Optimization across the Water-Energy Nexus for Integrating Heat, Power, and Water for Industrial Processes, Coupled with Hybrid Thermal-Membrane Desalination

摘要

The water energy nexus continues to gain traction around the world, because of the inherent merits in simultaneously considering both resources. In this paper, a systematic procedure is developed for maximizing the benefits of this interdependent relationship, when coupled with industrial processes exhibiting a net surplus of heat energy. The presented methodology utilizes a total site analysis to first screen the process for power and water generation potential. In addition to process water streams, seawater desalination is considered as an additional resource. Based on this analysis, heat integration is carried out to capture the options for steam production for process requirements, thermal desalination of seawater, and power production. For the power generation system, a turbine network is developed, whereas, for the water desalination system, a hybrid multieffect distillation reverse osmosis (MED-RO) system is utilized. A superstructure is constructed to embed the various configurations, and the associated optimization formulation is solved to obtain an optimal process that economically balances the need for water and power. A case study is solved to evaluate several scenarios for developing water and energy strategies for a gas-to-liquids (GTL) process in a region with various demands, as well as power and water exportation restrictions.