The primary objective of this dissertation is to introduce several algebraicprocedures to the targeting of material recycle networks. The problem involves theallocation of process streams and fresh sources to process units (sinks) with the objectiveof minimizing fresh purchase and waste discharge. In the case of composition-limitedsinks, allocation to process sinks is governed by feasibility constraints on flowrates andcompositions. A systematic non-iterative algebraic approach is developed to identifyrigorous targets for minimum usage of fresh resources, maximum recycle of processresources and minimum discharge of waste. These targets are identified a priori andwithout commitment to the detailed design of the recycle/reuse network. The approach isvalid for both pure and impure fresh resources. The devised procedures also identifies thelocation of the material recycle pinch point and addresses its significance in managingprocess sources, fresh usage, and waste discharge. The dissertation also addresses thetargeting of material-recycle networks when the constraints on the process units aredescribed through flowrates and properties. This property-integration problem is solvedusing a non-iterative cascade-based algebraic procedure. Finally, for more complex caseswith multiple fresh sources and with interception networks, a mathematical-programmingapproach is developed. Because of the nonlinear non-convex characteristics of theproblem, the mathematical model is reformulated to enable the global solution of theproblem. Several case studies are solved to illustrate the ease, rigor, and applicability ofthe developed targeting technique.
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