaces | BibTeX | Etiquetas: ) @conference{Ferrario2004460, title = {A framework for evaluating difficulties in ERP implementation}, author = { L.I. Ferrario and J.M. Montagna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-8444231669&partnerID=40&md5=78b4ffd593a8cff183586ceb23f191ca}, year = {2004}, date = {2004-01-01}, journal = {ICEIS 2004 - Proceedings of the Sixth International Conference on Enterprise Information Systems}, pages = {460-465}, abstract = {Various sources point out very high percentages of failures to implement ERF systems. In this work, the main difficulties for this task are analyzed and a systematic classification of fundamental reasons is intended. By considering the reasons that lead to failure, a simple and effective mechanism is generated to evaluate in advance complications the project might present. In this way, the tools to be used can be adjusted to the specific characteristics of the project. Somehow, it is intended to solve the problem presented by general methodologies, which are used for any kind of enterprise, without previously considering its conditions and state to face this type of projects.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {conference} } Various sources point out very high percentages of failures to implement ERF systems. In this work, the main difficulties for this task are analyzed and a systematic classification of fundamental reasons is intended. By considering the reasons that lead to failure, a simple and effective mechanism is generated to evaluate in advance complications the project might present. In this way, the tools to be used can be adjusted to the specific characteristics of the project. Somehow, it is intended to solve the problem presented by general methodologies, which are used for any kind of enterprise, without previously considering its conditions and state to face this type of projects. |
2003 |
M. Eggersmann, S. Gonnet, G.P. Henning, C. Krobb, H.P. Leone, W. Marquardt Modeling and understanding different types of process design activities (Artículo de revista) Latin American Applied Research, 33 (2), pp. 167-175, 2003, (cited By 19). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Eggersmann2003167, title = {Modeling and understanding different types of process design activities}, author = { M. Eggersmann and S. Gonnet and G.P. Henning and C. Krobb and H.P. Leone and W. Marquardt}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0037376839&partnerID=40&md5=7b95ea2f06bfe487251e75e69027e0be}, year = {2003}, date = {2003-01-01}, journal = {Latin American Applied Research}, volume = {33}, number = {2}, pages = {167-175}, abstract = {One of the major tasks addressed by the chemical industry is the design and revamping of production processes. Increasingly powerful computer-aided tools are available to face these complex tasks. Nevertheless, most design knowledge still rests in the minds of experienced designers. It is desirable to make it part of a computer support environment. Therefore, it is necessary to have a model of the design process. This contribution addresses this objective by introducing a model, based on the identification of three types of design activities: Synthesis, Analysis, and Decision. We discuss the intrinsic characteristics of each type of activity from two different view points: characteristic subactivities and products. Every type of activity consists of typical subordinate subactivities which are distinctive for the type and determine its behavior. On the other hand, activities operate on the results or products of the design process, called product data, including requirements, the representation of the design artifact itself, and arguments. These products also allow a specification of the three types. These ideas are exemplified by modeling the design of a separation system.}, note = {cited By 19}, keywords = {}, pubstate = {published}, tppubtype = {article} } One of the major tasks addressed by the chemical industry is the design and revamping of production processes. Increasingly powerful computer-aided tools are available to face these complex tasks. Nevertheless, most design knowledge still rests in the minds of experienced designers. It is desirable to make it part of a computer support environment. Therefore, it is necessary to have a model of the design process. This contribution addresses this objective by introducing a model, based on the identification of three types of design activities: Synthesis, Analysis, and Decision. We discuss the intrinsic characteristics of each type of activity from two different view points: characteristic subactivities and products. Every type of activity consists of typical subordinate subactivities which are distinctive for the type and determine its behavior. On the other hand, activities operate on the results or products of the design process, called product data, including requirements, the representation of the design artifact itself, and arguments. These products also allow a specification of the three types. These ideas are exemplified by modeling the design of a separation system. |
J.M. Montagna, A.R. Vecchietti Retrofit of Multiproduct Batch Plants Through Generalized Disjunctive Programming (Artículo de revista) Mathematical and Computer Modelling, 38 (5-6), pp. 465-479, 2003, (cited By 7). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Montagna2003465, title = {Retrofit of Multiproduct Batch Plants Through Generalized Disjunctive Programming}, author = { J.M. Montagna and A.R. Vecchietti}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0142020794&partnerID=40&md5=5d8a752587ba88ab5af57af8397f14c5}, year = {2003}, date = {2003-01-01}, journal = {Mathematical and Computer Modelling}, volume = {38}, number = {5-6}, pages = {465-479}, abstract = {The retrofit problem for multiproduct batch plants deals with the modification of the original structure of the plant to meet new production conditions such as the introduction of new products, a new supply pattern, etc. For this problem, a disjunctive model is presented, which takes into consideration every usual alternative about the configuration of units and storage tanks. A disjunction is generated for that purpose. The selection of one of those alternatives sets up all the corresponding constraints, which are: operation time, unit size and cost, etc. Finally, the performance of this approach is analyzed through the resolution of a set of examples. © 2003 Elsevier Ltd. All rights reserved.}, note = {cited By 7}, keywords = {}, pubstate = {published}, tppubtype = {article} } The retrofit problem for multiproduct batch plants deals with the modification of the original structure of the plant to meet new production conditions such as the introduction of new products, a new supply pattern, etc. For this problem, a disjunctive model is presented, which takes into consideration every usual alternative about the configuration of units and storage tanks. A disjunction is generated for that purpose. The selection of one of those alternatives sets up all the corresponding constraints, which are: operation time, unit size and cost, etc. Finally, the performance of this approach is analyzed through the resolution of a set of examples. © 2003 Elsevier Ltd. All rights reserved. |
A.R. Vecchietti, S. Lee, I.E. Grossmann Modeling of discrete/continuous optimization problems: Characterization and formulation of disjunctions and their relaxations (Artículo de revista) Computers and Chemical Engineering, 27 (3), pp. 433-448, 2003, (cited By 73). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Vecchietti2003433, title = {Modeling of discrete/continuous optimization problems: Characterization and formulation of disjunctions and their relaxations}, author = { A.R. Vecchietti and S. Lee and I.E. Grossmann}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0037443768&partnerID=40&md5=8dd4f16c4dd20a528bb8cf3834a9da19}, doi = {10.1016/S0098-1354(02)00220-X}, year = {2003}, date = {2003-01-01}, journal = {Computers and Chemical Engineering}, volume = {27}, number = {3}, pages = {433-448}, abstract = {This paper addresses the relaxations in alternative models for disjunctions, big-M and convex hull model, in order to develop guidelines and insights when formulating Mixed-Integer Non-Linear Programming (MINLP), Generalized Disjunctive Programming (GDP), or hybrid models. Characterization and properties are presented for various types of disjunctions. An interesting result is presented for improper disjunctions where results in the continuous space differ from the ones in the mixed-integer space. A cutting plane method is also proposed that avoids the explicit generation of equations and variables of the convex hull. Several examples are presented throughout the paper, as well as a small process synthesis problem, which is solved with the proposed cutting plane method. © 2002 Elsevier Science Ltd. All rights reserved.}, note = {cited By 73}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper addresses the relaxations in alternative models for disjunctions, big-M and convex hull model, in order to develop guidelines and insights when formulating Mixed-Integer Non-Linear Programming (MINLP), Generalized Disjunctive Programming (GDP), or hybrid models. Characterization and properties are presented for various types of disjunctions. An interesting result is presented for improper disjunctions where results in the continuous space differ from the ones in the mixed-integer space. A cutting plane method is also proposed that avoids the explicit generation of equations and variables of the convex hull. Several examples are presented throughout the paper, as well as a small process synthesis problem, which is solved with the proposed cutting plane method. © 2002 Elsevier Science Ltd. All rights reserved. |
S.F. Mussati, P.A. Aguirre, N.J. Scenna Novel configuration for a multistage flash-mixer desalination system (Artículo de revista) Industrial and Engineering Chemistry Research, 42 (20), pp. 4828-4839, 2003, (cited By 9). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Mussati20034828, title = {Novel configuration for a multistage flash-mixer desalination system}, author = { S.F. Mussati and P.A. Aguirre and N.J. Scenna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0141455019&partnerID=40&md5=fc432707bb59f9a1ba290472e12e9997}, year = {2003}, date = {2003-01-01}, journal = {Industrial and Engineering Chemistry Research}, volume = {42}, number = {20}, pages = {4828-4839}, abstract = {In this paper a systematic procedure for the synthesis and design of multistage flash-mixer desalination processes is presented. The process configuration, geometric design, and optimal operating conditions are determined by minimizing the total annualized cost for a given water production. Different possible arrangements for the desaltor are embedded in a superstructure. The multistage flash-mixer system is rigorously modeled considering the most important aspects of the real process. The resolution procedure involves two phases. First, a simplified model is solved in a preprocessing phase providing the initial values and bounds, and then from these values the rigorous model is easily solved. For the simplified model resolution in the preprocessing phase, there is no need for supplying and tuning external parameters for initialization. The preprocessing phase increases the robustness of the optimization algorithm. A new configuration of the multistage flash-mixer system system resulted. This new structure differs from the conventional one because it considers distillate extraction and a new allocation of the blowdown brine (generally placed at the last stage). Different study cases are presented to illustrate the methodology robustness and computational performance.}, note = {cited By 9}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper a systematic procedure for the synthesis and design of multistage flash-mixer desalination processes is presented. The process configuration, geometric design, and optimal operating conditions are determined by minimizing the total annualized cost for a given water production. Different possible arrangements for the desaltor are embedded in a superstructure. The multistage flash-mixer system is rigorously modeled considering the most important aspects of the real process. The resolution procedure involves two phases. First, a simplified model is solved in a preprocessing phase providing the initial values and bounds, and then from these values the rigorous model is easily solved. For the simplified model resolution in the preprocessing phase, there is no need for supplying and tuning external parameters for initialization. The preprocessing phase increases the robustness of the optimization algorithm. A new configuration of the multistage flash-mixer system system resulted. This new structure differs from the conventional one because it considers distillate extraction and a new allocation of the blowdown brine (generally placed at the last stage). Different study cases are presented to illustrate the methodology robustness and computational performance. |
M. Barttfeld, P.A. Aguirre Optimal synthesis of multicomponent zeotropic distillation processes. 2. Preprocessing phase and rigorous optimization of efficient sequences (Artículo de revista) Industrial and Engineering Chemistry Research, 42 (14), pp. 3441-3457, 2003, (cited By 10). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Barttfeld20033441, title = {Optimal synthesis of multicomponent zeotropic distillation processes. 2. Preprocessing phase and rigorous optimization of efficient sequences}, author = { M. Barttfeld and P.A. Aguirre}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0037999882&partnerID=40&md5=f632c8c9fa5ba9385ed533102ebc6c48}, year = {2003}, date = {2003-01-01}, journal = {Industrial and Engineering Chemistry Research}, volume = {42}, number = {14}, pages = {3441-3457}, abstract = {The optimal synthesis of zeotropic efficient distillation processes is addressed in this paper. The reversible distillation sequence model (RDSM) is rigorously approximated by a sequence of adiabatic units. Alternative superstructures representations involving different energy distributions are proposed for approximating the RDSM. The efficient distillation synthesis problem is formulated as a rigorous tray-by-tray mixed-integer nonlinear programming (MINLP) problem. Discrete decisions are related to the feed and heat-exchange locations while continuous choices select the operating conditions of the process. The most suitable representation is selected by computing the entropy production of each scheme. The solution procedure includes an automatic preprocessing phase where reversible distillation theory is combined with mathematical programming to generate initial values and bounds for the variables involved in the rigorous MINLP problem. Convergence and robustness of the formulations are considerably improved by including this preliminary phase. Numerical examples are reported for the separation of zeotropic mixtures to show the performance of the proposed methodology.}, note = {cited By 10}, keywords = {}, pubstate = {published}, tppubtype = {article} } The optimal synthesis of zeotropic efficient distillation processes is addressed in this paper. The reversible distillation sequence model (RDSM) is rigorously approximated by a sequence of adiabatic units. Alternative superstructures representations involving different energy distributions are proposed for approximating the RDSM. The efficient distillation synthesis problem is formulated as a rigorous tray-by-tray mixed-integer nonlinear programming (MINLP) problem. Discrete decisions are related to the feed and heat-exchange locations while continuous choices select the operating conditions of the process. The most suitable representation is selected by computing the entropy production of each scheme. The solution procedure includes an automatic preprocessing phase where reversible distillation theory is combined with mathematical programming to generate initial values and bounds for the variables involved in the rigorous MINLP problem. Convergence and robustness of the formulations are considerably improved by including this preliminary phase. Numerical examples are reported for the separation of zeotropic mixtures to show the performance of the proposed methodology. |
