re: Hydrogen, I explain it as hydrogen in this case is just a battery. You either crack water with electricity given to you free by unicorns or you get it from fossil fuel.
IF you could get pure hydrogen out of a well, then it would be a fossil fuel.
Mentioning natural gas, the new Russian gas fields provide a nice service to their customers... The natural gas supplied for burning is pretty close to pure methane. All the non-burnable impurities are removed before the gas goes in the pipeline.
Of course Russia then has a nice supply of these things (like helium) if you wish to buy them...separate from the fuel gas.