IIT Guwahati Develops Two-Stage Microalgae Process to Boost CO2 Capture and Bioenergy

Key facts

• Researchers at the Indian Institute of Technology (IIT) Guwahati have developed a two-stage microalgae cultivation process that enhances CO2 capture, biomass production, and bioenergy generation.
• The first stage grows microalgae under 15% CO2 for rapid growth, while the second stage reduces CO2 to 5% and adds calcium and phosphorus to stabilise pH and promote self-flocculation.
• The process achieved 25.7% higher biomass production, 35.4% higher CO2 fixation, 1.86 times higher lipid productivity, and a 37.65% improvement in total intracellular bioenergy efficiency.
• The addition of calcium enabled auto-sedimentation of microalgal biomass, increasing biomass recovery efficiency to 98.46%.
• The biodiesel derived from the microalgae complies with biodiesel standards in India, the United States, and Europe.
• The findings were published in the journal Renewable Energy.