M.C. Mussati, M. Fuentes, N.J. Scenna, P.A. Aguirre Optimizing load policy in anaerobic biofilm reactors for wastewater treatment (Artículo de revista) Latin American Applied Research, 33 (3), pp. 301-305, 2003, (cited By 1). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Mussati2003301, title = {Optimizing load policy in anaerobic biofilm reactors for wastewater treatment}, author = { M.C. Mussati and M. Fuentes and N.J. Scenna and P.A. Aguirre}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0038676418&partnerID=40&md5=0b2bbc2e77d97765bf7bfcf34828f540}, year = {2003}, date = {2003-01-01}, journal = {Latin American Applied Research}, volume = {33}, number = {3}, pages = {301-305}, abstract = {A rigorous dynamic model of anaerobic biofilm reactor (Mussati et al., 1998) is used to optimize and evaluate different loading strategies in anaerobic wastewater treatment systems. This work includes variations in the original model so that the results of process simulation also represent the initial events of the start up operation as regards the biofilm growth. The model was implemented in gPROMS (General Process Modeling System). Different dynamic optimization formulations are evaluated. Start up strategies are considered and discussed. A sensitivity analysis regarding kinetic data on optimal start up policies under two different conditions is included. The first condition consists of a fixed maximum load, and the other one is the maximum load supported by the system, which varies according to the kinetic data being used. Changes in maximum specific growth rate, half saturation constant and specific death rate of Monod's model generate different optimal start up periods; whereas optimal start up time did not change when the maximum allowed load for each reactor is considered.}, note = {cited By 1}, keywords = {}, pubstate = {published}, tppubtype = {article} } A rigorous dynamic model of anaerobic biofilm reactor (Mussati et al., 1998) is used to optimize and evaluate different loading strategies in anaerobic wastewater treatment systems. This work includes variations in the original model so that the results of process simulation also represent the initial events of the start up operation as regards the biofilm growth. The model was implemented in gPROMS (General Process Modeling System). Different dynamic optimization formulations are evaluated. Start up strategies are considered and discussed. A sensitivity analysis regarding kinetic data on optimal start up policies under two different conditions is included. The first condition consists of a fixed maximum load, and the other one is the maximum load supported by the system, which varies according to the kinetic data being used. Changes in maximum specific growth rate, half saturation constant and specific death rate of Monod's model generate different optimal start up periods; whereas optimal start up time did not change when the maximum allowed load for each reactor is considered. |
S.F. Mussati, P.A. Aguirre, N.J. Scenna A hybrid methodology for optimization of multi-stage flash-mixer desalination systems (Artículo de revista) Latin American Applied Research, 33 (2), pp. 141-147, 2003, (cited By 6). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Mussati2003141, title = {A hybrid methodology for optimization of multi-stage flash-mixer desalination systems}, author = { S.F. Mussati and P.A. Aguirre and N.J. Scenna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0037376074&partnerID=40&md5=1587606e59c27aa0ccea50d05d05b557}, year = {2003}, date = {2003-01-01}, journal = {Latin American Applied Research}, volume = {33}, number = {2}, pages = {141-147}, abstract = {In this paper, a new strategy involving an evolutionary algorithmic procedure for the optimization of Multiple Stage Flash (MSF-M) Systems is presented. A "detailed model" of an MSF-M System is developed according to rigorous material, momentum and energy balances for each stage. The model of the MSF-M System is represented as a complex NLP, which incorporates a high number of nonlinear constraints that difficult the global optimum determination. Here we present a hybrid methodology that uses optimal solutions obtained from a "thermodynamic method" to find the "economic global optimal solution". A pre-processing stage (solving successive NLPs) is used to initialize the final NLP problem. A Case Study and a discussion of the results are presented.}, note = {cited By 6}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, a new strategy involving an evolutionary algorithmic procedure for the optimization of Multiple Stage Flash (MSF-M) Systems is presented. A "detailed model" of an MSF-M System is developed according to rigorous material, momentum and energy balances for each stage. The model of the MSF-M System is represented as a complex NLP, which incorporates a high number of nonlinear constraints that difficult the global optimum determination. Here we present a hybrid methodology that uses optimal solutions obtained from a "thermodynamic method" to find the "economic global optimal solution". A pre-processing stage (solving successive NLPs) is used to initialize the final NLP problem. A Case Study and a discussion of the results are presented. |
M. Barttfeld, P.A. Aguirre, I.E. Grossmann Alternative representations and formulations for the economic optimization of multicomponent distillation columns (Artículo de revista) Computers and Chemical Engineering, 27 (3), pp. 363-383, 2003, (cited By 25). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Barttfeld2003363, title = {Alternative representations and formulations for the economic optimization of multicomponent distillation columns}, author = { M. Barttfeld and P.A. Aguirre and I.E. Grossmann}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0037443161&partnerID=40&md5=8febee13238f23ebfe84782cce76de52}, doi = {10.1016/S0098-1354(02)00213-2}, year = {2003}, date = {2003-01-01}, journal = {Computers and Chemical Engineering}, volume = {27}, number = {3}, pages = {363-383}, abstract = {This paper examines alternative models for the economic optimization of multicomponent distillation columns. Different column representations are modeled involving rigorous Mixed Integer Nonlinear Programming (MINLP) and General Disjunctive Programming (GDP) formulations. The different representations involve various ways of representing the choices for the number of trays and feed tray location. Also, alternatives are considered for modeling the heat exchange when the number of trays of the column must be determinated. A preprocessing procedure developed in a previous paper [Ind. Eng. Chem. Res. (2002a)] is extended in this work to provide good initial values and bounds for the variables involved in the economic models. This initialization scheme increases the robustness and usefulness of the optimization models. Numerical results are reported on problems involving the separation of zeotropic and azeotropic mixtures. Trends about the behavior of the different proposed alternative models are discussed. © 2002 Elsevier Science Ltd. All rights reserved.}, note = {cited By 25}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper examines alternative models for the economic optimization of multicomponent distillation columns. Different column representations are modeled involving rigorous Mixed Integer Nonlinear Programming (MINLP) and General Disjunctive Programming (GDP) formulations. The different representations involve various ways of representing the choices for the number of trays and feed tray location. Also, alternatives are considered for modeling the heat exchange when the number of trays of the column must be determinated. A preprocessing procedure developed in a previous paper [Ind. Eng. Chem. Res. (2002a)] is extended in this work to provide good initial values and bounds for the variables involved in the economic models. This initialization scheme increases the robustness and usefulness of the optimization models. Numerical results are reported on problems involving the separation of zeotropic and azeotropic mixtures. Trends about the behavior of the different proposed alternative models are discussed. © 2002 Elsevier Science Ltd. All rights reserved. |
S.F. Mussati, P.A. Aguirre, N. Scenna Dual-purpose desalination plants. Part II. Optimal configuration (Artículo de revista) Desalination, 153 (1-3), pp. 185-189, 2003, (cited By 7). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Mussati2003185, title = {Dual-purpose desalination plants. Part II. Optimal configuration}, author = { S.F. Mussati and P.A. Aguirre and N. Scenna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0037985557&partnerID=40&md5=edeedc28a8fa7c1adf569c51548c5d75}, doi = {10.1016/S0011-9164(02)01126-8}, year = {2003}, date = {2003-01-01}, journal = {Desalination}, volume = {153}, number = {1-3}, pages = {185-189}, abstract = {Large dual-purpose power desalination plants are used to reduce the production cost of both electricity and water. Various combinations of power-desalination systems are conceivable in order to satisfy both power and water demands. The preference of one scheme over another would depend mainly on many factors, such as the required power to water ratio, cost of fuel energy charged to the desalting process, electricity sales, capital costs, and local requirements. The allocation of the total annual cost of a dual-purpose plant to desalted water and electricity can be made by various methods. In this paper, credit method is adopted to calculate the total annual cost. Credit methods allocate a predetermined value to one of the products and determine the cost of the other product by subtraction from the total cost of the dual-purpose plant. In this way, according with the power credit method, the total cost is calculated in the following way: Cwater=Ctotal - W; where W is the benefit of the net electrical generated. Non-linear equations are extensively used for the cost equipment and for the plant performance. The aim of this paper is to design a dual-purpose plant system at minimum cost determining the equipment configuration and its corresponding operating conditions given the water production. The optimal solution is selected from a superstructure containing different possible configurations. One case study illustrating the methodology, robustness and computational performance is presented.}, note = {cited By 7}, keywords = {}, pubstate = {published}, tppubtype = {article} } Large dual-purpose power desalination plants are used to reduce the production cost of both electricity and water. Various combinations of power-desalination systems are conceivable in order to satisfy both power and water demands. The preference of one scheme over another would depend mainly on many factors, such as the required power to water ratio, cost of fuel energy charged to the desalting process, electricity sales, capital costs, and local requirements. The allocation of the total annual cost of a dual-purpose plant to desalted water and electricity can be made by various methods. In this paper, credit method is adopted to calculate the total annual cost. Credit methods allocate a predetermined value to one of the products and determine the cost of the other product by subtraction from the total cost of the dual-purpose plant. In this way, according with the power credit method, the total cost is calculated in the following way: Cwater=Ctotal - W; where W is the benefit of the net electrical generated. Non-linear equations are extensively used for the cost equipment and for the plant performance. The aim of this paper is to design a dual-purpose plant system at minimum cost determining the equipment configuration and its corresponding operating conditions given the water production. The optimal solution is selected from a superstructure containing different possible configurations. One case study illustrating the methodology, robustness and computational performance is presented. |
S.F. Mussati, P.A. Aguirre, N. Scenna Dual-purpose desalination plants. Part I. Optimal design (Artículo de revista) Desalination, 153 (1-3), pp. 179-184, 2003, (cited By 4). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Mussati2003179, title = {Dual-purpose desalination plants. Part I. Optimal design}, author = { S.F. Mussati and P.A. Aguirre and N. Scenna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0037985556&partnerID=40&md5=d520f85d47f4e6a7cbda5b62636c930a}, doi = {10.1016/S0011-9164(02)01124-4}, year = {2003}, date = {2003-01-01}, journal = {Desalination}, volume = {153}, number = {1-3}, pages = {179-184}, abstract = {In this paper, a methodology for optimization of a given system configuration for dual-purpose desalination plants will be presented. The whole system is represented as a non-lineal programming (NLP) model solved using general algebraic modeling system (GAMS) [1]. The rigorous model incorporates a high number of non-linear restrictions; so the achievement of the optimal solutions is difficult. It is important to point out that the initialization of variables are very important, especially to guarantee the convergence and the determination of the optimal solutions. The proposed methodology in this work consists on the resolution of simplified model in order to provide the initial values and critical bounds to solve the rigorous model. In this way, a procedure for the optimization of a given configuration involving the total annual cost (TAC) minimization is presented. The results obtained from one study case applying the methodology are analyzed.}, note = {cited By 4}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, a methodology for optimization of a given system configuration for dual-purpose desalination plants will be presented. The whole system is represented as a non-lineal programming (NLP) model solved using general algebraic modeling system (GAMS) [1]. The rigorous model incorporates a high number of non-linear restrictions; so the achievement of the optimal solutions is difficult. It is important to point out that the initialization of variables are very important, especially to guarantee the convergence and the determination of the optimal solutions. The proposed methodology in this work consists on the resolution of simplified model in order to provide the initial values and critical bounds to solve the rigorous model. In this way, a procedure for the optimization of a given configuration involving the total annual cost (TAC) minimization is presented. The results obtained from one study case applying the methodology are analyzed. |
