New source of energy or recipe for disaster?

[Wyvern]

Around where I live we have for long been used to the problems from mining. Contaminated land and rivers. Subsidence of houses roads and railways. So you'd think we'd be fairly blasé about the subject.

No doubt you've heard of fracking, (which from last weeks's BBC Horizon is coming to the Peak District National Park) with all sorts of potential problems such as earthquakes at Blackpool and methane in well-water.

Well this looks ten times worse:

Coming to Britain: Underground Coal Gasification

If intentionally starting fires deep underground sounds dangerous, that’s because it is. -. . . . . . . .While it’s true that UCG has been tested in the past – in the US, China and by the Soviet Union – on a scale significantly smaller than is proposed in the Britain, these attempts have been plagued by disaster. Recent experiments in Australia resulted in two out of three plants being shut down in 2010. One, in Queensland, exploded after just five days. Carcinogens benzene and toluene were then found in ground water and the fat of grazing animals. Previous tests in the US and Europe have also been plagued by explosions and groundwater contamination.

 

[Yew]

But we can already extract gas from old coal mines, Alkane do it in loads of places. Its just a shame many mines where filled with concrete when they where closed.

 

[Wyvern]

But we can already extract gas from old coal mines, Alkane do it in loads of places. Its just a shame many mines where filled with concrete when they where closed.

Yes but we dont set them on fire. I know there have been underground fires in the past without too much damage but not on the scale this article seems to be talking about.

 

[Royston Vasey]

Gasification is not a fire or burning in the sense you're thinking or that hysterical blog is trying to portray. There is no flame. It is the controlled partial oxidation of coal in the presence of steam, under pressure, to produce a mixture of CO and hydrogen, called synthesis gas, a very useful starting material.

This can then undergo 1) controlled combustion in above-ground turbines for power or 2) catalytic transformation to hydrocarbons like jet fuel/diesel, or ammonia or other useful chemical intermediates or 3) separated and used as industrial gases, in chemical processes etc.

Fairly well established technology in China, Australia and the US already. It makes it viable to extract coal without having to mine and transport it as a solid, particularly where the volume would typically be uneconomic to extract. I know from working with partners in the UCG sector that in fact the industry is far from "plagued with disaster".

 

[Wyvern]

OK Thanks for that.

 

[Royston Vasey]

OK Thanks for that.

No problem. Unlikely to be intrinsically any more dangerous or environmentally disruptive than conventional coal mining, actually much cleaner, and a use of a resource which would typically not be useable. And also, benzene and toluene are not usually produced in the gasification process, which is essentially a breaking down of long hydrocarbons into carbon atoms.

The story the blog erroneously cites UCG as the direct cause, whereas actually it was merely a spill of process water which should have been treated on the surface before being released. The benzene and toluene were used in BTEX, a chemical used for fracturing the coal seams, but two things could have prevented this, 1) using different fracturing compounds or a different extraction approach - such as conventional drilling and 2) proper treatment/containment of the water.

BTEX has since been banned; there are safer alternatives.

This is merely a development process that all heavy industry goes through to optimize and continuously improve safety and minimize environmental damage. You'd be surprised how accountable companies have to be when it comes to environmental performance.

Background on the Queensland issue:

http://www.ehp.qld.gov.au/management/ucg/