Unmineable coal bed storage
CO2 can be injected into deep coal bed store cover methane
which is trapped in the porous structure of coal seams.This
process,called CO2 enhanced coal bed methane(CO2-ECBM),
allows CO2 to be stored in the void fraction made available by
removal of the trapped methane in the coal seams.Extraction of
coal bed methane(CBM)has been adopted in coal seams for many
years and there are several commercial CBM extraction sites in the
world,mostly in the USA(Table6). White et al. [127] conducted a
very comprehensive review on the CO2 sequestration in deep
unmineable coal beds with recovery of methane gas.Several key
issues, such as estimation of potential storage capacity,storage
integrity,physical and chemical processes,environmental health
and safety,etc.,were highlighted in their study.