(422e) Process Integration Using Block Superstructure
In this work, we extend the block representation to incorporate various process integration problems by considering their common features. Process units, including regenerators/interceptors, are embedded in blocks. The feed flow and product flow in each block represent sources and sinks, respectively. Adjacent blocks interact with each other through direct connecting streams equipped with heaters/coolers for adjusting the temperature. Besides, we also introduce 'jump flow' among all blocks to avoid more intermediate blocks connecting nonadjacent blocks while maintaining or increasing the number of process alternatives. The block superstructure size is dependent on the number of layers with mixing operations, process units, product streams and heat integration stages. We formulate the general process integration problem as a mixed-integer nonlinear optimization (MINLP) problem to minimize the total annual cost. With the proposed MINLP model, we investigate various process integration problems involving mass integration, heat integration, simultaneous mass and heat integration, and property integration. These case studies showed that the same reported optimal integration networks and/or better network designs can be generated using the proposed block representation approach.
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