Nowadays, gas condensates sweetening is used solely to prepare them for transportation. Requirements for mercaptan removal from gas condensate are applied only to light most corrosive methyl and ethyl mercaptan, total content must not exceed 0.004% wt.
Gas condensates are sweetened from light (C1-C2) mercaptans by extraction with alkaline solutions and subsequent regeneration of alkali in the presence of phthalocyanine catalyst and oxygen. The resulting disulfides are not separated from gas condensate. Thus, concentration of sulfur compounds in gas condensate remains unchanged.
From gas condensate containing large amount of light C1-C4 mercaptans, can be separated disulfide oil. It is a valuable raw material for petrochemical industry and used for sulfidation of catalysts of hydrogenation processes and as an inhibitor in pyrolysis.
In the EAEC (former USSR) gas condensates sweetening processes mainly used in Kazakhstan, where gas condensates characterized by high content of mercaptan compounds. In Russia gas condensates with high content of mercaptans are produced in Astrakhan, Orenburg and Samara regions.