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CONFIDENTIAL
Outline
• What is “the 4th Generation” of refrigerants?– Candidates
– Development targets
• Mexichem project activity• Future direction
4th Generation – what’s in a name?
• First generation – the pioneering fluids
Ammonia, ethyl chloride, sulphur dioxide, carbon dioxide…
• Second generation – the CFCs and HCFCs
Developed with “safety in use” as main driver
• Third generation – the HFCs
Developed in response to concern over the ozone depletion
potential of the second generation
• Fourth generation…
Drive to reduce the global warming potential (GWP) of fluids
compared to previous generations
3
Low GWP refrigerant development overview
• Need to balance sometimes conflicting requirements
– Toxicology
– Flammability
– Technical suitability for application conditions
• Need to ensure that the carbon footprint of usage is the
focus
- Headline GWP value is not a reliable metric of environmental
impact
- Hydrofluoroolefins “HFOs” are an interesting family with
potential for reduced GWP
HFOs
• Leading candidates are;
R-1234yf (2,3,3,3-tetrafluoropropene)
CF3-CF=CH2
R-1234ze(E) and (Z) (1,3,3,3-tetrafluoropropene)
CF3-CH=CHF
R-1233zd(E) and (Z) (1-chloro,3,3,3-trifluoropropene)
CF3-CH=CHCl
R-1243zf (3,3,3-trifluoropropene)
CF3-CH=CH2
5
Refrigeration
Air conditioning
Propellant/blowing agent
Solvent
R134a R245fa
R365mfc
R410A
R404A
R407A
R744 (CO2) R-1234ze(Z)
R-1233zd(E)
R-1233zd(Z)
R-1234yf
R-1234ze(E)
R-1243zf
R-717 (NH3)
R-32
Propane
Propene
Mexichem blend development programmeWhy blend?
• Whilst HFOs have very low GWP values (4-8) they have
limited boiling point range
Requirement to blend to reach other application areas
Scope for performance optimisation
• HFOs of current interest are flammable to some extent
Mostly ASHRAE A2L rated
May require blending to provide further reduction in
flammability for certain application areas
Mexichem blend development programme
• Three main classes of refrigerant in development by
Mexichem
– AC series: Medium temperature/pressure (R-134a
alternative)
– LTR series: Low temperature refrigeration (R-407/R-404
alternative)
– HP series: Heat pump (high pressure) fluids (R-410A
alternative)
• …but also
– R-32 (an HFC) also seen as an attractive R-410A alternative
with GWP around one-third of that of R-410A
8
Mexichem blend development programme
• Currently major focus on blends using R-1234ze(E)
– Significantly weaker flammability than R-1234yf
– Potential for improved energy efficiency
– Production chemistry already proven on large scale
• ASHRAE A1 (non-flammable) and A2L (marginally
flammable) options within each family of fluids
• Strike appropriate balance between flammability, GWP
and efficiency
Reduced flammability generally associated with increased
GWP
9
Future development & Regulation
• European F-Gas proposed HFC cap and phase-down
Whilst HFOs are likely to have a role to play in reducing
carbon emissions from use of refrigerants, there are things
we can, and need, to do now:
R-404A conversion to R-407A
R-32 as a heat pump/air conditioning fluid
• Development of regulation varies throughout the world
with significant uncertainty
GWP and flammability balance with GWP-based regulation?
Some applications require A1 ratings
10
Future development
• Many barriers ahead before the next generation can be
clearly identified and commercialised
Large scale production capacity for HFOs does not exist yet
Complicated IP position
Blend proliferation
• Refrigerant development continuing
HFO-based blend and application technology development
through in-house research and participation in industry-
based programmes such as AREP, and industry groups such
as SAE
HFO manufacturing route development
11
THANK YOU!
• Contacts:– COMMERCIAL: [email protected]
– TECHNICAL: [email protected]
– TECHNICAL: [email protected]