COAL CHARACTERISATION

Technology

The world demand for energy is increasing, oil is getting harder to find, bio fuels and wind require to much land, and no-one wants nuclear in their back garden. Coal is abundant and can sustain the UK for the foreseeable future, but the days of the traditional deep mines are past and open cast can be environmentally damaging and is unsuitable for the bulk of the reserves. The answer is underground coal gasification.
UCG, converts the coal into a synthetic gas in situ, this sysngas can then be processed into fuels such as diesel, used as chemical feedstock or for power generation. The three sites that BCG has identified are believed to allow for commercial development of the coal resource will refine the technology and techniques required to further develop the onshore and offshore coal reserves.




SUITABLE TYPES OF COAL >>


	There are four main types of coal; Lignite (soft), sub bituminous (medium soft), Bituminous (medium-hard) and Anthracite (hard). Each have there advantages and disadvantages for use with UCG.	All types of coal can be gasified, but for underground coal gasification we are looking for coals that will not swell when heated as this can reduce gas flow. The moisture in the lower order coals; Lignite and Sub bituminous, can provide certain advantages when gasifying.

LOCATION / DEPTH / INCLINATION >>

	UCG can be performed, onshore, offshore or in estuarine locations, which are unaccessible to conventional mining techniques. Target depths are from 200m to 1500m with some advantage being gained by targeting the deeper coals.

FAULTING >>

	With conventional mining it's often the faulting of the coal that causes major problems to mining. With UCG the direction drilling employed can steer around minor faults.