Optimization-Based Approach to Process Synthesis for Process Intensification: Synthesis of Reaction-Separation Processes

Abstract

Process synthesis and intensification are powerful tools for the development of cost-and energy-efficient chemical processes. However, even though their combination maximizes the potential for improvements, they are mostly applied separately. The current article presents the extension of a phenomena-based process synthesis method by an aditional building block for reactor network synthesis and reactive separations. The method facilitates the automatic generation of thermodynamically feasible phenomena-based flowsheet variants by means of superstructure optimization, which are subsequently translated into equipment-based flowsheets taking into account classical as well as intensified equipment. By composing a flowsheet from mass and energy transfer phenomena instead of predefined unit operations, counterintuitive solutions and significant improvements can be achieved. In the current contribution, the capabilities of the method are demonstrated using the transesterification of propylene carbonate with methanol as a case study. The resulting optimal flowsheet represents a combination of integrated and hybrid separation steps for overcoming the intrinsic limitations of this system. The obtained result presents significant cost saving potential compared to those flowsheet variants previously generated by an alternative process synthesis method.

Analysis of TBA‐Based ETBE Production by Means of an Optimization‐Based Process‐Synthesis Approach

“…The method was initially introduced with regards to the design of intensified separation processes for the case study of ethanol dehydration . It was furthermore extended for a simultaneous design of a reaction and separation process and demonstrated for the transesterification of propylene carbonate . Within the current article a new (reactive) pervaporation block is introduced, which enables the consideration of pervaporation‐based membrane reactor concepts.…”

“…The following subsections provide a brief description of the framework, as well as the PBB. Further details on the framework as well as specific PBB models and the implemented optimization approach are provided in preceding articles, which introduced the method for the case studies of ethanol dehydration and the transesterification of propylene carbonate .…”

“…While it is listed in the overall framework for completeness, it is considered as optional for process synthesis and furthermore not considered in the current article. An illustration of the full synthesis framework, including the fifth step, is provided in previous work for the case study of transesterification of propylene carbonate .…”

“…Neither temperature and concentration polarization nor pressure drop are considered for the PBB models, for an ideal and equipment‐independent performance evaluation. The mathematical models for the VL‐PBB and the VP‐PBB as well as the RN‐PBB have been introduced in the preceding articles on the optimization‐based approach to process synthesis for process intensification , . As indicated by the gray box in Fig.…”

Process Modeling, Simulation and Optimization: From Single Solutions to a Multitude of Solutions to Support Decision Making

“…Esche et al ). Therefore, a framework like MOSAIC would be an excellent candidate for setting up such optimization problems or concepts with full accessibility to powerful optimization environments like AMPL or GAMS and could also be used for methods like described by Kuhlmann et al without being limited to a specific simulation environment. The use of these methods could be a service of an expert user group which could paste results of promising candidates into a common rigorous simulation environment for further elaboration of the process concept by a process designer.…”