So.....is the semiconductor powder the actual fuel?
Sounds more like a catalyst................
“So.....is the semiconductor powder the actual fuel?”
No the semiconductor turns photons inot electrons that are then used to pull one of the oxygen atoms away from CO2 turning it into CO and O. You need two electrons per O atom split off. Then some of the electrons also split H2O into H2 and aanother O. The overall reaction is CO+HaI= CO + H2 + O2 in this case the negative Gibbs energy is supplied by solar UV photons hitting a semiconductor photo electric powder which then uses those electrons to drive the Gibbs reaction.
It’s an elegant use of solar photons. Plants are at best as in the number one photosynthetic land plant CAM not C3 or C4 and it’s Agave Webber at just over 1% solar photons to TOTAL plant biomass. Corn is a C4 plant and manages 8/10s of a percent to TOTAL plant mass and since corn kernels are only a small fraction of the whole plant biomass which includes it’s riot system far FAR less than one half of one percent of solar energy ends up in the corn kernels.
Photoelectric semiconductors are 25 to 40% solar photons to electrons you can immediately see why you would want to go the semiconductor route. There is another group that has electrochemical cell that is 90% Faraday efficient at turning electrons into a slew of C2 products (ethene,ethane,ethanol,acetone) that means 90% of the electrons energy ended up in the final products.
No photosynthetic plant ever anywhere is going to approach these levels of output or efficiency.So no you can’t just grow plants. The sticking point has been how do you feed the electrocell high purity CO2 when it is only 400ppm in air.to get 25 to 40x yields you need concentrated CO2 not 400ppm. This group split up the capture phase and the production phase using the waste heat of the other 60% of solar energy the semiconductor would miss as the heat source to drive the CO2 off the absorbent it’s elegant in its synergy.
Once you get to syngas CO+H2 you can get yo every other hydrocarbon via FT synthesis using CH2 blocks all the way to polymers and lubricants. If you have a nitrogen source you can also make amino acids, proteins too. Ask Lanzatech to use their bacteria which eat CO or H2 or both to make you over 150 chemicals in their portfolio. Complete protein, starches and lipids are in the 150 that’s known as food to Joe six pack. Every alcohol, every alkane from C1 to C20 that’s natural gas, jet fuel and diesel. Lanzatech has huge refineries in China making ethanol from steel mill off gas that is near pure CO by the million tonnes per year they are a fully commercial and industrial.scale players.
Once you have syngas the while petrochemical world is open. Methanol is the obvious choice it needs a 1:1 CO+H2 ratio which is an even balance for the semiconductor output. Methanol can be made into gasoline in a single step via Exxon MTG zeolite with 80/20 split petrol and LPG both valuable and liquids. There is a slew of bacteria that eat methanol and yield pure protein China has a coal to methanol to protein factory for animal.feed that is 1000 times the yield per hectare vs soybeans pigs don’t care if their feed was grown in a fermenter tank or field.