Okay to summarize I have a planet with an approximate atmosphere of 44% nitrogen gas, 30% hydrogen gas, 23% methane and 3% other trace gases. I am working on an intelligent alien race on this planet that needs fire to advance but oxygen is not present in the atmosphere so traditional aerobic fires wont be possible.
My question is basically what are some anaerobic alternatives that can serve the same function as aerobic fire on this planet? A traditional visual "flame" is not necessary. So long as the chemical reaction produces enough heat for cooking, metallurgy and is "relatively" easy to produce. Be it compounds found in mines, in the air or on the ground. No need to be conservative go crazy with possible anaerobic fires and assume the compounds needed exist on the planet.
Writing down the chemical formula would be greatly appreciated.