[Ghengis]

Acetone is used in acetylene tanks to facilitate the burning of the acetylene gas. What you commonly see in the gas cutting torch, brazing welding outfits in conjunction with an oxygen tank.

I have driven LP (Propane) and Natural Gas vehicles. You lose a tad bit of performance, but the engines run longer between tune-ups and oil changes and last much longer. Plus, you get a little better fuel mileage as I recall.

[coloradan]

No, acetone is used to reduce the pressure of the acetylene for a given tank capacity. High pressure acetylene is dangerously explosive, but you don't need a high pressure to get a decent amount of it in tank if you first fill the tank with wood chips soaked in acetone. Those tanks are only ~300 psi, as opposed to 2500 or 3000 psi for cylinders of oxygen, argon, nitrogen. (Propane liquefies under fairly low pressure, but it isn't explosive anyway. Acetylene doesn't.)

[meatloaf]

Acetylene is actually dissolved in the acetone in the bottle for safety purposes. Otherwise in a liquid state, it's much more explosive.

http://www.answers.com/topic/acetylene