Is there a reaction to get hydrogen from hydrocarbons?

Combustion of hydrocarbons reveals hydrogen, but not sure at what efficiency. Is there a reaction to get hydrogen from hydrocarbons? 




Hydrocarbons are in fact the main source of hydrogen gas. According to [Wikipedia](https://en.wikipedia.org/wiki/Hydrogen#Steam_reforming), 95% of all hydrogen is produced by the [steam reforming reaction](https://en.wikipedia.org/wiki/Steam_reforming):


$$\ce{CH4(g) + H2O(g) -> 3H2(g) + CO(g)}$$


This is a very important industrial process which has been studied in depth. It is done at very high temperatures (~1000 °C) and under pressure (~20 atm), and can be "[up to 75% 
efficient](https://web.archive.org/web/20060204211916/http://www.getenergysmart.org/Files/HydrogenEducation/6HydrogenProductionSteamMethaneReforming.pdf)" (though efficiency here may not be defined as solely reaction yield). 


As an aside, the fact that so much hydrogen is obtained from methane (itself generally sourced from natural gas, a fossil fuel) is one reason why hydrogen fuel cells currently have limited environmental benefit, though there is a huge amount of research into more efficient techniques for obtaining hydrogen from water splitting (especially using light) which could be carbon-neutral.


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