Analysis of shaking effect on photo-fermentative hydrogen production under different concentrations of corn stover powder

Abstract

High solid phase and easily congeal affect the mass transfer in the photo-fermentative biohydrogen production when taken straw biomass as substrate. Hence, oscillator was adopted to provide the shaking condition to enhance the mass transfer situation in this paper. Diverse shaking velocity (0, 80, 120 and 160 rpm) and substrate concentration (0, 2, 4, 6, 8 and 10 g) were studied, to evaluate the influence on the hydrogen yield capacity. The results showed that shaking could help to accelerate of gas release, shorten the fermentation time, and improve hydrogen production rate. Hydrogen yield was significantly enhanced at high substrate concentration under shaking condition. Highest hydrogen yield of 57.08 ± 0.83, 57.62 ± 1.37, 62.28 ± 0.84 mL/g-volatile solids (VS) were observed at shaking velocities of 80, 120 and 160 rpm with 6, 8 and 10 g corn stover powder, respectively. On the contrary, shaking significantly reduced the potential of hydrogen yield at a low substrate concentration, and the lower hydrogen yield obtained at the higher shaking velocity. As the lowest hydrogen yields of 27.68 ± 1.02 and 41.93 ± 0.40 mL/g VS were obtained at shaking velocity of 160 rpm with 2 and 4 g corn stover powder, respectively.