Maximizing total site water reuse via a two-way centralized water header

Abstract

Water is widely used in industry for processes such as washing, stripping, extraction, heating and cooling. Water minimization has become an urgent need in industry due to the scarcity of quality water, stricter environmental regulations, rising price of freshwater as well as the cost of wastewater treatment. In some countries and regions, water is more important than energy. Even though there have been numerous research works on Total Site Water Integration, the methodologies may still need further development from aspects of practical implementation. Superstructures considering all possibilities of water exchange among sources and demands in industrial sites typically result in complex industrial water networks that may be practically very challenging to implement due to plant layout and economic constraints as well as coordination issues. Total Site Centralized Water Integration is developed to address these issues through the use of a centralized water reuse header. In this paper, a U-shaped, two-way centralized water reuse header is designed to improve the Total Site water exchange. As compared to a one-way centralized water reuse header the minimum freshwater requirement for the two-way centralized water reuse header further reduces fresh water requirement from 51.8% to 56.2% and wastewater generation, from 51.5% to 55.9%. The two-way header also reduces the payback period from 5 to 4.7 y.