Study On High-Concentration Bio-hydrogen Production From Food Waste

With traditional fuel energy decreased and the environment problem deteriorated, the great potential and prospect of renewable energy has been recently realized. As an ideal energy carrier, Hydrogen has advantages of high energy density, high convert efficiency and cleanness.Food waste is rich in water, organic compounds and other complicated nutrients. Nowadays, food waste becomes a great part of the municipal waste. The integration of hydrogen production by anaerobic fermentation and bio-processing of food waste has a great development and utilizing prospect. It was reported that 7.05 LH₂·L^-1·d^-1 has been reached in Sun-Kee Han's research, the people who did a lot research in the field of hydrogen production from food waste.Semi-continuous production of hydrogen by anaerobic fermentation of food waste in anaerobic bioreactor was investigated in this article. The optimal conditions for hydrogen production were as follows: temperature 37℃, pH6.0, the dilution rate (D) ranged from 1.0d^-1 to 2.4d^-1. The anaerobic sludge boiled for 15mins was taken as seed, food waste as substrate. While D is equal to 2.4d^-1, ethanol, acetic acid, propionic acid, butyric acid and valeric acid in the effluent of fermentation occupied 5.9%, 29.6%, 5.4%, 58.5% and 0.9%, respectively. Finally, the content of hydrogen in the collected gas was about 60%. The yield of hydrogen was 4390mL and 54.8mL was produced per gram t of food waste of dry weigh. The maximum generation rate of hydrogen was 5.49 LH₂·L^-1·d^-1. When the effluent was used as the dilute water back to the reactor, the yield of hydrogen could be greatly enhanced. With the reflux ratio R=0.8, the generation rate of hydrogen and the content of hydrogen were 10.9 LH₂·L^-1·d^-1 and 65%, respectively. A gram of food waste of dry weight could generate 94.4 mL hydrogen. The generation capacity of hydrogen has been enhanced 130%.In this thesis, the technologies of CO2 fixation by PSB and hydrogen production by cooperation of anaerobic fermentation and photosynthetic process also were...