The potential of microalgae for carbon capture and sequestration

Abstract

Microalgae have been highlighted as a contributor to CO₂ sequestration due to their efficient photosynthetic system. However, calculations on their actual potential for CO₂ sequestration are often lacking. Here, we calculated the potential of microalgae for the capture of CO₂ by integrating it with a large emitter (gas-based energy plant) and a low emitter (dairy farms), and also discussed if such integrated systems can be considered as carbon sequesters given that the final use of the biomass often quickly releases the captured CO₂. Moreover, the CO₂ footprint of microalgal systems is highlighted as a critical point of attention for future developments. Such considerations are of utmost importance to avoid false promises that ultimately harm this sector, as large investments are made following untruthful claims that, when proven wrong, result in a loss of interest. Finally, key definitions are proposed to improve clarity and help in such discussions.