Integrated Computational and Experimental Studies of Microalgal Production of Fuels and Chemicals

Microalgae are sunlight-driven cell factories that carry out the same process and mechanism of photosynthesis as higher plants converting sunlight into biomass, performing more efficiently than crops (Chisti, 2007). Nevertheless, high substrate and fertilizer input requirements as well as harvesting and oil extraction costs have been found to play a significant role in both the economic viability and sustainability of microalgal biofuels production (Pittman et al., 2011). Therefore, attention has been drawn to experimental and computational studies on the microalgal oil production, aiming to increase the productivity either through the photosynthesis process or through the application of metabolic engineering (Chisti, 2007) to improve the sustainability and competitiveness of the algal-derived biofuels industry. The objective of this work is the establishment of links between algal strains grown in large raceway open ponds and innovative bioproduct generation technologies including fuels and chemicals in order to achieve positive energy balance and environmental sustainability. Multi-parameter quantification has been employed leading to a predictive model to describe algal growth and lipid accumulation in lab-scale batch systems. The model can also take into account the effects of temperature, light and pH, in order to improve the productivity of microalgae cultivation technologies. Experiments have been conducted to analyse the effect of different input parameters. The model was fitted to data from bench-scale batch experiments. The experimental setup involved tris-acetate-phosphate (TAP) media containing 1.575 g/L and 2.1 g/L acetic acid and 0.098147 g/L nitrogen under constant light illumination of 125 μEm−2s−1. An in-house developed optimization framework (Vlysidis et al., 2011) has been used for the estimation of the key parameters. The predictive capabilities of the model were tested on batch systems comprising TAP media containing 2.625 g/L acetic acid.