Underground Coal Gasification is totally different to Coal Seam Gas

14 May 2018

Did you know, Underground Coal Gasification (UCG) and Coal Seam Gas (CSG) production processes are completely different?

Underground coal gasification (UCG)

Underground Coal Gasification (UCG) converts or “gassifies” solid coal underground into a complex mixture of gases. The process involves partial combustion of the coal seam at high temperatures to produce the gases in-situ which are then extracted using wells. The “syngas”, or synthesis gas, produced is usually a mixture of hydrogen, carbon monoxide and carbon dioxide. Syngas can be processed used as a fuel, or for electricity generation; or processed further to produce synthetic natural gas. UCG is considered a coal extraction activity and in Queensland is managed under the Mineral Resources Act 1989.

The UQ Centre for Coal Seam Gas doesn't undertake UCG research. 

For an independent review (2017) of US research and development from the Lawrence Livermore National Laboratory view A Review of Underground Coal Gasification Research and Development in the US.  

Coal Seam Gas (CSG)

Coal Seam Gas (CSG) is natural gas that is trapped in underground coal seams by water and ground pressure. Wells are drilled into the ground until they reach the coal seams to extract the gas, which is primarily methane. The methane is released from the coals when the water levels are reduced in the CSG wells to reduce pressure. In Queensland CSG production is managed under the Petroleum & Gas (Production and Safety) Act 2004.

Learn more about the differences between CSG and UCG from the frequently asked questions section on the GasFields Commission Queensland website.