The following article was published on the Guardian’s Comment is Free website on 4 September 2007.
Coal and gas-fired power stations could be much cleaner if creative technologies were combined with sound political leadership
John Harris writes of a “new coal rush”, and to a degree he’s right. There is a renewed interest in coal-fired electricity generation in the west, or rather a greater diversity in baseload generation.
And why is this? Two reasons stand out. Western Europe is currently developing an unhealthy reliance on Russian gas, thereby storing up political problems for the future, and the US is keen to kick its addiction to foreign oil.
Elsewhere coal is king, and especially in China and India as these countries industrialise and pull millions out of grinding poverty. Communities will always fall back on whatever natural resources they have to hand. Coal will continue to be used for some time to come, so we had better implement ways of burning the stuff as cleanly and efficiently as possible.
Coal has a reputation as a dirty fuel, but it could be a lot cleaner. There are a number of technologies for reducing the environmental impact of coal-fired power stations, but their poor take up is largely down to political and economic inertia, not engineering limits. Where there’s a will there’s a way.
Personally, I agree with Greenpeace’s criticism of carbon capture and storage (CCS), and liken the technology to a lazy householder brushing dirt underneath the carpet. Out of sight, out of mind. And such a waste. I’m interested in more imaginative solutions such as trapping carbon dioxide and using it to produce useful chemicals.
Here’s one example which shows that scientists and engineers are working on the problem, even if politicians continue to sit on their hands and emit copious amounts of hot air.
I had an article published recently in a B2B journal called Nanomaterials News about controlling the power station combustion process with a porous membrane made from an advanced ceramic material known as LSCF. The research work was carried out by Ian Metcalfe and Alan Thursfield at Newcastle University, together with Kang Li at Imperial College London. There is a technical paper in the Journal of Solid State Electrochemistry (subscription required), and a news report that describes the technology in more detail than I have room for here.
In short, microscopic tubes of LSCF can filter all gases other than oxygen from the air, and burning natural gas or gassified coal in pure oxygen rather than nitrogen-rich air leaves almost pure carbon dioxide as a waste product. That carbon dioxide exhaust could then be used cost-effectively to produce useful chemicals such as methanol.
The LSCF technique is simple and elegant, and, if the researchers can account for a small amount of missing carbon (most probably in the form of solid deposits), the process could prove viable on a large scale. How soon this technology could be implemented depends on research funding, accelerating the development through industrial collaborations, and political initiative.
Asked to comment on the LSCF membranes, Ian Brown of the Institution of Chemical Engineers said:
“This technology is only going to make a real difference to climate change if it’s combined with economic incentives – via the necessary level of carbon pricing – to persuade the energy industry to invest in it. Technology and economics working together will take us forward.”
In no way am I claiming that LSCF membranes or any other clean burning technologies are the Next Big Thing. But the stakes are very high, and it makes sense to tackle environmental problems on many fronts.
A few new coal-fired power stations in Britain will make little difference in the great scheme of things, and the presence of such plants would not bother me if they were used as test beds for new clean burning technologies that are then shared with the developing world. The Chinese are themselves doing a lot of research in this area, both on their own and in collaboration with others. One home-grown example is underground coal gassification.
It is in China and other fast developing countries that this issue matters, not Britain, and China is not going to stop burning coal anytime soon. In that case finding technical solutions to the environmental problems associated with this fossil fuel is imperative.