Double-effect Distillation And Heat Pump Energy-saving Technology In The Process Of Methanol Distillation

Crude methanol distillation is critical component of methanol production, its energy consumption is one of the key factors that affect costs. With the improvement of the energy saving requirements, effectively reducing the energy consumption of distillation, distillation separation has been the focus of the study. In-depth study of methanol distillation process system, the purpose of the energy consumption of methanol distillation process through rational design and optimization of the system so as to reduce, has great practical significance.This paper for the first time, study the existing methanol distillation process, combined with the latest developments in crude methanol distillation technology, the use of double-effect distillation and heat pump distillation technology for energy-saving technologies applied research methanol distillation process. The crude methanol distillation process has been simulated and analyzed by ProII.In the crude methanol multi-effect distillation process, the emphasis on the atmospheric tower and the tower pressure conditions for energy impact. In the distillation process parameters for the optimization process, the operating pressure, reflux ratio, feed temperature and other parameters were analyzed. By simulating different working conditions to the ethanol content of impurities in refined methanol as constraints, while energy consumption as a secondary selection criteria, multi-effect distillation process parameters were optimized to get the best work of methanol distillation conditions. Finally, the optimized parameters have been selected as follow:the operation pressure is650kPa, reflux ratio is2.35for pressured tower and the operation pressure is140kPa, reflux ratio is1.65for atmospheric tower. The feed temperature of the pressured tower is107℃and the feed temperature of the atmospheric tower is98.8℃.Heat pump technology in the methanol distillation, the main effects of heat-related parameters investigated,based on the double-effect distillation, result of the the overhead vapor recovery amount (cycle work quality), the compressor outlet pressure, the working fluid aftercooler outlet temperature and feed temperature have been studied. Optimized parameters have been selected as follow:the overhead vapor recovery amount (cycle work quality) is109200kg/h(reflux ratio2.36),outlet pressure of the compressor is900kPa, the working fluid aftercooler outlet temperature is118℃,the feed temperature is128℃for pressured tower at650kPa. The feed temperature is130.2℃for atmospheric tower at140kPa. The product of the pressured tower is32500kg/h and the product of the atmospheric tower is22800kg/h.This paper investigated the double effect distillation and heat pump technology in the methanol distillation, by analyzing the process setting, energy consumption, the difference on the advantages and disadvantages of operating costs of distillation technology in energy-saving measures and attempts to explore for energy saving reduction and to achieve effective utilization of energy looking for direction. Methanol for industrial distillation process provides the basis for data research and engineering support.