Synthesis of the optimal heat and water recovery system for reduction of the refinery CO2 emission

Petroleum refinery is one of the major CO2 emitters in the global industrial sector. The refinery has a number of various CO2 emission points including the utility plants and furnaces. Also, it consumes a large amount of industrial water as feedstock for utility. In particular, for those located in the Middle East area which is arid, the supply of the water resource turns out to be a serious problem, so it is highly demanded to utilize the water resource more efficiently. To overcome these challenges, the heat and water recovery (HWR) system applied to the steam plant of the petroleum refinery is proposed. The system allows recovering heat energy of hot flue gas streams to heat the condensate water through heat exchangers. Moreover, the flue gas streams are further cooled below the water dew point to recover water. The goal of this study is to formulate and solve an optimization problem for the heat exchanger network (HEN) synthesis of the system. The potential to CO2 reduction and cost saving are obtained with the optimal HEN configuration. In addition, sensitivity analysis is conducted by perturbing several economic parameters that affect the optimization results.