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R-22 use is being phased out in developing countries, where it is largely used for air conditioning applications. R-22 is prepared from chloroform: HCCl 3 + 2 HF → HCF 2 Cl + 2 HCl. An important application of R-22 is as a precursor to tetrafluoroethylene. This conversion involves pyrolysis to give difluorocarbene, which dimerizes: [3]
Being phased out: A widely used hydrochlorofluorocarbon (HCFC) and powerful greenhouse gas with a GWP equal to 1810. Worldwide production of R-22 in 2008 was about 800 Gg per year, up from about 450 Gg per year in 1998. R-438A (MO-99) is a R-22 replacement. [71] R-123 HCFC-123 CHCl 2 CF 3: 2,2-Dichloro-1,1,1-trifluoroethane: 292 79 US phase-out
R-410A was invented and patented by Allied Signal (now Honeywell) in 1991. [5] Other producers around the world have been licensed to manufacture and sell R-410A. [6] R-410A was successfully commercialized in the air conditioning segment by a combined effort of Carrier Corporation, Emerson Climate Technologies, Inc., Copeland Scroll Compressors (a division of Emerson Electric Company), and ...
For example, R-22 has one carbon atom, one hydrogen atom (2−1 = 1), two fluorine atoms, and one chlorine atom (4−2−1 = 1), so it is chlorodifluoromethane, while R-134 has two carbon atoms (2−1 = 1), two hydrogen atoms (3−1 = 2), four fluorine atoms, and no chlorine atoms (6−2−4 = 0), so it is one of the tetrafluoroethanes. This ...
Chlorodifluoromethane (R-22 or HCFC-22), a type of Freon. [9] [10] Dichlorodifluoromethane (R-12 or CFC-12), the most commonly used Freon brand refrigerant prior to its ban in many countries in 1996 and total ban in 2010. 1,1,1,2-Tetrafluoroethane (R-134a or HFC-134a), one of the main replacements for the formerly widespread R-12.
Abundances are given as pollution free monthly mean mole fractions in parts-per-trillion. Atmospheric concentration of pentafluoroethane at various latitudes since year 2007. HFC-125 is a non-ozone depleting replacement for chlorine - or bromine -containing chemicals such as Halon 1301 .
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The phasing out of CFC and HCFC refrigerants (e.g., HCFC-22, also known as R22) due to global warming concerns has helped to spur innovations in cooling technologies. [23] [24] Natural refrigerants such as carbon dioxide and propane (), as well as R-410A, have become attractive replacements for air conditioning and refrigeration applications.