Published December 2016
This report covers the four chlorinated methanes: methyl chloride (CH3C1), methylene chloride (CH2Cl2; dichloromethane), chloroform (CHCl3), and carbon tetrachloride (CCl4). Chlorinated methanes are chiefly used as precursors—methyl chloride for silicones and other materials, methylene chloride for its solvent properties, chloroform for hydrochlorofluorocarbon-22 (HCFC-22), and carbon tetrachloride, since the phaseout of CFC-11 and CFC-12, is consumed for the production of HFC-245fa and HFC-365mfc. As CFCs are being phased out, use of carbon tetrachloride for the alternatives—HFCs such as HFC-245fa and HFC-365mfc, and possibly HFO-1234yf/ze—is growing. Consumption of chlorinated methanes has been and will continue to be influenced by which fluorocarbons are produced and whether they are consumed as a refrigerant or used as a precursor in the production of other chemicals. In particular, chloroform is used in the production of HCFC-22, which in turn is consumed in the production of fluoropolymers and to a lesser extent, fluoroelastomers. Similarly, methylene chloride is consumed in the production of HFC-32. In general, fluorocarbon consumption is dependent on its ozone-depletion potential (ODP) and global-warming potential (GWP).
The following pie charts show world consumption of these four chlorinated methanes.
The refrigeration industry has been going through many changes, and will continue to do so. Hydrofluoroolefins (HFOs) are expected to have considerable growth during the next five years, particularly HFO-1234yf and HFO-1234ze. HFO- 1234yf has been introduced and is being widely accepted as a low-GWP replacement for HFC-134a in mobile air-conditioning units, and HFO-1234ze has been introduced as a blowing agent for polyurethane (PU) foams and as a propellant for aerosol applications, potentially displacing both HFCs and other nonfluorinated propellants as a low-GWP alternative.
Northeast Asia, led by China, is the largest consuming region for chloromethanes, accounting for nearly half of total consumption in 2016, followed by Western Europe at about 22% and the United States at about 14%. Northeast Asian consumption is forecast to grow at just over 3% annually, while Western Europe and the United States are forecast to grow only slightly during 2016–21. Carbon tetrachloride is forecast to grow the fastest, although from a much smaller base.
In 2016, consumption of methyl chloride to produce methyl chlorosilanes accounted for 85% of its total consumption. Production of methyl cellulose was second at about 8%, followed by production of quaternary ammonium compounds. A potential growth application is use of methyl chloride (and/or chloroform) in the production of HFO-1234yf as a replacement for HFC-134a in mobile air-conditioning systems.
Use as a solvent is the leading application for methylene chloride, particularly in closed industrial systems such as the production of pharmaceuticals, fine chemicals, polymers, and as an extraction solvent. Pharmaceuticals and chemical processing combined accounted for about 35% of total consumption, with pharmaceutical production accounting for about 30%. Adhesives, metal cleaning, HFC-32 production, and use as a paint remover are the next-largest applications, followed by foam blowing and aerosol uses.
The leading application for chloroform is the production of HCFC-22, accounting for about 98% of total consumption. HCFC-22 is used both as a refrigerant and for production of the fluoropolymers PTFE, FEP, PFA/MFA, and ETFE. Although legislation has impacted the use of HCFC-22 as a refrigerant, the resulting declines have been balanced by increasing use in the production of fluoropolymers and, to a lesser extent, fluoroelastomers.
Carbon tetrachloride is the least-consumed chloromethane. Four regions account for the vast majority of consumption: the United States, Western Europe, the Indian Subcontinent, and Northeast Asia. The production of hydrofluorocarbons HFC-245fa and HFC-365mfc accounted for 71% and 23%, respectively, of total carbon tetrachloride consumption in 2016.
Global consumption of chlorinated methanes is forecast to grow at an average annual rate of 2.0% during 2016–21.