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This paper presents a new design method for water and heat networks with single contaminant. The water network is designed first based on the concentration and temperature of water-using processes. Then, the thermal information of water streams in the water network can be used to design the corresponding heat network. The results of the illustrated examples show that the designs obtained in this work are comparable with those obtained in the literature with mathematical programming methods. The network structure obtained by using the proposed method is simple. Copyright © 2015 Curtin University of Technology and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract The heat integrated water networks have the features of complex network structure and high costs. To overcome the problems, this paper presents a new design method for heat integrated water networks with simple structure and low costs. The proposed method includes two steps: the water-using network is designed first by considering the concentration specifications of water-using processes, which is reflected by the values of concentration potentials. Then, the heat exchanger network can be designed based on the water network obtained in the first step. Self heating strategy is adopted in the design of heat exchanger network to reduce the complexity of the network. Examples are illustrated to demonstrate the effectiveness of the proposed method. The network structures obtained by using the proposed design method are simple, and the total annual costs calculated in this paper are comparable to that of literature results. [ABSTRACT FROM AUTHOR]

This paper reviews concentration potential concepts and their applications in the design of water-using networks (WUNs) with multiple contaminants. The concentration potential concepts were proposed to determine the concentration order of water streams of multiple contaminants based on the overall allocating possibility of source streams to demand streams on the analogy of single contaminant WUNs. The precedence order of water-using processes, which is crucial for the network design, can be effectively identified by the values of Concentration Potential of Demands (CPDs). The concentration potential concepts, which were originally presented for the water networks of fixed contaminant load model, up to now have been successfully used to design a verity of water-using networks. Computing software has also been developed by combining the concentration potential concepts and linear programming approach. The methods proposed based on the concentration potential concepts have the advantages of simple calculation and clear engineering meaning. The results obtained based on the concentration potential concepts are comparable to that obtained by the literature methods. It is shown that the concentration potential concepts are powerful tools for the design of WUNs with multiple contaminants. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a new method for design of water-using networks with two internal water mains. A conventional water-using network without internal water mains is obtained first by using the concentration potential method. The processes are divided into three parts to form an initial structure of the water-using network with two internal water mains, based on the features of the conventional water-using network obtained. The final design can be obtained in a few iterations by adjusting the amounts of the internal water mains. The results of a few literature examples show that the designs obtained in this work are comparable to that obtained in the literature. The significance of the work presented is that all the design steps, including the formation and adjustment of the internal water mains, are orientated with clear engineering meanings, which are expressed by the values of concentration potentials. [Copyright &y& Elsevier]

Abstract: In order to release resource shortage constraints, hydrogen effective use is of great importance for refineries nowadays. Hydrogen utility consumption in a hydrogen network involving regeneration can be reduced further compared to that of the network involving reuse only. In this article, an iterative method is presented for design of hydrogen networks involving regeneration reuse. The following new insight obtained in water networks is adopted: the hydrogen network involving regeneration can be formed by adding the regenerated stream into the original hydrogen network. This will simplify the design and targeting of the networks with regeneration unit(s). The iterative method proposed can be used to design and target the networks with both fixed regenerated concentration and that with fixed hydrogen recovery ratio. An estimation method is proposed to calculate the regenerated concentration and flow rate for the regeneration unit with fixed hydrogen recovery ratio. A few literature examples are investigated with the proposed method. The results obtained in this work are comparable to that obtained in the literature. It is shown that the method proposed is simple and effective. [Copyright &y& Elsevier]

Highlights: [•] Design of distributed wastewater treatment is investigated in this paper. [•] New method to reduce unreasoning stream-mixing in design is proposed. [•] Processes divided into three-unit groups based on minimum-mixing rule proposed. [•] Precedence of the units in the group selected is determined by heuristic rules. [•] It is shown that the design method proposed is simple and effective. [Copyright &y& Elsevier]

Abstract: This paper presents a new design method for regeneration recycling water-using networks with internal water mains by using the concentration potential concepts (Liu et al., 2009a. AIChE J. 55, 374–382). The precedence order of the processes is determined by the values of the Concentration Potential of the Demands (CPDs). The formation of the internal water mains is determined by the values of the Concentration Potential of the Sources (CPSs). An initial network with one regeneration unit is developed based on the concentration potential values. The final design can be obtained in a few iterations by adjusting the initial network. The results of the illustrated examples show that the designs obtained in this work are comparable to that obtained in the literature with computer programming methods. It is shown that the proposed method is simple and effective. It can be concluded that the concentration potential concepts are useful tools in design of water networks. [Copyright &y& Elsevier]

