高含硫天然气脱硫脱碳工艺技术在普光气田的应用研究

Application and research of high sulfur content gas desulfurization and decarbonization process on Puguang gas field

普光气田是我国迄今为止开发的规模最大、丰度最高的特大型海相碳酸盐岩整装气田,天然气中H2S含量高达13%～18%(φ),CO2为8%～10%(φ),有机硫化合物高达340.6mg/m3,常规脱硫脱碳工艺无法适用。该文通过对高含硫工艺技术进行研究分析,制定了普光气田天然气净化工艺路线,选用甲基二乙醇胺(MDEA)作为吸收溶剂,通过催化反应脱除天然气中有机硫,设置级间冷却器控制CO2的吸收,吸收溶剂通过串级吸收、联合再生,降低了装置能耗和运行成本。该工艺在普光气田应用后,外输产品气中H2S含量在6mg/m3以下,CO2含量低于3%(φ),总硫含量低于200mg/m3。

So far,Puguang gas field is the largest and most abundant oversize marine carbonate reservoir that has been exploited in China.The range of H2S and CO2 content in natural gas is 13%-18%(v) and 8%-10%(v) respectively,organic sulfur content is 340.6 mg/m3.The conventional acid gas removal process is not applicable.By research and analysis on high sulfur natural gas purification technology,the gas purification process of Puguang gas field is set up.MDEA is selected as main absorption solvent,and organic sulfur is removed by catalytic reaction.To control the CO2 absorption,an interstage cooler is set between the first main absorber and the second absorber.The rich MDEA from acid gas removal unit and tail gas treating unit is regenerated in the same stripper to reduce the cost and energy consumption.This technology has been applied in Puguang gas field for more than one year,and the technical specifications meet requirements,the content of H2S in product is lower than 6 mg/m3,CO2 is lower than 3%(v),and the total sulfur is lower than 200 mg/m3.