Chemical Sciences

The presence of mercaptans in petroleum products like LPG, naphtha, gasoline, aviation turbine fuel (ATF) and kerosene is undesirable due to their foul odor and highly corrosive nature which also may affect the activity of catalysts used in downstream processes. In commercial practice, the low molecular weight mercaptans present in LPG are first extracted with alkali and subsequently oxidized catalytically to disulfides. The process for converting mercaptans into less deleterious disulfides is termed as sweetening. CSIR-Indian Institute of Petroleum has developed a homogeneous catalyst, Thoxcat ESTM, which sweetens LPG cost-effectively.