J.M. Montagna The optimal retrofit of multiproduct batch plants (Artículo de revista) Computers and Chemical Engineering, 27 (8-9), pp. 1277-1290, 2003, (cited By 11). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Montagna20031277, title = {The optimal retrofit of multiproduct batch plants}, author = { J.M. Montagna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0041304630&partnerID=40&md5=eea5fb2f7f80e2bf145b0ee445387adb}, doi = {10.1016/S0098-1354(03)00052-8}, year = {2003}, date = {2003-01-01}, journal = {Computers and Chemical Engineering}, volume = {27}, number = {8-9}, pages = {1277-1290}, abstract = {This paper presents new alternatives in the retrofit model of multiproduct batch plants. Besides the duplication of the batch units implemented in previous works, the model considers the inclusion of intermediate storage tanks. These tanks can be plainly added or replace existing units that can be sold. The allocation of intermediate storage tanks is not considered in the previous retrofit works, even if this alternative is not new in the design of multiproduct batch plants. This option allows getting more efficient and real world solutions, although it requires working with a more complex model. © 2003 Elsevier Science Ltd. All rights reserved.}, note = {cited By 11}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents new alternatives in the retrofit model of multiproduct batch plants. Besides the duplication of the batch units implemented in previous works, the model considers the inclusion of intermediate storage tanks. These tanks can be plainly added or replace existing units that can be sold. The allocation of intermediate storage tanks is not considered in the previous retrofit works, even if this alternative is not new in the design of multiproduct batch plants. This option allows getting more efficient and real world solutions, although it requires working with a more complex model. © 2003 Elsevier Science Ltd. All rights reserved. |
2002 |
S. Oddone, O.A. Iribarren A modelling formalism for multiproduct and multiplant batch processes (Artículo de revista) Computer Aided Chemical Engineering, 10 (C), pp. 139-144, 2002, (cited By 0). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Oddone2002139, title = {A modelling formalism for multiproduct and multiplant batch processes}, author = { S. Oddone and O.A. Iribarren}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77956742572&partnerID=40&md5=c4c4780c6c176e2d3c84be29e6929496}, doi = {10.1016/S1570-7946(02)80051-7}, year = {2002}, date = {2002-01-01}, journal = {Computer Aided Chemical Engineering}, volume = {10}, number = {C}, pages = {139-144}, abstract = {Computer aided process engineering tools devised for batch processes are still well behind the performance of those developed for steady state processes. As commerical process simultors still lack optimisation capabilities, the alternative for optimising process recipes is resorting to programming languages like Gams, Matlab or gProms. This paper proposes a modelling formalism that could be implemented in such languages and is aimed at retaining a large degree of modularity (reuse of pre programmed modules) to expedite the set up of the problems, as well as reducing the computation time by exploiting the mathematical structure of the models at hand (this is especially conveninent for highly nested process structures, whose mass balances can be handled by a linear system of equations). The formalism is illustrated with a multiplant arrangement that produces sugar cane derivatives: sugar, bio ethanol and yeast. © 2002 Elsevier B.V. All rights reserved.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } Computer aided process engineering tools devised for batch processes are still well behind the performance of those developed for steady state processes. As commerical process simultors still lack optimisation capabilities, the alternative for optimising process recipes is resorting to programming languages like Gams, Matlab or gProms. This paper proposes a modelling formalism that could be implemented in such languages and is aimed at retaining a large degree of modularity (reuse of pre programmed modules) to expedite the set up of the problems, as well as reducing the computation time by exploiting the mathematical structure of the models at hand (this is especially conveninent for highly nested process structures, whose mass balances can be handled by a linear system of equations). The formalism is illustrated with a multiplant arrangement that produces sugar cane derivatives: sugar, bio ethanol and yeast. © 2002 Elsevier B.V. All rights reserved. |
J. Espinosa Integration of reaction and separation in a batch extractive distillation column with a middle vessel (Artículo de revista) Computer Aided Chemical Engineering, 10 (C), pp. 187-192, 2002, (cited By 0). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Espinosa2002187, title = {Integration of reaction and separation in a batch extractive distillation column with a middle vessel}, author = { J. Espinosa}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77957170653&partnerID=40&md5=6399ba54f8bc5646aa6c4237dc553743}, doi = {10.1016/S1570-7946(02)80059-1}, year = {2002}, date = {2002-01-01}, journal = {Computer Aided Chemical Engineering}, volume = {10}, number = {C}, pages = {187-192}, abstract = {In this work, the integration of reaction and separation in a batch extractive distillation column with a middle vessel/reactor is analyzed for azeotrope-forming mixtures. This equipment configuration has the potential to promote complete conversion of reactants and therefore, the main process characteristics are investigated. A mixture showing several azeotropes and suffering an esterification reaction was selected as an academic example. © 2002 Elsevier B.V. All rights reserved.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this work, the integration of reaction and separation in a batch extractive distillation column with a middle vessel/reactor is analyzed for azeotrope-forming mixtures. This equipment configuration has the potential to promote complete conversion of reactants and therefore, the main process characteristics are investigated. A mixture showing several azeotropes and suffering an esterification reaction was selected as an academic example. © 2002 Elsevier B.V. All rights reserved. |
J. Espinosa On the integration of reaction and separation in a batch extractive distillation column with a middle vessel (Artículo de revista) Industrial and Engineering Chemistry Research, 41 (15), pp. 3657-3668, 2002, (cited By 2). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Espinosa20023657, title = {On the integration of reaction and separation in a batch extractive distillation column with a middle vessel}, author = { J. Espinosa}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0037166955&partnerID=40&md5=1e2b2c32a21ae81e2ad36fde5fd53d23}, year = {2002}, date = {2002-01-01}, journal = {Industrial and Engineering Chemistry Research}, volume = {41}, number = {15}, pages = {3657-3668}, abstract = {In this work, the integration of reaction and separation in a batch extractive distillation column with a middle vessel/reactor is analyzed for azeotrope-forming mixtures. This equipment configuration has the potential to promote the complete conversion of reactants; therefore, the main process characteristics are investigated. A mixture showing several azeotropes and involving an esterification reaction was selected as an academic example. The first part of the paper deals with the phase-equilibrium analysis of the mixture. The nodes (pure components and azeotropes) and the distillation regions of the multicomponent mixture are obtained. The analysis of the topology of the residue-curve map is used to select one of the reagents as entrainer. Feasibility of the combined operation is studied based on the phase-equilibrium analysis and the investigation of the feasible cuts at infinite separation power. The second part of the contribution focuses on the different steps of the process. The influence of operating and process parameters on the operation performance is studied with the aid of a process simulator. Physical explanations are given for the results. Results show the advantages of integrating reaction and separation to enhance both reagents conversion and product separation.}, note = {cited By 2}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this work, the integration of reaction and separation in a batch extractive distillation column with a middle vessel/reactor is analyzed for azeotrope-forming mixtures. This equipment configuration has the potential to promote the complete conversion of reactants; therefore, the main process characteristics are investigated. A mixture showing several azeotropes and involving an esterification reaction was selected as an academic example. The first part of the paper deals with the phase-equilibrium analysis of the mixture. The nodes (pure components and azeotropes) and the distillation regions of the multicomponent mixture are obtained. The analysis of the topology of the residue-curve map is used to select one of the reagents as entrainer. Feasibility of the combined operation is studied based on the phase-equilibrium analysis and the investigation of the feasible cuts at infinite separation power. The second part of the contribution focuses on the different steps of the process. The influence of operating and process parameters on the operation performance is studied with the aid of a process simulator. Physical explanations are given for the results. Results show the advantages of integrating reaction and separation to enhance both reagents conversion and product separation. |
M. Vegetti, G. Henning, H.P. Leone An object-oriented framework for bill of materials in process industries (Artículo de revista) Computer Aided Chemical Engineering, 10 (C), pp. 991-996, 2002, (cited By 0). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Vegetti2002991, title = {An object-oriented framework for bill of materials in process industries}, author = { M. Vegetti and G. Henning and H.P. Leone}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77956784278&partnerID=40&md5=c8711eb9ff6ef6e9824104ad8a8e9a89}, doi = {10.1016/S1570-7946(02)80193-6}, year = {2002}, date = {2002-01-01}, journal = {Computer Aided Chemical Engineering}, volume = {10}, number = {C}, pages = {991-996}, abstract = {Products that were formerly quite standard turn now into custom-made ones, leading to an enormous increase in product variants. High degrees of redundancy can occur in data management when closely related product structures are treated as independent bills of materials. Since the bill of materials (BOM) is one of the most fundamental data in industrial enterprises a lot of work has been devoted to it in last years. In this contribution, a new object-oriented BOM has been proposed. It easily manages, crucial aspects that should be taken into account in a product representation, such as the efficient handling of product families and variants concepts, composition and decomposition structures and the possibility of describing restrictions. Moreover, the model easily accommodates the needs of various organizational units within a company. © 2002 Elsevier B.V. All rights reserved.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } Products that were formerly quite standard turn now into custom-made ones, leading to an enormous increase in product variants. High degrees of redundancy can occur in data management when closely related product structures are treated as independent bills of materials. Since the bill of materials (BOM) is one of the most fundamental data in industrial enterprises a lot of work has been devoted to it in last years. In this contribution, a new object-oriented BOM has been proposed. It easily manages, crucial aspects that should be taken into account in a product representation, such as the efficient handling of product families and variants concepts, composition and decomposition structures and the possibility of describing restrictions. Moreover, the model easily accommodates the needs of various organizational units within a company. © 2002 Elsevier B.V. All rights reserved. |
M. Vegetti, G.P. Henning, H.P. Leone An object-oriented model for complex bills of materials in process industries (Artículo de revista) Brazilian Journal of Chemical Engineering, 19 (4), pp. 491-497, 2002, (cited By 2). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Vegetti2002491, title = {An object-oriented model for complex bills of materials in process industries}, author = { M. Vegetti and G.P. Henning and H.P. Leone}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0036804371&partnerID=40&md5=1c8d5374bda045803a22790d761ab78b}, year = {2002}, date = {2002-01-01}, journal = {Brazilian Journal of Chemical Engineering}, volume = {19}, number = {4}, pages = {491-497}, abstract = {In recent years, many process industries have been forced to drastically increase their product variety and adopt mass customization production strategies. Many of them have found that traditional bill of material (BOM) processing systems do not sufficiently support the maintenance of the very large amounts of data (concerned with product structure) demanded by these new production policies. Due to the use of BOM technology within the framework of integrated information systems, there is a demand for both (i) a new representation of BOMs, able to deal efficiently with product variants and to handle decomposition-based production strategies, and (ii) its corresponding BOM information processing system. This paper describes a conceptual representation that integrates elements of semantic relationships with object-oriented concepts to develop a data model for a hybrid bill of materials. The proposed semantic relationship include composed-of, decomposed-into, variant-of, restriction-of, and their corresponding reverse relationships. The conceptual model has been implemented using object-oriented data-based management system (OODBMS) technology that allows creation of persistent Java objects. Preliminary tests show a remarkable reduction in the number of relationships when compared with former approaches.}, note = {cited By 2}, keywords = {}, pubstate = {published}, tppubtype = {article} } In recent years, many process industries have been forced to drastically increase their product variety and adopt mass customization production strategies. Many of them have found that traditional bill of material (BOM) processing systems do not sufficiently support the maintenance of the very large amounts of data (concerned with product structure) demanded by these new production policies. Due to the use of BOM technology within the framework of integrated information systems, there is a demand for both (i) a new representation of BOMs, able to deal efficiently with product variants and to handle decomposition-based production strategies, and (ii) its corresponding BOM information processing system. This paper describes a conceptual representation that integrates elements of semantic relationships with object-oriented concepts to develop a data model for a hybrid bill of materials. The proposed semantic relationship include composed-of, decomposed-into, variant-of, restriction-of, and their corresponding reverse relationships. The conceptual model has been implemented using object-oriented data-based management system (OODBMS) technology that allows creation of persistent Java objects. Preliminary tests show a remarkable reduction in the number of relationships when compared with former approaches. |
