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

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.