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Description:
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This research developed novel methodologies to achieve cost effective solutions to
overcome many of the difficulties associated with unsteady state material recovery
network synthesis . The work focuses on the development of three different
methodologies : the first is a hierarchical multi -step methodology developed for the
design and scheduling of batch water (material of interest ) recycle networks . A new
source - double tank -sink arrangement is introduced to overcome the limitation of samecycle
assignment by permitting sources to be optimally recycled within the same batch
cycle and /or storing and recycling sources to sinks in the following batch cycle . The
problem is solved in interconnected stages . First , network targets such as minimum fresh
water consumption and minimum waste water discharge are identified ahead of network
design . Once design targets have been identified , an iterative procedure is followed to
tradeoff fixed and operating cost to achieve a network design which has the minimum
total annualized cost (TAC ) . The second developed methodology is a one -step simultaneous approach to design and
schedule cost -effective batch water recycle networks . A new source -tank -sink
representation is developed to embed potential configurations of interest for design and
scheduling . As a result , water may be assigned from sources to sinks within the same
cycle (with or without a storage tank ) and in two subsequent cycles using a double tank
arrangement . A mathematical formulation is developed to determine the network design
and sufficient information on the scheduling of the network with the minimum TAC in
one step .
The third methodolgy this research developed is a systematic procedure to schedule the
operation of an unsteady state material recovery network . The network has a set design
and receives a number of feedstocks (sources ) that are to be processed into higher
value /quality products . The sources may be stored in tanks , mixed , and /or intercepted in
separation devices to produce the desired products while maximizing profits and meeting
all process constraints . The developed systematic procedure includes mathematical
formulations that allow available sources to be stored , mixed , intercepted and determine
the optimal scheduling scheme over time period ? ?with the objective of maximizing total
annualized profit of the network . |