So last night I was surprised to read and again today how an agreement in Rwanda to limit hydrofluorocarbons, a type of refrigerant: Obama hails global deal to limit powerful greenhouse gases - POLITICO Rwanda — Nearly 200 nations have reached a deal, announced Saturday morning after all-night negotiations, to limit the use of greenhouse gases far more powerful than carbon dioxide in a major effort to fight climate change. The talks on hydrofluorocarbons, or HFCs, were called the first test of global will since the historic Paris Agreement to cut carbon emissions was reached last year. HFCs are described as the world's fastest-growing climate pollutant and are used in air conditioners and refrigerators. Experts say cutting them is the fastest way to reduce global warming. . . . Sure there are greenhouse gases that are more potent that CO{2}. Methane, CH{4} is known to be more potent but decays into CO{2}. So I'm not surprised that HFCs, a manufactured gas, is tagged. But to read the popular press, HFCs are the new bad-boy, "the fastest way to reduce global warming." Since HFCs are used in air conditioning that mitigates local heat events, I can see a secondary effect. One that rates right up there with the CO{2} created in manufacturing. Don't get me wrong, seeing an effective action is better than not. Given typical attention spans, by Monday a new shiny things will come along. Well it is Saturday morning and I had a good day Friday. So consider this my 'old man rant for the week.' Bob Wilson
HFC's were phased out in the US many years ago. Commercially and industrially, R-11, R-12 and R-502 all went away. R-22 will be gone soon. I am not sure what this article is about. Maybe for countries other than the US.
Are you mixing up HFCs with the earlier CFCs and HCFCs of ozone depletion infamy? R-11 and R-12 are CFCs. R-502 and R-22 are HCFCs. HFCs, in contrast, have no ozone-depleting Chlorine. It is about anthropogenic global warming, not ozone depletion.
Montreal Protocol eliminated (perhaps too strong a word ) alkane refrigerants containing chlorine. Those undergo photochemical reactions in the atmosphere, leading to chlorine monoxide. Some of that leaks into the stratosphere where it accelerates ozone decomposition. Several replacements have been utilized, all similar but containing fluorine instead of chlorine. These do not lead to ozone decomposition (or much less at least) but they are excellent infrared absorbers. Also they have long atmospheric lifetimes. There may be only one current alternative that has much less IR absorption and 'drop-in' compatability with current hardware: 2,3,3,3-Tetrafluoropropene - Wikipedia I really don't know if that is the case. We depend so much on heat-transfer machinery, and that will surely grow. All of the working fluids (starting with toxic, flammable ammonia) appear to present one difficulty or another. It is really a muddle, and a disruptive technology would be most welcome here. One quote from the original link "Experts say cutting them is the fastest way to reduce global warming." Struck me very poorly. (a) it is not a very large slice of the IR absorption pie (b) Phasing out in a couple of decades does not mean all gas will be collected and disappear - rather, a lot of it will be vented (just as was the case with CFCs) (c) ~century lifetime of any in the atmosphere (d) all other possible ways to reduce global warming are less??? Gawd who told you that??? Perhaps I should just be glad that countries agreed on something, with a pretty much sciencey basis, without a lot of goofy contrarianism. But in fact we still need to 'refrigerate', the way forward (including sector growth) is not clear, and this is nothing approaching a climate-change victory. Which, of course, we may or may not need. What we certainly do need is more food, water, energy, obtained with smallest possible negative externalities. At worst, this agreement is just another of the long list of distractions from those certain goals. According to BobW above, we are limited to one old-man rant per week. I don't recall agreeing to that
All these volatile fluoroalkanes decompose slowly in the atmosphere forming trifluoroacetic acid TFA). Technology being dandy, TFA can be found in rain at very low levels. Anywhere in the world I suppose, though studies have focused in industrialized regions so far. A bottle of pure TFA is a fearsome thing. One hundred micrograms per liter has demonstrated negative effects on some plants. One-tenth that concentration has been reported in rain. So, yeah, it would probably not be a good idea to tenfold increase our use of volatile fluoroalkanes, quite apart from infrared absorption. In The Blob, Steve McQueen's early hit , A medical doctor* tried to destroy it with trichloroacetic acid. Did not work, but dang that was pretty serious chemistry for a 1950's horror movie. Would TFA have worked better? Maybe we can find out. Said Blob was 'stored frozen' in Antarctica and maybe will thaw out someday... The Blob, not to be confused with The Bob. *Doc might plausibly have had this for chemically removing warts. But such a big bottle? Downington must have been a pretty warty place.
