Using the hydrogen, methane or {HEAD ~ methanol} is produced by {TAIL ~ a methane or methanol producing unit} 
is produced by
Using the hydrogen , methane or { HEAD ~ methanol } is produced by { TAIL ~ a methane or methanol producing unit }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL