(579f) CO2 Mass Production from the Air Very Cheaply

Ca(OH)2 solution produced from CaO and water in separate small tanks, gradually intakes in corresponding ponds opened to the air, and capturing its diffused carbon dioxide by the said Ca(OH)2 in form of CaCO3 sediment, gradually extracted from the said ponds and thermally decomposed in CaO recycled and in CO2 as a product of USD 15.0/ton or much cheaper in quantity up to 320 ton annually per each m2 of the ponds’ area.

CO2 concentration is constant of 0.6 gram/m3 at the solution surface under the open air and diffused through the water at D (diffusion coefficient) = 0.185 m2/s

The system productivity is determined by Ca(OH)2 intake in the pond = Q2(g/s),

and by CO2(aq) diffusion through the pond being

Q1(g/s) = 0.185 m2/s * (0.6 g/m3 /H m) * S m2 = (0.11 / H) * S

Here H (m) is depth below which CO2 is completely captured, and S (m2) is its surface area.

Q2 (g/s) fully react with Q1 = (M=44/M=74) * Q2 = (0.11/ H) * S, so

Q2 = 0.11 * 74/44 * V / (H^2) = 0.187 * V / H^2, or

Q2 / V = 0.187 / H^2.

Here V (m3) = S * H

Q2 / V = Ca(OH)2 intake to the pond (g/s) per m3 of V, and can be less or equal to saturated concentration of Ca(OH)2 can be unchanging. Let it be equal 1600 g/m3/s, saturated.

So H^2 = (0.187/1600), so H = 0.01075 m.

The pond depth must be bigger than 2 * H, e.g. to be 1 m or less.

Q1 = 0.11 / H = 10.2 g/s / m2. CO2 is diffused from the air to the pond almost instantly, because diffusivity of CO2 in air is great D = 16.0 mm2/s, and practically instantly captured in thin layer by much more concentrated Ca(OH)2 especially, if pH >=10.0

Now we are ready to evaluate CO2 production:

Q1 = 10.0 g/s CO2/m2 of the pond, or 320 ton/m2/year. It is tremendously bigger, than any other rational alternatives from atmospheric air, and total worldwide 100.0 km2 ponds would be enough to provide the artificial oil production in quantity of all mankind demand.

Further we must extract the said carbon dioxide by thermal decomposition CaCO3 sediment in quantity 1.0 mol. CO2 per 1.0 mol. CaCO3, and energy for it being 180.0 kJ/mol., is a lion share of expenditures, while the others are relatively negligible.

Really,

CaCO3 = CaO + CO2 – 1207 kJ + 635 + 393 = - 180 kJ

1.0 mol. CO2 needs 180 kJ/3600 sec = 0.05 kWh, or 1140.0 kWh/ton CO2

Note: Referring to my archive of some decades of work, being constantly upgraded and updated, I can declare that solar and wind energy can be cheaper USD 0.01//kWh, even several times cheaper (as heat as electricity), even if at engineering level of past ages.

So CO2 cost is 1140 kWh * $ 0.01/kWh = USD 11.4/ton + 20 % for others = USD 13.7/ton.

So 15.0 USD/ton CO2 production was my estimation with good reserve.