propane conversion, is it possable?

me and my brother were talking about propane conversions on cars, and I started wondering if it was possible to convert a mower engine to propane, I think there would be some benefits to propane vs gas, like no ethanol to gum up the system, cleaner burning, no fuel spillage if you roll it so no chance of gas hitting hot exhaust pipe and igniting, and no need to carry a heavy fuel can of gas on a long ride, the mileage might be an issue however depending on the size propane tank used, but the real question is what would be required to do the conversion, if it's possible, and would it really be worth doing such a conversion?

I have seen Briggs has a Dual gas/propane conversion kit for like generators.

Propane Conversion Kits

To get a small engine to run on propane, just run a pipe from a propane tank to a hole in the air filter. You may have to adjust the amount of propane you give it but it will run once you find the sweet spot. To rev it up you will have to increase the propane (controls the fuel) and the throttle butterfly on the carb (which controls the air). I have ran engines on a butane/propane mix by putting the end of a blow lamp (unlit obviously) up to the air intake with the air filter off.

I like this idea.  I do see some commercial zero turns running propane.

There are commercial engines that run off propane (5 to 6.5 hp.). There are setups you can probably buy and just bolt on. I seen floor buffers that run on them. They use them inside the store.