Earlier quoted context omitted.
The source you're citing talks about 4.4 kg estimated per m^2 for algae in the open ocean, and notes that the maximum known rate is 9.16, so around 9 * (44/12) = 33 kg per m^2/yr converting C to CO^2, or around 11 square meters. In terms of CO^2 sequestration it doesn't seem implausible to fit a farm of that area in something the size of an apartment.. Of course the energy/water use would be insane, hopefully you cou…
Note that the article refers to both carbon and carbon dioxide fixation. CO2 weighs more than the carbon it contains, by a lot. Carbon has an atomic weight of 12, CO2 a molecular weight of 44 (12 + 2 16), or just shy 4x the mass of the carbon* component of CO2. The 4.4 kg I gave was carbon , the 16.3 kg CO2 . Your 9.16 kg refers to CO2, fixed per square meter per year, which is less than the CO2 fixation value I'd us…
> We will be conservative and say that our algal beds fix 2.5 kg of C per square meter per year and 2.5 kg of C works out to 9.167 kg of CO2.
But then a couple of paragraphs later:
> the maximum CO2 assimilation rate of algal beds which we will say is 9.167 kg of C per square meter per year.
I.e. they first mention a conservative "2.5 kg of C" in the context of the ocean, followed by a "maximum rate". 9 kg of carbon is around 33 kg of CO^2.
Maybe they meant "kg of CO2" in that second paragraph, it's certainly suspicious that it repeats the same 9.167 number, but why would they call that number both "conservative" and "maximum assimilation rate", hrm...