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The overall purpose of this work is to develop systematic methodology for the
simultaneous design and selection of processes and molecules (materials ) . A propertybased
approach is used to develop an interface between process and molecular
design /selection . In particular , we focus on the problem of designing /selecting materials
that are used in the context of a recycle /reuse system of process streams and for energy
applications . Fresh and recycled resources (e .g . , process streams , biomass , solvents , etc . )
are integrated with the process to satisfy property -based constraints for the process units
and to optimize the usage of the resources and the design of the process . For molecular
design , property operators for mixing streams and group contribution methods (GCM )
are used to consistently represent process sources , sinks , and different functional groups
on the same property -base . For material selection , property based criteria (e .g . , heat rate ,
high heating value , etc . ) are used to bridge the process with material . This consistent
representation enables the definition of the optimization problem formulation for product
design while taking into consideration the recycle /reuse of process streams . In particular ,
this dissertation addresses four integrated topics . First , a new graphical approach for
material targeting and substitution is presented . This graphical approach offers initial
solutions and valuable insights that can be effectively used for conceptual design and for
initializing mathematical programming techniques . Second , a mathematical optimization
approach is developed along with a decomposition -based global solution procedure for
material targeting and substitution using property integration . Third , an implementation
approach is developed to synthesize the details of a recycle /reuse process network design based on the targets identified through the graphical and /or the mathematical approaches .
Finally , property integration techniques are extended to a broader scope which deals with
the lifecycle analysis of biomass utilization for energy generation . A generic model is
developed to optimize the types and quantities of the feedstocks used to optimize power
generation with biomass -fossil fuel co -fed system . Important issues of biomass growth ,
harvesting , transportation , processing , and disposal are included . Property -based tracking
and constraints are included in the analysis . Also , the issues associated with greenhouse
gas (GHG ) emissions are incorporated in the analysis . Case studies are solved throughout
the dissertation to demonstrate the applicability of the developed procedures . |
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