Quote:
Originally Posted by Dragoneye
We, and our cars puke it out all day, everyday. That should help to silence the Enviro-nuts...No CO2 is actually going on the atmosphere and sitting there, it's more like recycling it back into the Algae through the atmosphere, which fuels our cars...
I'm reading those two sites now, I'll edit with any goodies I find. This does look very promising. Cellulosic Ethanol is still viable, but this seems to be... more viable. 
EDIT: nothing...there's no mention of yeild, or potential. Energy costs v energy yields; how much it can make, ect...nothing. |
Taking it out of air seems like a large challenge.
Suppose we want to make 1 barrel of oil equivalent product per hour.
Oil is about 90% by weight Carbon, The hydrocarbon product of this biological process should contain close to the same carbon, and the specific gravity will be close.
In a barrel of oil we need about 265 pounds of Carbon.
CO2 is 27% Carbon by weight and currently averages about 300 parts per million worldwide. At sea level air weighs about 0.08 pounds per cubic foot.
How many cubic feet of air does it take to hold 265 pounds of Carbon as CO2?
0.08 #/ft3 * 44/29 (weight correction) * 0.0003 (Concentration) = 0.0000364 lb. CO2/ft3
0.0000364 lb. CO2/ft3 * 0.27 lb C/lb. CO2 = 0.0000098 lb C/ft3
265 lb. C / 0.0000098 lb C/ft3 = 27 million cu. ft. of air.
IF the extraction is 100% complete. (Which I'm sure is far fetched).
In order to be efficient I'm sure the air must be transported to the algae. Natural convection would require an impossibly large area.
General engineering guideline is that it takes 0.15 horsepower to move 1000 CFM of air.
So to move 27 million CFH ( 450,000 CFM) it takes 67 horsepower or 50 killowatts. At $0.098 per kwh it has cost about $4.90 in electricity.
Making that electricity out of the fuel just produced would consume about 2 gallons.
Might be feasible to make 1 barrel of fuel per hour. Scaleup is staggering if you want to make 7 million barrels per hour. It would be equivalent to "washing" 100% of the CO2 out of 100% of the air above North America every two years! And that's if it were 100% efficient!
Has to come from somewhere other than CO2 in the atmosphere.