Design of a biodigester to treat cow dung in Botswana
- Valela, Innocent, Muzenda, Edison
- Authors: Valela, Innocent , Muzenda, Edison
- Date: 2019
- Subjects: Biogas , Cow dung , Design
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/403986 , uj:33871 , Citation: Valela, I. & Muzenda, E. 2019. Design of a biodigester to treat cow dung in Botswana.
- Description: Abstract: The biogas potential of Botswana, a cattle rich nation is explored using dung as a substrate. Biogas could be a good renewable and clean substitute for other forms of energy in rural Botswana, however, the technical and socio-economic potential remains largely unexploited. In this study, the cattle dung was characterized, followed by a lab-scale experiments on the biogas potential yields from the dung. The bio-digester design was selected using the multi criteria decision analysis. From the six digester models that were evaluated for selection, the KVIC was found to be the most suitable with its size ranging from 10 to 100 m3. The bio-digester was subsequently designed using data and mathematical models obtained from literature. The biogas plant was designed for Lemcke’s cattle farm, the best selected site, with 5000 herds. The feedstock was found to have an in-situ density of 1410 kg/m3 with a total solids (TS) content of 18.9%, volatile solids (TS) content of 80%. The suitable digester size was found to be 20 m3. An energy audit showed that the plant had a potential to produce a surplus of 45.3 MWh of energy annually.
- Full Text:
- Authors: Valela, Innocent , Muzenda, Edison
- Date: 2019
- Subjects: Biogas , Cow dung , Design
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/403986 , uj:33871 , Citation: Valela, I. & Muzenda, E. 2019. Design of a biodigester to treat cow dung in Botswana.
- Description: Abstract: The biogas potential of Botswana, a cattle rich nation is explored using dung as a substrate. Biogas could be a good renewable and clean substitute for other forms of energy in rural Botswana, however, the technical and socio-economic potential remains largely unexploited. In this study, the cattle dung was characterized, followed by a lab-scale experiments on the biogas potential yields from the dung. The bio-digester design was selected using the multi criteria decision analysis. From the six digester models that were evaluated for selection, the KVIC was found to be the most suitable with its size ranging from 10 to 100 m3. The bio-digester was subsequently designed using data and mathematical models obtained from literature. The biogas plant was designed for Lemcke’s cattle farm, the best selected site, with 5000 herds. The feedstock was found to have an in-situ density of 1410 kg/m3 with a total solids (TS) content of 18.9%, volatile solids (TS) content of 80%. The suitable digester size was found to be 20 m3. An energy audit showed that the plant had a potential to produce a surplus of 45.3 MWh of energy annually.
- Full Text:
Optimization of biogas production from City of Johannesburg market waste by anaerobic digestion for sustainable energy development
- Authors: Singh, Suraya
- Date: 2018
- Subjects: Biogas , Biomass energy
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/295034 , uj:32113
- Description: M.Tech. (Chemical Engineering) , Abstract: Biogas, as a renewable energy source, is regarded as a viable alternative to the burning of fossil fuels to meet energy demands. The production of biogas to meet energy needs not only has environmental benefits such as reduction in greenhouse gas emissions and responsible waste disposal but also socio-economic benefits, especially when applied to a rural setting, such as improvements in employment, professional qualification and overall food supply of the local population. The main objective of this study was to determine optimum biogas production from City of Johannesburg (CoJ) market waste, composed primarily of fruit and vegetable waste (FVW), under anaerobic condition. The influence of operational factors such as temperature, pH, loading rate and retention time were evaluated. The co-digestion of FVW with cow dung (CD) at varying mixing ratios was also evaluated as a technique to optimize biogas production. Mono-digestion of FVW at thermophilic temperatures were optimum for both biogas and methane production. Changes in organic loading rate (OLR) indicated that with increases in OLR there were increases in both biogas and methane production. The highest biogas and methane production occurred for an OLR of FVW: 200g. The optimum retention time for biogas and methane production was determined to be 14 days and 10 days respectively. The explanation for the prolonged biogas and methane production has been accredited to the fact that there was a greater component of biodegradable material available for breakdown by methanogenic bacteria but even more critical than that was the alkaline pH of 7.18 of this substrate mixture at the commencement of digestion. However, experimental results indicated that co-digestion is the preferred method to optimize biogas and methane production. According to the experimental results obtained, a mixing ratio of FVW: CD of 20:40g is the optimum substrate mixture for both biogas and methane production. The optimum environmental conditions for co-digestion was found to be at 37°C with a pH range between 7.12 to 7.18, while the optimal retention time was found to be 33 days. It was found that when the mixing ratios contained between 50% and less cow dung with corresponding increases in FVW, there were drastic reductions in the digester stability and overall production rates for those substrate mixing ratios. It was therefore concluded that in order to ensure sustained and good biogas and methane production via co-digestion, the CD content should remain above 50% of the total mixture.
- Full Text:
- Authors: Singh, Suraya
- Date: 2018
- Subjects: Biogas , Biomass energy
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/295034 , uj:32113
- Description: M.Tech. (Chemical Engineering) , Abstract: Biogas, as a renewable energy source, is regarded as a viable alternative to the burning of fossil fuels to meet energy demands. The production of biogas to meet energy needs not only has environmental benefits such as reduction in greenhouse gas emissions and responsible waste disposal but also socio-economic benefits, especially when applied to a rural setting, such as improvements in employment, professional qualification and overall food supply of the local population. The main objective of this study was to determine optimum biogas production from City of Johannesburg (CoJ) market waste, composed primarily of fruit and vegetable waste (FVW), under anaerobic condition. The influence of operational factors such as temperature, pH, loading rate and retention time were evaluated. The co-digestion of FVW with cow dung (CD) at varying mixing ratios was also evaluated as a technique to optimize biogas production. Mono-digestion of FVW at thermophilic temperatures were optimum for both biogas and methane production. Changes in organic loading rate (OLR) indicated that with increases in OLR there were increases in both biogas and methane production. The highest biogas and methane production occurred for an OLR of FVW: 200g. The optimum retention time for biogas and methane production was determined to be 14 days and 10 days respectively. The explanation for the prolonged biogas and methane production has been accredited to the fact that there was a greater component of biodegradable material available for breakdown by methanogenic bacteria but even more critical than that was the alkaline pH of 7.18 of this substrate mixture at the commencement of digestion. However, experimental results indicated that co-digestion is the preferred method to optimize biogas and methane production. According to the experimental results obtained, a mixing ratio of FVW: CD of 20:40g is the optimum substrate mixture for both biogas and methane production. The optimum environmental conditions for co-digestion was found to be at 37°C with a pH range between 7.12 to 7.18, while the optimal retention time was found to be 33 days. It was found that when the mixing ratios contained between 50% and less cow dung with corresponding increases in FVW, there were drastic reductions in the digester stability and overall production rates for those substrate mixing ratios. It was therefore concluded that in order to ensure sustained and good biogas and methane production via co-digestion, the CD content should remain above 50% of the total mixture.
