title: Analysis of green algal growth via dynamic model simulation and process optimization.
abstract: Chlamydomonas reinhardtii is a green microalga with the potential to generate sustainable biofuels for the future. Process simulation models are required to predict the impact of laboratory-scale growth experiments on future scaled-up system operation. Two dynamic models were constructed to simulate C. reinhardtii photo-autotrophic and photo-mixotrophic growth. A novel parameter estimation methodology was applied to determine the values of key parameters in both models, which were then verified using experimental results. The photo-mixotrophic model was used to accurately predict C. reinhardtii growth under different light intensities and in different photobioreactor configurations. The optimal dissolved CO2 concentration for C. reinhardtii photo-autotrophic growth was determined to be 0.0643 g·L(-1) , and the optimal light intensity for algal growth was 47 W·m(-2) . Sensitivity analysis revealed that the primary factor limiting C. reinhardtii growth was its intrinsic cell decay rate rather than light attenuation, regardless of the growth mode. The photo-mixotrophic growth model was also applied to predict the maximum biomass concentration at different flat-plate photobioreactors scales. A double-exposure-surface photobioreactor with a lower light intensity (less than 50 W·m(-2) ) was the best configuration for scaled-up C. reinhardtii cultivation. Three different short-term (30-day) C. reinhardtii photo-mixotrophic cultivation processes were simulated and optimised. The maximum biomass productivity was 0.053 g·L(-1) ·hr(-1) , achieved under continuous photobioreactor operation. The continuous stirred-tank reactor was the best operating mode, as it provides both the highest biomass productivity and lowest electricity cost of pump operation.
authors: Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK.
authors: Dongda
authors: D
authors: Zhang
authors: Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK.
authors: Ehecatl Antonio Del-Rio
authors: EA
authors: Chanona
authors: Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK.
authors: Vassilios S
authors: VS
authors: Vassiliadis
authors: Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Broadway 2007, NSW, Australia. bojan.tamburic@uts.edu.au.
authors: Bojan
authors: B
authors: Tamburic
mesh_terms: D018533:Biomass; D019149:Bioreactors / Q000382:microbiology; D002245:Carbon Dioxide / Q000378:metabolism; D016825:Chlamydomonas reinhardtii / Q000254:growth & development*; D003470:Culture Media / Q000737:chemistry; D052836:Heterotrophic Processes; D008027:Light; D008954:Models, Biological; D008962:Models, Theoretical; D052817:Phototrophic Processes
chemical_list: D003470:Culture Media; D002245:Carbon Dioxide
keywords: Chlamydomonas reinhardtii; dynamic simulation; microalgae; photobioreactor scale-up; process optimisation