Modeling Microalgae Productivity in Industrial-Scale Vertical Flat Panel Photobioreactors

Area of Science:

• Biotechnology
• Renewable Energy
• Algal Cultivation

Background:

• Economic viability of microalgae mass cultivation depends on biomass yields.
• Vertical flat panel photobioreactors are a promising technology for large-scale microalgae production.

Purpose of the Study:

• To develop and apply a computer model for estimating microalgae productivity in outdoor vertical flat panel photobioreactors.
• To identify optimal reactor design and operational parameters for maximizing biomass yield.

Main Methods:

• Computer modeling of reactor temperature and light distribution.
• Dynamic computation of shading and reflections based on reactor geometry and solar position.
• Annual yield estimations using site-specific weather and irradiation data for six climate zones.

Main Results:

• Thin panels (≤0.05 m) and north-south orientation are optimal for a cell density of 2 g L^-1.
• Panel spacings of 0.4-0.75 m and a panel height of 1 m are suitable for commercial applications.
• Yields of approximately 10 kg m^-2 a^-1 are achievable in most U.S. locations, with lower yields in hot climates.

Conclusions:

• Optimized vertical flat panel photobioreactor design can lead to significant microalgae biomass yields.
• Reactor temperature is a critical factor limiting productivity, especially in hot climates.
• The developed model provides valuable insights for the economic assessment and scale-up of microalgae cultivation.