▁ ▁Wood ▁gas ▁ ▁Un com pressed ▁hydro gen ▁or ▁com pressed ▁hydro gen ▁may ▁be ▁used ▁as ▁a ▁fuel ▁gas . ▁ ▁Bi og as ▁ ▁Bl ast ▁furn ace ▁gas ▁ ▁Ac et yl ene ▁ ▁Natural ▁gas ▁and ▁pet role um ▁g ases ▁In ▁the ▁ 2 0 th ▁century , ▁natural ▁gas , ▁composed ▁primarily ▁of ▁m eth ane , ▁became ▁the ▁dominant ▁source ▁of ▁fuel ▁gas , ▁as ▁instead ▁of ▁having ▁to ▁be ▁manufact ured ▁in ▁various ▁processes , ▁it ▁could ▁be ▁extracted ▁from ▁depos its ▁in ▁the ▁earth . ▁Natural ▁gas ▁may ▁be ▁combined ▁with ▁hydro gen ▁to ▁form ▁a ▁mixture ▁known ▁as ▁H C NG . ▁There ▁is ▁also ▁bi og as ▁which ▁can ▁be ▁created ▁artificial ly ▁through ▁an a er ob ic ▁dig estion ▁processes . ▁▁ ▁Add itional ▁fuel ▁g ases ▁can ▁result ▁as ▁a ▁process ▁of ▁ref ining ▁natural ▁gas ▁or ▁pet role um : ▁ ▁Prop ane ▁ ▁But ane ▁ ▁Reg as ified ▁li que f ied ▁pet role um ▁gas ▁ ▁Us es ▁F uel ▁g ases ▁have ▁been ▁used ▁in ▁numerous ▁applications . ▁One ▁of ▁the ▁earliest ▁was ▁gas ▁light ing , ▁which ▁enabled ▁the ▁w ides p read ▁ad option ▁of ▁street lam ps ▁and ▁the ▁ill um ination ▁of ▁buildings ▁in ▁towns ▁with ▁a ▁municipal ▁gas ▁supply . ▁F uel ▁gas ▁is ▁also ▁used ▁in ▁gas ▁burn ers , ▁in ▁particular ▁the ▁Bun sen ▁burn er ▁used ▁in ▁labor atory ▁settings . ▁It ▁may ▁also ▁be