Comparative Analysis of a Locally Developed Biogas Digester Using Selected Substrates

Author(s):  
Kevin N. Nwaigwe ◽  
Christopher C. Enweremadu

A work on the comparative analysis of selected substrates for biogas production using a developed digester is presented. The substrates utilized include cow dung and vegetable waste. The developed digester has 60 litres of substrate volume, incorporates ease of stirring the slurry and mobility of the digester within the farm. The digester was charged with cow dung and vegetable waste respectively with water in a ratio 1:2 at a mesophilic temperature range (20°C – 45 °C) for thirty days retention time and comparative yield within the same operating conditions was studied. The results obtained from the gas production showed that cow dung produced a cumulative biogas yield of 0.702 litres while vegetable waste produced a cumulative yield of 0.144 litres. This result showed that these wastes could be a source of renewable gas if operated on a large scale, while simultaneously reducing environmental pollution particularly within a farm. Also, the results highlight the selection options available to a rural farmer in terms of yield.

2018 ◽  
Vol 7 (2) ◽  
pp. 93-100 ◽  
Author(s):  
Agus Haryanto ◽  
Sugeng Triyono ◽  
Nugroho Hargo Wicaksono

The efficiency of biogas production in semi-continuous anaerobic digester is influenced by several factors, among other is loading rate. This research aimed at determining the effect of hydraulic retention time (HRT) on the biogas yield. Experiment was conducted using lab scale self-designed anaerobic digester of 36-L capacity with substrate of a mixture of fresh cow dung and water at a ratio of 1:1. Experiment was run with substrate initial amount of 25 L and five treatment variations of HRT, namely 1.31 gVS/L/d (P1), 2.47 gVS/L/d (P2), 3.82 gVS/L/d (P3), 5.35 gVS/L/d (P4) and 6.67 gVS/L/d (P5). Digester performance including pH, temperature, and biogas yield was measured every day. After stable condition was achieved, biogas composition was analyzed using a gas chromatograph. A 10-day moving average analysis of biogas production was performed to compare biogas yield of each treatment. Results showed that digesters run quite well with average pH of 6.8-7.0 and average daily temperature 28.7-29.1. The best biogas productivity (77.32 L/kg VSremoval) was found in P1 treatment (organic loading rate of 1.31 g/L/d) with biogas yield of 7.23 L/d. With methane content of 57.23% treatment P1 also produce the highest methane yield. Biogas production showed a stable rate after the day of 44. Modified Gompertz kinetic equation is suitable to model daily biogas yield as a function of digestion time.Article History: Received March 24th 2018; Received in revised form June 2nd 2018; Accepted June 16th 2018; Available onlineHow to Cite This Article: Haryanto, A., Triyono, S., and Wicaksono, N.H. (2018) Effect of Loading Rate on Biogas Production from Cow Dung in A Semi Continuous Anaerobic Digester. Int. Journal of Renewable Energy Development, 7(2), 93-100.https://doi.org/10.14710/ijred.7.2.93-100


Author(s):  
Christian C. Opurum

This research paper aimed to evaluate the kinetics of anaerobic digestion (AD) of mixtures of cabbage waste (CW) with (Poultry dropping (PD) and Cow dung (CD). The study was conducted in 10L bio-digesters for 35 days under mesophilic conditions (25 - 35OC). Logistic function equation was used to simulate the experimental data to test for its goodness of fit and kinetic parameters namely: maximum biogas potential (Pb), the maximum biogas production rate (Rm), and the lag phase duration (λ) were estimated in each treatment. Chemical analysis showed that individual substrates possess characteristics that could support microbial activities in biogas production. The biogas yield in terms of added  volatile solids (VS) in decreasing order was as follows: 0.022, 0.018, 0.017, 0.014, 0.014 and 0.013 dm3/g VS for CW/CD 2:1, CW/PD3:1, CW/CD 1:1, CW alone, CW/PD1:1 and  CW/PD 2:1, respectively. A significant difference (P ≤ 0.05) in biogas yield was recorded in CW/CD 2:1 with 7.19 dm3 (53.29% increase). The kinetic parameters (Pb, Rm, and λ) for CW/CD 2:1 was 7.01 dm3, 1.58 dm3.d, and 2.29 days, respectively. This was followed by CW/PD 3:1 (5.84 dm3); with 24.92% increase in gas production and CW/CD 1:1 (5.42 dm3) with 15.53% increase relative to CW alone, 4.69 dm3. The digesters fed with CW/PD 1:1 and CW/PD 2:1 exhibited inhibitory effects on biogas production, with 7.51 and 2.05% decrease in gas yield, respectively. The logistic function model demonstrated a strong relationship between the experimental and model-predicted data. The high correlation coefficient (R2) ranging between 0.978 - 0.993 is evident. The model proved to be a useful tool in predicting anaerobic digestion and biogas production process.


