Global emissions of HFC-23 estimated to year 2015

HFC-23 (trifluoromethane, fluoroform, CHF3) is a powerful greenhouse gas that is formed at the reactor stage of the manufacture of HCFC-22 (chlorodifluoromethane, CHClF2). The amount formed depends on the conditions used in the manufacturing process and, for individual plants, lies between 1% and 4% of the production of HCFC-22. While it is possible to reduce the formation of HFC-23 by optimising process conditions, it is not possible to eliminate its production. This requires destruction, generally by thermal oxidation. Under the Kyoto Protocol, developed countries have obligations to reduce greenhouse gas emissions and, in the developing world, there are projects under the Clean Development Mechanism for the incineration of HFC-23 waste streams. These should lead to a reduction in average global emission factors relative to production of HCFC-22. We present estimates of global production of HCFC-22 up to the year 2015 and also the calculated range of emissions of HFC-23 that may be consequences of this. In terms of the effect on climate change, the atmospheric burden of HFC-23 accumulated from emissions is calculated to contribute between 0.1% and 0.2% of the radiative forcing of climate in 2015. Annual emissions of HFC-23 would be equivalent to between 284 and 28 million tonnes of CO2 in that year, when total anthropogenic greenhouse gas emissions are predicted to lie between 46,000 million and 59,000 million tonnes of CO2 equivalent.