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In the "cradle-to-grave" accounting of warming impacts that is inherent in the Life Cycle Climate Performance (LCCP) concept, the warming impacts associated with the manufacture of any fluorocarbons must be accounted for. Two basic categories of fluorocarbon manufacturing related warming impact have been identified.

1. The warming impact associated with the energy consumed (electric energy and various fuels burned on site) to manufacture both the fluorocarbon and the raw materials used to make the fluorocarbon ( the so-called "embodied energy" or "embedded energy")
2. The direct warming impact of any byproduct greenhouse gases that are emitted by the manufacturing process (the so-called "fugitive" emissions).

The total manufacturing related warming impact is summarized in Table A-1 for R-22 and R-134a (the only compounds for which both energy and fugitive emissions data were available). The warming impact of fugitive emissions associated with R-22 production is due primarily to R-23 emissions. The manufacturing warming impact for R-22 is far larger than for any other compound.

Several other HFCs have important applications as refrigerants or refrigerant blend components, blowing agents, solvents, propellants, or fire suppressants --- HFC-32, HFC-125, HFC-143a, HFC-43-10 mee, HFC-227ea, HFC-152a, and HFC-245fa, among others --- but similar data is not available. Absent such data, HFC-134a has been taken to be representative of the HFC's as a class, and for LCCP calculations, 9 + 0.3% of GWP has been added to the published GWP values, to account for embodied energy and fugitive emissions, respectively. The resulting values are included in Table A-1.

A.1 Embodied Energy

Estimates of the embodied energy in the manufacture of several chlorocarbons and fluorocarbons are summarized in Table A-2. When expressed in terms of CO₂ warming equivalent, the estimates for various fluorocarbons range from 3 to 9, an insignificant amount compared to the 100 year ITH direct GWPs. No data was found for the embodied energy in manufacturing other HFCs. In this report, it has been assumed that the embodied energy for manufacturing all HFCs is, in GWP terms, 9 kg/kg HFC.

A.2 Fugitive Emissions

Fugitive emissions include process emissions due to byproduct venting and leakage and fluorocarbon product losses when transferring into onsite storage vessels at the plant, into transportation containers (primarily truck trailers and ISO containers having a capacity of 35,000 lb. and rail tank cars having a capacity of 180,000 lb.), and into bulk storage containers at customer facilities.

In 1997, AFEAS collected data on fugitive emissions from the manufacturing of four compounds --- three HCFC and one HFC --- from their members, which was aggregated by a third party auditor. Table A-3, which is reproduced from Reference 2, summarizes the results of this AFEAS exercise.

DuPont and Elf Atochem have provided figures on fugitive emissions, based on their reporting to the U.S. EPA for their North American facilities, that show that the actual values for fugitive emissions are considerably less than the values summarized in Table A-3. The total fugitives for the DuPont and Elf Atochem HFC-134a facilities range between less than 0.1% and 0.3% of HFC-134a output, and consists primarily of minute leaks of the product itself. In both the DuPont and Elf Atochem facilities, unwanted byproduct fluorocarbons are not vented directly to the atmosphere, but are destroyed by a thermal oxidizer. Taking the upper end of this range (0.3%), the effective GWP increment for R134a is 0.3% x 1300 = 3.9 ~ 4 kg CO₂/kg HFC-134a, a rather small level comparison with the +/-20% uncertainty of the GWP value (+/-20% of 1300 is +/-260). DuPont staff plan to present several papers on this topic at the Earth Technologies Forum this fall. For other HFCs, fugitive emissions have not been examined in this level of detail. A reasonable assumption is that total fugitive emissions of 0.3% is readily achieved by good plant design and operating practices, for any HFC. For the LCCP analysis in this report, the GWP of the fugitive emissions have been estimated as 0.3% of the GWP of the particular HFC (or HFCs for blends).

A.3 References

Campbell N.J. and A. McCulloch; "The Climate Change Implications of Manufacturing Refrigerants --- A Calculation of Production Energy Contents of Some Common Refrigerants", Transactions of the Institution of Chemical Engineers, Vol. 76, Part B, August 1998.

McCulloch, A., "Influences on Climate Change from the Production Stage of Fluorocarbons Life Cycles". Unpublished memorandum.

Werkema, T. (Elf Atochem); Personal Communication, July 1, 1999.

Bernhardt, S. (DuPont); Personal Communication, July 7, 1999.

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