2. A process in which an aqueous caustic solution is used to extract mercaptans from refinery streams.
Mercaptans are groups of organosulfur compounds that are derivatives of hydrogen sulfide in the same way that alcohols are derivatives of water; have a characteristically disagreeable odor, and are found with other sulfur compounds in crude petroleum; an example is "methyl mercaptan".
Mercaptans are found in crude petroleum, and methyl mercaptan is produced as a decayed product of animal and vegetable matter.
They also are produced by certain plants and animals; for example, allyl mercaptan is released when onions are cut, butanethiol (butyl mercaptan) derivatives are present in skunk secretion, and mercaptans are among the sulfur compounds causing the disagreeable odor of flatus.
T-butyl mercaptan blends are often added to the odorless natural gas used for cooking and serve to warn of gas leaks.
Mercaptans are included in a wide variety of chemical reactions and their principal uses are in jet fuels, pharmaceuticals, and livestock-feed additives.