Abstract: This paper presents new design procedures for the treatment systems with a single contaminant. For the systems with one treatment process, a simple procedure is proposed to determine the pinch stream. Then design of the systems can be obtained easily based on the pinch stream identified. For the systems with two treatment processes, the performing sequence is determined by the inlet concentration constraints of the treatment processes first. Then an initial structure is established, in which all streams are treated by the first process. The treatment network can be obtained by optimizing the treatment amounts of the processes. It is found that for some systems, when the cost ratio of the treatment processes changes, the optimal system structure changes as well. [Copyright &y& Elsevier]

Abstract: Water-using processes can be classified as either fixed flowrate operations or fixed contaminant load ones. This article presents a new design method for the water-using networks involving both fixed flowrate operations and fixed contaminant load ones. The definitions of the concentration potential concepts (, AIChE J. 55, 374–381) are improved to deal with recycling operation in the design. The values of the Concentration Potential of Demands (CPDs) are used as the key factor to determine the performing order: the process with the lowest CPD value will be performed first. While satisfying a demand stream, the internal source streams with descending order of the maximum quasi-allocation amounts will be considered first, and the external source streams will be chosen by the concentrations of the key contaminant (for fixed flowrate operation) or the minimum required amount (for fixed contaminant load operation). The results of a few illustrated examples show that the amounts of freshwater consumptions obtained in this work are close to the best results obtained using mathematical programming methods in the literature, and the calculation of the proposed method is simple. [Copyright &y& Elsevier]

Abstract: This paper develops a new method and computer software to design the water-using networks of multiple contaminants by combining the concentration potential concepts (Liu et al., 2009. AIChE Journal 55, 374–382) with a Linear Programming (LP) method. The precedence order of the process units is determined by the values of the Concentration Potential of the Demands (CPDs). The allocations from the sources to the demands are decided with the LP method. To reduce the consumption of high quality sources, each source is assigned a weighting factor, which is obtained based on the values of the Concentration Potential of Sources (CPSs). The results of a few illustrated examples obtained with the presented method are comparable to that obtained with the mathematical programming algorithms in the literature. Compared to the literature methods, the method proposed in this paper has the following characteristics: initial values are not required, and the calculation is simple. [Copyright &y& Elsevier]

Regeneration reuse/recycling of industrial wastewater can effectively reduce freshwater consumption and wastewater discharge amount. A new method is presented in this article to design regeneration recycling water networks with multiple contaminants. The concentration potentials and linear programming approach are combined for solving the problem of minimization of freshwater and regenerated stream flow rates. The values of concentration potential of demands are utilized to identify the precedence order of water-using processes. The allocations of sources to demands are formulated as linear programming models. To reduce the consumption amounts of high quality source streams, each source stream is assigned a weighting factor based on the quality of the sources. Two examples are solved to illustrate the effectiveness of the proposed approach. The consumptions of freshwater and regenerated stream obtained by using the proposed method are comparable with those obtained in the literature. The method has the characteristics of converging easily and needing no initial values. [ABSTRACT FROM AUTHOR]

Compared to the synthesis of simple networks in which only reuse, regeneration reuse/recycling, or wastewater treatment is considered individually, the integration of total water networks is more complex and practical. This paper presents an iterative method for design of total water networks with multiple contaminants, in which reuse, regeneration reuse/recycling and wastewater treatment are considered simultaneously. To start the design procedure, an initial reuse-subnetwork without recycling streams is designed first. The un-reused streams in the initial reuse-subnetwork are employed to estimate the possible recycling streams by designing the treatment-subnetwork. Adding the possible recycling streams estimated into reuse-subnetwork as known source streams, the reuse-subnetwork with recycling streams can be designed. In the first iteration, the recycling streams, which will be reused in the reuse-subnetwork, will be identified from the possible recycling streams. With several iterations, the final design of the total water network can be obtained. The results obtained with the proposed method are comparable to that obtained in the literature with mathematical programming method. It is shown that the design procedure proposed is simple and effective. • Design method proposed for total water networks with multiple contaminants. • Reuse, regeneration and wastewater treatment are considered simultaneously. • An iterative design procedure is proposed. • The final design can be obtained in a few iterations. • The design procedure proposed is simple and effective. [ABSTRACT FROM AUTHOR]