C1 Chlorinated Hydrocarbons

This report reviews the technology, economics, and market status of the C₁ chlorinated solvents. Methylene chloride is especially emphasized because of its emerging dominance in the market place over other chlorinated solvents and fluorocarbons, which are beset by problems related to stricter environmental standards, especially those related to the depletion of ozone.

In a detailed analysis of two major commercial processes using methane or methanol as the organic feed, methylene chloride is maximized as a product in relation to coproducts chloroform and carbontetrachloride. Methyl chloride is an intermediate in both processes and is recycled to extinction in making the other three chloromethanes. Methyl chloride is a largely captive intermediate in the production of silicones.

The technology for oxychlorination of methane is reviewed briefly, and relative economics are projected.

Two carbon tetrachloride processes are evaluated that account formost of the prevailing industrial capacity--the chlorination of cardisulfide and the coproduction of carbon tetrachloride and perchloroethylene-ethylene from C₁-C₃ hydrocarbons and chlorinated derivatives. A third process, the severe chlorinolysis of waste chlorinated residues is also included.

Detailed technical and economic evaluations are presented for the chloromethane processes with methane and methanol feeds, and less detailed analyses and abridged summaries are presented for the methane oxychlorination process and carbon tetrachloride processes.

The domestic and worldwide market status of C₁ chlorinated solvents are reviewed, along with summaries of past performance and emphasis on trends that may develop in response to problems associated with environmental pollution.