Dimensionless equations to describe microalgal growth in a planar cultivation system.

Abstract

To develop dimensionless equations to describe microalgal growth in planar photobioreactor or raceway pond systems that are generalized to all phototrophic species and reactor length scales. Expressions for biomass growth and mean light intensity within a nutrient replete, well-mixed, phototrophic cell culture in a planar cultivation system were developed in terms of dimensionless variables for biomass, time and light intensity, plus two new dimensionless parameters. The first dimensionless parameter represents a species-specific physiological characteristic based on maximum growth rate and cell maintenance, while the second represents the light input. Optimal biomass productivities and photosynthetic conversion efficiencies are easily determined from the dimensionless expressions and system-specific performances can be easily determined by back substituting with the relevant cell culture and photobioreactor parameters. The dimensionless expressions are useful for understanding and determining the relevant bioprocess parameters in a generalized form applicable to all strains and reactor length scales.