Hydrofluoroolefin
Hydrofluoroolefins are unsaturated organic compounds composed of hydrogen, fluorine and carbon. These organofluorine compound are of interest as refrigerants. Unlike traditional hydrofluorocarbons and chlorofluorocarbons, which are saturated, HFOs are olefins, otherwise known as alkenes.
HFO refrigerants are categorized as having zero ozone depletion potential and low global warming potential and so offer a more environmentally friendly alternative to CFCs, HCFCs, and HFCs. Many refrigerants in the HFO class are inherently stable chemically and inert, non toxic, and non-flammable or mildly flammable. Many HFOs have the proper freezing and boiling points to be useful for refrigeration at common temperatures. They also show promise as blowing agents, i.e. in production of insulation foams, food industry, construction materials, and others.
HFOs are being developed as "fourth generation" refrigerants with 0.1% of the GWP of HFCs.
HFOs in use include:
- 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene.
- cis-1,1,1,4,4,4-hexafluoro-2-butene shows also a promise in high temperature applications like cogeneration, heat recovery and medium temperature heat pumps.
- trans-1,1,1,4,4,4-hexafluoro-2-butene also has good properties, and is being investigated..
The largest brand of HFOs is Opteon, produced by Chemours.
