Modelling the kinetic of biogas production from co-digestion of pig waste and grass clippings
- Authors: Matheri, Anthony Njuguna , Belaid, Mohamed , Seodigeng, Tumisang , Ngila, Catherine Jane
- Date: 2016
- Subjects: Anaerobic , Co-digestion , Kinetics , Mesophilic temperature , Modified gompertz
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/93635 , uj:20372 , Citation: Matheri, A.N. et al. 2016. Modelling the kinetic of biogas production from co-digestion of pig waste and grass clippings.
- Description: Abstract: This work investigated the use of laboratory batch anaerobic digester to derive kinetics parameters for anaerobic co-digestion of pig waste and grass clippings. Laboratory experiment data from 10 litres batch anaerobic digester operating at ambient mesophilic temperature of 37 0C and pH of 6.9 was used to derive parameters for modified Gompertz model. The carbon/nitrogen (C/N) ratio of Pig waste was found to be 16.16 and grass clippings to be 20.54. Through co-digestion in ratio of 1:1, the C/N ratio settled at 17.28. The actual biogas yield was found to be 7725 ml/g COD. In the model of biogas production prediction, the kinetics constants of A (ml/g COD), μ (ml/g COD. day), λ (day) was 7920.70, 701.35, 1.61 respectively with coefficient of determination (R2) of 0.9994. Modified Gompertz plot showed better correlation of cumulative biogas production and these results show biogas production can be enhanced from co-digestion of substrates.
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The kinetic of biogas rate from cow dung and grass clippings
- Authors: Matheri, Anthony Njuguna , Belaid, Mohammed , Seodigeng, Tumisang , Ngila, Catherine Jane
- Date: 2016
- Subjects: Anaerobic digestion , Kinetic models , Modified Gompertz
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/91512 , uj:20110 , Citation: Matheri, A.N. et al. 2016. The kinetic of biogas rate from cow dung and grass clippings.
- Description: Abstract:In this study, we investigated the use of laboratory batch anaerobic digester to derive kinetics parameters for anaerobic co-digestion of cow dung and grass clippings. The Carbon/Nitrogen (C/N) ratio of cow dung was found to be 17.17 and grass clippings to be 20.54. Through co-digestion, the C/N ratio settled at 19.08. Laboratory experimental data from 10 litres batch anaerobic digester operating at mesophilic temperature of 37 0C and pH of 6.9 was used to derive parameters for Modified Gompertz model. The actual biogas yield was found to be 4370 ml/g COD. In the model of biogas production prediction, the kinetics constants of A (ml/g COD), μ (ml/g COD. day), λ (day) were 4319.20, 939.71, 1.91 respectively with coefficient of determination (R2) of 0.996.
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Mesophilic anaerobic co-digestion of cow dung, chicken droppings and grass clippings
- Authors: Matheri, Anthony Njuguna , Belaid, Mohamed , Seodigeng, Tumisang , Ngila, Catherine Jane , Mbohwa, Charles
- Date: 2016
- Subjects: Anaerobic digestion , Co-digestion , Mesophilic temperature
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/214105 , uj:21240 , Citation: Matheri, A.N. et al. 2016. Mesophilic anaerobic co-digestion of cow dung, chicken droppings and grass clippings.
- Description: Abstract: The main focus of this study was mesophilic anaerobic co-digestion of cow dung, chicken droppings and grass clippings using pilot bio-digesters. The biochemical methane potential (BMP) works under batch anaerobic digester operating in ambient mesophilic temperature of 35 oC and 37 0C and pH of 7 to generate biogas. The carbon/nitrogen (C/N) ratio for cow dung and chicken droppings was found to be 17.70 and 63.67 respectively and grass clippings to be 20.54. Through co-digestion in a ratio of 1:1, the C/N ratio for cow dung and grass clippings settled at 19.19 while that for chicken droppings and grass clippings settled at 20.49. The conversion rate of the reaction and biogas production increased with the increase in temperature and hydraulic retention time until an equilibrium state was achieved. At the temperature 37 OC, it was observed to be the suitable mesophilic temperature for anaerobic digestion due to high dissociation and collision leading to high rate of biogas production.
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