i just read a couple articles on propane vs butane. It looks like the burners are the same but the regulators are different. They have different boiling points thus pressures...So that's why the different regulator is required.
Just google Propane vs Butane and a bunch of information is available. I was just curious, and had to check it out.
In the USA butane is not as popular, it's used for cigarette lighters, mini torches, soldering irons..etc. Mostly little stuff as far as I know. Our portable grills, furnaces, stoves, etc. use propane or natural gas for fuel.