Digestion process, anaerobic

The performance of anaerobic digestion processes varies according to the type of unit, throughput, and feed concentration, but such processes are typically capable of removing between 75 and 85 percent of COD. ... 

The formation of hydrogen is accompanied with VFAs or solvent production during an anaerobic digestion process. Therefore, the distribution of VFA concentrations and their finctions is a usefiil indicator for monitoring hydrogen production. Fig. 3 shows the variations in alcohol and VFAs. Most of the VFAs were analyzed as acetate and butyrate, and most of the alcohols were analyzed as ethanol. The propionate concentration was below the analytical limit. It indicates that the anaerobic pathway in the reactor is not propionic-type fermentation but but5nrate-type fermentation. Clostridium butyricum is considered to be the dominant... 

Underslat slurry storage also influences environnement as well inside as outside the piggery because gases are released from the slurry. On the other hand anaerobic digestion processes will be avoid by daily removal and separate storage of faeces and urine. 

The monitoring scheme carried out on 5 Mi-scale plants, 4 demonstrative ones and an experimental one, shows high biogas yield (m3.Kg VS.d ). The anaerobic digestion process is shown to be stable, even when there are falls in digestion temperature, or breaks in the mixing and feeding process. Considerable problems were noted, however,... 

MARCHAIM, U., PERACH, Z., and KIMCHIE, S. An integrated approach to the anaerobic digestion process. In D.L.Wise (Ed.) Fuel Gas Systems . CRC Press Inc., Boca Raton, Florida, 141, 1984. 

In the following, a model of an anaerobic digestion process carried out in a continuous fixed bed reactor for the treatment of industrial wine distillery vinasses is considered [10] ... 

C. Aubrun, J. Harmand, O. Gamier, and J.P. Steyer. Fault detection filter design for an anaerobic digestion process. Bioprocess Engineering, 22(5) 413-420, 2000. 

M.W. Barnett and J.F. Andrews. Expert system for anaerobic digestion process operation. Journal of Environmental Engineering, 118(6) 949-963, 1992. 

J. Harmand and J.P. Steyer. Comparison of several advanced control approaches for anaerobic digestion processes Towards a new paradigm. In IWA Conf. Instr., Contr., and Automat. (ICA), pages 647-654, Malm5, Sweden, June 2001. 

S. Marsili-Libelli and A. Muller. Adaptive fuzzy pattern recognition in the anaerobic digestion process. Pattern Recognition Letters, 17(6) 651-659, 1996. 

J.P. Steyer, J.C. Bouvier, T. Conte, P. Gras, J. Harmand, and J.P. Delgenes. On-line measurements of COD, TOC, VPA, total and partial alkalinity in anaerobic digestion process using infra-red spectrometry. Wat. Sci. TechnoL, 45(10) 133-138, 2002. 

R. Antonelli, J. Harmand, J.P. Steyer, and A. Astolfi. Set-point regulation of an anaerobic digestion process with bounded output feedback. IEEE Trans. Contr. Syst. TechnoL, ll(4) 495-504, 2003. 

F. Mosey. Mathematical modeling of the anaerobic digestion process Regulatory mechanisms for the formation of short-chain volatile acids from glucose. Wat. Sci. TechnoL, 15 209-232, 1983. 

J.P. Steyer, P. BufHere, D. Rolland, and R. Moletta. Advanced control of anaerobic digestion processes through disturbances monitoring. Wat. Res.,... 

Fig. 8. Schematic view of the INRA anaerobic digestion process and the associated on-line instrumentation...

The acid-forming and methane-forming bacteria work simultaneously in the anaerobic digestion process. Oxygen is excluded from the digester and various other environmental conditions are controlled so that the methane-formers are maintained in balance with the acid-formers. Otherwise, the methane-formers would be inhibited and in some cases would cease to function entirely. 

Biological Process Stability. The anaerobic digestion process involves a complexity of interrelated biochemical reactions, many of which are not clearly understood. Anaerobic digestion therefore, has a poor reputation from a process-stability viewpoint. Municipal digesters are frequently attended by skilled operators with elaborate monitoring facilities at their disposal. The adoption of on-farm anaerobic digestion systems for methane production are unlikely to occur under such requirements for successful operation. 

AMONCO - Advanced prediction, monitoring and controlling of anaerobic digestion processes towards biogas usage in fuel cells. 

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