Abstract: A new technology with new COS hydrolysis catalyst and demercaptan solvent for liquefied petroleum gas refining without caustic alkali was developed by China petroleum university (Beijing) to solve problems of frequent change of caustic solution, large amount of waste alkaline and out-spec sulfur content of refined liquefied gas found in conventional LPG caustic fining process. Jointing with Sunway petrochemical engineering Co. Ltd., the technology was successfully applied in LPG sweetening unit of CNPC Harbin petrochemical company. The results show that the process has good effect in desulfurization. The total sulfur content in refined products is below 10 μg/g. Compared with the traditional alkaline cleaning method, the process discharge without waste alkaline and the washing water can be discharged directly into the sewage treatment plant. The process is simple and the operating conditions are ease. The COS hydrolysis catalyst has a high activity and a long service life. The sweetening agents can be recycled with lower loss.

Key words: liquiefied petroleum gas, refining, alkali-free refining, sweetening, caustic residue