Fermentative Hydrogen Production: Influence of Application of Mesophilic and Thermophilic Bacteria on Mass and Energy Balances

摘要

Fermentation of biomass residues and second generation biomasses is a possible way to enable a sustainable production of hydrogen. The HYVOLUTION-project investigates the production of hydrogen by a 2-stage fermentation process of biomass. It consists of a dark fermentation step of sugars to produce hydrogen, CO_2 and organic acids followed by a photo-heterotrophic fermentation, in which all intermediates are converted to more hydrogen and CO_2. This work compares the use of mesophilic and thermophilic bacteria in the dark fermentation step, analyzing the effects on the overall process. Based on experimental results, simulation models developed with Aspen Plus V7.1~? are used to calculate the mass- and energy balances of the process. Results show that dark fermentation at mesophilic conditions requires a higher amount of feedstocks but almost no heat input as well as smaller equipment. However, better economic performance is assumed for the thermophilic operation of the dark fermentation step.