There's a slight variation of what the GP is proposing, called methane pyrolysis [1]. In that, you separate the hydrogen and the carbon from methane, and then y

There's a slight variation of what the GP is proposing, called methane pyrolysis [1]. In that, you separate the hydrogen and the carbon from methane, and then you can burn the hydrogen to get energy, and store the carbon in a landfill. Burning hydrogen creates more energy than it takes to split the methane, so overall the process is exothermic. Right now that process is not economical yet (you need some catalysts, and the carbon doesn't just come out, it sticks to something, you need to wash it with some acids, then retrieve the acids, etc). But active research is ongoing, so there's a chance this will become viable in the next few years. [1] https://en.wikipedia.org/wiki/Pyrolysis#Methane_pyrolysis_for_hydrogen https://en.wikipedia.org/wiki/Pyrolysis#Methane_pyrolysis_fo...