Simulation And Optimization Of Methanol To Light Olefins Products Separation

Ethylene and propylene are very important chemical raw materials. At present, the production of olefins depends heavily on oil. With the scarcity of oil resources, the route of methanol to olefins (MTO) with coal or natural gas gradually attracts attentions of academia and industry. The products of MTO are the same with petroleum hydrocarbon cracking product, but they also has their own particularity. According to the distribution characteristics of the product for MTO, a new method to improve energy-saving product separation and system optimization process was proposed in this paper.In this paper, several separation processes of catalytic cracking of petroleum products in industry and methanol to olefins products are simulated by the process simulation software Aspen Plus. The front depropanizer process was choose as the energy saving process by comparing the different processes in the case that every process can meet the requirement of the purity and yield of ethylene and propylene.Demethanizer was found to be the highest energy consumption in all the module through the energy consumption analysis. The traditional method of separation light gases is cryogenic separation. By adding a scrubbing tower before the demethanizer, the problem of the high energy consumption for demethanizer and large amount of ethylene loss was solved.Pinch technology was used to analysis energy consumption, To make the process of hot and cold heat matching logistics, new heat exchange network was designed. It was found that energy consumption reduced to36.2%compared with the original process through heat integration.