Preferably, hydrogen is introduced into the coal bed in an amount within {HEAD ~ the range} of {TAIL ~ 0.2–1.0 standard cubic feet} of hydrogen for each standard cubic foot of methane recovered from the coal bed formation 
of
Preferably , hydrogen is introduced into the coal bed in an amount within { HEAD ~ the range } of { TAIL ~ 0.2–1.0 standard cubic feet } of hydrogen for each standard cubic foot of methane recovered from the coal bed formation
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH