Characterization of an acetogenic industrial flue gas fermentation process with Acetobacterium woodii

Abstract

The increasing concerns and activities around global climate change induced newenergy and emission policies. High industrial emissions must be targeted to lower the carbon dioxide impact.The focus of this work is on the first step of a two step biotechnological process with industrial flue gases containing hydrogen, carbon dioxide, carbon monoxide, oxygen, nitrogen and methane for conversion into valuable products. An autotrophic fermentation process with Acetobacterium woodii was characterized and described.The utilized facultative an aerobic bacteria Acetobacterium woodiiis known for growing chemolithoautotrophically on carbon dioxide and hydrogen with acetate as the sole product.Batch and chemostat cultivations were applied to study different influences such as mass transfer, specific reaction rates and productivity. Due to in adequate masstransfer the process was identified as hydrogen limited . Final acetate concentrations of 25 g/L were measured at low biomass concentrations of 0.8 to 1.2 g/L in less than five days under autotrophic conditions. The highest accomplished biomass specific reaction rate was 13.20 g/g d.Small scale serum bottle experiments were used to evaluate in hibitory effects ofcarbon monoxide and oxygen. Contradictory results were obtained from these tests.Furthermore, online calculators and possible online sensoring (within the processinformation management system Lucullus) for solid online process screening were evaluated. This led to effective online acetate monitoring via a soft sensor basedon the base signal.