Kinetic modelling of the hydrolysis, acidogenic and methanogenic steps in the anaerobic digestion of two-phase olive pomace (TPOP)
Kinetic modelling of the hydrolysis, acidogenic and methanogenic steps in the anaerobic digestion of two-phase olive pomace (TPOP)
A simplified kinetic model for studying the hydrolysis, acidogenic and methanogenic steps of the anaerobic digestion process of two-phase olive pomace (TPOP) was proposed on the basis of the experimental results obtained. The process was conducted in a laboratory-scale completely stirred tank reactor at mesophilic temperature (35 °C) operating at hydraulic retention times (HRT) in the range of 10–50 days. Hydrolysis and acidogenic steps prevailed at HRTs lower than 20 days, while the methanogenic step prevailed at higher HRT values. Four differential equations described the overall process. A first-order kinetics for hydrolysis of non-soluble organic matter and a Michaelis–Menten equation type for soluble organic matter decomposition, total volatile acids consumption and methane production. The following kinetic constants with their standard deviations were obtained for the above-mentioned anaerobic stages: (a) hydrolysis and solubilization of organic matter: k1 (kinetic constant for non-soluble organic matter degradation): 0.054 ± 0.003 day?1; k2 (maximum rate of soluble organic matter production): 4.2 ± 0.3 g soluble chemical oxygen demand (SCOD)/l day; k3 (saturation constant): 9.8 ± 0.5 g SCOD/l; (b) acidogenesis: k4 (maximum rate of soluble organic matter degradation): 3.6 ± 0.2 g SCOD/l day; k5 (saturation constant): 10.2 ± 0.5 g SCOD/l; and (c) methanogenesis: k6 (maximum rate of total volatile acids (TVA) consumption): 4.3 ± 0.2 g TVA-COD/l day; and k7 (saturation constant): 3.1 ± 0.2 g TVA-COD/l. The kinetic constants obtained and the proposed equations were used to simulate the different steps of the anaerobic digestion process of TPOP and to obtain the theoretical values of non-soluble and soluble CODs, TVA and methane production. The small deviations obtained (equal or lower than 10%) between the theoretical and experimental values suggest that the parameters obtained represent and predict the activity of the different microorganism types involved in the overall anaerobic digestion process of this waste.
kinetic modelling, anaerobic digestion, hydrolysis, acidogenic and methanogenic steps, two-phase olive pomace
1841-1847
Borja, R.
ed513484-04ff-4424-ab79-dc715ca63146
Martin, A.
169f0afa-12fc-43b5-a72d-7bfc493aa170
Sánchez, E.
8c460625-8a86-4050-baf5-c0d018fcd770
Rincón, B.
d8fe6652-8ff6-4662-bfb7-3b231d140957
Raposo, F.
47104451-511a-4b03-aaa9-67348da4567d
April 2005
Borja, R.
ed513484-04ff-4424-ab79-dc715ca63146
Martin, A.
169f0afa-12fc-43b5-a72d-7bfc493aa170
Sánchez, E.
8c460625-8a86-4050-baf5-c0d018fcd770
Rincón, B.
d8fe6652-8ff6-4662-bfb7-3b231d140957
Raposo, F.
47104451-511a-4b03-aaa9-67348da4567d
Borja, R., Martin, A., Sánchez, E., Rincón, B. and Raposo, F.
(2005)
Kinetic modelling of the hydrolysis, acidogenic and methanogenic steps in the anaerobic digestion of two-phase olive pomace (TPOP).
Process Biochemistry, 40 (5), .
(doi:10.1016/j.procbio.2004.06.026).
Abstract
A simplified kinetic model for studying the hydrolysis, acidogenic and methanogenic steps of the anaerobic digestion process of two-phase olive pomace (TPOP) was proposed on the basis of the experimental results obtained. The process was conducted in a laboratory-scale completely stirred tank reactor at mesophilic temperature (35 °C) operating at hydraulic retention times (HRT) in the range of 10–50 days. Hydrolysis and acidogenic steps prevailed at HRTs lower than 20 days, while the methanogenic step prevailed at higher HRT values. Four differential equations described the overall process. A first-order kinetics for hydrolysis of non-soluble organic matter and a Michaelis–Menten equation type for soluble organic matter decomposition, total volatile acids consumption and methane production. The following kinetic constants with their standard deviations were obtained for the above-mentioned anaerobic stages: (a) hydrolysis and solubilization of organic matter: k1 (kinetic constant for non-soluble organic matter degradation): 0.054 ± 0.003 day?1; k2 (maximum rate of soluble organic matter production): 4.2 ± 0.3 g soluble chemical oxygen demand (SCOD)/l day; k3 (saturation constant): 9.8 ± 0.5 g SCOD/l; (b) acidogenesis: k4 (maximum rate of soluble organic matter degradation): 3.6 ± 0.2 g SCOD/l day; k5 (saturation constant): 10.2 ± 0.5 g SCOD/l; and (c) methanogenesis: k6 (maximum rate of total volatile acids (TVA) consumption): 4.3 ± 0.2 g TVA-COD/l day; and k7 (saturation constant): 3.1 ± 0.2 g TVA-COD/l. The kinetic constants obtained and the proposed equations were used to simulate the different steps of the anaerobic digestion process of TPOP and to obtain the theoretical values of non-soluble and soluble CODs, TVA and methane production. The small deviations obtained (equal or lower than 10%) between the theoretical and experimental values suggest that the parameters obtained represent and predict the activity of the different microorganism types involved in the overall anaerobic digestion process of this waste.
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Published date: April 2005
Keywords:
kinetic modelling, anaerobic digestion, hydrolysis, acidogenic and methanogenic steps, two-phase olive pomace
Identifiers
Local EPrints ID: 53027
URI: http://eprints.soton.ac.uk/id/eprint/53027
ISSN: 1359-5113
PURE UUID: 7069fb26-747c-4b7e-9d34-b856cdca3559
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Date deposited: 18 Jul 2008
Last modified: 15 Mar 2024 10:39
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Author:
R. Borja
Author:
A. Martin
Author:
E. Sánchez
Author:
B. Rincón
Author:
F. Raposo
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