Simulation And Optimization Of 520,000 T/a MTP Product Separation Process

The product separation process in large-scale methanol to propylene was simulated and optimized at Aspen Plus simulation platform based on a 2,400 t/a MTP pilot plant and experimental data. The results have strong application background and industrial value.The separation process of MTP product was simulated by Aspen Plus. It was calculated and compared with experimental data by using thermodynamic model of RK-SOAVE and different modules. The error range was less than 5% and the reliability of the model was verified.There were lots of problems with the separation system including poor cooling effect, high compression ratio, methanol loss and distillation sequence. The separation process was optimized by a pre-cooling tower,4 stages of compression, a methanol recovery tower and front-end debutanization. Dividing wall column, partial condensation and heat pump distillation were applied to simplify the refining process and reduce energy consumption. The result showed that the mass fraction of propylene by the new process could reach 99.80%, which was higher than industrial data. And the energy consumption was reduced by 31.29%.On this basis, the separation process in large-scale was simulated. The heat exchanger network of refining unit was optimized by Pinch Technology. It was founded that energy consumption was reduced by 14.57% after heat integration. Under the circumstance of optimal parameters, a 520,000 t/a MTP product separation process was put forward.