Wow, this is very interesting. Imagine carbon neutral fuel!
http://www.sciencealert.com/audi-have-successfully-made-diesel-fuel-from-air-and-water
http://www.sciencealert.com/audi-have-successfully-made-diesel-fuel-from-air-and-water
first step involves harvesting renewable energy ... then use this energy to split water into oxygen and pure hydrogen, ...
...hydrogen is then mixed with carbon monoxide (CO), which is created from carbon dioxide (CO2) that’s been harvested from the atmosphere...
...The two react at high temperatures and under pressure, resulting in the production of the long-chain hydrocarbon compounds...
Simply sequestering or buying carbon credits just hasn't seemed like a real or long term answer. This really looks promising, now if they could use the dirty fracking waters also, so that material doesn't need to be pumped back underground.Good insight. I would like to know more about where the CO2 is coming from. If it is sequestered from industry or coal burning plants to be converted to fuel how much more attractive would that be then trying to trap it in salt mines.
Pure Argon is much more expensive to isolate regardless of it's relative abundance. CO2 is dirt cheap in comparison.Well, I think I see the basic point: Diesel fuel is carbon and hydrogen. We can get the carbon from a theoretically 'bad' gas in the atmosphere and water is 'everywhere'. With just a few more million in research grants, we might find some magic solution to make it feasible.
Though at some point, it becomes more about the laws of physics rather than technology or economics. I already mentioned the first electrolysis step of the process isn't economically advantageous enough to allow hydrogen to be used as fuel... let alone considering the other two equally high-energy steps. If you look at it another way, the Fischer–Tropsch process is basically the last two steps of CO + H > HC + O2...that process is not terribly economically feasible even considering solid carbon / coal as a starting point.
Considering atmospheric CO2 is only 400ppm or 0.04% concentration. For comparison, argon is ~ 0.935% ...over 23 times more plentiful. I think my last argon for TIG shielding gas was ~$80 for 240cf cylinder. Even assuming CO2 costs the same to isolate, back of the envelope scratching shows a cubic foot of CO2 is about 52 grams in total, though that's about 14 grams of usable carbon and 38 grams of 'useless' oxygen. That $80 gets you a little less than 7.5 lbs of carbon... pretty expensive chunk of coal.
Unfortunately, I think articles like are more common than ever, but are more about free publicity for the company, a source of 'feel good news', and a plea for more research funds than they are about any true technological breakthrough, or technology which will help the 'real world' anytime soon. But who knows... we can always dream ...and pay for more research.
Pure Argon is much more expensive to isolate regardless of it's relative abundance. CO2 is dirt cheap in comparison.
Most major producers are looking for uses for excess CO2. Sequestering it underground then pulling it out of the air is stupid.I know argon is expensive and CO2 is cheap in the current market, but we need to be sure to compare apples to apples. The main source of industrial argon is through liquefaction of air and separating out the oxygen, nitrogen, argon, etc. The main source of industrial CO2 is recovery from other chemical processes (ie making ammonia, etc. where it is in concentrated form) but NOT separating it from the air.
The original article was about pulling CO2 directly from the air. Granted, there are some easier pathways to getting CO2 from air than the liquefaction required to get argon. But we're still talking about an exceptionally small percent abundance, and even worse considering this process is really only interested in the carbon.
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IMO, however, as soon as you convert the RE electricity to a chemical fuel, you are now taking the thermodynamic hit burning it in a heat engine. Why would I take solar electricity, turn it to H2 at 80-90% eff, convert that diesel at 80% eff, and then dump it in a diesel engine running at 20% eff??
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Perhaps because you have a high energy density fuel that allows you to power a long range vehicle
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