@article{Serralunga201417200,
title = {Including disjunctions in real-time optimization},
author = { F.J. Serralunga and P.A. Aguirre and M.C. Mussati},
url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84910090255&partnerID=40&md5=1c4d95e34cdff669c48cd0b91b94e2c0},
doi = {10.1021/ie5004619},
year = {2014},
date = {2014-01-01},
journal = {Industrial and Engineering Chemistry Research},
volume = {53},
number = {44},
pages = {17200-17213},
abstract = {Real-time optimization (RTO) is widely used in industry to improve the steady-state performance of a process using the available measurements, reacting to changing prices and demands scenarios and respecting operating, contractual, and environmental constraints. Traditionally, RTO has used nonlinear continuous formulations to model the process. Mixed-integer formulations have not been used in RTO, because of the need of a fast solution (on the order of seconds or a few minutes), and because many discrete decisions, such as startups or shutdowns, are taken with less frequency in a scheduling layer. This work proposes the use of disjunctions in RTO models, listing a series of examples of discrete decisions (different to startups or shutdowns) that can be addressed by RTO. Two model adaptation approaches (the two-step approach and the modifier adaptation strategy) are revised and modified to make them suitable for RTO with discrete decisions. Some common techniques used in RTO (such as filtering the optimal inputs) are also analyzed and adapted for a formulation with disjunctions. The performance of RTO with disjunctions is shown by a case study in which a generic process is optimized. The results show that the performance of a process can be improved by RTO with discrete decisions. The system converges to the vicinity of the real plant optimum when constraints gradients are corrected, even under structural and parametric mismatch. © 2014 American Chemical Society.},
note = {cited By 0},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Pieragostini2014212,
title = {Life cycle assessment of corn-based ethanol production in Argentina},
author = { C. Pieragostini and P.A. Aguirre and M.C. Mussati},
url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84888787868&partnerID=40&md5=bf6dd3619813f592a596435124cd49c9},
doi = {10.1016/j.scitotenv.2013.11.012},
year = {2014},
date = {2014-01-01},
journal = {Science of the Total Environment},
volume = {472},
pages = {212-225},
abstract = {The promotion of biofuels as energy for transportation in the world is mainly driven by the perspective of oil depletion, the concerns about energy security and global warming. In Argentina, the legislation has imposed the use of biofuels in blend with fossil fuels (5 to 10%) in the transport sector.The aim of this paper is to assess the environmental impact of corn-based ethanol production in the province of Santa Fe in Argentina based on the life cycle assessment methodology.The studied system includes from raw materials production to anhydrous ethanol production using dry milling technology. The system is divided into two subsystems: agricultural system and refinery system. The treatment of stillage is considered as well as the use of co-products (distiller's dried grains with solubles), but the use and/or application of the produced biofuel is not analyzed: a cradle-to-gate analysis is presented. As functional unit, 1. MJ of anhydrous ethanol at biorefinery is chosen.Two life cycle impact assessment methods are selected to perform the study: Eco-indicator 99 and ReCiPe. SimaPro is the life cycle assessment software used. The influence of the perspectives on the model is analyzed by sensitivity analysis for both methods.The two selected methods identify the same relevant processes. The use of fertilizers and resources, seeds production, harvesting process, corn drying, and phosphorus fertilizers and acetamide-anillide-compounds production are the most relevant processes in agricultural system. For refinery system, corn production, supplied heat and burned natural gas result in the higher contributions. The use of distiller's dried grains with solubles has an important positive environmental impact. © 2013 Elsevier B.V.},
note = {cited By 3},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Mazzei201458,
title = {NLP model-based optimal design of LiBr-H2O absorption refrigeration systems},
author = { M.S. Mazzei and M.C. Mussati and S.F. Mussati},
url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84892596238&partnerID=40&md5=6c37da45569e26911b4d410ccc91d682},
doi = {10.1016/j.ijrefrig.2013.10.012},
year = {2014},
date = {2014-01-01},
journal = {International Journal of Refrigeration},
volume = {38},
number = {1},
pages = {58-70},
abstract = {This paper addresses the optimization of a single effect absorption refrigeration system operating with lithium bromide-water solution. A non-linear programming mathematical model is developed to determine the operating conditions and the distribution of the total heat transfer area (sizes) along the involved process units to optimize the following two objective functions: (i) maximization of the coefficient of performance for a given amount of the total heat transfer area, and (ii) minimization of the total heat transfer area of the system for a given cooling capacity. The proposed model can either be used for simulation or optimization purposes. Simulated or optimized values of temperature, pressure, composition and flow rate of all streams and sizing of each process unit are predicted. In addition, because of the non linear nature of the resulting model, a systematic solution procedure is proposed in order to guarantee the model convergence. A detailed discussion of the optimization results are presented through different case studies. © 2013 Elsevier B.V. All rights reserved.},
note = {cited By 1},
keywords = {},
pubstate = {published},
tppubtype = {article}
}