Details

Title:

Methane Fermentation Treatment of Nitrogen-Rich Resources with Biogas Circulation

Author(s):

Oshibe, H., Osaka, N., Matsui, T., Kida, K.

Document(s):

Abstract:

Methane fermentation experiments were conducted at bench scale and pilot scale for treatment of nitrogen­rich resources, using milk as the feedstock. Ammonia stripping was applied to reduce ammonia inhibition by circulating biogas to the methane fermenter. In the pilot experiment, 115 kg/day of milk was treated, corresponding to a volatile total solids (VTS) loading rate of 4.9 kg/(L·d). During operation, the produced biogas was washed in a water tank and a portion of the water­washed biogas was recirculated through the fermentation tank to reduce ammonia concentrations and resulting inhibition. The average concentration of ammonium ion in the water and the fermentation tanks was 903 mg/L and 1818 mg/L, respectively, indicating that ammonia in the fermentation tanks was successfully stripped by the biogas, avoiding significant accumulation of free ammonia in the digester. A methane yield of 493 L/kg VTS and a chemical oxygen demand decomposition rate of 80% were achieved. These results indicate that methane fermentation of nitrogen­rich materials can be stably conducted by stripping ammonia with produced biogas.

Keywords:

ammonia, anaerobic digestion, biogas

Topic:

R&D on Biomass Conversion Technologies for Heating, Electricity and Chemicals

Subtopic:

Anaerobic digestion for biogas production

Event:

21st European Biomass Conference and Exhibition

Session:

2DO.4.1

Pages:

692 - 695

ISBN:

978-88-89407-53-0

Paper DOI:

10.5071/21stEUBCE2013-2DO.4.1

Price:

FREE