Eliminating HFC's (non-ozone-depleting refrigerants) which are powerful greenhouse gases

[OKIsItJustMe]

http://www.nature.com/news/2009/090128/full/457518a.html

Published online 28 January 2009 | Nature 457, 518-519 (2009) | doi:10.1038/457518a

Cutting out the chemicals

The international treaty drawn up to tackle ozone-destroying substances is gearing up to curb greenhouse gases. Jeff Tollefson reports.

Ozone experts are exploring ways to curb powerful greenhouse gases of their own making under the Montreal Protocol, arguing that direct regulation would be faster and cheaper than using carbon markets under a global climate treaty.

The Montreal Protocol set a strong precedent for such an approach, having almost eliminated production of the once-ubiquitous chlorofluorocarbons (CFCs) that eat away at stratospheric ozone. Used in refrigerants, propellants and solvents, CFCs were initially replaced with hydrochlorofluorocarbons (HCFCs); now, chemical manufacturers have moved on to a third-generation replacement, hydrofluorocarbons (HFCs; see graphic). HFCs are cheap and perform well, but are also powerful greenhouse gases. Although in this respect many are less potent than their predecessors, their ability to trap heat can be thousands of times that of carbon dioxide.


Because HFCs do not affect ozone, they are not covered by the Montreal Protocol. As greenhouse gases, they are covered under the Kyoto Protocol, but many believe that they could be eliminated much faster — and at a fraction of the cost — if Montreal were expanded to include them. The Montreal agreement has broad international support, a network of experts worldwide and a 20-year track record of handling these types of chemicals.

"We created these chemicals, and we can get rid of them," says Durwood Zaelke, president of the Institute for Governance & Sustainable Development, an advocacy group in Washington DC. "We have the technology. We have the chemicals. We have the wherewithal within the treaty. It's just an administrative issue."

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[AZCat]

1. Someday we'll be back to using the classics...

ammonia and carbon dioxide. Actually, there are still quite a few ammonia chillers running. There's just the little problem of safety...

[GreenGreenLimaBean]

2. or better yet

thermo-electric cooling.....no refrigerant.

http://en.wikipedia.org/wiki/Thermo-electric_cooler

[AZCat]

3. This is not necessarily "better".

Besides the problems of applying Peltier cooling to large applications, the issue is more complex than just avoiding ozone-depleting refrigerants. Phase-change refrigerant cycles use a neat trick of thermodynamics to move a lot of heat without spending a lot of energy, and when the majority of our power in this country comes from coal burning power plants we need to pay attention to energy consumption as well as the consequences of our choice of refrigerant (or in the case of Peltier cooling - no refrigerant). Peltier systems are far less efficient at moving heat than phase-change systems, so you have to burn more coal in order to get the same amount of cooling. This has all sorts of environmental consequences that can be worse than the consequences from using a phase-change refrigerant cycle, especially if you're using a "green" refrigerant like CO2 or ammonia (or even water, aka R-718, but that's not beyond the prototype stage).