Research On Removal Of Organic Sulfur And Acid Gas In The High Sour Natural Gas

Usually a certain amount of acid gas, such as carbon dioxide (CO2), hydrogen sulfide (H2S) and organic sulfur, such as carbon disulfide (CS2), carbonyl sulfide,(COS), mercaptans (RSH), thioethers (R-S-R’), etc., are contained in the natural sour gas. For the domestic and industrial applications, the acid gas and organic sulfur in the natural gas should be firstly removed and cleaned before transportation. Yuanba and Puguang gas fields exploited by Sinopec group are containing high amount of H2S, CO2, and organic sulfur, such as COS, CS2and other organic sulfur. The amount of H2S reaches18%(vol) in the sour gas, while the amount of CO2reaches about10%(vol). And the amount of organic sulfur content is as high as300-500mg/m3.In the study a novel series of HA solvents are developed to treat the high sour natural gas with high acid gas and organic sulfur by laboratory test, mold test and curve test. In the tests, gas-liquid ratio, absorption temperature, packing height in the HA solvent process are studied and compared with the MDEA solvent process. Physical and chemical properties of HA are also studied. The test conclusions are as followed:(1) HA solvent has better acid gas removal ability than MDEA solvent. Compared with MDEA solvent the capacity of HA solution to remove acid gases can increase by30%at the same conditons of the solvent concentration, solution circulation rate and the height of packing in the same apparatus.(2) HA solvent is a good solvent for removing organic sulfur in the feed gas. Compared with MDEA solvent, HA solvent can effectively remove high acid gas. The removal effect of organic sulfur (COS, RSH, R-S-R’) by HA solvent is better than MDEA solvent. The process can be simplified and the process operation conditions of the process become easy.(3) HA solvnet is friendly to the equipment and pipe as MDEA solvent. Foaming tendency and corrosive aspects of HA solvent are associated with the MDEA solvent. Therefore, HA solvent can replace MDEA solvent on the original facility. And equipment transformation does not be required.