Antz

Artificial photosynthesis: formic acid.

The process takes in carbon-dioxide, water, and sunlight; it releases oxygen gas and formic acid (HCOOH). The formic is a fuel itself and, if you don’t like it, it stores hydrogen for other fuels. Mainly we use that acid as a preservative in animal-feed: think cereals. There’s a sideline in tanneries. And other uses, in active study.

The new process doesn’t leave byproducts as pollutants. Best I can tell, the main old process is for producing acetic vinegar, from which, formic IS the byproduct (and methanol).

It does require hydrogen, in the form of water, so this is for CO2 / water planets only, not for Venus or our Moon. Not that energy is a problem over Venus. Preserving food is not much of a problem over Venus, given that its growing season is pretty much permanent and that it is, er, not exactly biota-friendly ambience. Although one does expect it will be helpful in brining supplies for the trip home. It’s the other chemical processes we might have our eye on.

EFFICIENCIES 2/9/24: The acid electrolyte.

SEQUEL 1/12/2021: this same lab has acetic from carbon-monoxide.