New methodologies for integrating algae with CO₂ capture

Abstract

It is generally recognized, that algae could be an interesting option for reducing CO2 emissions. Based on light and CO2, algae can be used for the production various economically interesting products. Current algae cultivation techniques, however, still present a number of limitations. Efficient feeding of CO2, especially on a large scale, is one of them. Current methods for CO2 feeding to algae cultures rely on the sparging pure CO2 or directly from flue gas. The limiting factor in this system is the solubility of CO2in water, which demands a considerable amount of energy for an effective gas to liquid transfer and leads to losses to the atmosphere. Due to the current ineffective methods for CO2 introduction into algae ponds very large surface areas would be required for enough ponds to capture a considerable amount of the CO2. At TNO, an amine-based method have been developed for algae production utilization of CO2 where algae is used as photochemical desorber of CO2 from an absorption liquid. This methods brings the advantage of higher CO2 removal efficiencies compared to current CO2 feeding systems for algae and lower operational cost compared to both conventional CO2 removal using amines and conventional autotrophic algae cultivation.