The challenging task of designing biopharmaceutical downstream processes is initially to select the type of unit operations, followed by optimizing their operating conditions. For complex flowsheet optimizations, the ...
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The challenging task of designing biopharmaceutical downstream processes is initially to select the type of unit operations, followed by optimizing their operating conditions. For complex flowsheet optimizations, the strategy becomes crucial in terms of duration and outcome. In this study, we compared three optimization strategies, namely, simultaneous, top-to-bottom, and superstructure decomposition. Moreover, all strategies were evaluated by either using chromatographic Mechanistic Models (MMs) or Artificial Neural Networks (ANNs). An overall evaluation of 39 flowsheets was performed, including a buffer-exchange step between the chromatography operations. All strategies identified orthogonal structures to be optimal, and the weighted overall performance values were generally consistent between the MMs and ANNs. In terms of time-efficiency, the decomposition method with MMs stands out when utilizing multiple cores on a multiprocessing system for simulations. This study analyses the influence of different optimization strategies on flowsheet optimization and advices on suitable strategies and modeling techniques for specific scenarios.
Blending hydrogen into existing natural gas pipelines is considered the most feasible choice for long-distance, large-scale hydrogen transportation in the early stage of hydrogen economy development. To integrate the ...
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Blending hydrogen into existing natural gas pipelines is considered the most feasible choice for long-distance, large-scale hydrogen transportation in the early stage of hydrogen economy development. To integrate the optimization of hydrogen-blended natural gas pipeline network and subsequent hydrogen/natural gas separation process, this article presents a mixed-integer nonlinear programming model, aiming to minimize the total annual project net cost. To tackle the computational complexity resulting from the large-scale and nonlinear nature of practical design problems, a decomposition algorithm is tailored to the proposed model. Two case studies demonstrate that compared to stepwise model, the proposed pipeline-separation integrated model offers economic benefits and practical value, incorporating separation processes and satisfying constraints of hydrogen demand, pressure and blending ratio requirements, which achieves an economically optimal design for both pipeline transportation and separation systems, and provides a viable solution for the broader application of hydrogen-blended natural gas networks.
The coal-to-ethanol process,as the clean coal utilization,faces challenges from the energy-intensive distillation that separates multi-component effluents for pure *** to at least eight columns,the synthesis of the et...
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The coal-to-ethanol process,as the clean coal utilization,faces challenges from the energy-intensive distillation that separates multi-component effluents for pure *** to at least eight columns,the synthesis of the ethanol distillation system is impracticable for exhaustive comparison and difficult for conventional superstructure-based optimization as rigorous models are *** work adopts a superstructure-based framework,which combines the strategy that adaptively selects branches of the state-equipment network and the parallel stochastic algorithm for process ***-performance computing significantly reduces time consumption,and the adaptive strategy substantially lowers the complexity of the superstructure ***,parallel computing,elite search,population redistribution,and retention strategies for irrelevant parameters are used to improve the optimization efficiency *** optimization terminates after 3000 generations,providing a flowsheet solution that applies two non-sharp splitting options in its distillation *** a result,the 59-dimension superstructure-based optimization was solved efficiently via a differential evolution algorithm,and a high-quality solution with a 28.34%lower total annual cost than the benchmark was ***,the solution of the superstructure-based optimization is comparable to that obtained by optimizing a single specific configuration one by *** indicates that the superstructure-based optimization that combines the adaptive strategy can be a promising approach to handling the process synthesis of large-scale and complex chemical processes.
A systematic design of municipal solid waste (MSW) management system can lead to identify a promising and/or sustainable way of handling MSW by processing it into energy and valuable products. In this study, a systema...
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A systematic design of municipal solid waste (MSW) management system can lead to identify a promising and/or sustainable way of handling MSW by processing it into energy and valuable products. In this study, a systematic framework is developed for the superstructure-based optimization of MSW processing routes. The proposed superstructure includes the potential technological alternatives (such as recycling, composting, anaerobic digestion with electricity generation, gasification followed by catalytic transformation, gasification with electricity generation, plasma arc gasification with electricity generation, pyrolysis with electricity generation, incineration with electricity generation, and landfill with electricity generation) for producing valuable products from MSW. based on the developed superstructure, a mixed integer nonlinear programming (MINLP) model is developed to identify the optimal MSW processing pathways considering two different MSW handling scenarios. For ease of the solution, the MINLP model is linearized to its equivalent MILP form, and solved in GAMS. The solution to the optimization problem provides the optimal/promising route for the synthesis of useful products from MSW under chosen economic objective function. The developed framework is applied on a case study of Abu Dhabi Emirate to find the optimal processing pathway for handling and processing of MSW into energy and value-added products. The optimization results show that an integrated pathway comprising of recycling the recyclable components of MSW along with the production of bioethanol from the rest of the waste via gasification followed by catalytic transformation can provide potential economic benefits. A sensitivity analysis is also executed to investigate the effect of key economic and technical parameters on the optimization results. (C) 2017 Elsevier Ltd. All rights reserved.
This study addresses the sustainable design of processing pathways for the utilization and conversion of municipal solid waste (MSW) into energy and value-added products. based on the MSW superstructure we developed p...
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This study addresses the sustainable design of processing pathways for the utilization and conversion of municipal solid waste (MSW) into energy and value-added products. based on the MSW superstructure we developed previously (capable of producing recycled materials, compost, bioethanol, electricity), we assess the environmental performance of potential MSW processing pathways. A mixed integer nonlinear programming (MINLP) model is formulated with the environmental objective function in a generic way, to select the environmentally sustainable route for the processing of MSW to energy and valuable products that minimizes the greenhouse gas emissions (GHG). A case study of Abu Dhabi Emirate is considered, and the obtained results are discussed. The results show that the most environmentally sustainable route is comprised of (1) recycling of the recyclable components of MSW via material recycling facility, and (2) production of bioethanol via gasification of the rest of the waste followed by catalytic transformation. (C) 2019 The Authors. Published by Elsevier Ltd.
This study addresses the sustainable design of processing pathways for the utilization and conversion of municipal solid waste (MSW) into energy and value-added products. based on the MSW superstructure we developed p...
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This study addresses the sustainable design of processing pathways for the utilization and conversion of municipal solid waste (MSW) into energy and value-added products. based on the MSW superstructure we developed previously (capable of producing recycled materials, compost, bioethanol, electricity), we assess the environmental performance of potential MSW processing pathways. A mixed integer nonlinear programming (MINLP) model is formulated with the environmental objective function in a generic way, to select the environmentally sustainable route for the processing of MSW to energy and valuable products that minimizes the greenhouse gas emissions (GHG). A case study of Abu Dhabi Emirate is considered, and the obtained results are discussed. The results show that the most environmentally sustainable route is comprised of (1) recycling of the recyclable components of MSW via material recycling facility, and (2) production of bioethanol via gasification of the rest of the waste followed by catalytic transformation.
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