Optimization of Hydrogen Gas Production Conditions from Egyptian Chlamydomonas Sp

Abstract

Hydrogen gas could provide attractive options as ideal fuel for a world, in which environmental friendly and economically sustainable manner. Microalgae have the ability to bio-synthesis hydrogen gas. Algal H2 does do not generate any toxic or polluting bi-products and could potentially offer value-added products derived from algal biomass. In this work, the feasibility of coupling sulfur deprivation and light on hydrogen production by Chlamydomonas sp grown in photobioreactor was investigated. The cells growth, hydrogen production, total carbohydrate and chlorophyll content were determined. The results showed that, under optimum condition, algae cells were required 168 hr (7days) to reach the late logarithmic phase (the algal dry weight 4.11 g/L). Whereas the algae cells were needed about 18~22 days to reach this value (3.55 g/ L) when grow in optimum medium. The concentration of Chlorophyll (5.65%) and carbohydrate (39.46%) were accumulated in algae cells grow in S-deprives medium coupled with dark condition over that did in algae cells cultured in optimum medium. After about a 24 h of cultivation, photo-production of H2 was observed for C. sp either in absence or presence of sulfate. But under sulfur deprivation coupled with dark condition, higher H2 gas was obtained after 16 hr (7 several days) of incubation period. In new design photobioreactors (PhBRs), after 18 days of cultivation, the volume of H2 gas in was found to be 450 ml in cells grow in sulfur-deprived culture). This value was 360 ml in cells grow under optimal condition.