Deciphering Refinery Water System Design and Optimization: Superstructure and Generalized Mathematical Model

Abstract

The up-to-date approaches to optimizing water systems only include fresh water, regenerated water and wastewater and ignore other types of water in refinery, i.e., desalted water, deaerated water, circulated cooling water, steam with different pressure levels and condensate water. Therefore, the existing mathematical model for water system optimizaiton is not directly applicable for the optimization of practical refinery water systems. To overcome the limitation and bridge the theory and application, we first presented a generalized model of water-using processes including multiple types of water and a general superstructure for the optimization of refinery water system. The superstructure consists of water-using processes including multiple types of water in the main production units (i.e., crude oil distillation, fluid catalytic cracking), water pretreatment systems (i.e., fresh water station, desalted water station, steam power station) and wastewater treatment system. The flow rate balance equations f...