In view of its promise as sustainable process for CO2 capture and its potential in the production of feed, food and natural high value products such as omega-3 fatty acids and anti-oxidants such as astaxanthin, large scale algae cultivation is gaining commercial interest. Currently, most systems are based on directly contacting CO2 containing gas, e.g. flue gas, with the algae culture. However, applicable on small scale, this approach is not applicable on a commercially relevant large scale due to mass transfer limitations. There is need for a cost effective and scalable system. TNO has developed a scalable system for efficient capture of CO2 as feedstock for algae production. In this system, CO2 is absorbed in an absorption liquid as bicarbonate. Subsequently, the enriched absorption liquid is fed to the algae, which convert the solubilized CO2 into biomass and biobased products. Finally, biomass is recovered and the lean absorption liquid is recycled. TNO's integrated process concept was successfully demonstrated with continuous algae cultivation on a 2 L-scale for more than 150 days of which 40 days using flue gas as CO2 source.@en

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. At TNO, two novel methods have been developed for the integration of flue-gas from power plants with algae production for the capture and utilization of CO2. The first method can be described as being amine based whilst the second is carbonate based. Both methods have in common that algae is used as photochemical desorber of CO2 from absorption liquid. The advantages of these methods is that they are easy to scale-up, would lead to 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. The impact of the new strategies for integrating power plants with algae are described in order to provide more information on their novel aspects and their potential for CO2 mitigation.@en

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.@en