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Influence of digestate recirculation and recirculation percentage on biogas production from lawn grass via anaerobic digestion
- Sibiya, Noxolo T., Tesfagiorgis, Habtom B., Muzenda, Edison
- Authors: Sibiya, Noxolo T. , Tesfagiorgis, Habtom B. , Muzenda, Edison
- Date: 2015
- Subjects: Biogas , Digestate , Recirculation
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/72893 , uj:18343 , Citation: Sibiya, N.T., Tesfagiorgis, H.B. & Muzenda, E. 2015. Influence of digestate recirculation and recirculation percentage on biogas production from lawn grass via anaerobic digestion.
- Description: Abstract: Recirculation of digestate either in the form of liquid or solids has proven to enhance biogas production from energy crops including lawn grass. The explanation to this is that digestate contains suitable bacteria and trace elements (nutrients) needed by methanogens. Influence of digestate recirculation and recirculation percentage in biogas production from lawn grass via anaerobic digestion was studied in laboratory scale digester (1L plastic bottles) at mesophilic condition. Three scenarios were used: digester without recycle digestate (control) (WRD), digesters with recycled liquid digestate (RLD) and digesters with recycled solid digestate (RSD). Liquid recycled digestate was added in percentages variation ranging from 10%-60%, solid recycle digestate was added in percentages variation ranging from 10%-50%. The maximum biogas production with methane content of 55% was obtained in the digester with 60% RLD on the 8th day. During the study of recirculation of solids, highest biogas yield with methane content of 53% was observed in a digester with RSD of 40% on the 5th day. Retention time for both digesters with recycled digestate was reduced and biogas production rate was increased compared to the digester with no recycled digestate.
- Full Text:
- Authors: Sibiya, Noxolo T. , Tesfagiorgis, Habtom B. , Muzenda, Edison
- Date: 2015
- Subjects: Biogas , Digestate , Recirculation
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/72893 , uj:18343 , Citation: Sibiya, N.T., Tesfagiorgis, H.B. & Muzenda, E. 2015. Influence of digestate recirculation and recirculation percentage on biogas production from lawn grass via anaerobic digestion.
- Description: Abstract: Recirculation of digestate either in the form of liquid or solids has proven to enhance biogas production from energy crops including lawn grass. The explanation to this is that digestate contains suitable bacteria and trace elements (nutrients) needed by methanogens. Influence of digestate recirculation and recirculation percentage in biogas production from lawn grass via anaerobic digestion was studied in laboratory scale digester (1L plastic bottles) at mesophilic condition. Three scenarios were used: digester without recycle digestate (control) (WRD), digesters with recycled liquid digestate (RLD) and digesters with recycled solid digestate (RSD). Liquid recycled digestate was added in percentages variation ranging from 10%-60%, solid recycle digestate was added in percentages variation ranging from 10%-50%. The maximum biogas production with methane content of 55% was obtained in the digester with 60% RLD on the 8th day. During the study of recirculation of solids, highest biogas yield with methane content of 53% was observed in a digester with RSD of 40% on the 5th day. Retention time for both digesters with recycled digestate was reduced and biogas production rate was increased compared to the digester with no recycled digestate.
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Effect of temperature and pH on the anaerobic digestion of grass silage
- Sibiya, Noxolo T., Muzenda, Edison, Tesfagiorgis, Habtom B.
- Authors: Sibiya, Noxolo T. , Muzenda, Edison , Tesfagiorgis, Habtom B.
- Date: 2014
- Subjects: Biogas , Anaerobic digestion , Grass - Silage , pH (Chemistry) , Anaerobic digestion - Effect of temperature on
- Type: Article
- Identifier: uj:5051 , http://hdl.handle.net/10210/13590
- Description: The operating temperature and pH level in the digester during anaerobic digestion and the retention period are among the major factors that affect the rate of biogas production. Therefore, this paper evaluates the effects of temperature and pH in anaerobic digestion of grass silage. Grass silage was digested in 1000ml at different temperatures (35 ○C, 40 ○C, 45 ○C and 50 ○C) and pH (6.5, 6.8 &7.2). The digesters were shaken everyday to prevent the formation of surface crust which may prevent contact between microorganisms and the substrate. The characteristics of grass and cow dung and the optimal retention time are also reported. The results show that as the temperature was increased the biogas production and methane was also increased, however the high amount of biogas production rate and methane content was observed in the digester operated at 45 ○C and pH of 6.5. The process was carried out for 11days; however the optimal hydraulic retention time for digester that had high biogas was 8 days.
- Full Text:
- Authors: Sibiya, Noxolo T. , Muzenda, Edison , Tesfagiorgis, Habtom B.
- Date: 2014
- Subjects: Biogas , Anaerobic digestion , Grass - Silage , pH (Chemistry) , Anaerobic digestion - Effect of temperature on
- Type: Article
- Identifier: uj:5051 , http://hdl.handle.net/10210/13590
- Description: The operating temperature and pH level in the digester during anaerobic digestion and the retention period are among the major factors that affect the rate of biogas production. Therefore, this paper evaluates the effects of temperature and pH in anaerobic digestion of grass silage. Grass silage was digested in 1000ml at different temperatures (35 ○C, 40 ○C, 45 ○C and 50 ○C) and pH (6.5, 6.8 &7.2). The digesters were shaken everyday to prevent the formation of surface crust which may prevent contact between microorganisms and the substrate. The characteristics of grass and cow dung and the optimal retention time are also reported. The results show that as the temperature was increased the biogas production and methane was also increased, however the high amount of biogas production rate and methane content was observed in the digester operated at 45 ○C and pH of 6.5. The process was carried out for 11days; however the optimal hydraulic retention time for digester that had high biogas was 8 days.
