The use of algae for carbon dioxide fixation is based on their natural ability to photosynthesize. Dynamic experiments make it possible to calculate the short-term photosynthetic activity of microalgae strains in photobioreactors. In this study, the effect of temperature and culture time on the intensity of reproduction and on CO₂ absorption by some microalgae was evaluated. It was found that the maximum increase in biomass occurred during algae cultivation at 29–32 °C and pH = 8.4. A ratio of ~2.0 was observed between CO₂ absorption and the increase in biomass for different microalgae. When using the Chlorella genus, the increase in biomass under comparable conditions was greater than when cultivating microalgae of the Scenedesmus genus.