Recent progress on converting CO₂ into microalgal biomass using suspended photobioreactors

Area of Science:

• Biotechnology
• Renewable Energy
• Algal Cultivation

Background:

• Microalgal photosynthesis in photobioreactors (PBRs) is limited by inhomogeneous light distribution and poor CO2 transfer.
• Current PBRs face challenges in productivity and economic feasibility for microalgal biomass production.

Purpose of the Study:

• To systematically review and classify strategies for enhancing light and CO2 availability in PBRs.
• To provide guidance for designing high-performance PBRs.
• To present future directions for PBR development.

Main Methods:

• Classification of strategies for elevating light availability: increasing incident light, internal illumination, optimizing flow, regulating biomass, and enlarging illumination surfaces.
• Outline of strategies for enhancing CO2 availability: smaller bubbles, extended bubble residence time, and facilitated CO2 dissolution with additives.

Main Results:

• Novel classification of light enhancement strategies in PBRs.
• Comprehensive overview of CO2 enhancement techniques for microalgal cultivation.
• Identification of key areas for PBR improvement.

Conclusions:

• Effective enhancement of light and CO2 availability is crucial for high-performance PBRs.
• Addressing current limitations can improve microalgal biomass production efficiency and economic viability.
• This review serves as a valuable resource for advancing PBR technology.