高酸性天然气脱硫脱碳工艺技术研究

针对原料气中H2S和CO2摩尔分数均达到20%的高酸性天然气净化,通过工艺模拟计算结合室内实验评价的手段,筛选出一种具有良好脱硫性能、选择性及高酸气负荷的选择性脱硫溶剂CT8-5。通过室内实验进行工艺优化后,提出了包括气液比、吸收塔塔板数、贫液温度、再生温度等在内的一系列工艺参数。结果表明,在气液比为200的条件下,净化气中H2S质量浓度为3.9 mg/m3,CO2摩尔分数为1.86%,完全能满足GB 17820-2018《天然气》国家标准中对商品气的气质要求。对GB 17820-2018发布实施后高酸性天然气处理所面临的问题进行了探讨,提出了建议,可为高酸性天然气的气质达标处理提供技术思路。

Research on desulfurization and decarbonization process of highly sour natural gas

Aiming at the desulfurizing and decarbonizing of highly sour natural gas with H₂S and CO₂ molar fraction all up to 20%, a kind of selective desulfurization solvent CT8-5 was screened via process simulation calculation combined with laboratory experiment evaluation. The CT8-5 solution has better desulfurizing capability, selectivity and higher sour gas load. The process was optimized by laboratory experiment and a series of process parameters containing gas-liquid ratio, plate number of absorber, lean solution and regeneration temperature were put forward. The results showed that on the condition of gas-liquid ratio was 200, the H₂S mass concentration in purified gas was 3.9 mg/m³ and CO₂ molar fraction was 1.86%, which could completely meet the quality requirements of commodity gas in the national standard of GB 17820-2018 Natural Gas. Facing problems of treating highly sour natural gas were discussed and some suggestions were put forward, which could provide technical ideas for the treatment of highly sour natural gas to reach the standard of GB 17820-2018.