B Sampson, Deep pockets, Professional Engineering, May 2014, p 65

In UK, Five-Quarter plans to drill vertically onshore and then horizontally into the 2 bn tonne of coal in seams under the sea bed, within a 400 square km area from the mouth of the River Tyne to the Scottish border.   Drilling is due to start by the end of 2014.   The use of their underground gasification process will convert 3 mn tonne of coal per year to syngas which will be collected, cleansed of carbon dioxide and then sold to nearby power stations and chemical plants.   The gasification process consists essentially of injection of oxygen and steam to produce a syngas of hydrogen, carbon monoxide, carbon dioxide and methane.   In the future, offshore drilling is envisaged, together with the re-injection of the captured carbon dioxide.