초록
The present research work deals with the performance of packed bed reactor for continuous H<SUB>2</SUB> production using cane molasses as a carbon source. Maximum H<SUB>2</SUB> production rate of 1.7LL<SUP>-1</SUP>h<SUP>-1</SUP> was observed at a dilution rate and recycle ratio of 0.8h<SUP>-1</SUP> and 0.6, respectively which was corresponding to the lowest NADH/NAD<SUP>+</SUP> ratio. This suggests that the utilization of NADH pool for H<SUB>2</SUB> and metabolite production might lead to decrement in NADH/NAD<SUP>+</SUP> ratio. Thus NADH/NAD<SUP>+</SUP> ratio show inverse relation with hydrogen production. The substrate degradation kinetics was investigated as a function of flow rate considering the external film diffusion model. At a flow rate of 245mLh<SUP>-1</SUP>, the contribution of external film mass transfer coefficient and first order substrate degradation constant were 55.4% and 44.6% respectively. Recycle ratio of 0.6 improved the hydrogen production rates by 9%. The viable cell count was directly proportional to the recycle ratio (within the range 0.1-0.6). Taguchi design showed the significant influence of the feed pH on continuous H<SUB>2</SUB> production followed by dilution rate and recycle ratio. Thus environmentally friendly and cheaper solid matrix like coconut coir could be efficiently used for thermophilic continuous hydrogen production.