[coderenegade]

Methanol is probably better than ammonia as a vector for green hydrogen. It carries less hydrogen per volume, but it's a liquid at room temperature, trivial to transport, and it's generally less dangerous. It's also been used as a fuel for reciprocating engines for more than a century.

[japanuspus]

Methanol and ethanol share the same fundamental problem: they are both carbon-based, and despite global warming atmospheric CO2 is still well below 0.05% of the atmosphere which means it is very resource-consuming to extract it. As long as we still use some fossil fuels, you can capture at power plants, but in the long run it is a dead end.

Ammonia, on the other hand, just requires nitrogen which is 70% of the atmosphere and very easy to extract in industrial quantities.

[coderenegade]

You don't need to extract CO2 from the atmosphere using direct air capture (I agree that it's a dead end); you use existing sources of waste to intercept the carbon cycle. Sewerage, for example, contains carbon that was pulled from the atmosphere by a plant, or bacteria in the soil. Ditto for municipal solid waste, especially wood products and paper. If you need additional sources, you can grow fast-growing plants (seaweed is preferable, since it doesn't rely on good land) to pull carbon out.

When you make methanol, processes like gasification and pyrolysis leave you with excess carbon in the form of carbon black, or ash. If you sequester this before it oxidizes, fuel production becomes carbon negative. Methanol is better than ethanol because a) you can't drink it, b) the single carbon molecule means it burns cleaner, c) you get more fuel for the same initial amount of carbon, and d) it doesn't compete with food production for arable land.