Microalgae face significant challenges in carbon dioxide (CO₂) fixation due to environmental, technical, and biological constraints, limiting their scalability and efficiency as a carbon mitigation solution.
Key Message
Microalgae-based CO₂ fixation is hindered by environmental sensitivity, suboptimal system designs, and intrinsic biological limitations, requiring multidisciplinary solutions to enhance feasibility.
Supporting Data
1. Environmental Sensitivity
- O₂ inhibition: High O₂ concentrations in cultivation systems reduce photosynthetic efficiency by up to 50% [1]
- Light/temperature dependency: Productivity drops by 30–60% under non-optimal light (e.g., <100 μmol/m²/s) or temperature (>35°C) [4,5].
- Seasonal variability: Biomass yield fluctuates by 40–70% annually due to sunlight and temperature changes [3].
2. System Design Limitations
- Photobioreactor inefficiency: Open systems lose 20–30% of CO₂ to the atmosphere; closed systems face high costs (≈50% of total expenses) [2,4].
- Gas transfer barriers: Poor CO₂ dissolution in water reduces fixation rates by 15–25% [4,5].
3. Biological Constraints
- Slow growth rates: Microalgae double biomass in 3.5–24 hours, but terrestrial plants (e.g., fast-growing trees) outperform in long-term carbon storage [3,5].
- CO₂ tolerance limits: Most strains show reduced growth at >20% CO₂ concentrations due to cellular stress [4,5].