Answer: it's 3CO2+4H2O+Energy
Propane is a linear alkane of formula C3H8. It is mainly used as fuel (this is the main component of liquefied petroleum gas) in cooking and chemical industry reactions.
The reaction of its complete combustion by the presence of oxygen is:
C3H8 (gas) + 5O2 ==> 3 CO2 + 4H2O + energy (2220⋅kJ)
As we can see, propane can release carbon dioxide and water as every combustion reaction, and a lot of energy in the form of heat.