The Basic Research Of CO₂Absorption By Microalgae

The Gas-Liquid equilibrium and dynamics data of CO2dissolved in pure water and Micro algae medium was determined in a double drive stirring gas-liquid absorption apparatus designed by ourselves. The experimental temperature was293.15K,298.15K,303.15K,308.15K,313.15K, and CO2concentration of the inlet gas was2%,5%,10%,20%,100%. The results show that under the conditions of the same inlet gas CO2concentration and same temperature, with increasing of the absorption time, CO2concentration in the liquid phase increases, and the pH value decreases; under the conditions of the same absorption time and same inlet gas CO2concentration, with elevated the absorption temperature, CO2concentration in the liquid phase decreases, and the pH value increases; under the conditions of the same absorption temperature and the same absorption time, with increasing of inlet gas CO2concentration, the concentration of CO2in the liquid phase increasses, and the pH value decreases.By appling the two-film theory in the correlions of the experimental data of the absorption dynamics, the mass transfer coefficient of CO2in the pure water phase was calculated. By using the SRK (Soave-Redlich-Kwong) equation of state to describe the non-idealities of gas phase and eNRTL (electric Non-Random-Two-Liquids) equation to describe the non-idealities of liquid phase, the absorption equilibrium data was correlated. And the results show that the relative deviation between the calculated and experimental values of the total pressure of the system was less than3.25%, which shows that the model developed can describe the gas-liquid equilibrium of this system very well.An absorption tower was established for CO2absorption coupling with culture of micro algae. The results show that under the conditions of the different illumination, algae species, culture temperature, the process can meet the need of growth of micro algae by changing absorption tower circulation volume, adjusting the volume of CO2, and controlling the pH of the culture solution at a stable value.