Optimization of MTO Olefins Separation Process

Abstract

The separation process and the utility were considered simultaneously in order to reduce the cooling capacity of the propylene refrigeration system, and even to completely remove it. Two new types of heat pump distillation processes were proposed. The software Aspen Plus was used to simulate different heat pump distillation processes of ethylene and propylene to determine operating parameters and the best separation processes. The results show that the cold and hot utility would be reduced by 44.30% and 70.64% respectively when B-type and A-type heat pump distillation processes were used for ethylene and propylene separately. Furthermore, the temperature difference between hot and cold streams decreases after optimization by analyzing the T-H diagram. The energy has been more reasonably used, which proves the proposed processes are appropriate and effective.