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Studies on the improvement of biogas production from anaerobic digestion of animal wastes
- Authors: Sebola, Mmabyalwa Rebecca
- Date: 2015
- Subjects: Biogas , Sewage - Purification - Anaerobic treatment , Renewable energy sources , Biomass energy
- Language: English
- Type: Master’s Thesis
- Identifier: http://hdl.handle.net/10210/57296 , uj:16377
- Description: Abstract: The unsustainability of intensive reliance on fossil fuels and none-renewable resources as the main sources of energy, frequent rises in energy prices, the need for climate change mitigation and environmental protection have intensified the need for green energy. In this respect, green energy, in the form of biogas, has gained increased attention as a cost effective and environmentally cautious approach. This dissertation presents various studies aimed at improving the biogas production from anaerobic digestion of animal wastes. The experiments were conducted using the batch scale mesophilic tests. Characterisation studies (ultimate and proximate analysis) were conducted to identify key characteristics of the selected feedstocks. In addition, an economic assessment on the feasibility of anaerobic technology was conducted. The waste had average moisture content (MC) ranging from 7 – 34% and 70 – 81% for the dry and wet samples, respectively. The average volatile matter (VM) varied between 44 – 58% with the C/N for CD, CM, PM and SW being 26.20, 8.13, 17.64 and 8.57, respectively. Decreasing the particle size of the feedstock increased the amount of biogas significantly by increasing the total surface area of the material exposed to the anaerobic microbes. At optimal particle size (25μm), methane production was 3 – 30 % higher as compared to that of 100μm and above. Highest methane yields were achieved from CD to CM, PM and SW at ratio of 1:1:1:1. At optimum temperature (40˚C), the highest methane yield (62% CH4/ d) was obtained on Day 6. Adding 50% VS resulted in more methane yields (64% CH4/d) than 30 and 40%. An introduction of 40% recycled liquid and 60% fresh water to the digester gave the best performance, with 73% CH4/d of biogas produced within 5 days. Soaking the feedstock prior digestion improved both the methane and biogas yields and stability of the process. An economic evaluation over a period of 5 years with 8 hours daily operation and a breakeven of 1.5 years was assessed. The proposed model has debt repayments of R 2,478,551 with the total revenue from years 2 – 5 being R 2,360,800, R 2,930,158, R... , M.Tech. (Chemical Engineering)
- Full Text:
- Authors: Sebola, Mmabyalwa Rebecca
- Date: 2015
- Subjects: Biogas , Sewage - Purification - Anaerobic treatment , Renewable energy sources , Biomass energy
- Language: English
- Type: Master’s Thesis
- Identifier: http://hdl.handle.net/10210/57296 , uj:16377
- Description: Abstract: The unsustainability of intensive reliance on fossil fuels and none-renewable resources as the main sources of energy, frequent rises in energy prices, the need for climate change mitigation and environmental protection have intensified the need for green energy. In this respect, green energy, in the form of biogas, has gained increased attention as a cost effective and environmentally cautious approach. This dissertation presents various studies aimed at improving the biogas production from anaerobic digestion of animal wastes. The experiments were conducted using the batch scale mesophilic tests. Characterisation studies (ultimate and proximate analysis) were conducted to identify key characteristics of the selected feedstocks. In addition, an economic assessment on the feasibility of anaerobic technology was conducted. The waste had average moisture content (MC) ranging from 7 – 34% and 70 – 81% for the dry and wet samples, respectively. The average volatile matter (VM) varied between 44 – 58% with the C/N for CD, CM, PM and SW being 26.20, 8.13, 17.64 and 8.57, respectively. Decreasing the particle size of the feedstock increased the amount of biogas significantly by increasing the total surface area of the material exposed to the anaerobic microbes. At optimal particle size (25μm), methane production was 3 – 30 % higher as compared to that of 100μm and above. Highest methane yields were achieved from CD to CM, PM and SW at ratio of 1:1:1:1. At optimum temperature (40˚C), the highest methane yield (62% CH4/ d) was obtained on Day 6. Adding 50% VS resulted in more methane yields (64% CH4/d) than 30 and 40%. An introduction of 40% recycled liquid and 60% fresh water to the digester gave the best performance, with 73% CH4/d of biogas produced within 5 days. Soaking the feedstock prior digestion improved both the methane and biogas yields and stability of the process. An economic evaluation over a period of 5 years with 8 hours daily operation and a breakeven of 1.5 years was assessed. The proposed model has debt repayments of R 2,478,551 with the total revenue from years 2 – 5 being R 2,360,800, R 2,930,158, R... , M.Tech. (Chemical Engineering)
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Effect of nutrient addition during anaerobic digestion of potato peels and maize husk
- Ramatsa, Ishmael, Sibiya, Noxolo, Huberts, Roberth
- Authors: Ramatsa, Ishmael , Sibiya, Noxolo , Huberts, Roberth
- Date: 2014
- Subjects: Anaerobic bacteria , Renewable energy sources , Biomass energy , Biogas
- Type: Article
- Identifier: uj:5091 , http://hdl.handle.net/10210/13681
- Description: The composition of the substrate and nutrients addition plays a very significant role during the production of the biogas. For this reason this paper tries to evaluate the effect of nutrients addition during biogas production under anaerobic conditions. Potato peels wastes and maize husk were anaerobically digested in a 5 liter scale reactor at mesophilic conditions (32 o C). The characteristics of the potato peels were and maize husk are presented in Table 1. The results obtained indicated that the addition of the nutrients during anaerobic digestion has an influence on the biogas production, meanwhile methane content in biogas varied from 48 to 64%.
- Full Text:
- Authors: Ramatsa, Ishmael , Sibiya, Noxolo , Huberts, Roberth
- Date: 2014
- Subjects: Anaerobic bacteria , Renewable energy sources , Biomass energy , Biogas
- Type: Article
- Identifier: uj:5091 , http://hdl.handle.net/10210/13681
- Description: The composition of the substrate and nutrients addition plays a very significant role during the production of the biogas. For this reason this paper tries to evaluate the effect of nutrients addition during biogas production under anaerobic conditions. Potato peels wastes and maize husk were anaerobically digested in a 5 liter scale reactor at mesophilic conditions (32 o C). The characteristics of the potato peels were and maize husk are presented in Table 1. The results obtained indicated that the addition of the nutrients during anaerobic digestion has an influence on the biogas production, meanwhile methane content in biogas varied from 48 to 64%.
- Full Text:
Determination of the potential impact of domestic Anaerobic Digester Systems: a community based research initiative in rural Bangladesh
- Rahman, Khondokar M., Melville, Lynsey, Edwards, David J., Fulford, David, Thwala, Wellington Didibhuku
- Authors: Rahman, Khondokar M. , Melville, Lynsey , Edwards, David J. , Fulford, David , Thwala, Wellington Didibhuku
- Date: 2019
- Subjects: Anaerobic digestion , Biogas , Bangladesh
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/405057 , uj:33996 , Citation: Rahman, K.M., et al. 2019 : Determination of the potential impact of domestic Anaerobic Digester Systems: a community based research initiative in rural Bangladesh.
- Description: Abstract : This research examines the potential impact of domestic anaerobic digester (AD) systems adopted in Bangladesh and similar developing countries. Cattle dung and poultry litter feed stocks were specifically investigated, because these were freely available and plentiful to people living within agricultural areas of rural Bangladesh. Data was collected to ascertain whether these two representative AD facility types provide tangible social, economic and environmental impact that benefits homeowners. Primary quantitative and qualitative data was obtained by field data collection, and meeting with expert groups and stakeholders. Empirical analysis conducted revealed that variations were found in the biomass feedstocks available on different sites but also differences were apparent in terms of the operations and maintenance (O and M) systems of the biogas plants operated. The biogas and methane yield variation was also measured, and variations were found in the cattle dung and poultry litter AD yield capacity. Overall, 64% of feedstock was utilised, 91% of biogas plants remain underfed and energy yield efficiency was 57% from cattle smallholdings’ AD and 28% from poultry farms’ AD. These results showed that small scale AD can offer a significant impact upon rural lifestyles through augmented economics, improved social activities, relationship building with neighbours and improved lifestyle achieved via time savings accrued. These results could help rural entrepreneurs, AD equipment providers and government institutions to develop a road map to implement future AD installation on a much wider geographical scale.
- Full Text:
- Authors: Rahman, Khondokar M. , Melville, Lynsey , Edwards, David J. , Fulford, David , Thwala, Wellington Didibhuku
- Date: 2019
- Subjects: Anaerobic digestion , Biogas , Bangladesh
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/405057 , uj:33996 , Citation: Rahman, K.M., et al. 2019 : Determination of the potential impact of domestic Anaerobic Digester Systems: a community based research initiative in rural Bangladesh.
