1,3,3,3-Tetrafluoropropene

1,3,3,3-Tetrafluoropropene (HFO-1234ze(E), R-1234ze) is a hydrofluoroolefin. It was developed as a "fourth generation" refrigerant to replace fluids such as R-134a, as a blowing agent for foam and aerosol applications, and in air horns and gas dusters.[2] The use of R-134a is being phased out because of its high global warming potential (GWP). HFO-1234ze(E) itself has zero ozone-depletion potential (ODP=0), a very low global warming potential (GWP < 1 ), even lower than CO2, and it is classified by ANSI/ASHRAE[3] as class A2L refrigerant (lower flammability and lower toxicity).[4]

1,3,3,3-Tetrafluoropropene
Names
Preferred IUPAC name
(1E)-1,3,3,3-Tetrafluoroprop-1-ene
Other names
HFO-1234ze; trans-1,3,3,3-Tetrafluoro-1-propene; 1,3,3,3-Tetrafluoropropylene; 1,3,3,3-Tetrafluoroprop-1-ene
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.214.545
EC Number
  • 471-480-0
UNII
  • InChI=1S/C3H2F4/c4-2-1-3(5,6)7/h1-2H/b2-1+ checkY
    Key: CDOOAUSHHFGWSA-OWOJBTEDSA-N checkY
  • InChI=1/C3H2F4/c4-2-1-3(5,6)7/h1-2H/b2-1+
    Key: CDOOAUSHHFGWSA-OWOJBTEDBQ
  • F[C@H]=CC(F)(F)F
Properties
C3H2F4
Molar mass 114.043 g·mol−1
Appearance Colorless gas[1]
Boiling point −19 °C (−2 °F; 254 K)[1]
0.373 g/L[1]
Vapor pressure 703 kPa at 310 K
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

In open atmosphere however, HFO-1234ze actually might form HFC-23 as one of its secondary atmospheric breakdown products. HFC-23 is a very potent greenhouse gas with a GWP100 of 14,800. The secondary GWP of R-1234ze would then be in the range of 1,400±700 considering the amount of HFC-23 which may form from HFO-1234ze in the atmosphere. Besides the global warming potential, when HFOs decompose in the atmosphere, trifluoroacetic acid (TFA(A)) is formed, which also remains in the atmosphere for several days. The trifluoroacetic acid then forms trifluoroacetate (TFA), a salt of trifluoroacetic acid, in water and on the ground. Due to its high polarity and low degradability, it is difficult to remove TFA from drinking water (ICPR 2019).[5] Please note - the formation of R-23 and TFA by HFO-1234ze is contested in the scientific community - recent results indicate the statements in this paragraph to be false.

Uses

The increasing concerns about global warming and the related possible undesirable climate effects have led to an increasing agreement in developed countries for the reduction of greenhouse gas emissions. Given the relatively high global warming potential of most of the hydro-fluoro-carbons (HFCs), several actions are ongoing in different countries to reduce the use of these fluids. For example, the European Union's recent F-Gas regulation[6] specifies the mandatory GWP values of the refrigerants to be used as working fluids in almost all air conditioners and refrigeration machines beginning in 2020.[7]

Several types of possible replacement candidates have been proposed so far, both synthetic and natural. Among the synthetic options, hydro-fluoro-olefins (HFOs) are the ones appearing most promising thus far.

HFO-1234ze(E) has been adopted as a working fluid in chillers, heat pumps, and supermarket refrigeration systems.[8][9][10] There are also plans to use it as a propellant in inhalers.[11]

It has been demonstrated that HFO-1234ze(E) can not be considered as a drop-in replacement of HFC-134a. In fact, from a thermodynamic point of view, it can be stated that:

– The theoretical coefficients of performance of HFO-1234ze(E) is slightly lower than HFC-134a one;

– HFO-1234ze(E) has a different volumetric cooling capacity when compared to HFC-134a.

– HFO-1234ze(E) has saturation pressure drops higher than HFC-134a during two-phase heat transfer under the constraint of achieving the same heat transfer coefficient.[12]

So, from a technological point of view, modifications to the condenser and evaporator designs and to compressor displacement are needed to achieve the same cooling capacity and energetic performance of HFC-134a.[7]

See also

References
  1. "MSDS Resource Centre". msds-resource.honeywell.com.
  2. Honeywell Sells Novel Low-Global-Warming Blowing Agent To European Customers Archived 2016-03-03 at the Wayback Machine, Honeywell press release, Oct. 7, 2008
  3. ANSI/ASHRAE Standard 34, 2010. Designation and Safety Classification of Refrigerants.
  4. "The environmental alternative to traditional refrigerants". Honeywell. 2015. p. 2.
  5. Kauffeld, Michael (June 11, 2021). "Environmental impact of HFO refrigerants & alternatives for the future". Global Access Government.
  6. Regulation (EU) No 517/2014
  7. Giulia Righetti, Claudio Zilio, Simone Mancin & Giovanni A. Longo (2016): A review on in-tube two-phase heat transfer of hydro-fluoro-olefines refrigerants, Science and Technology for the Built Environment, DOI:10.1080/23744731.2016.1229528
  8. Longo, Giovanni A.; Zilio, Claudio; Righetti, Giulia; Brown, J. Steven (2014). "Condensation of the low GWP refrigerant HFO1234ze(E) inside a Brazed Plate Heat Exchanger". International Journal of Refrigeration. 38: 250–259. doi:10.1016/j.ijrefrig.2013.08.013.
  9. Longo, Giovanni A.; Mancin, Simone; Righetti, Giulia; Zilio, Claudio (2016). "HFO1234ze(E) vaporisation inside a Brazed Plate Heat Exchanger (BPHE): Comparison with HFC134a and HFO1234yf". International Journal of Refrigeration. 67: 125–133. doi:10.1016/j.ijrefrig.2016.04.002.
  10. Longo, Giovanni A.; Mancin, Simone; Righetti, Giulia; Zilio, Claudio (2016). "Saturated flow boiling of HFC134a and its low GWP substitute HFO1234ze(E) inside a 4 mm horizontal smooth tube". International Journal of Refrigeration. 64: 32–39. doi:10.1016/j.ijrefrig.2016.01.015.
  11. "AstraZeneca partners with Honeywell on development of HFO-1234ze MDIs". www.oindpnews.com.
  12. Brown, J.S., C. Zilio, R. Brignoli, and A. Cavallini. 2013. Heat transfer and pressure drop penalization terms (exergy losses) during flow boiling of refrigerants. International Journal of Energy Research 37:1669–79.
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