This pair of articles presents an optimization-based, automated procedure to determine the minimum resource consumption/target(s) for a single-impurity resource conservation network (RCN). This optimization-based targeting technique provides the same benefits as conventional insight-based pinch analysis, in yielding various targets for an RCN prior to detailed design. In addition, flexibility in setting the objective function is the major advantage of the automated targeting approach over a conventional pinch analysis technique. The model formulation is linear, which ensures that a global optimum can be found if one exists. In part 1 of this pair of articles, the model for direct material reuse/recycle is presented. Its application is then demonstrated for single, multiple, and impure external resources using several literature examples. Part 2 of this pair of articles extends the automated targeting technique for RCNs with waste-interception (regeneration) placement.

Part 1 of this pair of articles presents an automated targeting technique to identify minimum fresh resource flow rate/cost targets in a resource conservation network (RCN) with material reuse/recycle. After the potential for conservation through direct reuse/recycle is exhausted, fresh resource consumption can be further reduced by incorporating waste-interception (regeneration) processes. Hence, the proposed automated targeting technique in part 1 of this pair of articles is extended to determine the targets for RCNs with interception placement. The waste-interception systems are modeled as treatment processes with either fixed outlet concentrations or fixed impurity load removal ratios. The approach also distinguishes between single-pass and partitioning regenerators, which have different implications for RCNs. Literature examples and industrial cases are solved to illustrate the proposed approach.

Part 1 of this series of papers presented graphical and algebraic approaches that are used to identify waste streams in a total water network. In this part of the series, the interaction between waste treatment and water regeneration is explored. Appropriate selection of waste streams for regeneration or waste treatment will lead to the minimum impurity load to be processed in the regeneration and waste treatment units; hence, leads to the reduction of the network capital and operation costs. In addition, a novel wastewater composite curve for targeting the minimum impurity load removal is presented in this work. Targeting for the minimum treatment flow rate and the minimum number of treatment units is presented for the treatment system of the fixed outlet concentration and removal ratio type, respectively. Literature examples are solved to illustrate the proposed approaches.

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Over the past decades, numerous research works have been dedicated to in-plant water reuse/recycle. After the opportunities for maximum water recovery are exhausted through water reuse/recycle, water flow rates may be further reduced with regeneration processes. Before wastewater is discharged to the environment, wastewater will be treated to meet the requirements given in the emission legislation. In this series of papers, an overall framework called the “total water network” is analyzed. A total water network consists of water reuse/recycle and water regeneration, as well as wastewater treatment for final discharge. Part 1 of this series of papers presents a new targeting procedure utilizing the recent developed graphical and algebraic approaches to identify individual wastewater streams that are emitted from a water network. As will be shown in Part 2 of the series, identification of the individual waste streams is necessary to investigate the interactions among different elements of the total water network. Two literature examples are solved to illustrate the proposed approaches.

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A shift to utilize more renewable energy sources has been motivated by issues of energy security, environmental protection, and sustainable development. Biofuels are among the promising forms of renewable energy as they can be produced from a wide variety of feedstocks (e.g., traditional agriculture crops, energy crops, forestry products, municipal solid waste, etc.). Biorefineries are processing facilities that convert biomass into value-added products such as biofuels, specialty chemicals, and pharmaceuticals. To enhance material and energy recovery within processing facilities, an integrated biorefinery is proposed. Since the potential pathways and products in an integrated biorefinery are extensive, product allocation is a complex task. The main challenge in designing an integrated biorefinery is to synthesize a sustainable biorefinery with maximum economic performance while causing minimum environmental impact. Since such objectives are often conflicting in nature, fuzzy mathematical programming is adapted in this work to synthesize a sustainable integrated biorefinery that fulfills both considerations simultaneously.