The use of bicarbonate as carbon supply in a large scale photobioreactor for industrial microalgae production could reduce the compression and transportation costs associated with the direct use of CO2 from flue gas. Some microalgae species are able to directly exploit bicarbonate as a carbon source, but the actual yield in view of large scale production is not clear, in particular for eukaryotic and lipid-rich strains. In this work, the exploitation of bicarbonate as carbon source by Chlorella protothecoides was critically assessed. Both batch and continuous experiments were carried out with the addition of NaHCO3 to the culture medium. The growth of this species was found to be strongly affected by the increased pH, resulting in a reduced yield if compared with that from an airCO(2) bubbling supply. To overcome this issue, a pH control system was applied, so that the pH value was maintained below 8. In these conditions a specific growth rate was measured close to that obtained under CO2 bubbling, probably due to the equilibrium of carbonate, which is shifted to H2CO3 and free CO2. Thus, it appears that C. protothecoides is not able to directly use bicarbonate, but exploits the CO2 made available from the shifting of the carbonate equilibrium. In addition, the presence of bicarbonate also caused a lipid accumulation in C. protothecoides, up to about 40% dry weight, compared to the constitutive value of 1012% dry weight. On the basis of the results obtained, a process scheme was proposed, integrating microalgae cultivation with CO2 capture by absorption with a recirculating carbonate solution. Process simulation was carried out to show the technical feasibility of this process.