Clean Coal investigates UCG sites

1 min read

The UK Coal Authority has awarded licences to Clean Coal to investigate the potential for underground coal gasification at five offshore sites in Britain.

The licences have been granted at Canonbie, Dumfriesshire; Cromer, Norfolk; Humberside; Sunderland; and Swansea Bay. The combined coal reserves for the five sites are estimated at around one billion tonnes.

Underground coal gasification (UCG) is a method of converting deep-seam coals into syngas, a synthetic gas made up of hydrogen, methane, carbon monoxide and carbon dioxide.

Once extracted, it can either be piped or liquefied, allowing it to be used as feedstock for power generation, blast furnaces, gas-to-liquid processes or as a raw material in fertiliser production.

The UCG technology also allows CO2 sequestration, the ability to separate, capture and potentially store the CO2 produced in the gasification process.

The basic UCG process has two wells drilled into the coal, one for injection of the oxidants, another to bring the product gas to surface.

The studies will include seismic and borehole surveys and investigation areas range from 40 to 100km2. The depths of the coal range from 500 to 1200m below ground.  

If the investigations over the next year and a half prove to be successful, commercial operations could start between 2014 and 2015. According to Clean Coal, underground coal gasification could produce between three and five per cent of the UK’s total energy requirement by that date.

This would be the first time that gasification of underground coal has featured in the UK energy market.

Rohan Courtney, chairman of Clean Coal, said: ‘Recent developments in directional drilling technology and the growing need for new, secure and environmentally benign sources of energy means that underground coal gasification now merits serious investigation.

‘This is an exciting and commercially viable development that can bring significant benefit to the UK economy.’

Clean Coal expect to commence the site surveys in the first half of next year, and will host public exhibitions in each area to give local people the chance to know more about the work that will be undertaken.

This system, tested in European, American and Australian coal seams, creates dedicated inseam boreholes, using drilling and completion technology adapted from oil and gas production. It has a moveable injection point known as CRIP (controlled retraction i
This system, tested in European, American and Australian coal seams, creates dedicated inseam boreholes, using drilling and completion technology adapted from oil and gas production. It has a moveable injection point known as CRIP (controlled retraction injection point) and generally uses oxygen or enriched air for gasification.