exchanger 50 prior to entering catalyst 44 a catalyzed hot gas from catalyst 44 a is piped through pipe heating zone 46 a and then through gas heat exchanger 50 prior to exhausting to atmosphere the catalyzed hot gas leaving pipe cools as it passes through pipe heating zone 46 a but is still warm relative to the blend of fuel and air prior to entering catalyst 44 a consequently gas heat exchanger 50 can transfer heat from the catalyzed hot gas to noncatalyzed fuel and air prior to the catalyzed hot gas being exhausted to the atmosphere in certain applications heating the blend of fuel and air prior to catalyzing can increase efficiency of that catalytic process as with the first embodiment pipes 30 b 30 d can also be heated as described in the second embodiment fig4 is a schematic diagram of a third embodiment of a portion of heating system 12 the third embodiment of heating system 12 is similar to the first embodiment of heating system 12 except that fuel tank 38 and compressed gas tank 40 are replaced with tridyne tank 52 tridyne is a gas that includes various mixtures of inert gas and relatively small fractions of fuel and oxidizer tridyne is non reactive under ordinary conditions but becomes reactive upon exposure to a catalyst the fuel used for tridyne can be hydrogen methane ethane or.