Optimization of biohydrogen production from microalgae by response surface methodology (RSM)

In the present study, the design and fabrication of a micro-photobioreactor to produce the bio-hydrogen are aimed. Furthermore, the optimization of variables affecting hydrogen production was optimized using the response surface methodology (RSM). A quadratic model was used to predict the behavior of samples. The central composite design was applied using 20 treatments and 6 replications in the central points. Independent variables for evaluation included sulfur concentration (0.5–1%), run time (5–120 h) and algal biomass concentration (50–100 g/L). The results suggested that test length had a significant impact on hydrogen production and that sulfur content and biomass concentration had no significant effect on hydrogen production but did cause a little increase. The experimental values of response variable in these optimal conditions match the predicted values. Optimal conditions to produce bio-hydrogen were identified as the sulfur concentration of 0.75%, run time of 101.96 h, and biomass concentration of 53.31 g/L for maximum production of bio-hydrogen (66.32 mL g-VS−1). In conclusion, the response surface methodology can predict the production and extraction of bio-hydrogen in photobioreactors.