What is the difference between butane and propane?

A gas barbecue works on butane, propane or a mixture of these two types of gas. The difference is the boiling point; the temperature at which it changes from liquid to gas and vice versa. At a lower temperature, gas becomes liquid and therefore unusable for your barbecue. With butane this boiling point is around 0°C and with propane at about -42°C. Butane is therefore unusable for a winter barbecue or when used high in the mountains. Butane gas, on the other hand, is cheaper than propane and gives off more combustion heat.