费托合成过模拟及尾气处理分析

Fischer-Tropsch (F-T) synthesis converts coal into a liquid fuel similar to petroleum and is an indirect coal liquefaction technology. The process consists of five main parts: coal gasification, water-gas shift, gas purification, synthesis of liquid fuels and combined cycle power generation. In addition to the generation of liquid fuel products, the process of synthesizing liquid fuel also produces tail gas, the main components of which are CO, H2, C1-C4 and other light alkanes, and contains a small amount of heavy alkanes, the tail gas can be burned to generate electricity and steam, to meet the needs of the system public works, and if the effective components such as CO and H2 are recovered, the output of fuel products can be increased. In this paper, the chemical process simulation software Aspen Plus was used to simulate the five parts of the whole process of Fischer-Tropsch synthesis, and the exhaust gas treatment was analyzed. In this paper, three kinds of tail gas treatment methods are studied: all the tail gas is burned to generate electricity and steam to meet the needs of the system utilities, and if there is a surplus, it can be transported to the peripheral power grid and steam pipeline network; The exhaust gas recovers effective components such as H2 and CO, increases product output, and meets the utility needs of the system by burning coal; If the electricity and steam supply in the process is insufficient and coal is needed to replenish it, this example sets up different proportions of exhaust gas recovery schemes. Through the analysis of process flow and public engineering system, the system operation cost and process income of each scheme are comprehensively compared, and it is determined that the economic benefit of 20% exhaust gas recovery is the largest, and the economic benefit is the smallest when the exhaust gas is fully recovered.