A review on demercaptan process of natural gas

The technical features of three demercaptan methods from natural gas were introduced which include physico-chemical mixed solvent, mixed amine process and molecular sieves process. It could also be concluded that: ① the demercaptan efficiency of physico-chemical mixed solvent might reach over 90%, but it was inapplicable for the associated gas containing higher content of heavy hydrocarbons; ② methyl mercaptan removal efficiency of new mixed amine solvent with active agents might reach about 90% and mole fraction of hydrocarbon in acid gas would decrease to ≤1.25%; ③ for the raw gas containing high content of mercaptan, when mercaptan mass concentration ≤16 mg/m³ was required in purified gas, using "rough removal + refine removal"("1+1" technology) might be suitable; ④ the process of simultaneous removal of water and mercaptan by molecular sieves was complex and especially for treating associated gas there were a lot of mutual influence and interfere among water, mercaptan and heavier hydrocarbon. In addition the raw gas composition and purified gas requirements were closely related to the selection of molecular sieves and their operating parameters.