Overview

This talk explored algae-based carbon sequestration as a nature-based solution to address rising CO₂ emissions, while simultaneously generating valuable bio-based products. Focusing on both microalgae and macroalgae (seaweeds), the presentation demonstrated how algae can capture atmospheric and flue-gas CO₂, integrate with wastewater treatment, and be processed into fertilizers, fuels, chemicals, and bioproducts—offering a utilization-focused alternative to conventional carbon storage.

 
Expert Insights & Key Takeaways

Algae as an efficient biological carbon sink
Algae capture CO₂ through photosynthesis and convert it into biomass rich in proteins, carbohydrates, and lipids. Approximately 1.8 tons of CO₂ can be removed per ton of algae produced, making algae a highly effective carbon capture pathway.

Carbon utilization vs. carbon storage
Unlike geological storage, algae-based sequestration creates economic value by converting captured carbon into usable products, while also producing oxygen and improving environmental quality.

Diverse cultivation platforms enable scalability
Algae can be grown in open raceway ponds, photobioreactors, revolving belt systems, and ocean-based macroalgae farms. Marine systems avoid freshwater competition and unlock the concept of blue carbon, where oceans sequester more carbon annually than terrestrial systems.

Integration with wastewater treatment
Algae–bacteria consortia can remove nutrients from municipal and industrial wastewater while producing harvestable biomass. This approach reduces sludge disposal challenges and creates a feedstock for downstream bioenergy and fertilizer applications.

Harvesting remains a key cost driver
Algae separation is energy-intensive, but multiple methods—settling, centrifugation, filtration, electrocoagulation, bio-flocculation, and magnetic separation—can be combined to reduce costs and improve efficiency.

Algae-derived fertilizers reduce emissions
Field and greenhouse studies showed that algae-based fertilizers can replace up to 50% of conventional chemical fertilizers without reducing crop yield, while improving root structure, nutrient uptake, and plant stress tolerance.

Soil health and resilience benefits
Algae enhance soil porosity, water retention, nitrogen fixation, and microbial activity, helping crops withstand drought, salinity, and biotic stress.

Pelletized and stabilized algae formulations
Dry granules and freeze-dried algae overcome shelf-life and transport challenges of liquid products, enabling scalable agricultural deployment.
 

Future Outlook

Algae-based carbon capture offers a circular, utilization-driven pathway for decarbonization that links climate mitigation with food, agriculture, water treatment, and energy systems. As cultivation, harvesting, and processing technologies mature, algae could play a central role in a low-carbon bioeconomy, transforming CO₂ from a liability into a renewable resource while delivering environmental and economic co-benefits.

Guest Speakers

Venktash Balan

Associate Professor

Biomedical Engineering

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