M. Barttfeld, P.A. Aguirre Optimal synthesis of multicomponent zeotropic distillation processes. 1. Preprocessing phase and rigorous optimization for a single unit (Artículo de revista) Industrial and Engineering Chemistry Research, 41 (21), pp. 5298-5307, 2002, (cited By 16). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Barttfeld20025298, title = {Optimal synthesis of multicomponent zeotropic distillation processes. 1. Preprocessing phase and rigorous optimization for a single unit}, author = { M. Barttfeld and P.A. Aguirre}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0037120855&partnerID=40&md5=27e1e3a5ac02b02f56b40bbdb280813f}, year = {2002}, date = {2002-01-01}, journal = {Industrial and Engineering Chemistry Research}, volume = {41}, number = {21}, pages = {5298-5307}, abstract = {Separations performed by distillation involve large operation costs due to either large heat loads or large amounts of solvent used in azeotropic mixtures. Thermodynamic aspects helpfully lead the process synthesis to energetically efficient designs. The reversible distillation sequence model (RDSM) is employed in this work as a theoretical and ideal thermodynamic model. The aim of the paper is to present an automatic methodology for the synthesis of simple distillation columns that approximate reversible conditions. A preprocessing phase is considered where proper values to initialize and bound the variables involved in the rigorous model are calculated by successively solving auxiliary optimization models. In all cases studied, the solutions obtained are very similar to those in the so-called reversible separation. This fact is used as a test criterion for global optimality of the solutions.}, note = {cited By 16}, keywords = {}, pubstate = {published}, tppubtype = {article} } Separations performed by distillation involve large operation costs due to either large heat loads or large amounts of solvent used in azeotropic mixtures. Thermodynamic aspects helpfully lead the process synthesis to energetically efficient designs. The reversible distillation sequence model (RDSM) is employed in this work as a theoretical and ideal thermodynamic model. The aim of the paper is to present an automatic methodology for the synthesis of simple distillation columns that approximate reversible conditions. A preprocessing phase is considered where proper values to initialize and bound the variables involved in the rigorous model are calculated by successively solving auxiliary optimization models. In all cases studied, the solutions obtained are very similar to those in the so-called reversible separation. This fact is used as a test criterion for global optimality of the solutions. |
2001 |
E.C. Martínez, G.D. López Adaptive optimal operation of the Fenton's batch process for industrial wastewater treatment (Artículo de revista) Computer Aided Chemical Engineering, 9 (C), pp. 237-242, 2001, (cited By 1). (Enlaces | BibTeX | Etiquetas: ) @article{Martinez2001237, title = {Adaptive optimal operation of the Fenton's batch process for industrial wastewater treatment}, author = { E.C. Martínez and G.D. López}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77956719074&partnerID=40&md5=6c3598b623cd8ac00b3d6908f894393c}, doi = {10.1016/S1570-7946(01)80035-3}, year = {2001}, date = {2001-01-01}, journal = {Computer Aided Chemical Engineering}, volume = {9}, number = {C}, pages = {237-242}, note = {cited By 1}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
M.R. Galli, J. Cerdá Retrofit of heat exchanger networks with topology changes under designer control (Artículo de revista) Latin American Applied Research, 31 (4), pp. 247-254, 2001, (cited By 1). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Galli2001247, title = {Retrofit of heat exchanger networks with topology changes under designer control}, author = { M.R. Galli and J. Cerdá}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0346311305&partnerID=40&md5=51740002f678c939963a0cff9e8b5b2b}, year = {2001}, date = {2001-01-01}, journal = {Latin American Applied Research}, volume = {31}, number = {4}, pages = {247-254}, abstract = {This paper addresses the problem of determining the optimal retrofit of an existing heat exchanger network (HEN), The proposed algorithmic approach not only takes into account the selection of heat matches and their heat loads but also the proper unit-match reassignments, the need of new units and the requirement of additional area in existing exchangers. Moreover, it provides the retrofitted network at the level of structure. The model formulation was developed by incorporating new constraints and further variables for controlling the structural changes in the neighbor-based network model recently proposed by Galli and Cerdá (1998a,b,c). The problem goal is to minimize the total network retrofit cost including those related to manpower for moving exchangers to other sites, re-piping, purchasing of new units and/or additional area for existing exchangers. Non-linearity of the exchanger design equation has been overcome by fixing the temperature driving force in each exchanger at some specified minimum value and developing a computationally efficient iterative solution procedure. At each iteration, temperature driving forces are properly updated and the resulting MILP problem is subsequently solved until convergence is achieved. In this way, a MILP-based methodology has been derived and applied to the retrofit of existing networks under different user-specified topology restrictions.}, note = {cited By 1}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper addresses the problem of determining the optimal retrofit of an existing heat exchanger network (HEN), The proposed algorithmic approach not only takes into account the selection of heat matches and their heat loads but also the proper unit-match reassignments, the need of new units and the requirement of additional area in existing exchangers. Moreover, it provides the retrofitted network at the level of structure. The model formulation was developed by incorporating new constraints and further variables for controlling the structural changes in the neighbor-based network model recently proposed by Galli and Cerdá (1998a,b,c). The problem goal is to minimize the total network retrofit cost including those related to manpower for moving exchangers to other sites, re-piping, purchasing of new units and/or additional area for existing exchangers. Non-linearity of the exchanger design equation has been overcome by fixing the temperature driving force in each exchanger at some specified minimum value and developing a computationally efficient iterative solution procedure. At each iteration, temperature driving forces are properly updated and the resulting MILP problem is subsequently solved until convergence is achieved. In this way, a MILP-based methodology has been derived and applied to the retrofit of existing networks under different user-specified topology restrictions. |
S. Gonnet, G. Mannarino, H.P. Leone, G. Henning An environment for modeling and managing the process design process (Artículo de revista) Latin American Applied Research, 31 (5), pp. 419-425, 2001, (cited By 0). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Gonnet2001419, title = {An environment for modeling and managing the process design process}, author = { S. Gonnet and G. Mannarino and H.P. Leone and G. Henning}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0039842231&partnerID=40&md5=1baecf8eb96d1477b692a72fe9d1030f}, year = {2001}, date = {2001-01-01}, journal = {Latin American Applied Research}, volume = {31}, number = {5}, pages = {419-425}, abstract = {A three-layer object based environment architecture (Client, Application Server and Server) to support the modeling and management of the process design process is presented. It guides the design process and explicitly maintains the evolution of the design knowledge as a consequence of each design decision that is adopted during a particular design project. The Client encapsulates the interface of the designer to the design environment. The Application Server is responsible for managing the designer requirements by resorting to the Server data. It manages the definition of generic design tasks and the administration of the scenarios that are generated when a particular design process is carried out. Design tasks are defined according to the Coordinates language syntax. Basically, a design process is viewed as a set of tasks that are linked by temporal relationships and/or a set of resources they share. Generic design tasks can be instantiated and used in a specific design project. The Server contains the data that are created, used or modified by the Application Server.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } A three-layer object based environment architecture (Client, Application Server and Server) to support the modeling and management of the process design process is presented. It guides the design process and explicitly maintains the evolution of the design knowledge as a consequence of each design decision that is adopted during a particular design project. The Client encapsulates the interface of the designer to the design environment. The Application Server is responsible for managing the designer requirements by resorting to the Server data. It manages the definition of generic design tasks and the administration of the scenarios that are generated when a particular design process is carried out. Design tasks are defined according to the Coordinates language syntax. Basically, a design process is viewed as a set of tasks that are linked by temporal relationships and/or a set of resources they share. Generic design tasks can be instantiated and used in a specific design project. The Server contains the data that are created, used or modified by the Application Server. |
A. Lozano, O.J. Chiotti Supervising control support system of a multipurpose batch plant structured by process and by activity (Artículo de revista) Latin American Applied Research, 31 (5), pp. 551-557, 2001, (cited By 0). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Lozano2001551, title = {Supervising control support system of a multipurpose batch plant structured by process and by activity}, author = { A. Lozano and O.J. Chiotti}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0040435147&partnerID=40&md5=c5432564eba805f26cc6b08fcc82a811}, year = {2001}, date = {2001-01-01}, journal = {Latin American Applied Research}, volume = {31}, number = {5}, pages = {551-557}, abstract = {The aim of this work is to describe the supervising control support system (SCSS) of an order driven multipurpose batch plant operated by processes and by activities. This system generates a control structure in which 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 process (order). In first place, we briefly describe a framework based on a strategy that uses Petri nets to represent the supervising control. The strategy permits to automate the modeling of the supervising control. In second place, we describe the supervising control support system that we developed based on this framework.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } The aim of this work is to describe the supervising control support system (SCSS) of an order driven multipurpose batch plant operated by processes and by activities. This system generates a control structure in which 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 process (order). In first place, we briefly describe a framework based on a strategy that uses Petri nets to represent the supervising control. The strategy permits to automate the modeling of the supervising control. In second place, we describe the supervising control support system that we developed based on this framework. |
J.M. Montagna, A.R. Vecchietti, O.A. Iribarren, J.M. Pinto, J.A. Asenjo The role of process variables in the design of multiproduct batch protein production plants (Artículo de revista) Latin American Applied Research, 31 (5), pp. 411-417, 2001, (cited By 0). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Montagna2001411, title = {The role of process variables in the design of multiproduct batch protein production plants}, 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-s2.0-0039250545&partnerID=40&md5=f892cc3c76863d702087714657f2156a}, year = {2001}, date = {2001-01-01}, journal = {Latin American Applied Research}, volume = {31}, number = {5}, pages = {411-417}, abstract = {This work reports findings about the role of process variables in the design of multiproduct batch plants. Unlike continuous processes, batch processes are subject to size and time constraints which depend on the structure of the plant: the number of units at each stage and the provision of intermediate storage. We used simple process performance models (yet involving all the process variables with significant economic impact) to get explicit expressions for these size and time factors. The traditional approach uses fixed size and time factors. So the addition of those expressions to the original fixed factors model, permitted to simultaneously optimize the plant structure and process variables, and study the role of the latter in the design. We found that if the plant structure constraints are isregarded (with a Free Unlimited Storage operating policy), process variables behave just alike in continuous processes. They trade off cost components with the Total Annual Cost being quite insensitive to them in the neighborhood of the optimal solution. As setting the process variables sets the size and time factors, this means that near the optimal set of process variables, cycle times and size factors can be accommodated to the plant structure, with little effect on the cost of equipment.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } This work reports findings about the role of process variables in the design of multiproduct batch plants. Unlike continuous processes, batch processes are subject to size and time constraints which depend on the structure of the plant: the number of units at each stage and the provision of intermediate storage. We used simple process performance models (yet involving all the process variables with significant economic impact) to get explicit expressions for these size and time factors. The traditional approach uses fixed size and time factors. So the addition of those expressions to the original fixed factors model, permitted to simultaneously optimize the plant structure and process variables, and study the role of the latter in the design. We found that if the plant structure constraints are isregarded (with a Free Unlimited Storage operating policy), process variables behave just alike in continuous processes. They trade off cost components with the Total Annual Cost being quite insensitive to them in the neighborhood of the optimal solution. As setting the process variables sets the size and time factors, this means that near the optimal set of process variables, cycle times and size factors can be accommodated to the plant structure, with little effect on the cost of equipment. |
