I know this much, algae’s not the answer. Requires a ton of water, heat, and light.
Ironically, algae could be a wonderful substitute for carbon scrubbers for coal plants, which cost a ton ($400MM), and wear out.
Algae sequesters CO2, NO2 pretty well, and the BYPRODUCT is ethanol if you care to extract it.
Wanna hear the funny part? The carbon nazis don’t want to convert it to ethanol. The carbon is sequestered in the algae very nicely. What the carbon nazis want is to bury it in the ground. Guess what - nobody will underwrite the liability of it. Nobody is willing to dig the hole, put the slop in the ground, and then wait around to find out if it does any lasting groundwater damage.
I’m telling you, the whole business is a con.
Open ocean farming of saltwater algae is the obvious long term answer. Saltwater algae is where all the energy in petroleum originally came from, as well as most of the oxygen in the air. There are many problems to solve in ocean farming but like farming on land they are eventually solvable. Greenhouse farming on land for fuel though will always be too capital intensive.
Bury it? It could make great animal feed. There are a lot of projects that on paper and in the research lab look good. Making a viable industrial process is difficult mostly because of stingy conservative capital.
The equation has to look good, when compared to oil or LNG produced with little regulation. High bar to cross.