- Description: Abstract : This research examines the potential impact of domestic anaerobic digester (AD) systems adopted in Bangladesh and similar developing countries. Cattle dung and poultry litter feed stocks were specifically investigated, because these were freely available and plentiful to people living within agricultural areas of rural Bangladesh. Data was collected to ascertain whether these two representative AD facility types provide tangible social, economic and environmental impact that benefits homeowners. Primary quantitative and qualitative data was obtained by field data collection, and meeting with expert groups and stakeholders. Empirical analysis conducted revealed that variations were found in the biomass feedstocks available on different sites but also differences were apparent in terms of the operations and maintenance (O and M) systems of the biogas plants operated. The biogas and methane yield variation was also measured, and variations were found in the cattle dung and poultry litter AD yield capacity. Overall, 64% of feedstock was utilised, 91% of biogas plants remain underfed and energy yield efficiency was 57% from cattle smallholdings’ AD and 28% from poultry farms’ AD. These results showed that small scale AD can offer a significant impact upon rural lifestyles through augmented economics, improved social activities, relationship building with neighbours and improved lifestyle achieved via time savings accrued. These results could help rural entrepreneurs, AD equipment providers and government institutions to develop a road map to implement future AD installation on a much wider geographical scale.
- Full Text:
Municipal solid waste utilisation for green energy in Gauteng province - South Africa : a review
- Pilusa, Tsietsi J., Muzenda, Edison
- Authors: Pilusa, Tsietsi J. , Muzenda, Edison
- Date: 2014
- Subjects: Biogas , Solid waste management - South Africa - Johannesburg , Green energy
- Type: Article
- Identifier: uj:4958 , http://hdl.handle.net/10210/13059
- Description: This short paper discusses the potential of utilizing various municipal solids waste streams as feed stock for green energy production. These waste streams includes but not limited to mixed combustible waste, rubber and plastic waste, health care risk waste, organic biodegradable waste, biomass and sewage sludge. Technologies such as anaerobic digestion, gasification and pyrolysis have been reviewed relative to the location and waste stream quantities in the selected sample area. It was discovered that there are environmental, social and economic benefits in waste to energy approach for the waste streams reviewed. The feasibility of implementing such technologies is mainly dependent on the initial capital investment and operational cost of the facility. Other factors include the size of the waste stream, product price and demand.
- Full Text:
- Authors: Pilusa, Tsietsi J. , Muzenda, Edison
- Date: 2014
- Subjects: Biogas , Solid waste management - South Africa - Johannesburg , Green energy
- Type: Article
- Identifier: uj:4958 , http://hdl.handle.net/10210/13059
- Description: This short paper discusses the potential of utilizing various municipal solids waste streams as feed stock for green energy production. These waste streams includes but not limited to mixed combustible waste, rubber and plastic waste, health care risk waste, organic biodegradable waste, biomass and sewage sludge. Technologies such as anaerobic digestion, gasification and pyrolysis have been reviewed relative to the location and waste stream quantities in the selected sample area. It was discovered that there are environmental, social and economic benefits in waste to energy approach for the waste streams reviewed. The feasibility of implementing such technologies is mainly dependent on the initial capital investment and operational cost of the facility. Other factors include the size of the waste stream, product price and demand.
- Full Text:
A review of biogas production optimization from grass silage
- Muzenda, Edison, Sibiya, Noxolo
- Authors: Muzenda, Edison , Sibiya, Noxolo
- Date: 2014
- Subjects: Biogas , Grass - Silage , Anaerobic digestion
- Type: Article
- Identifier: uj:5033 , http://hdl.handle.net/10210/13553
- Description: Anaerobic digestion (AD) of organic materials offers an alternative source of renewable energy, as bio-methane has a potential to replace fossil fuels for energy production for heat and power, vehicular fuel and as well as valuable material recovery. In addition AD can address pollution problems by minimizing and utilizing biodegradable waste. This is a well-researched and technologically advanced technique with various successful small to large scale plants in the developed world. For developing countries, not much success has been reported due to operational and maintenance challenges, low biogas production and public perceptions among other several contributing factors. This paper reviews AD process optimization focusing on parameters such as temperature, pH, loading rate, hydraulic retention time and agitation. Several studies have shown optimum biogas production from grass in mesophilic, alkaline or neutral conditions at retention times of about 30 days. This review is the background and basis of our current work on optimizing biogas production from selected South African grass species.
- Full Text:
- Authors: Muzenda, Edison , Sibiya, Noxolo
- Date: 2014
- Subjects: Biogas , Grass - Silage , Anaerobic digestion
- Type: Article
- Identifier: uj:5033 , http://hdl.handle.net/10210/13553
- Description: Anaerobic digestion (AD) of organic materials offers an alternative source of renewable energy, as bio-methane has a potential to replace fossil fuels for energy production for heat and power, vehicular fuel and as well as valuable material recovery. In addition AD can address pollution problems by minimizing and utilizing biodegradable waste. This is a well-researched and technologically advanced technique with various successful small to large scale plants in the developed world. For developing countries, not much success has been reported due to operational and maintenance challenges, low biogas production and public perceptions among other several contributing factors. This paper reviews AD process optimization focusing on parameters such as temperature, pH, loading rate, hydraulic retention time and agitation. Several studies have shown optimum biogas production from grass in mesophilic, alkaline or neutral conditions at retention times of about 30 days. This review is the background and basis of our current work on optimizing biogas production from selected South African grass species.
- Full Text:
Bio-methane generation from organic waste : a review
- Authors: Muzenda, Edison
- Date: 2014
- Subjects: Anaerobic digestion , Biodegradable material , Biogas
- Type: Article
- Identifier: uj:4987 , ISSN 2078-0966 , http://hdl.handle.net/10210/13119
- Description: Anaerobic digestion of organic waste can address both energy recovery and pollution control. A variety of agricultural, industrial and domestic wastes can be anaerobically digested as they contain easily biodegradable material. Biogas contains 50 -70% methane and 30-50% carbon dioxide as well as small a amounts of other gases with calorific value of about 21-24 MJ/m3. This paper reviews the history of biogas, biogas production stages and operating parameters. The anaerobic digestion configuration and potential substrates for biogas production are also considered.
- Full Text:
- Authors: Muzenda, Edison
- Date: 2014
- Subjects: Anaerobic digestion , Biodegradable material , Biogas
- Type: Article
- Identifier: uj:4987 , ISSN 2078-0966 , http://hdl.handle.net/10210/13119
- Description: Anaerobic digestion of organic waste can address both energy recovery and pollution control. A variety of agricultural, industrial and domestic wastes can be anaerobically digested as they contain easily biodegradable material. Biogas contains 50 -70% methane and 30-50% carbon dioxide as well as small a amounts of other gases with calorific value of about 21-24 MJ/m3. This paper reviews the history of biogas, biogas production stages and operating parameters. The anaerobic digestion configuration and potential substrates for biogas production are also considered.
