Butane Fuel for lighters
Most people, including myself, haven’t ever had a second thought about butane. The only time in life I’ve really thought about butane was when my lighter wasn’t working. If I could see that my lighter had fuel in it, I would assume I just had a bad torch lighter. 
This isn’t always the case but we’ll get to that in a minute.
In today’s world, the butane that is used for lighters is more than just the fuel itself. It is a combination of butane, isobutene, mixed with propane, and some air. Cans of this fuel are pressurized so that when you fill up a lighter the fuel