Effects of separation sequences on the reactive distillation coupled with extractive distillation under different pressures

Reaction and separation of complex azeotropic systems in reactive distillation processes are difficult to optimize simultaneously, which severely hinders the economic performance of the process. This study focused on the nonlinear relationship between product separation sequence and reaction evaluation indexes (yield, productivity and selectivity) under different pressures. Based on thermodynamic methods and phase diagram analysis, initial processes for intensified reactive distillation at four pressures were designed. Quantum chemistry, toxicity and relative volatility were used to select the best extractant. The multi-objective genetic algorithm was used to optimize different operating variables. Heat integration technology was presented to reduce process energy consumption. By comparing synthesis and purification processes of isobutyl formate with different feed ratios, it was found that the higher the pressure, the better the product separation sequence, the more conducive it is to reaction separation, and the higher the process profit.