微細藻類による閉鎖系大気のCO₂除去・O₂再生に関する研究

低濃度CO₂含有大気の再生に関する基礎的検討

抄録

We have investigated microalgae culture systems for CO₂ elimination and O₂ regeneration in the closed system containing low CO₂ concentration (800ppm to 1%). A stainless steel reaction vessel (20l) with fluorescent lamps (20W×11) was constructed. We have already studied the effects of temperature, pH, O₂ concentration in supply gas using the reactor aerated with low CO₂ concentration on the cell growth of Chlorella sorokiniana ATCC22521 and the CO₂ elimination rate in the reaction vessel.
CO₂ elimination and O₂ regeneration were investigated with Chlorella sorokiniana ATCC-22521 under two light energy conditions (using 20W×11 fluorescent lamps and 20W×6 fluorescent lamps).
As the result, both cell growth of Chlorella and CO₂ elimination rate under the high light energy condition were higher than that under the low light energy conditions. But in comparison to the photosynthetic activity based on the chlorophyll content in the Chlorella cell was almost the same under two lighting condition.
We further investigated culture conditions for operating the system continuously with a half-batch culture.
We confirmed that the microalgae culture system maintained the ability of continuous CO₂elimination and O₂ generation when cell number and the concentration of nitrogen source in the medium were kept under the adequate conditions. However bacterial contamination in the vessel inhibited of the CO₂ elimination.