> how the different gases work
In the US there's two different fuel gasses.
"City" or "street" gas comes through pipes throughout the town. It was originally a byproduct of making coke for metallurgy. You toast the gasses out of brown coal, get pure carbon coke and a gas which can burn in lamps. Crime fell when cities installed street lights. Gas light inside the home was less smokey than candles or oil lamps. These gasses were NOT "pure", having a large portion of CO (a poor fuel) and lots of CO2 and N. Since the gas was delivered by pipe it was not worth the cost to make it purer. (Actually the trouble was making it clean enough to not rot the pipes.) In the US, huge quantity of natural (petro) gas was nearly free in Oklahoma and Texas. The coal and oil markets and the demands of WWII brought pipelines to urban areas. Natural gas comes in various purities but is cut-down to the part-strength typical of coke-gas. (Despite the name, "natural" gas today is very highly processed to give the customary heat-content *and* remove any partials which are worth more than street-gas.)
When you need to put it in a bottle, you want the PURE stuff to minimize bottle and trucking costs.
Liquefied Petroleum Gas from the well-head is various strengths (stronger is preferred) but needs deep cold to stay liquid. Shipped around the world as raw stock for refining or large fuel users. You never want to see this.
Propane (and Butane) is a distillate (from well oil and gas) that can be a liquid in a reasonable pressure tank but a gas near ambient pressure. If you want fuel gas, and don't have "natural" gas, this is what you get. I have three 4-foot bottles aside my house, Guy comes most winter months and pumps liquid Propane into them, heats my house. (40,000BTUh ~~ 13KW) While oil and wood are common home heat here, banks and pizza-shops and doctors etc etc burn Propane. So do the local tourist buses. Butane is similar but no-good for cold weather- cigarette lighters (normally kept in pockets) use Butane. Also some warming-trays for wedding buffets etc. Warm-weather camping stoves, because But does not need the heavy tank of Prope.
Because of the difference in density/viscosity and heat content, piping Propane into a Nat-Gas burner will usually burn something out. They use different regulator settings and different nozzles. Propane is so hot that the nozzles are often sintered porous pills, because a simple orifice would dirt-clog.
Gas fuels and oil fuels are "tame" compared to wood. While it is possible to simmer a wood fire, it takes great care not to have a flare-up. Wood has to reduce from a large gassy lump to a dense bed of coals. The result is that a wood stove has to survive red-heat, glowing iron, while the tame fuels are throttled for a safe heat. I would NOT consider burning wood in a oil/gas box without the Maker's approval. (And it would be illegal here; woodstove fires are a big deal.)
