How to Synthesize Water on the Moon?

[sanman]

Even if water ice is not found on the Moon, the fact is that hydrogen and oxygen can be found on the Moon in other forms. How then could could these other materials containing hydrogen and oxygen be processed in bulk, in order to obtain water from them? What would be the most practical way?

I'm thinking that the simplest approach would be thermal cracking, putting raw materials into a nuclear reactor to break them down and allow the hydrogen and oxygen to recombine into the water.

What other methods would be good choices to achieve high throughput?

It's funny - I don't think I've ever heard of much research going into synthesis of water, since it's such a naturally abundant substance on Earth.

 

[Bob S]

The best source of water on the Moon is recycled water from condensation from the air conditioning system and waste processing systems in the Moon space station. The biggest requirement for water on the moon will probably be for the food agriculture (hydroponic) systems (Agriculture on Earth consumes about 75% of all water usage). The best source of oxygen on the Moon may be from the reaction
6CO2 + 6H2O ==> C6H12O6 +6O2 (also called photosynthesis).
Food is another byproduct.

 

[sanman]

But what if we wanted to have much more water, as a store/buffer. Are you saying we should only bring it all from Earth? There's no practical means or justification to use the abundant supply of materails on the Moon to transform them into critical materials like water?

I would think that water is your key limiting reagent on the Moon. If you have enough water, you could quickly breed enough biology to have all the bio-processors you need for everything else.

Also, you might want a lot of water to use as propellant, which would again make sense to make it on the Moon.

While we all know about biologically catalyzed reactions to make various substances, is there any biologically-catalyzed pathway to make water? I realize that we all take water for granted as an abundant starting material here on Earth. But what if you had to make water from something else? Is there a biological way to do it?

 

[sanman]

http://adsabs.harvard.edu/abs/1988lhfp.rept..115G

Hydrogen abundances were determined for grain size separates of five lunar soils and one soil breccia. The hydrogen abundance studies have provided important baseline information for engineering models undergoing study at the present time. From the studies is appears that there is sufficient hydrogen present in selected lunar materials which could be recovered to support future space activities. It is well known that hydrogen can be extracted from lunar soils by heating between 400 and 800 C. Recovery of hydrogen for regolith materials would involve heating with solar mirrors and collecting the released hydrogen. Current baseline models for the lunar base are requiring the production of 1000 metric tons of oxygen per year. From this requirement it follows that around 117 metric tons per year of hydrogen would be required for the production of water. The ability to obtain hydrogen from the lunar regolith would assist in lowering the operating costs of any lunar base.

So I guess now we now how it could be done.