J.M. Pinto, J.A. Asenjo, J.M. Montagna, A.R. Vecchietti, O.A. Iribarren Incorporating process information in the optimal design of biotechnological plants (Artículo de revista) Latin American Applied Research, 31 (5), pp. 487-493, 2001, (cited By 0). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Pinto2001487, title = {Incorporating process information in the optimal design of biotechnological plants}, author = { J.M. Pinto and J.A. Asenjo and J.M. Montagna and A.R. Vecchietti and O.A. Iribarren}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0039842225&partnerID=40&md5=9dfa6bb3972ec58855bafa4ab38896a1}, year = {2001}, date = {2001-01-01}, journal = {Latin American Applied Research}, volume = {31}, number = {5}, pages = {487-493}, abstract = {In this work we propose optimization approaches that make use of process information for the design of multiproduct batch plants. First, we develop an optimization model for designing multiproduct batch plants. The plant consists of several parallel stages, which can work either in phase or out-of-phase. Processing times and size factors for each unit of the plant rely on first level of detail posynomial models. A particular feature of these models is that they may contain composite units where semi continuous items operate on the material contained by batch items. Secondly, we propose an approach in which the optimization model includes process performance models for the unit stages and a posynomial model for the multiproduct batch plant. The process performance models define the size and time factors of the posynomial model, as functions of the process variables selected to optimize the plant. These are expressed as algebraic equations obtained from the analytical integration of simplified mass balances and kinetic expressions that describe each unit operation Both approaches result in Mixed Integer Non Linear Programming (MINLP) models. In the first approach, since unit as well as structural plant constraints are posynomial, a convexified MINLP is solved to global optimality The decision variables are the number of parallel units in phase and out of phase and their size at each batch stage, the installation or not of intermediate storage between the batch stages and their size. In the second approach, we simultaneously optimize the structure of the plant, the batch plant decision variables and the process decision variables. A biotechnological plant consisting of eight stages operating in Single Product Campaign mode was modeled and optimized by using both approaches. Using this example, it is shown that the additional degrees of freedom introduced by the process performance models with respect to a fixed size and time factor model has a noticeable impact on improving the plant design.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this work we propose optimization approaches that make use of process information for the design of multiproduct batch plants. First, we develop an optimization model for designing multiproduct batch plants. The plant consists of several parallel stages, which can work either in phase or out-of-phase. Processing times and size factors for each unit of the plant rely on first level of detail posynomial models. A particular feature of these models is that they may contain composite units where semi continuous items operate on the material contained by batch items. Secondly, we propose an approach in which the optimization model includes process performance models for the unit stages and a posynomial model for the multiproduct batch plant. The process performance models define the size and time factors of the posynomial model, as functions of the process variables selected to optimize the plant. These are expressed as algebraic equations obtained from the analytical integration of simplified mass balances and kinetic expressions that describe each unit operation Both approaches result in Mixed Integer Non Linear Programming (MINLP) models. In the first approach, since unit as well as structural plant constraints are posynomial, a convexified MINLP is solved to global optimality The decision variables are the number of parallel units in phase and out of phase and their size at each batch stage, the installation or not of intermediate storage between the batch stages and their size. In the second approach, we simultaneously optimize the structure of the plant, the batch plant decision variables and the process decision variables. A biotechnological plant consisting of eight stages operating in Single Product Campaign mode was modeled and optimized by using both approaches. Using this example, it is shown that the additional degrees of freedom introduced by the process performance models with respect to a fixed size and time factor model has a noticeable impact on improving the plant design. |
J.M. Pinto, J.M. Montagna, A.R. Vecchietti, O.A. Iribarren, J.A. Asenjo Process performance models in the optimization of multiproduct protein production plants (Artículo de revista) Biotechnology and Bioengineering, 74 (6), pp. 451-465, 2001, (cited By 29). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Pinto2001451, title = {Process performance models in the optimization of multiproduct protein production plants}, author = { J.M. Pinto and J.M. Montagna and A.R. Vecchietti and O.A. Iribarren and J.A. Asenjo}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0035922103&partnerID=40&md5=62d352e0b6d2aa1250493ed5ed4b2caa}, doi = {10.1002/bit.1136}, year = {2001}, date = {2001-01-01}, journal = {Biotechnology and Bioengineering}, volume = {74}, number = {6}, pages = {451-465}, abstract = {In this work we propose a model that simultaneously optimizes the process variables and the structure of a multiproduct batch plant for the production of recombinant proteins. The complete model includes process performance models for the unit stages and a posynomial representation for the multiproduct batch plant. Although the constant time and size factor models are the most commonly used to model multiproduct batch processes, process performance models describe these time and size factors as functions of the process variables selected for optimization. These process performance models are expressed as algebraic equations obtained from the analytical integration of simplified mass balances and kinetic expressions that describe each unit operation. They are kept as simple as possible while retaining the influence of the process variables selected to optimize the plant. The resulting mixed-integer nonlinear program simultaneously calculates the plant structure (parallel units in or out of phase, and allocation of intermediate storage tanks), the batch plant decision variables (equipment sizes, batch sizes, and operating times of semicontinuous items), and the process decision variables (e.g., final concentration at selected stages, volumetric ratio of phases in the liquid-liquid extraction). A noteworthy feature of the proposed approach is that the mathematical model for the plant is the same as that used in the constant factor model. The process performance models are handled as extra constraints. A plant consisting of eight stages operating in the single product campaign mode (one fermentation, two microfiltrations, two ultrafiltrations, one homogenization, one liquid-liquid extraction, and one chromatography) for producing four different recombinant proteins by the genetically engineered yeast Saccharomyces cerevisiae was modeled and optimized. Using this example, it is shown that the presence of additional degrees of freedom introduced by the process performance models, with respect to a fixed size and time factor model, represents an important development in improving plant design. © 2001 John Wiley & Sons, Inc.}, note = {cited By 29}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this work we propose a model that simultaneously optimizes the process variables and the structure of a multiproduct batch plant for the production of recombinant proteins. The complete model includes process performance models for the unit stages and a posynomial representation for the multiproduct batch plant. Although the constant time and size factor models are the most commonly used to model multiproduct batch processes, process performance models describe these time and size factors as functions of the process variables selected for optimization. These process performance models are expressed as algebraic equations obtained from the analytical integration of simplified mass balances and kinetic expressions that describe each unit operation. They are kept as simple as possible while retaining the influence of the process variables selected to optimize the plant. The resulting mixed-integer nonlinear program simultaneously calculates the plant structure (parallel units in or out of phase, and allocation of intermediate storage tanks), the batch plant decision variables (equipment sizes, batch sizes, and operating times of semicontinuous items), and the process decision variables (e.g., final concentration at selected stages, volumetric ratio of phases in the liquid-liquid extraction). A noteworthy feature of the proposed approach is that the mathematical model for the plant is the same as that used in the constant factor model. The process performance models are handled as extra constraints. A plant consisting of eight stages operating in the single product campaign mode (one fermentation, two microfiltrations, two ultrafiltrations, one homogenization, one liquid-liquid extraction, and one chromatography) for producing four different recombinant proteins by the genetically engineered yeast Saccharomyces cerevisiae was modeled and optimized. Using this example, it is shown that the presence of additional degrees of freedom introduced by the process performance models, with respect to a fixed size and time factor model, represents an important development in improving plant design. © 2001 John Wiley & Sons, Inc. |
S. Xu, H.E. Salomone, O.A. Iribarren A short-cut approach for the design of batch stripping distillation (Artículo de revista) Latin American Applied Research, 31 (4), pp. 261-265, 2001, (cited By 1). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Xu2001261, title = {A short-cut approach for the design of batch stripping distillation}, author = { S. Xu and H.E. Salomone and O.A. Iribarren}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0347572229&partnerID=40&md5=9921e526bb51a17453d2a11718bb35a0}, year = {2001}, date = {2001-01-01}, journal = {Latin American Applied Research}, volume = {31}, number = {4}, pages = {261-265}, abstract = {Batch stripping distillation is different from the conventional batch distillation (which is actually a rectification column) in that the holding vessel feeds the top while the products leave the column from the bottom. The batch stripper is convenient for separating mixtures with small amounts of light components by removing the heavy components as bottom product. In this paper we present a shortcut design procedure for the batch stripping distillation, based on our earlier work in Salomone et al (1997) and Zamar et al (1998) on batch rectification, which is equivalent to the Fenske-Underwood-Gilliland procedure for continuous distillation. Given a separation task, we propose to compute the minimum number of stages Nmin and minimum reboil ratio Rbmin required to perform it by batch stripping. We propose them to be computed as the number of stages and reboil ratio required by a hypothetical batch stripping column operating at total reboil ratio or having an infinite number of stages, respectively. Then, it is shown that the performance of batch stripping columns with a finite number of stages and reboil ratio, does correlate in Gilliland coordinates constructed with these minimum stages Nmin and minimum reboil ratio Rbmin.}, note = {cited By 1}, keywords = {}, pubstate = {published}, tppubtype = {article} } Batch stripping distillation is different from the conventional batch distillation (which is actually a rectification column) in that the holding vessel feeds the top while the products leave the column from the bottom. The batch stripper is convenient for separating mixtures with small amounts of light components by removing the heavy components as bottom product. In this paper we present a shortcut design procedure for the batch stripping distillation, based on our earlier work in Salomone et al (1997) and Zamar et al (1998) on batch rectification, which is equivalent to the Fenske-Underwood-Gilliland procedure for continuous distillation. Given a separation task, we propose to compute the minimum number of stages Nmin and minimum reboil ratio Rbmin required to perform it by batch stripping. We propose them to be computed as the number of stages and reboil ratio required by a hypothetical batch stripping column operating at total reboil ratio or having an infinite number of stages, respectively. Then, it is shown that the performance of batch stripping columns with a finite number of stages and reboil ratio, does correlate in Gilliland coordinates constructed with these minimum stages Nmin and minimum reboil ratio Rbmin. |
S. Xu, J. Espinosa, H.E. Salomone, O.A. Iribarren Operation of a batch stripping distillation column (Artículo de revista) Chinese Journal of Chemical Engineering, 9 (2), pp. 141-144, 2001, (cited By 3). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Xu2001141, title = {Operation of a batch stripping distillation column}, author = { S. Xu and J. Espinosa and H.E. Salomone and O.A. Iribarren}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0035324467&partnerID=40&md5=7968212cc32258547c47a21432112fa3}, year = {2001}, date = {2001-01-01}, journal = {Chinese Journal of Chemical Engineering}, volume = {9}, number = {2}, pages = {141-144}, abstract = {A stripping batch distillation column is preferred when the amount of the light component in the feed is small and the products are to be recovered at high purity. The operation modes of a batch stripping are believed to be the same as those of a rectifier. However, the control system of a stripper is different. In this paper, we explore three different control methods with Hysys (Hyprotech Ltd. 1997) for a batch stripper. The main difference is the control scheme for reboiler liquid level: (a) controlled by reflux flow; (b) controlled by reboiler heat duty; (c) controlled by bottom product flow. The main characteristics of operating a batch stripper with different control scheme are presented in this paper. Guidelines are provided for the startup of a batch stripper, the effects of some control tuning parameters on the column performance are discussed.}, note = {cited By 3}, keywords = {}, pubstate = {published}, tppubtype = {article} } A stripping batch distillation column is preferred when the amount of the light component in the feed is small and the products are to be recovered at high purity. The operation modes of a batch stripping are believed to be the same as those of a rectifier. However, the control system of a stripper is different. In this paper, we explore three different control methods with Hysys (Hyprotech Ltd. 1997) for a batch stripper. The main difference is the control scheme for reboiler liquid level: (a) controlled by reflux flow; (b) controlled by reboiler heat duty; (c) controlled by bottom product flow. The main characteristics of operating a batch stripper with different control scheme are presented in this paper. Guidelines are provided for the startup of a batch stripper, the effects of some control tuning parameters on the column performance are discussed. |
