Authors:
Jules Thibault
1
;
Rubens Maciel Filho
2
;
Marina O. S. Dias
3
;
Tassia L. Junqueira
3
;
Otavio Cavalett
3
;
Charles D. F. Jesus
3
;
Carlos E. V. Rossell
3
and
Antonio Bonomi
3
Affiliations:
1
University of Ottawa, Canada
;
2
Universidade Estadual de Campinas, Brazil
;
3
Laboratório Nacional de Ciência e Tecnologia do Bioetanol - CTBE/CNPEM, Brazil
Keyword(s):
Ethanol Fermentation, in Situ Recovery, Vacuum Fermentation, Simulation, Optimization.
Related
Ontology
Subjects/Areas/Topics:
Application Domains
;
Chemical and Petroleum Engineering
;
Plant Simulation
;
Simulation and Modeling
;
Simulation Tools and Platforms
Abstract:
With the overall objective of optimizing an integrated first and second generation bioethanol production plant, a simple illustrative example is first used to examine the advantages and challenges of using a combination of VBA and UniSim Design for multi-objective optimization. In this paper, the simulation and optimization of a vacuum fermentation system using glucose and xylose as substrates is performed. The simulation of the fermentation system and the optimization are performed in the VBA environment, while UniSim Design is used to provide thermodynamic data necessary to perform calculations and used to simulate the downstream portion of the fermentation vacuum system. The Pareto domain of the system was circumscribed based on three decision variables (starting time of vacuum, rate of broth removal by vacuum and condenser temperature) and four objective functions (minimum ethanol loss, maximum productivity, minimum residual sugars and minimum compression energy). The procedure d
eveloped has allowed to easily circumscribe the Pareto domain of this system and to observe clearly the compromises that are required when all objective functions are optimized simultaneously. Some challenges to overcome are the time required for exchanging information between VBA and UniSim Design and the risk of non-converging for complex problems. For this procedure to be implemented effectively for the integrated ethanol plant, some innovative measures need to be developed.
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