乙腈-水体系萃取精馏三塔流程的模拟与优化OA

Anhydrous acetonitrile is widely used as an organic solvent,while a large amount of acetonitrile waste liquid with high water content is generated during some chemical industrial processes.An extractive distillation pre-dehydration process of three towers is proposed to effectively separate the azeotropic system of acetonitrile-water and reduce energy consumption.In ChemCAD,binary interaction parameters were fitted via the NRTL model to construct a thermally coupled process including a dehydration column,an extractive distillation column,and a solvent recovery column.The system structure was optimized to achieve energy integration.Operating conditions and equipment parameters were optimized to establish a plantwide material-thermal coupling model by coupling excess energy from process streams.The simulation results show that the purity of acetonitrile,water products,and circulating extractant is greater than 99.9%(mass fraction)and the energy consumption of the thermal coupling process is 1535.6 kWh,and the total annual cost is 3.639×106 CNY/a.Compared with the conventional process of three towers,the thermal coupling process declines energy by 33.96%and reduces the total annual cost by 27.25%.