H.E. Salomone, J. Espinosa Prediction of homogeneous azeotropes with interval analysis techniques exploiting topological considerations (Artículo de revista) Industrial and Engineering Chemistry Research, 40 (6), pp. 1580-1588, 2001, (cited By 8). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Salomone20011580, title = {Prediction of homogeneous azeotropes with interval analysis techniques exploiting topological considerations}, author = { H.E. Salomone and J. Espinosa}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0035925662&partnerID=40&md5=93ea89aeb39baf10ea68a94c1697d8e0}, year = {2001}, date = {2001-01-01}, journal = {Industrial and Engineering Chemistry Research}, volume = {40}, number = {6}, pages = {1580-1588}, abstract = {In this paper, we present an efficient method for the prediction of homogeneous azeotropes. The method is an adaptation of a former method based on interval analysis techniques. An interval Newton with generalized bisection (IN/GB) technique is used to find all the roots of a set of equations representing the azeotropy condition. The novel contribution is to combine this robust technique with the Zharov - Serafimov topological index theory. By checking the topological consistency, it is possible to avoid the numerical verification of the nonexistence and therefore to reduce significantly the total computation time. In addition, a simplified model is selectively used at the first stage of the algorithm for providing good starting points for the second stage, where the full model is used for solution refining. In this way, more computation time is saved without compromising the reliability of the method. As a result, the performance of the method is comparable to the one of the fastest local methods.}, note = {cited By 8}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, we present an efficient method for the prediction of homogeneous azeotropes. The method is an adaptation of a former method based on interval analysis techniques. An interval Newton with generalized bisection (IN/GB) technique is used to find all the roots of a set of equations representing the azeotropy condition. The novel contribution is to combine this robust technique with the Zharov - Serafimov topological index theory. By checking the topological consistency, it is possible to avoid the numerical verification of the nonexistence and therefore to reduce significantly the total computation time. In addition, a simplified model is selectively used at the first stage of the algorithm for providing good starting points for the second stage, where the full model is used for solution refining. In this way, more computation time is saved without compromising the reliability of the method. As a result, the performance of the method is comparable to the one of the fastest local methods. |
S. Xu, H.E. Salomone, O.A. Iribarren Shortcut procedure for inverted batch distillation column (I) multicomponent ideal system (Artículo de revista) Chinese Journal of Chemical Engineering, 9 (1), pp. 28-33, 2001, (cited By 3). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Xu200128, title = {Shortcut procedure for inverted batch distillation column (I) multicomponent ideal system}, author = { S. Xu and H.E. Salomone and O.A. Iribarren}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0035241831&partnerID=40&md5=b19561fa3309408136c3909f2ff64918}, year = {2001}, date = {2001-01-01}, journal = {Chinese Journal of Chemical Engineering}, volume = {9}, number = {1}, pages = {28-33}, abstract = {Inverted batch distillation column(stripper) is opposed to a conventional batch distillation column(rectifier). It has a storage vessel at the top and products leave the column at the bottom. The batch stripper is favourable to separate mixtures with a small amount of light components by removing the heavy components as bottom products. In this paper, we are presenting a shortcut procedure based on our earlier work for design and simulation of the inverted batch distillation column, which is equivalent to the Fenske-Underwood-Gilliland procedure for continuous distillation. Given a separation task, we propose to compute the minimum number of stages(Nbmin) and the minimum reboil ratio(Rbmin) required in a batch stripper,which are the stages and reboil ratio required in a hypothetical inverted batch distillation column operating in total reboil ratio or having an infinite number of stages, respectively. Then, it is shown that the performance of inverted batch columns with a finite number of stages and reboil ratios could be correlated in Gilliland coordinates with the minimum stages Nbmin and the minimum reboil ratio Rbmin.}, note = {cited By 3}, keywords = {}, pubstate = {published}, tppubtype = {article} } Inverted batch distillation column(stripper) is opposed to a conventional batch distillation column(rectifier). It has a storage vessel at the top and products leave the column at the bottom. The batch stripper is favourable to separate mixtures with a small amount of light components by removing the heavy components as bottom products. In this paper, we are presenting a shortcut procedure based on our earlier work for design and simulation of the inverted batch distillation column, which is equivalent to the Fenske-Underwood-Gilliland procedure for continuous distillation. Given a separation task, we propose to compute the minimum number of stages(Nbmin) and the minimum reboil ratio(Rbmin) required in a batch stripper,which are the stages and reboil ratio required in a hypothetical inverted batch distillation column operating in total reboil ratio or having an infinite number of stages, respectively. Then, it is shown that the performance of inverted batch columns with a finite number of stages and reboil ratios could be correlated in Gilliland coordinates with the minimum stages Nbmin and the minimum reboil ratio Rbmin. |
P.A. Aguirre, G. Corsano, M. Barttfeld Optimal synthesis of multicomponent distillation processes (Artículo de revista) Latin American Applied Research, 31 (4), pp. 281-286, 2001, (cited By 0). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Aguirre2001281, title = {Optimal synthesis of multicomponent distillation processes}, author = { P.A. Aguirre and G. Corsano and M. Barttfeld}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0346311304&partnerID=40&md5=09bdbec7cc7b79157a0a9ab53b2ee299}, year = {2001}, date = {2001-01-01}, journal = {Latin American Applied Research}, volume = {31}, number = {4}, pages = {281-286}, abstract = {The Optimal Synthesis of Distillation Processes involving zeotropic mixtures is addressed in this work. The Reversible Distillation Sequence Model (RDSM) generates the structure and supplies the operating conditions for a set of distillation columns, which satisfy special tasks. From the point of view of Mathematical Programming such models give rise to large mixed integer non-linear programming (MINLP) models (Bauer and Stichlmair 1998). The aim of this work is to present a detailed MINLP model of Distillation Sequences and a Hybrid Methodology which generate the initial Superstructure based on the RDSM. By using appropriate objective functions and constraints, the RDSM can be globally solved. The number of stages in each column allows operating the columns close to minimum reflux conditions. Both reboil and reflux are provided by means of mass coupling between adjacent columns. Departing from this solution, optimal cost alternatives can be computed in a second step.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } The Optimal Synthesis of Distillation Processes involving zeotropic mixtures is addressed in this work. The Reversible Distillation Sequence Model (RDSM) generates the structure and supplies the operating conditions for a set of distillation columns, which satisfy special tasks. From the point of view of Mathematical Programming such models give rise to large mixed integer non-linear programming (MINLP) models (Bauer and Stichlmair 1998). The aim of this work is to present a detailed MINLP model of Distillation Sequences and a Hybrid Methodology which generate the initial Superstructure based on the RDSM. By using appropriate objective functions and constraints, the RDSM can be globally solved. The number of stages in each column allows operating the columns close to minimum reflux conditions. Both reboil and reflux are provided by means of mass coupling between adjacent columns. Departing from this solution, optimal cost alternatives can be computed in a second step. |
S.F. Mussati, P.A. Aguirre, N.J. Scenna Optimal synthesis of multiple stage flash evaporation (Artículo de revista) Latin American Applied Research, 31 (4), pp. 293-299, 2001, (cited By 1). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Mussati2001293, title = {Optimal synthesis of multiple stage flash evaporation}, author = { S.F. Mussati and P.A. Aguirre and N.J. Scenna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0012377347&partnerID=40&md5=454979d63c36cd9e977a631b38adb390}, year = {2001}, date = {2001-01-01}, journal = {Latin American Applied Research}, volume = {31}, number = {4}, pages = {293-299}, abstract = {A detailed mathematical No-Lineal Programm (NLP) of a Multiple Stage Flash process is presented. The model has potential local optimal points due to high number of non-lineal restrictions. Different initial points were used to initialize the NLP model and the results are presented. The aim of this work is to present a methodology to formulate the problem based on a thermodynamic criterion and to initialize the optimal synthesis problem by using the information of structural and continuous variables from a simplified model and its optimal solution.}, note = {cited By 1}, keywords = {}, pubstate = {published}, tppubtype = {article} } A detailed mathematical No-Lineal Programm (NLP) of a Multiple Stage Flash process is presented. The model has potential local optimal points due to high number of non-lineal restrictions. Different initial points were used to initialize the NLP model and the results are presented. The aim of this work is to present a methodology to formulate the problem based on a thermodynamic criterion and to initialize the optimal synthesis problem by using the information of structural and continuous variables from a simplified model and its optimal solution. |
S.F. Mussati, P.A. Aguirre, N.J. Scenna Optimal MSF plant design (Artículo de revista) Desalination, 138 (1-3), pp. 341-347, 2001, (cited By 14). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Mussati2001341, title = {Optimal MSF plant design}, author = { S.F. Mussati and P.A. Aguirre and N.J. Scenna}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0035921716&partnerID=40&md5=53ab8010dadc9c93aca33c14406f836e}, doi = {10.1016/S0011-9164(01)00283-1}, year = {2001}, date = {2001-01-01}, journal = {Desalination}, volume = {138}, number = {1-3}, pages = {341-347}, abstract = {The aim of this paper is to present a rigorous model for Multi-Stage Flash Evaporation System (MSF). The MSF system is represented as a No Linear Programming (NLP) model. The model incorporates a high number of non-linear restrictions; so the achievement of the global optimum is difficult. Here, the study of an algorithm for the system optimisation is presented.}, note = {cited By 14}, keywords = {}, pubstate = {published}, tppubtype = {article} } The aim of this paper is to present a rigorous model for Multi-Stage Flash Evaporation System (MSF). The MSF system is represented as a No Linear Programming (NLP) model. The model incorporates a high number of non-linear restrictions; so the achievement of the global optimum is difficult. Here, the study of an algorithm for the system optimisation is presented. |
P.A. Aguirre, G. Corsano, M. Barttfeld A hybrid method for optimal synthesis of multicomponent distillation processes [Metodo hibrido para la sintesis optima de procesos de destilacion multicomponente] (Artículo de revista) Informacion Tecnologica, 12 (1), pp. 119-126, 2001, (cited By 6). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Aguirre2001119, title = {A hybrid method for optimal synthesis of multicomponent distillation processes [Metodo hibrido para la sintesis optima de procesos de destilacion multicomponente]}, author = { P.A. Aguirre and G. Corsano and M. Barttfeld}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0035062544&partnerID=40&md5=1ecbe7388b5a8694170fac47a1d9b197}, year = {2001}, date = {2001-01-01}, journal = {Informacion Tecnologica}, volume = {12}, number = {1}, pages = {119-126}, abstract = {An optimal synthesis for distillation processes which include non-ideal multicomponent mixtures is analyzed. A detailed, mixed integer non-linear model (MINLP) is proposed for sequences of distillation, plus a hybrid method which generates an initial superstructure based on the reversible Distillation Sequence Model (RDSM). The RDSM generates the structure and provides the operational conditions for a group of columns which generate the separation scheme. By using appropriate objective functions and constraints, the RDSM can be globally solved. The number of stages in each column allow operating the columns close to the minimum reflux conditions. Both reboil and reflux are provided by means of mass coupling between adjacent columns. Results indicate that the solutions obtained and the numerical behavior are satisfactory, which allows determination of economically optimal alternatives.}, note = {cited By 6}, keywords = {}, pubstate = {published}, tppubtype = {article} } An optimal synthesis for distillation processes which include non-ideal multicomponent mixtures is analyzed. A detailed, mixed integer non-linear model (MINLP) is proposed for sequences of distillation, plus a hybrid method which generates an initial superstructure based on the reversible Distillation Sequence Model (RDSM). The RDSM generates the structure and provides the operational conditions for a group of columns which generate the separation scheme. By using appropriate objective functions and constraints, the RDSM can be globally solved. The number of stages in each column allow operating the columns close to the minimum reflux conditions. Both reboil and reflux are provided by means of mass coupling between adjacent columns. Results indicate that the solutions obtained and the numerical behavior are satisfactory, which allows determination of economically optimal alternatives. |
2000 |
