Some Industrial Sulfur Compounds; Novelties in their Manufacture, Main Uses and Potential Developments

Abstract

Much progess has been made in recent years in the manufacture of the main basic sulfur compounds.

Emphasis has been placed on improvement of the quality and consistency of industrial sulfur compounds; reducing by-products, residual organic chlorides and catalyst impurities; and dealing with environmental problems tied to odor and the toxicity of most of these products. This explains the tendancy to look for synthetic routes which avoid chlorine-containing raw materials and to select solid catalysts which are easier to separate.

In the mercaptan series, methyl mercaptan, which is the major product by virtue of its use in methionine production, is now experiencing the increasing development of carbamates as insecticides. The main uses of other mercaptans involve manufacture of agrochemicals in the thiocarbamate and thiophosphate series.

The mercaptocarboxylic acids are commonly used as plastic additives, in heat-stabilizers for PVC and as antioxidants for polyolefins. However, thioglycolic acid is experiencing promising developments in the field of thiophenic derivatives.

We must mention the specific and important developments of dimethyldisulfide as a safe sulfur donor in the refining industry and as a thiomethylating agent. Dimethylsulfoxide is becoming increasingly important as a solvent for organic synthesis and as a reactant in the pharmaceutical industry.

Other versatile reactants are methanesulfonyl chloride, a convenient building block for synthesis of pharmaceutical and agrochemical intermediates, and methanesulfonic acid which is experiencing strong growth as an acid catalyst, an electrolyte, a solvent and a reagent for pharmaceutical and agrochemical syntheses.