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Bio-methane potential of the organic fraction of municipal solid waste
- Mojapelo, N., Muzenda, Edison, Kigozi, R., Aboyade, A. O.
- Authors: Mojapelo, N. , Muzenda, Edison , Kigozi, R. , Aboyade, A. O.
- Date: 2014
- Subjects: Biogas , Bio-methane , Municipal solid waste
- Type: Article
- Identifier: uj:5022 , http://hdl.handle.net/10210/13165
- Description: Biogas is a gas formed from the breakdown of biomass by microorganisms in an anaerobic environment composed of methane (50%–70%) and carbon dioxide (30%–50%). The upgrading of biogas by the removal of carbon dioxide to increase the percentage of methane to over 92% produces bio-methane which is a potent versatile clean fuel. This paper represents a study that was carried out at the University of Johannesburg’s Doornfontein Campus (UJ DFC) to ascertain the potential of bio-methane recovery from the organic fraction of municipal solid waste (OFMSW) collected at the campus’ cafeteria and student residences. ...
- Full Text:
- Authors: Mojapelo, N. , Muzenda, Edison , Kigozi, R. , Aboyade, A. O.
- Date: 2014
- Subjects: Biogas , Bio-methane , Municipal solid waste
- Type: Article
- Identifier: uj:5022 , http://hdl.handle.net/10210/13165
- Description: Biogas is a gas formed from the breakdown of biomass by microorganisms in an anaerobic environment composed of methane (50%–70%) and carbon dioxide (30%–50%). The upgrading of biogas by the removal of carbon dioxide to increase the percentage of methane to over 92% produces bio-methane which is a potent versatile clean fuel. This paper represents a study that was carried out at the University of Johannesburg’s Doornfontein Campus (UJ DFC) to ascertain the potential of bio-methane recovery from the organic fraction of municipal solid waste (OFMSW) collected at the campus’ cafeteria and student residences. ...
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Mathematical modelling for biogas production
- Authors: Matheri, Anthony Njuguna
- Date: 2016
- Subjects: Sewage - Purification - Anaerobic treatment , Sewage - Purification - Mathematical models , Renewable energy sources , Biomass energy , Biogas
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/213006 , uj:21066
- Description: Abstract: The main focus of this dissertation is the experimental, modelling and simulation of anaerobic digestion processes from pilot bio-digesters. For this purpose, biochemical kinetic models were utilized together with corresponding simulation software; DYNOCHEM. By application of the anaerobic digestion (AD), different parameters have been investigated and simulated including adjustments of the process model and corresponding modifications. To validate the process model, the modelled data was compared with experimental monitored laboratory results. Bio-chemical kinetics modelling was applied as a systematic tool in order to support the process design and optimization of a demonstration of the biogas processes which constitutes the main scientific framework and background of this dissertation. Monitored laboratory-scale biogas production data were used for parameter calibration in order to predict plant performance. The calibration focused on the influent characterization of both substrates and on selection of kinetic of the coefficients in order to generate a uniform set of parameters which are applicable for the simulation of codigestion. In this study, it was observed that the experiment work under laboratory scale using conventional bio-methane potential (BMP) analyzers under mesophilic optimum temperature of 35 oC and 37 oC, and pH of 7 for co-digestion of organic fraction of municipal solid waste (OFMSW) with cow dung and manure with grass clippings. The substrate characterization moisture content ranged from 60-95%, volatile content 55-95%, total solid 10-90% and carbon to nitrogen ratio 16-20 for manure and 5-15 for OFMSW. All trace elements concentration were below the threshold of 32 mg/l that leads to inhibition of micro-organisms activity. The rate of conversion increased with retention time. According to the findings, 54-62% of methane composition was evaluated. The kinetics constant evaluated ranged from 0.009-0.35 d-1 and coefficient of determination (R2) ranged from 0.9989-0.9998. The Michaelis-Menten and Monod models provided goodness of fit of 0.9997 with confidential level of 95%. The simulations confirmed that the rate of conversion increased as temperature increases and conversion of reactants increased with retention time, until an equilibrium state was reached. The AD process modelling using DYNOCHEM was successfully modified and implemented to account for unsteady operation which is generally the case of full-scale reactor by developed methodology. , M.Tech. (Chemical Engineering)
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- Authors: Matheri, Anthony Njuguna
- Date: 2016
- Subjects: Sewage - Purification - Anaerobic treatment , Sewage - Purification - Mathematical models , Renewable energy sources , Biomass energy , Biogas
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/213006 , uj:21066
- Description: Abstract: The main focus of this dissertation is the experimental, modelling and simulation of anaerobic digestion processes from pilot bio-digesters. For this purpose, biochemical kinetic models were utilized together with corresponding simulation software; DYNOCHEM. By application of the anaerobic digestion (AD), different parameters have been investigated and simulated including adjustments of the process model and corresponding modifications. To validate the process model, the modelled data was compared with experimental monitored laboratory results. Bio-chemical kinetics modelling was applied as a systematic tool in order to support the process design and optimization of a demonstration of the biogas processes which constitutes the main scientific framework and background of this dissertation. Monitored laboratory-scale biogas production data were used for parameter calibration in order to predict plant performance. The calibration focused on the influent characterization of both substrates and on selection of kinetic of the coefficients in order to generate a uniform set of parameters which are applicable for the simulation of codigestion. In this study, it was observed that the experiment work under laboratory scale using conventional bio-methane potential (BMP) analyzers under mesophilic optimum temperature of 35 oC and 37 oC, and pH of 7 for co-digestion of organic fraction of municipal solid waste (OFMSW) with cow dung and manure with grass clippings. The substrate characterization moisture content ranged from 60-95%, volatile content 55-95%, total solid 10-90% and carbon to nitrogen ratio 16-20 for manure and 5-15 for OFMSW. All trace elements concentration were below the threshold of 32 mg/l that leads to inhibition of micro-organisms activity. The rate of conversion increased with retention time. According to the findings, 54-62% of methane composition was evaluated. The kinetics constant evaluated ranged from 0.009-0.35 d-1 and coefficient of determination (R2) ranged from 0.9989-0.9998. The Michaelis-Menten and Monod models provided goodness of fit of 0.9997 with confidential level of 95%. The simulations confirmed that the rate of conversion increased as temperature increases and conversion of reactants increased with retention time, until an equilibrium state was reached. The AD process modelling using DYNOCHEM was successfully modified and implemented to account for unsteady operation which is generally the case of full-scale reactor by developed methodology. , M.Tech. (Chemical Engineering)
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Green energy (biomethane) production from codigestion of abattoir, market and grass waste as substrates
- Matheri, Anthony Njuguna, Mwiinga, Masonga Sichibanze, Zelda, Rasmeni Zenzile, Mohamed, Belaid
- Authors: Matheri, Anthony Njuguna , Mwiinga, Masonga Sichibanze , Zelda, Rasmeni Zenzile , Mohamed, Belaid
- Date: 2019
- Subjects: Biogas , Biomethane , Digestion
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/402179 , uj:33645 , Citation: Matheri, A.N. et al. 2019. Green energy (biomethane) production from codigestion of abattoir, market and grass waste as substrates.
