文档介绍：ARTICLE IN PRESS
Biomass and Bioenergy 31 (2007) 820–830
ate/biombioe
Regulation and optimization of the biogas process:
Propionate as a key parameter
Henrik Bangsø NielsenÃ, Hinrich Uellendahl, Birgitte Kiær Ahring
Bioprocess Science and Technology, BioCentrum-DTU, Building 227, Technical University of Denmark, DK-2800 Lyngby, Denmark
Received 5 May 2006; received in revised form 6 April 2007; accepted 8 April 2007
Available online 18 June 2007
Abstract
The use of volatile fatty acids (VFA) as process indicators in biogas reactors treating manure together with industrial waste was
studied. At a full-scale biogas plant, an online VFA sensor was installed in order to study VFA dynamics during stable and unstable
operation. During stable operation acetate increased significantly during the feeding periods from a level of 2–4 to 12–17 mM, but the
concentration generally dropped to about the same level as before feeding. The fluctuations in the propionate were more moderate than
for acetate but the average level rose during 1 week of operation from to mM. A process disturbance caused by overloading with
industrial waste was reflected by a significant increase in all VFA concentrations. During the recovery of the process, the return of
propionate back to the steady-state level was 2–3 days slower than any other VFA and propionate could best describe the normalizing of
the process. In a lab-scale continuously stirred tank reactor experiment, with manure as main substrate, the prospective of using either
propionate concentration or methane production as single process indicators was studied. Propionate was found to be the best indicator.
Thus, a process breakdown caused anic overloading with meat and bone meal and lipids was indicated by changes in propionate
concentration 12–18 days before a decrease in methane production was observed. Furthermore, a more efficient and stable utilization of
the substrate was observed when propionate was us