Synthesis of heat-integrated distillation sequences with mechanical vapor recompression by stochastic optimization

Abstract

A method of synthesis of heat-integrated distillation sequences with mechanical vapor recompression (MVR-HIDSs) is proposed based on stochastic optimization in this study. The purpose is to introduce heat pump operation, which can be driven by green electricity, to distillation sequencing as a way of altering stream temperatures to increase the chance of heat integrations. Two types of MVR-HIDSs, namely the vapor recompression heat-integrated distillation sequences (VR-HIDSs) and bottom flashing heat-integrated distillation sequences (BF-HIDSs), are considered for the synthesis separately. To illustrate the proposed method, a case for separating five-component alcohol mixture is solved by the proposed method. The results show that the incorporation of the MVR can provide effectively higher economic efficiency compared with the traditional optimal heat-integrated and thermal coupled distillation sequences. The proposed method makes it possible to synthesize distillation sequences that use green electricity to partially replace the fossil fuel based thermal energy to reduce CO2 emission.