(388f) A General Framework for Process and Utility Networks Synthesis
In this work, we extend the approach to provide a general framework for the synthesis of different networks using a similar representation using building blocks. Here, each block has feed and product streams ensuring interaction with the surroundings and can be viewed as sources and sinks, respectively. Also, streams between blocks are equipped with compressors or expanders depending on the source and sink block pressures. Mass and energy flow within the superstructure are facilitated via block material and energy balances and heating and cooling requirements are decided accordingly. Separation operations, such as gas membrane separations, are represented via two neighboring blocks separated by a semi-restricted boundary. The decisions over the assignment of boundary types between blocks are enabled via use of decision variables. By using all of these features of the building block superstructure, several different process network synthesis problems can be accommodated in a single superstructure with n and m number of blocks in row and column respectively. It should be noted that for different network synthesis problem, the block superstructure size could be reduced to improve the computation performance, i.e, using 2×m superstructure to represent a pooling problem without intermediate pools. The overall process network synthesis problem is formulated as a mixed-integer nonlinear optimization (MINLP) problem where the nonlinear terms are due to splitting, energy balances and/or work calculations and discrete variables are for assigning alternative operations to each block and boundary in the superstructure. In this work, we will demonstrate that the proposed method is capable of unifying the superstructure representations for different class of process network synthesis problems via a range of literature problems.
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