Apparently Blob-> Arctic (somewhere) not Antarctic. Meltout thus may be more likely. Get some TFA ready but careful with that stuff. The Great Escape was a much better movie
Volatile fluoroalkanes are used in anesthesia as well, though it must be a small pie slice and (I think) outside the agreement. Fascinating topic; maybe I can draw some real doctor into the discussion with my misperceptions Like ether and nitrous oxide before them, some anesthetics work by making cell membranes (in general) more permeable. Long chains of nerve cells are most susceptible, as getting 'news' (somebody is slicing me open) to the brain depends on high baud rates.
Impressive tochatihu, reading medical textbooks in your spare time? If we get to the point where the next lowest hanging fruit for anthropogenic global warming is medical anesthetic gases, we've done good...maybe good enough. Doubt many physicians, even anesthesiologists, have taken such an interest in this very specific subject. But excellent question. Not sure anyone has quantified the escape of anesthetic volatile fluoroalkanes. Even if by industry it's a small amount, none of it is recaptured. How that emission rate compares to the rest of industry, not sure?
Folks should note that another alternative, which unfortunately is not hardware compatible, is R744. R744 is simply CO{2}, our 'favorite' AGW gas. Ounce for ounce (common cooling systems generally need less than a pound, not the tons spewed out by our vehicles and powerplants), it has much lower global warming potential than other common refrigerants, with virtually no consequence (compared to other emissions) if simply vented when the appliance reaches end of life. The bad news is that R744 needs to run at much higher pressure than other refrigerants, so requires new and more expensive hardware. But once that hardware is installed, it also runs at better efficiency than the old technology. The R744 heat pump water heaters available in Japan and Australia significantly outperform the non-R744 equipment here in the U.S.
It's confusing to know what this HFC phase out means in real life. Where are they used, and if the answer is everywhere (house/cars) I assume there is an easy replacement, or else the phase out is going to be slow. In general I agree with the concept to go after controllable emissions.
If we haven't put y'all to sleep yet, maybe this will: Inhalation anaesthetics and climate change +++ As a biology grad study I taught pre-med undergraduates at a reasonably well-known college . Other than that my interests are mostly on the 'chemical side' of doctoring. One upshot was that in (only one) hospitalization I was a bad patient. If the staff could not give me a good reason for a particular treatment, I refused it. But all turned out OK and we parted on good terms. My interests in air-pollution epidemiology (reasonable) and poisons (bizarre) are in the same vein
fuzzy1 presents yet another good thing about CO2. See also, decaffeinated coffee. See also travertine. I could go on... We might ought to refrigerate with CO2. Hoping that a Peltier thermoelectric magic bullet can be found though. Put all these pumpy systems into museums.
NY Times article- Honeywell drop-in for autos instread of R134a Solstice® yf Refrigerant | Refrigerants Americas So basically saying get rid of R134a which most A/C systems today use, and go with newer substitutes on the market per YouTube below.
That's OK though I can buy the theory that a man-made crazy molecule is a potential big problem. Just hope the next gen materials have side effects that can be managed.
Honeywell and Dupont hold patent rights to a chemical that fits well. They are manufacturing it in China as well as US. If somebody else come up with a different chemical that fits requirements and is large-scale manufacturable, I suppose they'd get rich too. Enviro-type regulations are often effectively calls for innovation even if the wording is not "OK kids there will now be a new demand for (goods or services) and if you can provide them best you get the money"
