Raw syngas produced from a coal gasification unit is shifted in a sour shift unit to increase the hydrogen content and purified in an acid gas removal (AGR) unit to remove sulphur and excess carbon dioxide. It is then fed to a methanation unit based on the use of CRG technology.

Alternatively the raw syngas can pass directly to the AGR unit and then to the methanation unit followed by post methanation carbon dioxide removal.  Whichever scheme is selected the basic methanation process is the same and suitable catalysts from the CRG product family are used in either case.