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2,3,3,3-Tetrafluoropropene

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2,3,3,3-Tetrafluoropropene
Names
IUPAC name
2,3,3,3-tetrafluoroprop-1-ene
Other names
HFO-1234yf; R1234yf; 2,3,3,3-Tetrafluoropropylene
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.104.879 Edit this at Wikidata
  • InChI=1S/C3H2F4/c1-2(4)3(5,6)7/h1H2 checkY
    Key: FXRLMCRCYDHQFW-UHFFFAOYSA-N checkY
  • Key: FXRLMCRCYDHQFW-UHFFFAOYAB
  • C=C(F)C(F)(F)F
  • FC(=C)C(F)(F)F
Properties
C3H2F4
Molar mass 114 g/mol
Appearance colorless gas
Density 1.1 g/cm3 at 25 °C (liquid); 4, air = 1 (gas)
Boiling point -30 °C
198.2 mg/l at 24 °C, 92/69/EEC, A.6
log P 2.15, n-octanol/water, 92/69/EEC, A.8
Vapor pressure 6,067 hPa at 21.1 °C; 14,203 hPa at 54.4 °C
Hazards
Explosive limits 6.2 %(v); 12.3 %(v)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

2,3,3,3-Tetrafluoropropene, or HFO-1234yf, is a hydrofluoroolefin with the formula CH2=CFCF3. It has been proposed as a replacement for R-134a as a refrigerant in automobile air conditioners.[1][2]

HFO-1234yf is the first in a new class of refrigerants acquiring a global warming potential (GWP) rating 335 times less than that of R-134a (but still 4 times higher than the alternative substitute R-744) and an atmospheric lifetime of about 400 times shorter. It was developed to meet the European directive 2006/40/EC that went into effect in 2011 requiring that all new car platforms for sale in Europe use a refrigerant in its AC system with a GWP below 150.[3]

HFO-1234yf, which has a 100 year GWP of 4,[4] could be used as a "near drop-in replacement" for R-134a,[5] the current product used in automobile AC systems, which has a 100 year GWP of 1430. This means that automakers would not have to make significant modifications in assembly lines or in vehicle system designs to accommodate the product. HFO-1234yf has the lowest switching cost for automakers among the currently proposed alternatives, although the initial cost of the product is much higher than that of R134a. The product could be handled in repair shops in the same way as R-134a, although it would require different, specialized equipment to perform the service. One of the reasons for that is the mild flammability of HFO-1234yf. Another issue affecting the compatibility between HFO-1234yf and R-134a-based systems is the choice of lubricating oil.Current oil is showing signs of damage to plastic, aluminium and issues with health, mouth dryness, rash, sore throat among others affects.[6]

Shortly after confirmation from automakers that HFO-1234yf would be adopted as a replacement of R134a automotive air-conditioning refrigerant, Honeywell and DuPont announced that they will jointly build a manufacturing facility to produce HFO-1234yf[4] which is in operation now. Although others claim to be able to make and sell HFO-1234yf, Honeywell and DuPont hold most or all of the patents registered for HFO-1234yf.[4]

On July 23, 2010, General Motors announced that it will introduce HFO-1234yf in 2013 Chevrolet, Buick, GMC and Cadillac models in the U.S.[7]

Although the product is classified slightly flammable by ASHRAE, several years of testing by SAE proved that the product could not be ignited under conditions normally experienced by a vehicle. In addition several independent authorities evaluated the safety of the product in vehicles and some of them concluded that it was as safe to use as R134a, the product in use in cars today. In the atmosphere, HFO-1234yf degrades to trifluoroacetic acid,[8] which is a mildly phytotoxic[9] strong organic acid[10] with no known degradation mechanism in water. In case of fire it can release highly corrosive and toxic hydrogen fluoride.

See also

References

  1. ^ Material Safety Data Sheet
  2. ^ Honeywell HFO-1234yf
  3. ^ 134A Replacement - HFO-1234yf
  4. ^ a b c "Automakers Go HFO", Chemical & Engineering News, July 26, 2010
  5. ^ Mobile Air Conditioning - HFO-1234yf
  6. ^ High initial prices are projected for HFO-1234yf, raising questions about the rate of OE deployment and whether aftermarket service shops will use it at all
  7. ^ GM First to Market Greenhouse Gas-Friendly Air Conditioning Refrigerant in U.S.
  8. ^ Hurley MD, Wallington TJ, Javadi MS, Nielsen OJ (2008). "Atmospheric chemistry of CF3CF=CH2: Products and mechanisms of Cl atom and OH radical initiated oxidation". Chemical Physics Letters. 450 (4–6): 263–267. doi:10.1016/j.cplett.2007.11.051.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  9. ^ Boutonnet JC, Bingham P, Calamari D, de Rooij C, Franklin J, Kawano T, Libre J-M, McCulloch A, Malinverno G, Odom JM, Rusch GM, Smythe K, Sobolev I, Thompson R, Tiedje JM (1999). "Environmental risk assessment of trifluoroacetic acid". International Journal of Human and Ecological Risk Assessment. 5 (1): 59–124. doi:10.1080/10807039991289644.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  10. ^ Henne AL, Fox CJ (1951). "Ionization constants of fluorinated acids". Journal of the American Chemical Society. 73 (5): 2323–2325. doi:10.1021/ja01149a122.
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