- Description: Abstract: South Africa had in the past years been experiencing an increased energy demand. High energy crisis called for research and development in a quest for alternative energy sources (waste to energy) that drive the Nation economy forward in line with Sustainable and National development goals. Utilizing organic waste to produce biogas as a source of energy could significantly help alleviate this problem. Biogas is renewable energy, a mixture primarily consisting of methane (CH4) and carbon dioxide (CO2). The study evaluated mono-digestion of market waste (MW), abattoir waste (AW), and grass (G) and co-digestion of the three mix of substrate by determining their biomethane potential under mesophilic conditions of 37oC. It was found that the mono-digestion of grass produced high methane (1035.3 Nml) after the stipulated 14 days of hydraulic retention time, Abattoir waste, and market waste produced 722.1 Nml and 470.7 Nml of methane respectively, and the co- digestion of all substrates produced 1013.1 Nml of methane after 14 days. Co-digestion of the substrates assisted to regulate the anaerobic digestion condition or variables for biomethane production. Co-digestion of the substrate was recommended for optimality or increase in methane yield.
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- Authors: Matheri, Anthony Njuguna , Mwiinga, Masonga Sichibanze , Zelda, Rasmeni Zenzile , Mohamed, Belaid
- Date: 2019
- Subjects: Biogas , Biomethane , Digestion
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/402179 , uj:33645 , Citation: Matheri, A.N. et al. 2019. Green energy (biomethane) production from codigestion of abattoir, market and grass waste as substrates.
- Description: Abstract: South Africa had in the past years been experiencing an increased energy demand. High energy crisis called for research and development in a quest for alternative energy sources (waste to energy) that drive the Nation economy forward in line with Sustainable and National development goals. Utilizing organic waste to produce biogas as a source of energy could significantly help alleviate this problem. Biogas is renewable energy, a mixture primarily consisting of methane (CH4) and carbon dioxide (CO2). The study evaluated mono-digestion of market waste (MW), abattoir waste (AW), and grass (G) and co-digestion of the three mix of substrate by determining their biomethane potential under mesophilic conditions of 37oC. It was found that the mono-digestion of grass produced high methane (1035.3 Nml) after the stipulated 14 days of hydraulic retention time, Abattoir waste, and market waste produced 722.1 Nml and 470.7 Nml of methane respectively, and the co- digestion of all substrates produced 1013.1 Nml of methane after 14 days. Co-digestion of the substrates assisted to regulate the anaerobic digestion condition or variables for biomethane production. Co-digestion of the substrate was recommended for optimality or increase in methane yield.
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Optimising biogas production from anaerobic co-digestion of chicken manure and organic fraction of municipal solid waste
- Matheri, A. N., Ndiweni, S. N., Belaid, M., Muzenda, E., Hubert, R.
- Authors: Matheri, A. N. , Ndiweni, S. N. , Belaid, M. , Muzenda, E. , Hubert, R.
- Date: 2017
- Subjects: Anaerobic , Biogas , Co-digestion
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/241017 , uj:24803 , Citation: Matheri, A.N. et al. 2017. Optimising biogas production from anaerobic co-digestion of chicken manure and organic fraction of municipal solid waste.
- Description: Abstract: In this study, it was observed that in experimental work under laboratory scale using conventional biochemical methane potential (BMP) assay, the loading rate ratio 4:1 had optimum biodegradability rate than other ratios which were investigated, while the loading rate ratio of 1:1 had optimum biogas and methane yield after 15 days hydraulic retention time. It was concluded that chicken waste (CM) monodigestion has higher biodegradability rate compare to organic fraction municipality solid waste (OFMSW) mono-digestion. Co-digestion of OFMSW and CM stabilizes conditions in digestion process such as carbon to nitrogen (C:N) ratio in the substrate mixtures as well as macro and micronutrients, pH, inhibitors or toxic compounds, dry matter and thus increasing biogas production. It was concluded that the organic waste generated in the municipal landfills could be co-digested with CM to produce methane which can be used as a source of environmentally friendly and clean energy for the transport sector, industries and residential homes.
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- Authors: Matheri, A. N. , Ndiweni, S. N. , Belaid, M. , Muzenda, E. , Hubert, R.
- Date: 2017
- Subjects: Anaerobic , Biogas , Co-digestion
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/241017 , uj:24803 , Citation: Matheri, A.N. et al. 2017. Optimising biogas production from anaerobic co-digestion of chicken manure and organic fraction of municipal solid waste.
- Description: Abstract: In this study, it was observed that in experimental work under laboratory scale using conventional biochemical methane potential (BMP) assay, the loading rate ratio 4:1 had optimum biodegradability rate than other ratios which were investigated, while the loading rate ratio of 1:1 had optimum biogas and methane yield after 15 days hydraulic retention time. It was concluded that chicken waste (CM) monodigestion has higher biodegradability rate compare to organic fraction municipality solid waste (OFMSW) mono-digestion. Co-digestion of OFMSW and CM stabilizes conditions in digestion process such as carbon to nitrogen (C:N) ratio in the substrate mixtures as well as macro and micronutrients, pH, inhibitors or toxic compounds, dry matter and thus increasing biogas production. It was concluded that the organic waste generated in the municipal landfills could be co-digested with CM to produce methane which can be used as a source of environmentally friendly and clean energy for the transport sector, industries and residential homes.
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Parametric study of single and double stage membrane configuration in methane enrichment process
- Masebinu, S. O., Aboyade, A. O., Muzenda, E.
- Authors: Masebinu, S. O. , Aboyade, A. O. , Muzenda, E.
- Date: 2014
- Subjects: Biogas , Methane enrichment , Membrane configuration
- Type: Article
- Identifier: uj:5003 , http://hdl.handle.net/10210/13143
- Description: Operational study of a biogas upgrading plant with cleaning and methane (CH4) enrichment has been presented in this study. Parametric study was conducted to investigate the effect of variation of process conditions for single stage without recycle (SSWR) and double stage with permeate recycle (DSPR) on product purity, CH4 recovery and compression power requirement. In the study, achieving high CH4 recovery and product purity simultaneously could not be attained in SSWR configuration. The performance of DSPR yielded a better result but with higher membrane area and compression power. DSPR configuration achieved high CH4 recovery and purity at increasing feed pressure, selectivity and feed flow. The CH4 losses increased in both configurations as %CO2 increased in the feed. DSPR configuration is considered the best configuration due to the end use of the product, as vehicular fuel, which requires high product purity.
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- Authors: Masebinu, S. O. , Aboyade, A. O. , Muzenda, E.
- Date: 2014
- Subjects: Biogas , Methane enrichment , Membrane configuration
- Type: Article
- Identifier: uj:5003 , http://hdl.handle.net/10210/13143
- Description: Operational study of a biogas upgrading plant with cleaning and methane (CH4) enrichment has been presented in this study. Parametric study was conducted to investigate the effect of variation of process conditions for single stage without recycle (SSWR) and double stage with permeate recycle (DSPR) on product purity, CH4 recovery and compression power requirement. In the study, achieving high CH4 recovery and product purity simultaneously could not be attained in SSWR configuration. The performance of DSPR yielded a better result but with higher membrane area and compression power. DSPR configuration achieved high CH4 recovery and purity at increasing feed pressure, selectivity and feed flow. The CH4 losses increased in both configurations as %CO2 increased in the feed. DSPR configuration is considered the best configuration due to the end use of the product, as vehicular fuel, which requires high product purity.
