For what reason is methanol added to propane fuel in hot air balloons?

Methanol is added to propane fuel in hot air balloons primarily as an anti-icing additive. When propane gas is used in a balloon system, particularly in colder conditions, it can lead to the formation of ice on the fuel lines or injectors due to the low temperatures associated with the propane vaporization process. If ice forms, it can obstruct the flow of fuel, impairing the performance of the burner and compromising the safe operation of the balloon.

By incorporating methanol into the propane fuel mixture, it lowers the freezing point of the fuel and helps to prevent ice from forming, ensuring that the fuel can flow freely and consistently. This practice enhances safety and performance, especially in colder weather conditions, making it a crucial consideration for balloon operators.