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Updated: Jun 28, 2026
11:31
Continuously-stirred Anaerobic Digester to Convert Organic Wastes into Biogas: System Setup and Basic Operation
Published on: July 13, 2012
Serial CSTR digester configuration for improving biogas production from manure
Kanokwan Boe1, Irini Angelidaki
1Department of Environmental Engineering, Technical University of Denmark, Miljoevej Building 113, DK-2800 Kgs. Lyngby, Denmark.
Water Research
|November 4, 2008
Summary
Serial manure digesters significantly boost biogas production by 11% compared to single units. The second reactor effectively processes volatile fatty acids (VFAs), enhancing overall efficiency and effluent quality.
Area of Science:
- Environmental Science
- Biotechnology
- Chemical Engineering
Background:
- Manure digesters are crucial for renewable energy production.
- Optimizing digester configuration is key to maximizing biogas yield.
- Thermophilic continuous-flow stirred tank reactors (CSTRs) are widely used.
Purpose of the Study:
- To investigate a novel serial CSTR configuration for enhanced biogas production.
- To compare the performance of serial CSTRs against a single CSTR.
- To analyze the impact of digester configuration on volatile fatty acid (VFA) concentrations and effluent quality.
Main Methods:
- Laboratory-scale investigation of manure digesters.
- Comparison of a single CSTR with serial CSTR configurations (90/10 and 80/20 volume ratios).
- Operation at a total hydraulic retention time (HRT) of 15 days.
- Organic pulse load tests to assess VFA utilization.
Main Results:
- Serial CSTR configurations achieved an 11% higher biogas yield than a single CSTR.
- The second reactor in serial configurations contributed significantly to total biogas yield (12-16%).
- VFAs were concentrated in the first reactor and utilized in the second, improving effluent quality.
Conclusions:
- Serial CSTR configurations offer a superior approach for increasing biogas production from manure.
- The staged VFA utilization in serial digesters enhances process stability and efficiency.
- This configuration improves effluent quality and overall conversion efficiency.
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