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Enrichment of biogas for use as vehicular fuel: a review of the upgrading techniques
- Masebinu, S. O., Aboyade, A., Muzenda, Edison
- Authors: Masebinu, S. O. , Aboyade, A. , Muzenda, Edison
- Date: 2014
- Subjects: Biogas , Biogas enrichment
- Type: Article
- Identifier: uj:4912 , ISSN 2349-1442 , http://hdl.handle.net/10210/13012
- Description: Biogas, a renewable energy, can be captured, upgraded and used to fuel a vehicle as an alternative to fossil fuel, thus, reducing greenhouse gas emission. Biogas is environmentally hazardous if emitted directly into the environment. Increasing demand for bio-methane to be used as vehicular fuel has called for efficient use of waste and technology that is optimal yet economical. Biogas in its raw state contains impurities that reduce its heating value to be used directly as fuel, hence, a need to enhance it by upgrading to bio-methane. Several techniques exist for upgrading biogas to bio-methane. This paper present four upgrading techniques; absorption, adsorption, membrane and cryogenic techniques, a brief theoretical background, advantages and operational issues associated with each technique.
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- Authors: Masebinu, S. O. , Aboyade, A. , Muzenda, Edison
- Date: 2014
- Subjects: Biogas , Biogas enrichment
- Type: Article
- Identifier: uj:4912 , ISSN 2349-1442 , http://hdl.handle.net/10210/13012
- Description: Biogas, a renewable energy, can be captured, upgraded and used to fuel a vehicle as an alternative to fossil fuel, thus, reducing greenhouse gas emission. Biogas is environmentally hazardous if emitted directly into the environment. Increasing demand for bio-methane to be used as vehicular fuel has called for efficient use of waste and technology that is optimal yet economical. Biogas in its raw state contains impurities that reduce its heating value to be used directly as fuel, hence, a need to enhance it by upgrading to bio-methane. Several techniques exist for upgrading biogas to bio-methane. This paper present four upgrading techniques; absorption, adsorption, membrane and cryogenic techniques, a brief theoretical background, advantages and operational issues associated with each technique.
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Operational study and simulation of a biogas upgrading plant
- Masebinu, S. O., Aboyade, A. O., Muzenda, E.
- Authors: Masebinu, S. O. , Aboyade, A. O. , Muzenda, E.
- Date: 2014
- Subjects: Gas permeation , Biogas , Methane recovery
- Type: Article
- Identifier: uj:5020 , http://hdl.handle.net/10210/13163
- Description: The drive for finding alternative energy to supplement fossil based fuel within the South African energy sector has led to research on waste to energy in particular biomethane as vehicular fuels. Biogas is produced from the anaerobic decomposition of organic matter with 40-70% vol. of methane. Biogas if upgraded, by removing the non-combustible component, can achieve 99% methane concentration which makes it a potent vehicle fuel and a direct substitute to natural gas. In this paper, a biogas upgrading plant operation that uses gas permeation technique for methane enrichment of biogas was studied and simulated. The effect of recycling permeate stream on methane recovery was studied. Recycling of the permeate stream improved the methane recovery of the simulated process by 18%. The overall methane recovery of the simulated process is 81.23%.
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- Authors: Masebinu, S. O. , Aboyade, A. O. , Muzenda, E.
- Date: 2014
- Subjects: Gas permeation , Biogas , Methane recovery
- Type: Article
- Identifier: uj:5020 , http://hdl.handle.net/10210/13163
- Description: The drive for finding alternative energy to supplement fossil based fuel within the South African energy sector has led to research on waste to energy in particular biomethane as vehicular fuels. Biogas is produced from the anaerobic decomposition of organic matter with 40-70% vol. of methane. Biogas if upgraded, by removing the non-combustible component, can achieve 99% methane concentration which makes it a potent vehicle fuel and a direct substitute to natural gas. In this paper, a biogas upgrading plant operation that uses gas permeation technique for methane enrichment of biogas was studied and simulated. The effect of recycling permeate stream on methane recovery was studied. Recycling of the permeate stream improved the methane recovery of the simulated process by 18%. The overall methane recovery of the simulated process is 81.23%.
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Anaerobic treatment of opaque beer wastewater with enhanced biogas recovery through Acti-zyme bio augmentation
- Manyuchi, M. M., Mbohwa, Charles, Muzenda, E.
- Authors: Manyuchi, M. M. , Mbohwa, Charles , Muzenda, E.
- Date: 2018
- Subjects: Bio augmentation , Biogas , BOD/COD
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/285563 , uj:30884 , Citation: Manyuchi, M.M., Mbohwa, C. & Muzenda, E. 2018. Anaerobic treatment of opaque beer wastewater with enhanced biogas recovery through Acti-zyme bio augmentation. South African Journal of Chemical Engineering, 26:74-79. , Link to Published Version: https://doi.org/10.1016/j.sajce.2018.10.002
- Description: Abstract: This study investigates the potentially of biologically treating opaque beer wastewater using the bio augmentation technology at the same time harnessing biogas and bio solids as value added products. Wastewater sample were collected in 5L containers and the sludge was separated from the liquid. The liquid and sludge were bio augmented with Acti-zyme with loadings of 5 g/L, 10 g/L and 15 g/L and were left to settle over a period of 30 days under anaerobic conditions. The wastewater and treated effluent BOD, COD, TKN, TP, TSS, TDS and pH were measured using standard methods. Whereas the amount of biogas generated was measured using the water displacement and its composition quantified. The BOD, COD, TKN, TP, TSS, TDS were significantly reduced by 93%, 77%, 87%, 89%, 90% and 90% respectively. The BOD/COD ratio was 0.72 initially and reduced to 0.21 for all the Acti-zyme loadings. Biogas with a methane composition of 65–70% was recovered.
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- Authors: Manyuchi, M. M. , Mbohwa, Charles , Muzenda, E.
- Date: 2018
- Subjects: Bio augmentation , Biogas , BOD/COD
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/285563 , uj:30884 , Citation: Manyuchi, M.M., Mbohwa, C. & Muzenda, E. 2018. Anaerobic treatment of opaque beer wastewater with enhanced biogas recovery through Acti-zyme bio augmentation. South African Journal of Chemical Engineering, 26:74-79. , Link to Published Version: https://doi.org/10.1016/j.sajce.2018.10.002
- Description: Abstract: This study investigates the potentially of biologically treating opaque beer wastewater using the bio augmentation technology at the same time harnessing biogas and bio solids as value added products. Wastewater sample were collected in 5L containers and the sludge was separated from the liquid. The liquid and sludge were bio augmented with Acti-zyme with loadings of 5 g/L, 10 g/L and 15 g/L and were left to settle over a period of 30 days under anaerobic conditions. The wastewater and treated effluent BOD, COD, TKN, TP, TSS, TDS and pH were measured using standard methods. Whereas the amount of biogas generated was measured using the water displacement and its composition quantified. The BOD, COD, TKN, TP, TSS, TDS were significantly reduced by 93%, 77%, 87%, 89%, 90% and 90% respectively. The BOD/COD ratio was 0.72 initially and reduced to 0.21 for all the Acti-zyme loadings. Biogas with a methane composition of 65–70% was recovered.
