Optimization of coal-based methanol distillation scheme using process superstructure method to maximize energy efficiency

Despite the current methanol distillation system (MDS) touching a highly energy-efficient level, there are still opportunities to cut more corners when moving eyesight from heating media to electricity and work efficiency of rotary equipments. To simultaneously optimize this process for higher overall energy efficiency, methodologically an improved substitute pathway is herein proposed of corresponding process superstructure. In detail, it is an all-in-one integration of heat and work exchanger networks (HEN-WEN), exemplified by a 4-column double-effect methanol distillation scheme popular among Chinese coal-based factories. The completion of this work indicates a hope of potential reductions of pump electricity and reboiler steam consumption of the whole unit by further 68.38% and 15.83%, respectively.