Title:
Syngas Fermentation at Elevated Pressure - Experimental Results
Author(s):
Stoll, I.K., Boukis, N., Sauer, J.
Document(s):
Paper
Abstract:
Gas fermentation using anaerobic bacteria as a biocatalyst is an attractive biotechnological process for the sustainable conversion of synthesis gas for the production of green fuels and chemicals. A known bottleneck of syngas fermentation are low gas-liquid mass transfer rates, caused by the low solubility of syngas components in the fermentation liquid. This work presents the results of an experimental study on syngas fermentation at elevated pressure, which can be employed to enhance gas solubility according to Henry’s Law. Gas fermentation with a process pressure up to 7 bar were performed in a high-pressure stirred-tank reactor. Clostridium ljungdahlii was used as biocatalyst, converting a mixture of H2, CO and CO2 to acetic acid, ethanol and formic acid. Gas consumption, cell growth, and product concentration are determined during fermentation. Results show a positive effect of a moderate pressure increase on cell growth and acetate productivity. The highest cell density (1.05 g L-1) as well as highest acetate concentration (16.9 g L-1) are observed at a pressure of 4 bar. Gas conversion rates are increased, with CO conversion reaching nearly 99 %. A further direct pressure increase up to 7 bar leads to a decrease in fermentation stability.
Keywords:
fermentation, pressure, syngas, anaerobic process, biochemical, Clostridium Ljungdahlii
Topic:
Biomass Conversion Technologies for Energy Carriers, Chemicals and Materials
Subtopic:
Biorefineries
Event:
27th European Biomass Conference and Exhibition
Session:
3CV.3.4
Pages:
1255 - 1261
ISBN:
978-88-89407-19-6
Paper DOI:
10.5071/27thEUBCE2019-3CV.3.4
Price:
FREE
