your on the right track, oil has a very big byproduct and the process of converting H20 or water into a water fuel-cell process has shown us the exhaust featured back into the dynamics of this process can make us a wonderful engine, and oil has a big exhaust footprint. The issue is how do we facilitate this process so that we can output a substance that wont harm the environment, this usually is done with a lot of heat or energy or a catalyst or both or all of the above, (but i don't see anyone freezing this shit, dont keep N- Nitrogen alone 🙂 ) lets see what is to come this is an exciting field of study...