Re:New ammonia production process: generates electricity ins...
by rasmusei on Monday February 06, 2017 @01:28PM
(#13582400)
Yes, it can be a net energy producer given a source of hydrogen, but hydrogen is typically not available for free. See my other comment.
Re:New ammonia production process: generates electricity ins...
by kmm on Monday February 06, 2017 @02:10PM
(#13582814)
Nobody is saying hydrogen is free. Nor will the production of ammonia from compounds we have in abundance (i.e. water, air and rock) ever produce energy, as it's a high energy compound, releasing quite a bit of energy when combusted. But that is absolutely not what this is about.
However, I was refuting the GP's wrong assertion that the energy cost equation of this reaction shows that it cannot be a net energy producer.
It makes sense to optimize this step, because the energy equation shows the energy is just wasted as heat, as it's not contained in the compound itself.
The reason the Haber process is so costly is because it uses very high pressures and temperatures to overcome the activation energy, even with the best catalysts we have. Not because creating ammonia from nitrogen and hydrogen needs energy. It's in effect wasted energy.
Enzymes can't change the cost equation, but luckily it's in our favor. If they can reduce the activation energy without wasting a ton of energy, it can be a net energy producer.
0: https://en.wikipedia.org/wiki/Ammonia 1: https://en.wikipedia.org/wiki/Haber_process