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Summary-view : biomass anaerobic respiration technology in South Africa
- Manala, Cecil, Madyira, Daniel, Mbohwa, Charles, Shuma, Ruben
- Authors: Manala, Cecil , Madyira, Daniel , Mbohwa, Charles , Shuma, Ruben
- Date: 2016
- Subjects: Anaerobic respiration , Bio-digester , Biogas
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/217135 , uj:21602 , Citation: Manala, C. et al. 2016. Summary-view : biomass anaerobic respiration technology in South Africa.
- Description: Abstract: This paper reports on a biomass anaerobic decomposition technologies with particular reference to South Africa as a developing country taking strides on green energy production in an effort to lower the carbon foot print and preserve the environment. It explores the utilisation, implementation and operation of biomass anaerobic respiration technology in the production of biogas as an emerging alternative energy source. This review is a summary of different aspects of the design and operation of small-scale, household, biogas digester technologies. It covers different biomass anaerobic technology projects, both small and large scale (municipal solid waste, abattoirs, farms, wastewater treatment facilities) currently in operation and under construction in the republic of South Africa from the introduction of the technology through to the current generation of the technology. This also includes projects that were visited during the City of Johannesburg-University of Johannesburg waste to energy project capacity building exercise. Various efforts have been made in the past to assess the feasibility of the application of biogas technology in South Africa. These are identified mainly by reviewing the available literature. Recommendations are made on how best to tackle biogas production challenges and promote the notion of biogas production in South Africa.
- Full Text: false
- Authors: Manala, Cecil , Madyira, Daniel , Mbohwa, Charles , Shuma, Ruben
- Date: 2016
- Subjects: Anaerobic respiration , Bio-digester , Biogas
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/217135 , uj:21602 , Citation: Manala, C. et al. 2016. Summary-view : biomass anaerobic respiration technology in South Africa.
- Description: Abstract: This paper reports on a biomass anaerobic decomposition technologies with particular reference to South Africa as a developing country taking strides on green energy production in an effort to lower the carbon foot print and preserve the environment. It explores the utilisation, implementation and operation of biomass anaerobic respiration technology in the production of biogas as an emerging alternative energy source. This review is a summary of different aspects of the design and operation of small-scale, household, biogas digester technologies. It covers different biomass anaerobic technology projects, both small and large scale (municipal solid waste, abattoirs, farms, wastewater treatment facilities) currently in operation and under construction in the republic of South Africa from the introduction of the technology through to the current generation of the technology. This also includes projects that were visited during the City of Johannesburg-University of Johannesburg waste to energy project capacity building exercise. Various efforts have been made in the past to assess the feasibility of the application of biogas technology in South Africa. These are identified mainly by reviewing the available literature. Recommendations are made on how best to tackle biogas production challenges and promote the notion of biogas production in South Africa.
- Full Text: false
Biogas purification and upgrading for vehicular fuel application
- Authors: Maile, Olivia Ireen
- Date: 2016
- Subjects: Reneable energy sources , Biogas , Biomass energy
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/243015 , uj:25082
- Description: M.Tech. (Chemical Engineering) , Abstract: Energy is used in the form of electricity, heat, and fuel for lighting, cooking, transportation, and manufacturing of different kind of products. South Africa has faced a long-term struggle on energy shortages which may be related to the 20% growth in the country’s electricity consumption and underinvestment on energy. Thus, the need for producing clean energy from alternative renewable and sustainable energy sources remains an attractive technology. Biogas is energy produced by anaerobic digestion of biodegradable organic waste such as garden waste, food waste, municipal waste, industrial waste and sewage sludge. However, it may not be fully exploited because it contains impurities which limit its application. It can be purified and upgraded using techniques such as high-pressure water scrubbing, pressure swing adsorption, membrane separation, activated carbon sieve, cryogenic separation, chemical absorption. This study focuses on chemical absorption as it can yield biogas with over 95 % CH4 by volume. The substrate used to produce biogas in this study was grass inoculated with cow dung. Sodium hydroxide and acetic acid were used to adjust the pH of the feedstock. The chemicals absorbents of focus are sodium hydroxide, potassium hydroxide, ammonia solution and monoethanolamine. Two kinds of setups were used for this study; biochemical methane potential (BMP) assay tests using the Bioprocess Control AMPTS II and a custom made setup using Buchner flasks. Gas Chromatography was used for biogas analysis. The raw biogas contained on average 52% CH4 by volume which improved to over 80% CH4 after CO2 absorption. The CO2 removal efficiency improved from 22% to 66% for the alkalis and was also quite comparable for MEA and NH3 as it increased from 51% to 67%. The removal efficiency for NH3 and MEA increased from 69% to 79% on average with CH4 concentration reaching over 85% volume at 40 °C. The achievable calorific value for this study ranged from 25 to 33.5 MJ/Nm3.
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- Authors: Maile, Olivia Ireen
- Date: 2016
- Subjects: Reneable energy sources , Biogas , Biomass energy
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/243015 , uj:25082
- Description: M.Tech. (Chemical Engineering) , Abstract: Energy is used in the form of electricity, heat, and fuel for lighting, cooking, transportation, and manufacturing of different kind of products. South Africa has faced a long-term struggle on energy shortages which may be related to the 20% growth in the country’s electricity consumption and underinvestment on energy. Thus, the need for producing clean energy from alternative renewable and sustainable energy sources remains an attractive technology. Biogas is energy produced by anaerobic digestion of biodegradable organic waste such as garden waste, food waste, municipal waste, industrial waste and sewage sludge. However, it may not be fully exploited because it contains impurities which limit its application. It can be purified and upgraded using techniques such as high-pressure water scrubbing, pressure swing adsorption, membrane separation, activated carbon sieve, cryogenic separation, chemical absorption. This study focuses on chemical absorption as it can yield biogas with over 95 % CH4 by volume. The substrate used to produce biogas in this study was grass inoculated with cow dung. Sodium hydroxide and acetic acid were used to adjust the pH of the feedstock. The chemicals absorbents of focus are sodium hydroxide, potassium hydroxide, ammonia solution and monoethanolamine. Two kinds of setups were used for this study; biochemical methane potential (BMP) assay tests using the Bioprocess Control AMPTS II and a custom made setup using Buchner flasks. Gas Chromatography was used for biogas analysis. The raw biogas contained on average 52% CH4 by volume which improved to over 80% CH4 after CO2 absorption. The CO2 removal efficiency improved from 22% to 66% for the alkalis and was also quite comparable for MEA and NH3 as it increased from 51% to 67%. The removal efficiency for NH3 and MEA increased from 69% to 79% on average with CH4 concentration reaching over 85% volume at 40 °C. The achievable calorific value for this study ranged from 25 to 33.5 MJ/Nm3.
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