? About single butane travel burners

It’s hard to say exactly since I’m never using it continuously and for long cooking (boiling pasta) I always turn down the gas output to conserve fuel. If I had to guesstimate, I’d say a 40 minutes to an hour on medium high (not fully open but high enough). Keep in mind that as the can runs low on fuel, it loses pressure. A third-full can may now only provide a medium flame.