Dark fermentation for hydrogen production is an attractive source of renewable energy. Hydrogen production via dark fermentation shares many features with the process of anaerobic digestion, with the exception that to maximize hydrogen production, the activity of hydrogen consuming methanogenic bacteria has to be avoided. To inhibit the methane producing microbes, thermal treatments could be applied to anaerobic sludge, used as inoculum. The objectives of this research were a) the evaluation of the effects of heat treatments on the viability of microbial community of the anaerobic sludge in order to optimize the inoculum pre-treatment; b) to investigate the hydrogen production yields achieved by the pre-treated inoculum at different pH values. A 2-to-4 hour treatment at 100° C combined with a pH value of 5.5 resulted to be efficient for the selection of microbial strains that showed the best hydrogen production performances. This study demonstrates that heat treatment could be crucial for the inoculum conditioning and for the selection of the hydrogen producing bacteria. It should be carefully defined according to the structure of the sludge microbial community since its effects are not only the inhibition of methanogenic bacteria but also the selection of most effective hydrogen producing microbes
Biological Hydrogen and Methane potential from sweet sorghum residues
LAVAGNOLO, MARIA CRISTINA;SPAGNI, ALESSANDRO;
2007
Abstract
Dark fermentation for hydrogen production is an attractive source of renewable energy. Hydrogen production via dark fermentation shares many features with the process of anaerobic digestion, with the exception that to maximize hydrogen production, the activity of hydrogen consuming methanogenic bacteria has to be avoided. To inhibit the methane producing microbes, thermal treatments could be applied to anaerobic sludge, used as inoculum. The objectives of this research were a) the evaluation of the effects of heat treatments on the viability of microbial community of the anaerobic sludge in order to optimize the inoculum pre-treatment; b) to investigate the hydrogen production yields achieved by the pre-treated inoculum at different pH values. A 2-to-4 hour treatment at 100° C combined with a pH value of 5.5 resulted to be efficient for the selection of microbial strains that showed the best hydrogen production performances. This study demonstrates that heat treatment could be crucial for the inoculum conditioning and for the selection of the hydrogen producing bacteria. It should be carefully defined according to the structure of the sludge microbial community since its effects are not only the inhibition of methanogenic bacteria but also the selection of most effective hydrogen producing microbesPubblicazioni consigliate
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