NASA Is Offerring $1 Million To Turn CO2 Into Sugar (space.com)

NASA is challenging people in the United States to come up with an efficient method to convert carbon dioxide into glucose, a simple sugar. The atmosphere of Mars consists predominantly of CO2 (95%), and glucose is a great fuel for microbe-milking "bioreactors" that could manufacture a variety of items for future settlers of the Red Planet, NASA officials said. Space.com reports: The new competition consists of two phases. During Phase 1, applicants submit a detailed description of their CO2-to-glucose conversion system. Interested parties must register by Jan. 24, 2019 and submit their proposals by Feb. 28, 2019. In April, NASA will announce the selection of up to five finalists from this initial crop, each of whom will receive $50,000. Phase 2 will involve the construction and demonstration of a conversion system. Winning this round is worth $750,000, bringing the competition's total purse to $1 million (assuming five finalists are indeed selected from Phase 1). You don't have to win, or even participate in, Phase 1 to compete in Phase 2. The challenge is open to citizens and permanent residents of the United States; foreign nationals can compete if they're part of a U.S.-based team. To register or learn more, go to the CO2 Conversion Challenge website.

Comments

Plants & CO2 & sunlight

[Alain Williams]

Where do I claim my prize ?

Re:Plants & CO2 & sunlight

[Rei]

The key is "efficient". Sugar crops as a whole generally only yield a fraction of a percent of their received solar energy as sugar. Even just considering the leaves alone, they only net about 5% net sugar yield.

If you want efficiency, you're going to want a direct chemical process. I looked into this at one point and was surprised at how complicated it appears to be to make simple sugars, in terms of the number of requisite steps. Much simpler would probably be a direct conversion to fatty acids; they're carboxylic acids and there's a number of ways to directly synthesize free carboxylic acids from simple raw materials (the main challenge would be specificity)

Where does the Hydrogen come from?

[Grog6]

Glucose has Carbon Hydrogen and Oxygen.

For every 6 CO2 molecules and Water molecules you put in, you get 1x glucose molecule, and 1x O2 molecule.

That's at 100% efficiency.

Water and CO2 are the two lowest energy states for those atoms, so it takes a lot of energy too.

With unlimited solar, anything's possible, but it will be interesting to watch.

Re:Yeah, that's kinda what I mean...

[crunchygranola]

The only way something like this works is if there's a good source of Treatable water.

If you have to run it thru a desalination plant, that likely includes perchlorates, it's going to be even that much harder.

...

Water is found in the regolith ("soil") of Mars everywhere in significant quantities. You will have to strip mine it, but as mining operations go it is easy to get. From The microbial case for Mars and its implication for human expeditions to Mars, Gerda Horneck, Acta Astronautica 63 (2008) 1015 – 1024:

From the global neutron mapping of the Mars Odyssey mission, the present distribution of water in the shallow subsurface was divided in four types of regions: (i) regions with dry soil with a water content of about 2 wt%; (ii) northern permafrost regions with a high content of water ice (up to 53 wt% of water); (iii) southern permafrost regions with high content of water ice (>60 wt% of water) covered by a dry layer of regolith; and (iv) regions with water-rich soil at moderate latitudes (about 10 wt% of water).

So we get to decide how important the water content is when selecting a site to set up operations. At worst the content would be 2%, or 20 liters per tonne, but we may prefer those "moderate latitudes" with 100 liters per tonne. Extraction would involve simply heating the soil in a retort and condensing the escaped water. You will be digging up a lot of soil (especially in the 2% case) and discarding it as the water is extracted.

Preparing regolith for use as a cultivation medium will probably take a few steps, but removing the perchlorates will be the easiest of those steps. Simply use said water to extract them as perchlorates are highly water soluble. Hydroponics is all about circulating water through a growing medium, so extraction of all soluble compounds is inherently part of the operation. I suspect that some sort of granulating/pelletizing process would be used to get an appropriate porosity. Martian regolith is naturally high in phosphorus and potassium, and trace elements, so the only thing lacking is usable nitrogen. A Haber process system to make ammonia is the most likely way of getting that, and the ammonia could be dissolved directly in the water. A bit different from how hydroponics is done on Earth, which used an inert medium with all the nutrients in solution, but not that different.