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Methanol would burn cleanly, not so much ammonia. If you synthesize alcohols from atmospheric CO2, the process is carbon-neutral.

We had a claim earlier that dimethyl ether should be a candidate for an energy carrier.

tens of millions of people stand to see their lives ruined because the bureaucrats at the ECB don't understand introductory economics -- Dean Baker

by Carrie (migeru at eurotrib dot com) on Wed Jan 25th, 2012 at 11:47:01 AM EST
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It's not a matter of burning (hideously inefficient for all but heating applications) but about fuel cells. Apparently it's really hard to build a good ammonia fuel cell.

It is rightly acknowledged that people of faith have no monopoly of virtue - Queen Elizabeth II
by eurogreen on Wed Jan 25th, 2012 at 11:54:07 AM EST
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Presumably an ammonia cell would produce nitrous oxide?

tens of millions of people stand to see their lives ruined because the bureaucrats at the ECB don't understand introductory economics -- Dean Baker
by Carrie (migeru at eurotrib dot com) on Wed Jan 25th, 2012 at 12:26:57 PM EST
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Research seems to be ongoing, but it seems that direct ammonia fuel cells may be high temperature. I came across a description of a "moderate" temperature approach, where that implies ~500C, with ammonia cracked to H2 and N2, used in an alkaline fuel cell, which has good rejection of unprocessed traces of ammonia, with the exhaust gas burned to heat the cracker.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
by BruceMcF (agila61 at netscape dot net) on Fri Jan 27th, 2012 at 07:21:57 PM EST
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Also, note from this source that ammonia can be a reducing agent for 2*NOx->N2+O2 with a proper catalyst, with some base metal catalysts working in the 450C to 800C range. Since an ammonia fuel cell would obviously have an ongoing supply of ammonia for that reducing reaction, it seems like good NOx control ought to be possible for the combustion of the exhaust hydrogen to drive the cracker.

The temperature for the base metal catalyst seems to support the 2*NH3->N2+3*H2 cracking approach I noted above for an alkaline fuel cell that works well in the 500C range ~ the gas over the catalyst would already by in the right temperature range.

A lot of this is that hydrogen fuel cells have been pursued for quite a long while, and the push to develop the technologies for ammonia as an easier to control and manage hydrogen carrier seems to be substantially more recent.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Sun Jan 29th, 2012 at 12:14:51 AM EST
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Ammonia <-> Hydrogen+Nitrogen  storage has been studied in detail and is considered practical but unproven on a large scale.  Avoiding mixing with air has many advantages too (avoid contamination of the air and of the cells) and NH3 and N2 +H2 take up roughly the same volume*pressure allowing the same storage to be used for charged and discharged fuels (you can store H2 and N2 mixed together safely at room temp, they only burn with a catalyst or high temps).
by njh on Wed Jan 25th, 2012 at 12:52:02 PM EST
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DME I do believe in, as an energy vector for heavy vehicles. It can be used in slightly modified diesel engines, and be made out of everything from coal to black liquor.

Peak oil is not an energy crisis. It is a liquid fuel crisis.
by Starvid on Thu Jan 26th, 2012 at 03:18:07 AM EST
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