Chinese Researchers Advance Underground Coal Gasification 16
July 2007 |Structure of the experimental gasifer. Click to
enlarge.| Researchers in China are reporting the development and
successful field-testing of an improved method for an
underground coal gasification (UCG) process that could lead to
more economical operation. The researchers describe their work
in a paper in the 18 July issue of the journal Energy & Fuels.
The new process, designed for thin, high-angle coal seams,
consists of blind-hole electric ignition of an underground
gasifier, a forward and backward firepower seepage method, and
gasification of a small shaftlike gasifier. In general,
underground coal gasification (UCG) involves injecting steam and
air or oxygen (O2) into a coal seam from a surface well. The
injected gases react with coal to form a syngas that is brought
to the surface in a production well to be cleaned and used as a
fuel or chemical feedstock. As the coal burns, the roof of the
seam collapses, resulting in lateral growt