E.C. Martínez Systems thinking and functional modeling of batch process management using projects (Artículo de revista) Computers and Chemical Engineering, 24 (2-7), pp. 1657-1663, 2000, (cited By 1). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Martinez20001657, title = {Systems thinking and functional modeling of batch process management using projects}, author = { E.C. Martínez}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0034661149&partnerID=40&md5=e7857121838e45c13873bb0e86a60102}, doi = {10.1016/S0098-1354(00)00446-4}, year = {2000}, date = {2000-01-01}, journal = {Computers and Chemical Engineering}, volume = {24}, number = {2-7}, pages = {1657-1663}, abstract = {Intense competition and rapid environmental changes are revealing severe limitations in the effectiveness of the hierarchical, stable and Tayloristic management system currently used by the vast majority of batch manufacturing industries. A project-oriented enterprise model of batch plants which results of integrating together systems thinking and functional modeling is proposed here. The latter refers to the set of intents and relationships between goals, functions and components (both physical and abstract) that comprise an analytical viewpoint of batch processes involving product recipes, equipment capabilities, constraints and human competencies (skills and knowledge). Complementarily, the systemic perspective accounts for the organizational setting (roles, objectives and actors), and provides an orthogonal view through the duality of whole- parts relationships and the ubiquitous concepts of boundary, emergence and hierarchy upon which the project-oriented enterprise model is built. A case study that comprises a dairy facility involving the production + 100 different fresh products using an order-driven management system will be presented. To support the prototype implementation of a plant information system using a hierarchy of project-based objects, a conceptual design has been developed. The implementation of the resulting enterprise model in Project 98(TM) will be discussed to highlight its easy and cheap implementation, and a number of advantages including: accumulation of information and knowledge, direct tracing of activities and cost analysis. (C) 2000 Elsevier Science Ltd. Intense competition and rapid environmental changes are revealing severe limitations in the effectiveness of the hierarchical, stable and Tayloristic management system currently used by the vast majority of batch manufacturing industries. A project-oriented enterprise model of batch plants which results of integrating together systems thinking and functional modeling is proposed here. The latter refers to the set of intents and relationships between goals, functions and components (both physical and abstract) that comprise an analytical viewpoint of batch processes involving product recipes, equipment capabilities, constraints and human competencies (skills and knowledge). Complementarily, the systemic perspective accounts for the organizational setting (roles, objectives and actors), and provides an orthogonal view through the duality of whole-parts relationships and the ubiquitous concepts of boundary, emergence and hierarchy upon which the project-oriented enterprise model is built. A case study that comprises a dairy facility involving the production +100 different fresh products using an order-driven management system will be presented. To support the prototype implementation of a plant information system using a hierarchy of project-based objects, a conceptual design has been developed. The implementation of the resulting enterprise model in Project 98 will be discussed to highlight its easy and cheap implementation, and a number of advantages including: accumulation of information and knowledge, direct tracing of activities and cost analysis.}, note = {cited By 1}, keywords = {}, pubstate = {published}, tppubtype = {article} } Intense competition and rapid environmental changes are revealing severe limitations in the effectiveness of the hierarchical, stable and Tayloristic management system currently used by the vast majority of batch manufacturing industries. A project-oriented enterprise model of batch plants which results of integrating together systems thinking and functional modeling is proposed here. The latter refers to the set of intents and relationships between goals, functions and components (both physical and abstract) that comprise an analytical viewpoint of batch processes involving product recipes, equipment capabilities, constraints and human competencies (skills and knowledge). Complementarily, the systemic perspective accounts for the organizational setting (roles, objectives and actors), and provides an orthogonal view through the duality of whole- parts relationships and the ubiquitous concepts of boundary, emergence and hierarchy upon which the project-oriented enterprise model is built. A case study that comprises a dairy facility involving the production + 100 different fresh products using an order-driven management system will be presented. To support the prototype implementation of a plant information system using a hierarchy of project-based objects, a conceptual design has been developed. The implementation of the resulting enterprise model in Project 98(TM) will be discussed to highlight its easy and cheap implementation, and a number of advantages including: accumulation of information and knowledge, direct tracing of activities and cost analysis. (C) 2000 Elsevier Science Ltd. Intense competition and rapid environmental changes are revealing severe limitations in the effectiveness of the hierarchical, stable and Tayloristic management system currently used by the vast majority of batch manufacturing industries. A project-oriented enterprise model of batch plants which results of integrating together systems thinking and functional modeling is proposed here. The latter refers to the set of intents and relationships between goals, functions and components (both physical and abstract) that comprise an analytical viewpoint of batch processes involving product recipes, equipment capabilities, constraints and human competencies (skills and knowledge). Complementarily, the systemic perspective accounts for the organizational setting (roles, objectives and actors), and provides an orthogonal view through the duality of whole-parts relationships and the ubiquitous concepts of boundary, emergence and hierarchy upon which the project-oriented enterprise model is built. A case study that comprises a dairy facility involving the production +100 different fresh products using an order-driven management system will be presented. To support the prototype implementation of a plant information system using a hierarchy of project-based objects, a conceptual design has been developed. The implementation of the resulting enterprise model in Project 98 will be discussed to highlight its easy and cheap implementation, and a number of advantages including: accumulation of information and knowledge, direct tracing of activities and cost analysis. |
E.C. Martínez Batch process modeling for optimization using reinforcement learning (Artículo de revista) Computers and Chemical Engineering, 24 (2-7), pp. 1187-1193, 2000, (cited By 11). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Martinez20001187, title = {Batch process modeling for optimization using reinforcement learning}, author = { E.C. Martínez}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0034662259&partnerID=40&md5=fe8a8037e34bfc022c4af48d07d0cdec}, doi = {10.1016/S0098-1354(00)00354-9}, year = {2000}, date = {2000-01-01}, journal = {Computers and Chemical Engineering}, volume = {24}, number = {2-7}, pages = {1187-1193}, abstract = {Imperfect and incomplete understanding of reaction kinetics compounded with uncontrollable variations not only prevent achieving an optimal operation of batch and semi-batch reactors, but also give rise to potential risks of violating product end- use properties, ecological or safety constraints. This paper proposes a sequential experiment design strategy based on reinforcement learning to accomplish the specific goal of modeling for optimization in batch reactors by making the most effective use of cumulative data and an approximate model. Reactor operating condition is incrementally improved over runs by integrating together estimation of a probabilistic measure of success using an imperfect model and a gradient-based approach so as to trade off exploitation with exploration. An improved operating policy is found by incrementally shrinking the region of interest for policy parameters. The solution strategy focuses on 'learning by doing' using a value function that accounts for endpoint performance and feasibility. Simulation results reveal the robustness of reinforcement learning to parametric and structural modeling errors. (C) 2000 Elsevier Science Ltd. Imperfect and incomplete understanding of reaction kinetics compounded with uncontrollable variations not only prevent achieving an optimal operation of batch and semi-batch reactors, but also give rise to potential risks of violating product end-use properties, ecological or safety constraints. This paper proposes a sequential experiment design strategy based on reinforcement learning to accomplish the specific goal of modeling for optimization in batch reactors by making the most effective use of cumulative data and an approximate model. Reactor operating condition is incrementally improved over runs by integrating together estimation of a probabilistic measure of success using an imperfect model and a gradient-based approach so as to trade off exploitation with exploration. An improved operating policy is found by incrementally shrinking the region of interest for policy parameters. The solution strategy focuses on 'learning by doing' using a value function that accounts for endpoint performance and feasibility. Simulation results reveal the robustness of reinforcement learning to parametric and structural modeling errors.}, note = {cited By 11}, keywords = {}, pubstate = {published}, tppubtype = {article} } Imperfect and incomplete understanding of reaction kinetics compounded with uncontrollable variations not only prevent achieving an optimal operation of batch and semi-batch reactors, but also give rise to potential risks of violating product end- use properties, ecological or safety constraints. This paper proposes a sequential experiment design strategy based on reinforcement learning to accomplish the specific goal of modeling for optimization in batch reactors by making the most effective use of cumulative data and an approximate model. Reactor operating condition is incrementally improved over runs by integrating together estimation of a probabilistic measure of success using an imperfect model and a gradient-based approach so as to trade off exploitation with exploration. An improved operating policy is found by incrementally shrinking the region of interest for policy parameters. The solution strategy focuses on 'learning by doing' using a value function that accounts for endpoint performance and feasibility. Simulation results reveal the robustness of reinforcement learning to parametric and structural modeling errors. (C) 2000 Elsevier Science Ltd. Imperfect and incomplete understanding of reaction kinetics compounded with uncontrollable variations not only prevent achieving an optimal operation of batch and semi-batch reactors, but also give rise to potential risks of violating product end-use properties, ecological or safety constraints. This paper proposes a sequential experiment design strategy based on reinforcement learning to accomplish the specific goal of modeling for optimization in batch reactors by making the most effective use of cumulative data and an approximate model. Reactor operating condition is incrementally improved over runs by integrating together estimation of a probabilistic measure of success using an imperfect model and a gradient-based approach so as to trade off exploitation with exploration. An improved operating policy is found by incrementally shrinking the region of interest for policy parameters. The solution strategy focuses on 'learning by doing' using a value function that accounts for endpoint performance and feasibility. Simulation results reveal the robustness of reinforcement learning to parametric and structural modeling errors. |
S.D. Zamar, S. Xu, O.A. Iribarren An analytical process performance model for batch distillations (Artículo de revista) Computer Aided Chemical Engineering, 8 (C), pp. 1021-1026, 2000, (cited By 0). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Zamar20001021, title = {An analytical process performance model for batch distillations}, author = { S.D. Zamar and S. Xu and O.A. Iribarren}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77956829683&partnerID=40&md5=0feabe83827db4488ee00420c79c22d1}, doi = {10.1016/S1570-7946(00)80172-8}, year = {2000}, date = {2000-01-01}, journal = {Computer Aided Chemical Engineering}, volume = {8}, number = {C}, pages = {1021-1026}, abstract = {In this paper we propose an approximate analytical prediction of the minimum reflux ratio required by a batch distillation task, arriving to a completely analytical process performance model for batch distillations. The paper presents the derivation of the analytical prediction of Rmin and compares it with the numerical integration predictions, analyzing and quantifying their discrepancy. Also, it puts together the analytical prediction of Rmin with previously derived analytical predictions of Nmin and the Performance Correlation that relates Nmin, Rmin, N and R to construct the analytical process performance model for batch distillation. © 2000 Elsevier B.V. All rights reserved.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper we propose an approximate analytical prediction of the minimum reflux ratio required by a batch distillation task, arriving to a completely analytical process performance model for batch distillations. The paper presents the derivation of the analytical prediction of Rmin and compares it with the numerical integration predictions, analyzing and quantifying their discrepancy. Also, it puts together the analytical prediction of Rmin with previously derived analytical predictions of Nmin and the Performance Correlation that relates Nmin, Rmin, N and R to construct the analytical process performance model for batch distillation. © 2000 Elsevier B.V. All rights reserved. |
M.R. Galli, J. Cerdá Synthesis of heat exchanger networks featuring a minimum number of constrained-size shells of 1-2 type (Artículo de revista) Applied Thermal Engineering, 20 (15), pp. 1443-1467, 2000, (cited By 10). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Galli20001443, title = {Synthesis of heat exchanger networks featuring a minimum number of constrained-size shells of 1-2 type}, author = { M.R. Galli and J. Cerdá}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0034301674&partnerID=40&md5=101b50bd3b7b4c330b8ce265a9a74056}, doi = {10.1016/S1359-4311(00)00018-1}, year = {2000}, date = {2000-01-01}, journal = {Applied Thermal Engineering}, volume = {20}, number = {15}, pages = {1443-1467}, abstract = {In chemical plants requiring a high number of heat exchangers, standard sizes are established so that most of the services can be satisfied through arrays of a limited number of different standard-type units. If such an industrial practice is not taken into account during the heat recovery network synthesis task, the optimality of the proposed design could be doubtful. This paper addresses the HENS problem allocating multiple constrained-size shells rather than a single one to accomplish a heat match. Two cases are considered: (a) pure countercurrent exchangers and (b) shell-and-tube exchangers of 1-2 type. The neighbor-based HENS framework of Galli and Cerda (1998) has been generalized in order to adopt a more realistic fixed-cost target, i.e. the overall number of constrained-size shells. Therefore, new 0-1 variables have been defined to stand for the additional shells needed to get both, a shell size below the specified upper bound, and simultaneously, an FT correction factor above the threshold value everywhere. The resulting MILP problem formulation is now able to find network structures reaching the heat recovery target, under some structural constraints on the network design specified by the user, at near-minimum capital cost. The proposed algorithmic approach has been successfully applied to the solution of a couple of example problems and produced significant capital cost savings compared with prior HENS techniques.}, note = {cited By 10}, keywords = {}, pubstate = {published}, tppubtype = {article} } In chemical plants requiring a high number of heat exchangers, standard sizes are established so that most of the services can be satisfied through arrays of a limited number of different standard-type units. If such an industrial practice is not taken into account during the heat recovery network synthesis task, the optimality of the proposed design could be doubtful. This paper addresses the HENS problem allocating multiple constrained-size shells rather than a single one to accomplish a heat match. Two cases are considered: (a) pure countercurrent exchangers and (b) shell-and-tube exchangers of 1-2 type. The neighbor-based HENS framework of Galli and Cerda (1998) has been generalized in order to adopt a more realistic fixed-cost target, i.e. the overall number of constrained-size shells. Therefore, new 0-1 variables have been defined to stand for the additional shells needed to get both, a shell size below the specified upper bound, and simultaneously, an FT correction factor above the threshold value everywhere. The resulting MILP problem formulation is now able to find network structures reaching the heat recovery target, under some structural constraints on the network design specified by the user, at near-minimum capital cost. The proposed algorithmic approach has been successfully applied to the solution of a couple of example problems and produced significant capital cost savings compared with prior HENS techniques. |
