Multi-objective Optimization of Heat Integrated Water Networks in Petroleum Refineries

Abstract

Heat and water integrations for large scale chemical processes have become important due to economic and environmental reasons. These reduce consumption of both fresh water and energy, thus improving the sustainability of industrial processes. In chemical and related industries, water is used as a reactant, separation solvent and heating/cooling medium. An optimal water network reduces the consumption of fresh water by efficient reuse and recycling of water in the plant itself. In this work, onepetroleum refinery water network is optimized for two objectives: quantity of fresh water and total flow at the inlet of regenerator units simultaneously, using the e-constraint method. Then, selected optimal water network designs are studied for heat integration, using Aspen Energy Analyzer. The proposed approach gives better insights by providing a range of alternative designs, which is useful in the final selection of one optimal network design.