The SyFy.com article If we’re going to go to Mars, this is how we’ll have to deal with trash ends with
Mars and deep space will be an even greater challenge because astronauts will be too far from the home planet to receive regular shipments of supplies or send bulging trash bags back in cargo ships. The Heat Melt Compactor (top photo) is being developed to evaporate the water from trash before compacting it, and another emerging technology will turn trash into methane gas to use as rocket fuel.
Now, that is something that hasn’t yet been seen in a science fiction movie.
Yet. (emphasis added)
Both liquid hydrogen (LH2) and liquids of long hydrocarbons such as kerosene (in the US as RP-1) have been widely used in rockets to help get payloads to Earth orbit, the Moon, and beyond, and Goddard's early experiments even used gasoline! However, the use of single-carbon liquid methane has been popularized more recently for engines such as BE-4 and Raptor.
Methane's usefulness as a rocket fuel was no secret, it's just that hydrogen and RP-1 ended up being used first, a little bit like Uranium and Plutonium were explored first for nuclear reactors (on Earth) even though Thorium had known potential. Decisions had to be made. See also answers to Why did it take so long for methane to be used as a rocket propellant?.
I'd like to know, when was methane first described as a rocket fuel in an SF story or plot? For the purposes of this question it should be a "space rocket", not just a rocket-propelled plane, train, or automobile, etc.
I'm also curious to know if the advantage of it being product of decomposition (natural gas, swamp gas, garbage fermentation, etc.) ever mentioned or used as a plot device. The block quote suggests this has never been part of a science fiction movie plot, but that leaves the much larger body of written SF still open.
More about the advantages of methane in several answers to Why is SpaceX considering Methane as fuel for their next engine, the Raptor?