Perspectives on microalgal CO2-emission mitigation systems — A review

The problem of climate change arising mainly from CO2 emission is currently a critical environmental issue. Biofixation using microalgae has recently become an attractive approach to CO2 capture and recycling with additional benefits of downstream utilization and applications of the resulting microalgal biomass. This review summarizes the history and strategies of microalgal mitigation of CO2 emissions, photobioreactor systems used to cultivate microalgae for CO2 fixation, current microalgae harvesting methods, as well as applications of valuable by-products. It is of importance to select appropriate microalgal species to achieve an efficient and economically feasible CO2-emission mitigation process. The desired microalgae species should have a high growth rate, high CO2 fixation ability, low contamination risk, low operation cost, be easy to harvest and rich in valuable components in their biomass.