IIT Guwahati researchers develop efficient CO₂ capture and biofuel process

Researchers at the Indian Institute of Technology (IIT) Guwahati have developed a two-stage cultivation process designed to improve carbon dioxide (CO₂) capture and microalgal biomass production for bioenergy.

Led by Professor Kaustubha Mohanty and research scholar Deepesh Singh Chauhan, the team addressed the issue of nutrient depletion and reduced photosynthetic performance caused by prolonged high CO₂ exposure. The process involves an initial stage of growth under 15% CO₂ to promote rapid growth, followed by a second stage where CO₂ concentration is reduced to 5%. During this second stage, calcium and phosphorus are added to stabilize the environment, restore pH balance, and promote self-flocculation for easier harvesting.

According to findings published in the journal Renewable Energy, the method resulted in a 25.7% increase in biomass production, 35.4% higher CO₂ fixation, and 1.86 times higher lipid productivity. The research also demonstrated a 37.65% improvement in total intracellular bioenergy efficiency.