Author(s):  
Giang Van Tran ◽  
Yuwalee Unpaprom ◽  
Rameshprabu Ramaraj

The biochemical methane potentials for common reed (Phragmites australis) and cow dung from northern Thailand, Chiang Mai city were investigated. This study aims to evaluate optimal parameters for the substrate of common reed and cow dung with different ratios (i.e. 1:1, 2:1 and 1:2) for improving the quality of methane content and biogas production. The effect of the co-substrate mixture was carried out in a batch reactor operated under room temperature and hydraulic retention time (HRT) of 45 days. The experiments were conducted in the fermenter with a working volume of 2.5 L and a total volume of 3L. The substrate was containing 15% of total solids (TS) and fermentation at initial pH 7. Biodegradation of substrate stated that chemical oxidation demand (COD) removal was 52.38%, the utilization of volatile solid was 75.46%. The results were achieved at ratio 2:1 (common reed and cow dung) reached the highest methane content and total biogas yield are 70% and 20,015 ml, respectively. Consequently, the results of this study suggested that mixing ratios of influence on the fermentation process and monitoring parameters were significant for further scale up or large-scale design of enriched methane content and biogas production.


2007 ◽  
Vol 18-19 ◽  
pp. 519-525 ◽  
Author(s):  
S.J. Ojolo ◽  
R.R. Dinrifo ◽  
K.B. Adesuyi

In this work, a comparative study of biogas production from poultry droppings, cattle dung, kitchen waste, fruit waste and vegetable waste was done under the same operating conditions. 3kg of each waste was mixed with 9kg of water and loaded into the 5 constructed digesters. Biogas production was measured using water displacement method for a period of 40 days and at an average temperature of 30.5oC. Results indicated that poultry droppings produced 0.0332dm3/day, cow dung produced 0.0238dm3/day, Kitchen waste produced 0.0080dm3/day, vegetable waste produced 0.0066dm3/day and fruit waste with 0.0022dm3/day. It is concluded that poultry droppings produced more biogas because it contains more nutrients and nitrogen compared with plant and other animal waste


2021 ◽  
Author(s):  
Amit Kumar Chaurasia ◽  
Puneet Siwach ◽  
Prasenjit Mondal

Abstract ABSTRACT Pretreatment of the fruit, food and vegetable waste materials could enhance the biogas generation in a shorter time along with waste reduction. The aim of the present work was to assess the effectiveness of alkaline, hydrothermal, thermal and ultrasonication pretreatment of fruit, food, and vegetable waste with cow dung for the mesophilic anaerobic co-digestion. The mesophilic anaerobic co-digestion of fruit food and vegetable waste as single substrate with cow dung were performed in a laboratory scale 1L batch digester for 30 days at 40 ± 2 oC temperature. Obtained result show that pretreatment process has enhanced the biogas and biomethane production by 35 % and 44.4 % with 19.89 % TS and 17.30 % VS removal in case of ultrasonication pretreatment (100.45 ml biogas/gVS and 27.92 ml CH4/gVS,), while slight increase is found with thermal and hydrothermal pretreatment as compared to untreated FFVW. The biogas production is enhanced by 35%, 20.4%, 5%, 6% and biomethane production are enhanced by 44.4%, 22%, 11%, 9.8% in the case of ultrasonication, alkaline, thermal and hydrothermal pretreatment process, respectively. The stable mesophilic anaerobic co-digestion operation was achieved and impacts of the different pretreatment methods on the biogas yield and net energy recovery along with viability of anaerobic co-digestion have been explored.


