Modeling of Anaerobic Digestion of Complex Substrates

Document Type : Research Article

Authors

1 Atomic Energy Organization of Iran, P.O. Box 11365-8486, Tehran, I.R. IRAN & Department of Chemical Engineering, Tehran University, P.O. Box 11365-4563, Tehran, I.R. IRAN

2 Department of Chemical Engineering, Tehran University, P.O. Box 11365-4563, Tehran, I.R. IRAN

3 Atomic Energy Organization of Iran, P.O. Box 11365-8486, Tehran, I.R. IRAN

Abstract

A structured mathematical model of anaerobic conversion of complex organic materials in non-ideally cyclic-batch reactors for biogas production has been developed. The  model is based on multiple-reaction stoichiometry (enzymatic hydrolysis, acidogenesis, acetogenesis and methanogenesis), microbial growth kinetics, conventional material balances in the liquid and gas phases for a cyclic-batch reactor, liquid-gas interactions, liquid-phase equilibrium reactions and a simple mixing model which considers the reactor volume in two separate sections: the flow-through and the retention regions. The dynamic model describes the effects of reactant’s distribution resulting from the mixing conditions, time interval of feeding, hydraulic retention time and mixing parameters on the process performance. The model is applied in the simulation of anaerobic digestion of cattle manure under different operating conditions. The model is compared with experimental data and good correlations are obtained.

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Main Subjects


[1] Constant, M., Naveau, H., Ferrero, J. L. and Nyns, E. J., Biogas end-uses in the European  Community. Elsevier Science Publishing Company, New York, (1989).
[2] Andrews, J. F., Dynamic model of the anaerobic digestion process.,  J.  Sanit.  Engng  Div.  Proc.  Am. Soc. Civ. Engrs SA 1, 95-116, (1969).
[3] Buhr, H. O. and Andrews, J. F., The thermophilic anaerobic digestion process., Water Res., 11, 129-143, (1977).
[4] Hill, D. T. and Barth, C. L., A dynamic model for simulation of animal waste digestion., J. Water Pollut. Control Fed., 49, 2129-2143, (1977).
[5] Angelidaki, I. and Ahring, B. K., Thermophilic anaerobic digestion of livestock waste: The effect of ammonia., Appl. Microbiol. Biotechnol., 38, 560-564, (1993).
[6] Angelidaki, I., Ellegaard L. and Ahring, B. K., A mathematical model for dynamic simulation of anaerobic digestion of complex substrates: Focusing on ammonia inhibition., Biotech. and Bioengng., 42, 159-166, (1993).
[7] Buffiere, P., Steyer, J. P., Fonade, C. and Moletta, R., Comprehensive modeling of methanogenic biofilms in fluidized bed systems: Mass transfer limitations and multisubstrate aspects., Biotech. and Bioengng., 48, 725-736, (1995).
[8] Kalyuzhnyi, S.V. and Davlyatshina, M.A., Batch anaerobic digestion of glucose and its mathematical modeling., Bioresource Technology,59, 73-80, (1997).
[9] Batstone, D.J., Keller, J., Newell, R. B. and Newland, M., Modeling anaerobic degradation of complex wastewater., Bioresource Technology, 75(1), 67-74, (2000).
[10] Nielsen, J. and Villadesen, J., Modeling of microbial kinetics., Chem. Engng Sci., 47, 4225-4270, (1992).
[11] Montieth, H. D. and Stephenson, J. P., Mixing efficiencies in full-scale anaerobic digesters by tracer methods., J. WPCF, 53, 78-84, (1981).
[12] Kalia,A.K. and Knawar, S. S., Long-term evaluation of a fixed dome Janata biogas plant in hilly conditions., Bioresource Technology, 65, 61-63, (1998).
[13] Ong, H.K., Greenfield, P.F. and Pullammanappallil, P. C., An operational strategy for improved biomethanation of cattle manure slurry in an unmixed single stage digester., Bioresource Technology, 73(1), 87-89, (2000).
[14] Sterling, M. C., Jr., Lacey, R. E., Engler, C. R. and Ricke, S. C., Effect of ammonia nitrogen on H2 and CH4 production during anaerobic digestion of dairy cattle manure., Bioresource Technology, 77(1), 9-18, (2001).
[15] Levenspiel, O., “Chemical Reaction Engineering”, Second Edition, Wiley & Sons Book Company, New York, (1972).
[16] Keshtkar, A., Ghaforian, H., Abolhamd, G. and Meyssami, B., Dynamic simulation of cyclic batch anaerobic digestion of cattle manure., Bioresource Technology, 80, 9-17, (2001).
[17] Dean, J. A., “Lange’s Handbook of Chemistry”, Fourteenth Edition, McGraw Hill Book Company, New York, (1992).
[18] Archer, D. B., Enzyme Microbiol. Technol., 5, 162-167, (1983).
[19] Dugba, P. N., Zhang, R., Treatment of dairy waste-water with two-stage anaerobic sequencing batch reactor systems- thermophilic versus mesophilic operations., Bioresource Technology, 68, 225-233, (1999).