Underground Coal Gasification
In-situ Production
Under ground coal gasifi c ation (UCG) is an industrial process which converts coal into syngas, and this process takes place in-situ, i.e. in un-mined coal seams. The basic UCG process consists of drilling one production well into the un-mined coal-seam for the injection of oxygen, while another production well is drilled alongside in order to bring the product gas to the surface. The product gas is synthetic gas (or syngas) which can be used as a fuel for chemicals or for power generation. UCG is suitable for deep coal seams, often too deep to be mined. Also, and most importantly, compared to traditional coal mining and gasification, un der ground coal gas ifica tion does much less damage to the environment.
Modern Technology
Under ground coal gasifi c ation was pioneered by the Soviet Union during the Cold War. Today UCG is a competitive technology which produces ultra-clean diesel or gasoline, jet fuel, electricity and many different chemicals. Moreover, in contrast to water-intensive coal mining and pulverized coal-fired energy production, UCG does not require an external water source, and this is a major benefit to the environment.
First Under ground coal gasifi c ation Project in Russia
In Russia, for the first time in decades an Under ground coal gasifi c ation project has been launched in the Kemerovo region in Siberia, by CBM Partners, a subsidiary of Red Mountain Energy. Initially the syngas from UCG will be used to generate power for a local town. Currently, CBM Partners has a team of experienced exploration geologists working on a UCG feasibility study.
Criteria for UCG
Under ground coal gasifi c ation is only viable in coal seams which meet the following criteria:
- Coal seams must lie underground at a depth of between 30 and 800 meters (100 and 2,600 ft).
- Seam thickness must be more than 5 meters (16 ft).
- Ash content of coal must be less than 45%.
- Coal seams must have minimal discontinuities.
- There must be no aquifers near the site (to avoid polluting drinking water).
Gasification of Heavy Petroleum Residues
Gasification is one of the most environmentally friendly and flexible ways of processing different cheap petroleum residues, such as black oil from primary petroleum refining, tar, asphalt from de-asphalting, wastes from oil production, cracking residues, heavy gas-oil cuts from direct refining and secondary origin, all of which produce valuable products such as electrical power, hydrogen, nitrogen fertilizers, synthetic fuels, etc.
Gasification of heavy petroleum residues is energy efficient and means that refineries can:
- Increase petroleum processing depth to between 97% and 99%
- Produce hydrogen without using natural gas
- Generate less waste, be more efficient and increase output
- Convert petroleum wastes into a useful source of energy
