Refrigerants global warming potential

Kayukawa et al. [17] studied the PVT properties of triiluoromethyl methyl ether, because it is a possible refrigerant with zero ozone depletion potential and low global-warming potential. One series of their data is shown in Table 5.6. Calculate Z, the compressibihty factor, and the molar volume in mol m from the given data, and fit the data for Z as a function of 1 /Pm to both a linear and a quadratic equation to see whether a third virial coefficient is warranted by the data. 

HFCs, including HFC-134a, have been developed as an alternative to CFCs, which are known to contribute to the breakdown of ozone to oxygen in the stratosphere. HFCs do not contribute to the destruction of stratospheric ozone, but some HFCs have global warming potential. They primarily serve as replacements for CFCs in refrigeration equipment and mobile air conditioning they also have pharmaceutical applications (e.g., as propellants for metered-dose inhalers used to treat asthma). 

Environmental concerns are extremely important when designing a refrigerant system and need to be taken into consideration. Several factors come into play and need to be mentioned. These are global warming potential (GWP), total equivalent warming impact (TEWI), and ODP. 

The European Commission has proposed legislation that will phase out any refrigerant with a global warming potential greater that 150 by May of 2008 [14], The commission further states [14] ... 

RF-01 Replace Refrigerants with Natural or Lower Global Warming Potential (GWP) Gases RF-04 Install MicroChannel Components and Heat Exchangers... 

Studies of natural refrigerants continue. For example, Annex 22 of the International Energy Agency implemented a three-year project, Compression Systems with Natural Working Fluids, in 1995. Air, water, ammonia, hydrocarbons, and carbon dioxide have a low or zero direct global-warming potential and zero ODP, as shown in Table R-2. 

As can be seen from Table 9.2, ozone depletion values are zero for all compounds with the exception of R12. As stated earlier, the ozone depletion potential is the relative amount of damage that the particular chemical causes to the ozone relative to R-ll (Figure 9.2). Figure 9.3 shows the global warming impact of various refrigerant... 

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