| Summary: | The primary objective of this dissertation is to introduce several algebraic
procedures to the targeting of material recycle networks. The problem involves the
allocation of process streams and fresh sources to process units (sinks) with the objective
of minimizing fresh purchase and waste discharge. In the case of composition-limited
sinks, allocation to process sinks is governed by feasibility constraints on flowrates and
compositions. A systematic non-iterative algebraic approach is developed to identify
rigorous targets for minimum usage of fresh resources, maximum recycle of process
resources and minimum discharge of waste. These targets are identified a priori and
without commitment to the detailed design of the recycle/reuse network. The approach is
valid for both pure and impure fresh resources. The devised procedures also identifies the
location of the material recycle pinch point and addresses its significance in managing
process sources, fresh usage, and waste discharge. The dissertation also addresses the
targeting of material-recycle networks when the constraints on the process units are
described through flowrates and properties. This property-integration problem is solvedusing a non-iterative cascade-based algebraic procedure. Finally, for more complex cases
with multiple fresh sources and with interception networks, a mathematical-programming
approach is developed. Because of the nonlinear non-convex characteristics of the
problem, the mathematical model is reformulated to enable the global solution of the
problem. Several case studies are solved to illustrate the ease, rigor, and applicability of
the developed targeting technique.
|
|---|
