Applications of Pinch Analysis and Mathematical Programming Methods for Synthesizing Non-Isothermal Water Networks

Processes industries consume large amounts of natural resources and generate large amounts of waste/emissions into the environment. Consequently, important issues and challenges within the process industries are rational use of raw materials, water and energy, pollution prevention, minimization of waste generation, and achieving profitability and sustainability of industrial processes [1, 2]. In order to successfully address those challenges systematic methods [3], and computer aided tools can be applied during synthesis and operation of the industrial processes. Over the last several decades there have been an increasing number of applications of systematic methods based on pinch analysis and mathematical programming in order to minimize water/energy usage, and wastewater generation within a manufacturing sector. In early studies these methods have been only applied for heat or water integration. However, in recent years water and heat integration within the process water networks have been performed simultaneously [4]. This paper presents recent advancements and applications of pinch analysis and mathematical programming methods for synthesizing of non-isothermal water networks through illustrative case studies. Case studies of non-isothermal water networks reported in the literature are of different complexities, including a network of water-using units, a network of wastewater treatment units, an integrated network of process water-using and wastewater treatment units, single and multiple contaminants, pinched and threshold problems, etc. [5]. Those problems have been solved using different synthesis concepts, tools and solution strategies. The main goal of this paper is to present and discuss the current state of the art of pinch analysis and mathematical programming methods for solving the synthesis problems of non-isothermal water networks of different complexities, and highlight challenges and possible further directions in this field.