As an option for handling the large quantities of carbon dioxide released into the atmosphere, fossil-fired utilities are pursuing deep geological sequestration in response to the pressure to reduce emissions. Though not fully known, liability issues for deep sequestration are potentially significant. Flue gas separation is expensive, and for smaller emitters of carbon dioxide, access to geological sequestration is limited and costly.

This study is on the use of the fresh water microalgae, Chlorella vulgaris for photosynthetic mitigation of carbon dioxide emissions in a vertical packed bubble column photobioreactor and the search for an affordable and environmentally sustainable approach to reduce atmospheric carbon dioxide concentration from point-sources.

Results/Conclusions

Using the vertical packed bubble column microalgal photobioreactor as carbon dioxide mitigation system is a practical approach for the capture of carbon dioxide emissions. Rate of carbon dioxide removal was 15 to 40% in semi-continuous cultivation of Chlorella vulgaris alga cultures in the photobioreactor in conditions aerated with 2 to 10% carbon dioxide.

Biological reduction of carbon dioxide can be increased using a packed bubble column photobioreactor system consisting of multiple units. As algae based energy systems move to the forefront of energy research, the concept of capturing and recycling carbon dioxide through industrial energy systems that simultaneously produce biofuels offer an alternative and sustainable solution.