Water and energy optimization through process integration in industrial processes
The main objective of this research is to develop, validate, and apply the methodology that addresses the interaction of the various processes in industrial system in order to optimize water and energy consumption. To achieve this, the following studies will be carried out:
- Water Network Design: The water network in process industries consists of three elements: water using processes, regeneration and effluent treatment processes. In this study, optimized network design for each of these elements will be developed. Also interaction of all these processes will be considered to finally achieve the global optimum water network design.
- Water Network Retrofit: A heuristic methodology will be developed to consider all interactions amongst water network elements and find possible water minimization opportunities. Effective and economic process changes will then be proposed to achieve the economic optimum water network system. Those changes will further be tested using a new cost screening tool for economic justification with the desired payback period set by the plant owner.
- Heat Integrated Water Network design: Heat exchanger network plays a significant role in complex process industries to distribute the energy effectively and economically. In this study, a new heat exchanger network design approach will be developed in order to reduce the energy and water consumption simultaneously with the minimum payback period.
Significance and Contribution:
According to a 2008 report by the United Nations Environment Programme, industry is the second largest user of freshwater worldwide after agriculture, while freshwater constitutes only 1% of worldwide water resources. Also, energy efficiency is flagged by International Energy Agency as one of the most important activity for greenhouse gas mitigation. Process Integration is an emerging research field for resource conservation during last decade. However, there is lack of investigation to consider both water and energy conservation simultaneously in process industries. Water and energy have close interaction with each other thermodynamically in process industries. Optimisation the water and energy consumption separately cannot guarantee the global optimum. Thus, developing a framework which can address water and energy optimization holistically will provide a significant benefit to process plants. The specific contribution of this project include:
- Development of a novel integrated model which can holistically consider interactions of all water-energy flows within the entire process network;
- Development of a novel mathematical algorithm to solve the model;
- Development of a new graphical management tool in order to consider all water-energy saving opportunities (e.g. reuse/recycle, source elimination and reduction, etc.) in the plant; and
- Development of a new cost screening tool to track the profitability of all process changes.