L. Marín, M. Hassan, A. Lozano, G. Manassero, O.J. Chiotti Design of a data warehouse to support the management of academic institutions (Artículo de revista) Management Information Systems, 2 , pp. 161-170, 2000, (cited By 0). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Marín2000161, title = {Design of a data warehouse to support the management of academic institutions}, author = { L. Marín and M. Hassan and A. Lozano and G. Manassero and O.J. Chiotti}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-4544383687&partnerID=40&md5=543ec23052bc9aaf54b96356c4c7e193}, year = {2000}, date = {2000-01-01}, journal = {Management Information Systems}, volume = {2}, pages = {161-170}, abstract = {This work presents a development model of Data Warehouse - Data Marts (DW-DMs) of two academic institutions. The model proposes as development base a joint analysis and design of both the operational systems and DW-DMs. The data models are defined from three organizational requirement sources: operational processes, decision processes and planned mining activities. Conceptually, the model implies replacing the usual DW-DMs development paradigm that integrates the existing data in the organization by a new paradigm, which proposes to integrate the required data in the organization.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } This work presents a development model of Data Warehouse - Data Marts (DW-DMs) of two academic institutions. The model proposes as development base a joint analysis and design of both the operational systems and DW-DMs. The data models are defined from three organizational requirement sources: operational processes, decision processes and planned mining activities. Conceptually, the model implies replacing the usual DW-DMs development paradigm that integrates the existing data in the organization by a new paradigm, which proposes to integrate the required data in the organization. |
A.R. Vecchietti, I.E. Grossmann Modeling issues and implementation of language for disjunctive programming (Artículo de revista) Computers and Chemical Engineering, 24 (9-10), pp. 2143-2155, 2000, (cited By 37). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Vecchietti20002143, title = {Modeling issues and implementation of language for disjunctive programming}, author = { A.R. Vecchietti and I.E. Grossmann}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0034306975&partnerID=40&md5=734b4d6d52a1202c9069735831c5685e}, doi = {10.1016/S0098-1354(00)00582-2}, year = {2000}, date = {2000-01-01}, journal = {Computers and Chemical Engineering}, volume = {24}, number = {9-10}, pages = {2143-2155}, abstract = {This paper describes a number of key modeling issues for the development of tools for solving nonlinear discrete/continuous problems where logic/disjunctive constraints are included in the formulation. A generalized hybrid representation of these problems is presented. A comparison between Constraint logic programming (CLP) and generalized disjunctive programming (GDP) is established together with several constraint transformations from CLP to GDP. The components and expressions of a modeling language for setting up disjunctions and logic constraints are proposed. The language allows the specification of problems with complex logic formulations. A parser is developed for the analysis and translation of the logic sentences into files ready to be used by the solvers. An overview of the solution algorithms is also given together with several aspects about the implementation as a superset of GAMS mathematical programming language. Examples illustrating the capabilities of the proposed system are described. (C) 2000 Elsevier Science Ltd. This paper describes a number of key modeling issues for the development of tools for solving nonlinear discrete/continuous problems where logic/disjunctive constraints are included in the formulation. A generalized hybrid representation of these problems is presented. A comparison between Constraint logic programming (CLP) and generalized disjunctive programming (GDP) is established together with several constraint transformations from CLP to GDP. The components and expressions of a modeling language for setting up disjunctions and logic constraints are proposed. The language allows the specification of problems with complex logic formulations. A parser is developed for the analysis and translation of the logic sentences into files ready to be used by the solvers. An overview of the solution algorithms is also given together with several aspects about the implementation as a superset of GAMS mathematical programming language. Examples illustrating the capabilities of the proposed system are described.}, note = {cited By 37}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper describes a number of key modeling issues for the development of tools for solving nonlinear discrete/continuous problems where logic/disjunctive constraints are included in the formulation. A generalized hybrid representation of these problems is presented. A comparison between Constraint logic programming (CLP) and generalized disjunctive programming (GDP) is established together with several constraint transformations from CLP to GDP. The components and expressions of a modeling language for setting up disjunctions and logic constraints are proposed. The language allows the specification of problems with complex logic formulations. A parser is developed for the analysis and translation of the logic sentences into files ready to be used by the solvers. An overview of the solution algorithms is also given together with several aspects about the implementation as a superset of GAMS mathematical programming language. Examples illustrating the capabilities of the proposed system are described. (C) 2000 Elsevier Science Ltd. This paper describes a number of key modeling issues for the development of tools for solving nonlinear discrete/continuous problems where logic/disjunctive constraints are included in the formulation. A generalized hybrid representation of these problems is presented. A comparison between Constraint logic programming (CLP) and generalized disjunctive programming (GDP) is established together with several constraint transformations from CLP to GDP. The components and expressions of a modeling language for setting up disjunctions and logic constraints are proposed. The language allows the specification of problems with complex logic formulations. A parser is developed for the analysis and translation of the logic sentences into files ready to be used by the solvers. An overview of the solution algorithms is also given together with several aspects about the implementation as a superset of GAMS mathematical programming language. Examples illustrating the capabilities of the proposed system are described. |
J.A. Asenjo, J.M. Montagna, A.R. Vecchietti, O.A. Iribarren, J.M. Pinto Strategies for the simultaneous optimization of the structure and the process variables of a protein production plant (Artículo de revista) Computers and Chemical Engineering, 24 (9-10), pp. 2277-2290, 2000, (cited By 18). (Resumen | Enlaces | BibTeX | Etiquetas: ) @article{Asenjo20002277, title = {Strategies for the simultaneous optimization of the structure and the process variables of a protein production plant}, author = { J.A. Asenjo and J.M. Montagna and A.R. Vecchietti and O.A. Iribarren and J.M. Pinto}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0034307150&partnerID=40&md5=b79b2a17136c59abeb94ed949578bc75}, doi = {10.1016/S0098-1354(00)00572-X}, year = {2000}, date = {2000-01-01}, journal = {Computers and Chemical Engineering}, volume = {24}, number = {9-10}, pages = {2277-2290}, abstract = {Process performance models for a multiproduct batch protein plant are used to exploit alternative strategies in the optimization of both the process variables and the structure of the plant. Simple process performance models are used to describe the unit operations, which renders explicit expressions for the size and time factor model in the design of batch plants. In the proposed approach the process variables are optimized regardless the plant structure constraints, which are left as a posterior decision. This optimization is done in a single product-free intermediate storage (SP-FIS) scenario, unbiased with any plant structure. The approach is compared to the case of recipe values for the process variables and to the best optimal solution for the nonconvex mixed integer nonlinear program (MINLP), which arises when simultaneously optimizing the structure and the process variables. This last optimization model is hard to solve and its global solution remains as an open problem. The proposed approach generates solutions very close to the ones obtained from nonconvex MINLP and is quite superior than simply resorting to recipes. We also study the role of process variables in this approach. It is found that they behave as in continuous processes by trading off cost components, with a smooth dependence on the overall cost. Moreover, for feasible designs that include the size and time constraints that correspond to the plant structure, the process variables accommodate the size and time factors to reduce idle times and equipment under-occupancy. (C) 2000 Elsevier Science Ltd. Process performance models for a multiproduct batch protein plant are used to exploit alternative strategies in the optimization of both the process variables and the structure of the plant. Simple process performance models are used to describe the unit operations, which renders explicit expressions for the size and time factor model in the design of batch plants. In the proposed approach the process variables are optimized regardless the plant structure constraints, which are left as a posterior decision. This optimization is done in a single product-free intermediate storage (SP-FIS) scenario, unbiased with any plant structure. The approach is compared to the case of recipe values for the process variables and to the best optimal solution for the nonconvex mixed integer nonlinear program (MINLP), which arises when simultaneously optimizing the structure and the process variables. This last optimization model is hard to solve and its global solution remains as an open problem. The proposed approach generates solutions very close to the ones obtained from nonconvex MINLP and is quite superior than simply resorting to recipes. We also study the role of process variables in this approach. It is found that they behave as in continuous processes by trading off cost components, with a smooth dependence on the overall cost. Moreover, for feasible designs that include the size and time constraints that correspond to the plant structure, the process variables accommodate the size and time factors to reduce idle times and equipment under-occupancy.}, note = {cited By 18}, keywords = {}, pubstate = {published}, tppubtype = {article} } Process performance models for a multiproduct batch protein plant are used to exploit alternative strategies in the optimization of both the process variables and the structure of the plant. Simple process performance models are used to describe the unit operations, which renders explicit expressions for the size and time factor model in the design of batch plants. In the proposed approach the process variables are optimized regardless the plant structure constraints, which are left as a posterior decision. This optimization is done in a single product-free intermediate storage (SP-FIS) scenario, unbiased with any plant structure. The approach is compared to the case of recipe values for the process variables and to the best optimal solution for the nonconvex mixed integer nonlinear program (MINLP), which arises when simultaneously optimizing the structure and the process variables. This last optimization model is hard to solve and its global solution remains as an open problem. The proposed approach generates solutions very close to the ones obtained from nonconvex MINLP and is quite superior than simply resorting to recipes. We also study the role of process variables in this approach. It is found that they behave as in continuous processes by trading off cost components, with a smooth dependence on the overall cost. Moreover, for feasible designs that include the size and time constraints that correspond to the plant structure, the process variables accommodate the size and time factors to reduce idle times and equipment under-occupancy. (C) 2000 Elsevier Science Ltd. Process performance models for a multiproduct batch protein plant are used to exploit alternative strategies in the optimization of both the process variables and the structure of the plant. Simple process performance models are used to describe the unit operations, which renders explicit expressions for the size and time factor model in the design of batch plants. In the proposed approach the process variables are optimized regardless the plant structure constraints, which are left as a posterior decision. This optimization is done in a single product-free intermediate storage (SP-FIS) scenario, unbiased with any plant structure. The approach is compared to the case of recipe values for the process variables and to the best optimal solution for the nonconvex mixed integer nonlinear program (MINLP), which arises when simultaneously optimizing the structure and the process variables. This last optimization model is hard to solve and its global solution remains as an open problem. The proposed approach generates solutions very close to the ones obtained from nonconvex MINLP and is quite superior than simply resorting to recipes. We also study the role of process variables in this approach. It is found that they behave as in continuous processes by trading off cost components, with a smooth dependence on the overall cost. Moreover, for feasible designs that include the size and time constraints that correspond to the plant structure, the process variables accommodate the size and time factors to reduce idle times and equipment under-occupancy. |