Effect of post-digestion temperature on serial CSTR biogas reactor performance.
The effect of post-digestion temperature on a lab-scale serial continuous-flow stirred tank reactor (CSTR) system performance was investigated. The system consisted of a main reactor operated at 55 degrees C with hydraulic retention time (HRT) of 15 days followed by post-digestion reactors with HRT of 5.3 days. Three post-digestion temperatures (55 degrees C, 37 degrees C and 15 degrees C) were compared in terms of biogas production, process stability, microbial community and methanogenic activity. The results showed that the post-digesters operated at 55 degrees C, 37 degrees C and 15 degrees C gave extra biogas production of 11.7%, 8.4% and 1.2%, respectively. The post-digester operated at 55 degrees C had the highest biogas production and was the most stable in terms of low VFA concentrations. The specific methanogenic activity tests revealed that the main reactor and the post-digester operated at 55 degrees C and 37 degrees C had very active acidogens and methanogens. In contrast, very low methanogenic activity was observed at 15 degrees C.
Boe
Kanokwan
K
Department of Environmental Engineering, Technical University of Denmark, Building 113, DK-2800 Kgs. Lyngby, Denmark.
Karakashev
Dimitar
D
Trably
Eric
E
Angelidaki
Irini
I
D001105:Archaea / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism; D019149:Bioreactors / Q000592:standards*; D005232:Fatty Acids, Volatile / Q000032:analysis; D005740:Gases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D013696:Temperature
D005232:Fatty Acids, Volatile; D005740:Gases