关键词: 天然气, 轻烃回收, 分离, 模拟, 优化设计

Abstract: Compared with the existing methods of light hydrocarbon recovery from low pressure natural gas, a new modified adsorption recovery process, which can reduce consumption and increase recovery ratio, has been put forward. The process consists of two stage temperature and pressure swing adsorptions (T-PSA). Water in raw gas is removed in the first stage, and light hydrocarbon is recovered from raw gas in the second stage. When the pressure of recovered liquid light hydrocarbon is not less than 1.6MPa, the hydrocarbon dew point, storage and transportation safety can meet project requirements, then the light hydrocarbon can be deemed as products. The recovery ratio of propane and butane are both higher than 94%, which have been increased by 30%—40% compared with common cryogenic recovery process and one stage temperature swing adsorption for light hydrocarbon recovery, economic benefits are obvious. Meanwhile, compared with the cryogenic recovery process, the operating flexibility and applicability of two stage temperature and pressure swing adsorption is higher and broader. And it is particularly applicable for small scale production or mobile facility. As a consequence, the modified adsorption recovery process is good for industrial application.

Key words: natural gas, light hydrocarbon recycling, separation, simulation, optimal design