School project...Methanol/Natural Gas, yes! you can use it.
 

Kid in my Government class did a project on how to clean up the air, his solution was to use Natural Gas in all vehicles (Methanol). He said if your car has 9.5:1 compression then your car can run on Methanol. Is this true? I was thinking...this could help us stangers get through emissions just a little bit easier. Not all of us have to pass, but some of us do and this could be a good solution. But i'm no mechanic so i'm asking, is this dude on the right track or not?

I think your freind is trying to use Methane for a fuel. Methanol is a polar solvent (alcohol),
That said. I guess natural gas could be used as a fuel in a car and has been in some developemental vehicles. Somebody around here a few years ago had a whole fleet of vehicles running on methane so yeah, it can be done. A lot of the irrigation engines you see along the roadways run on methane. It's cheap and if there's a pipeline nearby, plentiful. The problems with using methane for fuel in cars is the boiling point of the gas. To use it in a car, you have to liquify the gas in order to get enough in the tank to go past the end of the driveway. Methane has to be either cooled to -160 degrees (f) or compressed enough to raise the boiling point higher than ambient temperature. That done, you've changed it to a liquid. You can do it but, the pressures you have to maintain in the fuel tank are a bit high to be flying down the highway at 70 mph. This is the biggest reason you don't see tanker trucks carrying methane. It is safer and more economical to ship it through a high pressure pipeline. Add to the storage problems the fact that it doesn't make an engine run too well. Works great for irrigation engines but there's little power to be found in LPG's in general. Lots of folks around here use propane in their trucks and all I have talked to say there is a marked difference in power when they switch from gasoline to propane. Gallon for gallon, LPG's (although methane isn't classified as a liquified petroleum gas) are about half the cost of gasoline. Down side is, it uses about twice as much LPG to do the same work. It's cleaner burning but still.

why do certain vehicles use propane? ...i know a number of police cars do...its cheaper, but i dont think i should be putting propane into my gastank...

You can't put propane into your gas tank even if you wanted to ,as stated above it must be compresed into a liquid state thus , your gas tank would never hold the pressure.
What you are seeing is a engine that runs on a alternating/dual (two seperate) fuel system.

you can do a propane injection system on a diesal. Sopposedly it adds a good deal of power hehe.

One reason for using propane as a fuel is for the emissions. The stuff burns super clean and to get back to the original question, yes, it would be a good way to pass an emissions test. As far as why people use it, you can go a little further on propane per dollar. The problem with outfitting a whole fleet is the rediculous expense of installing the equipment to do it. You can liken it to NOS. You have a pressurized tank, the extra fuel line and the switches and valves to switch back and forth between the two fuels. Same hardware. . .but no power gain. Another plus is the ability to gat an equal amount of work out of a fuel tank that is a lot smaller compared to a gasoline tank. 1 cu.ft. of liquid propane expands to 270 cu, ft of gas. It's hard for me, with my limited brain, to draw the correlation between gallons of gasoline vs. pounds of propane but when all pans out they're about the same costwise. Plus. . as I said earlier, the performance loss doesn't seem worth the trouble.

Around here I think that most of the irrigation pumps (we call'em power units) run off either gas or diesel. I think very few run on propane. It kinda depends on what kind of engine the person has. If it's a gas burner then it's going to be a 240 or 300-6 Ford or a 250 inline 6 Chevy. For a diesel, I think most of the people run International or Catapillar motors.

Daniel.