ONSHORE coal-bed methane has been picking up pace in the UK, with the likes of Australia’s Dart Energy and home-grown IGas Energy combing the land for potential reserves.
However, a firm in Newcastle-upon-Tyne has been exploring the opportunities for exploiting subsea coal beds using coal gasification.
University spin-out Five Quarter is hoping to tap what it claims are substantial coal reserves underneath the North Sea.
The company, formed by professors at Newcastle University, says there is huge potential for underground coal gasification and carbon capture and storage off the coast of the north-east of England and elsewhere.
It claims the potential gas deposits derived from the coal could be equivalent to 75% of the total natural gas extracted from the entire North Sea to date.
The company has secured licences giving it access to 400 sq km containing 2billion tonnes of coal deposits under the North Sea off the coast of Northumberland.
It has also appointed London-based investment bank Numis Securities to help raise an initial £30million to get a commercial project off the ground, which could then find further research.
Dermot Roddy, Science City professor of energy at Newcastle University and a director of Five Quarter, said: “There are at least 50billion tonnes of coal in UK territories,
“We know it is expensive, but we can do it. At the moment there is a general view that peak oil will come, if it hasn’t already, and the same with gas.
“But coal will last a lot longer, and with these technologies we could be looking at a lot longer. We are interested in pushing the boundaries but need a real project to fund the work.”
Prof. Roddy, who has a background in industrial chemistry, said the idea is to go after coal deposits that are not mineable. The coal would be partially burned underground, sacrificing about 10% of the deposit before oxygen is withdrawn and then effectively steamed to create syngas – a combination of hydrogen and carbon monoxide.
The controlled ignition is created down one well and the gas then extracted through another well to be used for potentially direct uses such as cooking, or purified and used for power generation. Directional drilling would mean large areas could be covered.
CO created during the process could then be pumped back into the underground areas from which the gas was extracted.
It is hoped the cash to be raised by Numis will fund an initial commercial pilot, which would then help take the principle further, said Mr Roddy.
A long-term aim is to use any excess gas for uses other than energy, such as synthesising the gas with ammonia to get fertiliser, while it is not being used for power to manage the swings in renewables availability.
He said players in the oil and gas industry could contribute to the technology, especially offshore, but the project would require bringing together the energy and chemistry disciplines.
The idea of underground coal gasification dates back to the 1800s.
Sir William Ramsey began experiments in the Durham coalfields, but his work was interrupted by World War I.
His work was taken up by the researchers behind Five Quarter who have spent several years studying the development of unconventional gas deposits.