Originally Posted by Geof  No it is not. The high temperature dissociation of water into oxygen and hydrogen is old hat. You must have heard of coal gas? I do not know how extensively it was ever used in North America but it was widely used in the UK. You maybe also know that it was highly poisonous and this was due to the carbon monoxide content.
Coal gas is made by heating coking coal, not all coal is suitable, in an oxygen limited atmosphere. Some burns to provide the heat but there is a lot of coal unburnt and is incandescent. Water in the form of steam is injected into the hot bed of coal and is dissociated into hydrogen and oxygen by the heat. Reactions take place between the oxygen but because there is a great excess of carbon over oxygen the end product is not carbon dioxide but is carbon monoxide. The carbon monoxide and hydrogen being gases can be separated from the coal residue and they are mostly what comprise coal gas although there are some gaseous carbon compounds such methane and ethane.
But it is energetically inefficient, far more inefficient than the eletrolysis of water to get hydrogen and oxygen. Any high temperature dissociation process is energetically inefficient.
Mariss said it; there is no free lunch. |
Hi Geof,
It may be inefficient but if the input energy is free CSP, then it can be done with less electrical (not free) energy. I'm just saying there are ways of doing these things that have to be analyzed on a cost benefit basis. You will admit that these things can technically be done. The question is only one of cost. You have to find a process that can be done cheaply enough to be viable. Some process out there will work. There always is, whether it's biodiesel from algae, or hydrogen from water, there will be a process found that will be cost effective. These processes that I've mentioned can be done, the question is the cost. And at some point as the price of crude continues to climb, one of these processes will prove cost effective.
Donna