Paper details

Title:

Analysis of Optimal Fermentation Temperature for On-Farm Biogas Production of Dairy Manure

Author(s):

Leitner, V., Krennhuber, K., Jäger, A., Kahr, H., Kuttner, P.

Document(s):

Abstract:

Animal manure is a potential feedstock for biogas production but only 3% of the available amount in Austria is used. Low energy density of manure limits the feasible transport distance but on­farm digestion can hardly be operated profitably. The adaption of existing slurry pits could reduce investment cost. Slurry pits in Austria by law have to provide a storage capacity of at least 6 months, so detention times of up to 92 days are realizable without additional investments. Dairy manure (DM = 50 g kg­1) was anaerobically digested in 12 L stirred tank reactors at temperatures between 15 and 38°C for 33 to 132 days. Based on the correlations found, predictions for biogas yields as a function of temperature and detention time are possible and allow temperature optimisation. The highest biogas d­1 yield was 559 NL kg VS ­1 at a detention time of 66 days and 38°C. It was verified that biogas yields of psychrophilic fermentation can reach those of mesophilic fermentation when the detention time is tripled. Highest net energy yields were achieved at 25°C with 145 days detention time. For the process concept of on­farm with a maximum detention time of 92 days 30°C results in the highest net energy yields.

Keywords:

biogas, manure, decentralised, farm

Topic:

Biomass Conversion Technologies for Heating, Cooling and Electricity

Subtopic:

Anaerobic digestion for biogas production

Event:

22nd European Biomass Conference and Exhibition

Session:

2CV.1.22

Pages:

815 - 817

ISBN:

978-88-89407-52-3

Paper DOI:

10.5071/22ndEUBCE2014-2CV.1.22

Price:

FREE