Comments on: Ammonia as Fuel

By: bill northlich

bill northlich — Thu, 03 Jun 2010 16:57:33 +0000

Larry L. …er – where do you think the electricity for “electric vehicles” comes from?

By: Craig Shields

Craig Shields — Sat, 27 Feb 2010 19:45:33 +0000

Yes, this helps a great deal. That’s a fantastic report you have online, btw. Thanks very much.

In addition to great content, I love the way you British scholars write. You use “candidature” rather than “candidacy.” Fantastic!

By: David Nugent

David Nugent — Sat, 27 Feb 2010 00:28:22 +0000

It is right to highlight the possibility that NH3 combustion engines will produce NOx emissions. The solution to this problem is well known and documented. I am referring of course to Selective Catalytic Reduction according to the forward reactions:

4 NO + 4 NH3 + O2 >> 4N2+6 H2O (1)
6 NO2 + 8 NH3 >> 7 N2 + 12 H2O (2)

SCR is already used to minimise NOx emissions in diesel engines. Where do they get the NH3 from? Either be decarbonating urea or by reforming fuel to produce H2, which is then combined with atmospheric nitrogen in a mini Haber Bosch reactor.

http://en.wikipedia.org/wiki/Selective_catalytic_reduction

This problem is trivial for a NH3 engine since the exhaust need only be bubbled through the fuel tank. No, I don’t mean this literally, but you get the idea.

Hope this helps.

PS: You might want to read this report I wrote back in 2007, and published in 2008. Downloadable here:

http://www.elucidare.co.uk/for-media.php

By: Ammonia–Fuel of the Future? « Biofuels Seminar

Ammonia–Fuel of the Future? « Biofuels Seminar — Sun, 31 Jan 2010 02:53:41 +0000

[...] is the inevitable by-product of NOx, a large contributor to the formation of smog. Despite this, the benefits of ammonia use as a fuel source may still outweigh the negatives. It has already been show to work in a vehicle [...]

By: Larry Lemmert

Larry Lemmert — Sat, 09 Jan 2010 20:42:05 +0000

Oops. Neutralization of NOx would be with a base, not an acid.

By: Larry Lemmert

Larry Lemmert — Sat, 09 Jan 2010 20:34:58 +0000

Ammonia as a fuel does not make a whole lot of sense. First, like hydrogen, it is not a source of energy but a mere transfer of energy medium. That is not really bad in itself since transformation is a necessity for virtually all of the actual root sources of energy.
The problem with ammonia is in its use as a fuel. It burns well with a good energy output but the byproducts of combustion are the various nitrogen oxides (NOx) and water. While NOx can be neutralized to make a nitrate fertilizer, the burden of carrying the neutralizing agent, an acid, in large quantities, and then the storage requirement for the resulting fertilizer solution becomes a literal burden.
Hydrogen serves the same nitche as ammonia with fewer drawbacks. I am not a proponent of a hydrogen economy by any means but ammonia would be further down the list of choices when hydrocarbons are phased out. Electric vehicles with battery storage is at the top of my personal list.
Larry L