2011 ◽  
Vol 697-698 ◽  
pp. 326-330 ◽  
Author(s):  
S.X. Zhou ◽  
Y.P. Dong ◽  
Y.L. Zhang

Microbial pretreatment was applied to enhance biogas production from corn stover through solid-state anaerobic digestion, but the price of microbial strains is high. The objective of this study was to find the effects on biogas production by the naturally microbial pretreatment method. The highest cumulative biogas yield for 60-day solid-state anaerobic digestion was obtained in B group (the pretreated corn straws with cow dung), which was 19.6% higher than that of the untreated samples. The D group(the pretreated corn straws with the sludge)cumulative biogas yield for 60-day solid-state anaerobic digestion was obtained, which was 18.87% higher than that of the untreted samples. The biogas of D group increased to the range of 55%~60% methane content, while B group with the range of 75%~80%.The results indicated that the pretreated corn straws mixing cow manure can improve both the biogas production yield and the content of methane in CH4。


2014 ◽  
Vol 1008-1009 ◽  
pp. 121-126
Author(s):  
Lin Jun Shi ◽  
Wen Lan Liu ◽  
Hui Fen Liu ◽  
Wei Yu Zhang ◽  
Li Tong Ban

Anaerobic digestion of single dairy manure, single vegetable waste, mixture of dairy manure and vegetable waste was conducted to produce biogas. Startup characteristic, leachate parameters and inoculation amount were investigated. The experimental results showed that anaerobic digestion can start up quickly with acclimated thickening sludge as inoculation sludge and 30% was appropriate inoculation percentage. Digestion of single dairy manure and mixture of dairy manure and vegetable waste appeared better buffering ability with higher alkalinity than single vegetable waste. Compared to single digestion of dairy manure or vegetable waste, mixture of dairy manure and vegetable waste is more suitable for anaerobic digestion. Under the conditions of TS=10% and T=(36±1)°C, cumulative biogas production of mixture of dairy manure and vegetable waste is 5281 mL during the period of 30 days and average daily gas production is about 176 mL. These results could provide theoretical data for practical biogas engineering.


2011 ◽  
Vol 64 (9) ◽  
pp. 1851-1856 ◽  
Author(s):  
Nathan D. Park ◽  
Ronald W. Thring ◽  
Randy P. Garton ◽  
Michael P. Rutherford ◽  
Steve S. Helle

Anaerobic digestion is a well established technology for the reduction of organic matter and stabilization of wastewater. Biogas, a mixture of methane and carbon dioxide, is produced as a useful by-product of the process. Current solid waste management at the city of Prince George is focused on disposal of waste and not on energy recovery. Co-digestion of fresh fruit and vegetable waste with sewer sludge can improve biogas yield by increasing the load of biodegradable material. A six week full-scale project co-digesting almost 15,000 kg of supermarket waste was completed. Average daily biogas production was found to be significantly higher than in previous years. Digester operation remained stable over the course of the study as indicated by the consistently low volatile acids-to-alkalinity ratio. Undigested organic material was visible in centrifuged sludge suggesting that the waste should have been added to the primary digester to prevent short circuiting and to increase the hydraulic retention time of the freshly added waste.


2019 ◽  
Vol 4 (6) ◽  
Author(s):  
KO Ansah Amano ◽  
E Appiah-Danquah ◽  
E Adom ◽  
AG Ntiri-Asiedu ◽  
ES Amoamah ◽  
...  

Management of waste is a key concern in several communities in Ghana. The exponential growth in waste generation imposes serious threats such as environmental pollution, health risk and scarcity of dumping site to our society. A large variety of organic rich materials inherent in this waste have high potential to be treated by the use of anaerobic digestion. In this study, eight (8) Laboratory scale biodigesters were used for the anaerobic co-digestion of household and market waste with cow dung as inoculum, controlled at a pH range of 6.53-7.04 and at a mesophilic temperature of 35±2˚C. The study was also conducted in batch mode at a hydraulic retention time of 21 days. The anaerobic co-digestion process was developed and optimized at varying feedstock to inoculum ratio to determine the potential biogas yield from each proportion. The results obtained indicate sample S8, containing market waste and inoculum in the ratio of 6:1 produced the optimum concentration of methane (51% v/v biogas) while the least was recorded by sample S2 primarily made up of market waste. ANOVA results show that the concentration of methane produced from the substrate is significantly affected by the hydraulic retention time and pH value of the anaerobic digestion process.


2020 ◽  
Vol 10 (1) ◽  
pp. 27-35
Author(s):  
Soeprijanto Soeprijanto ◽  
I Dewa Ayu Agung Warmadewanthi ◽  
Melania Suweni Muntini ◽  
Arino Anzip

Water hyacinth (Eichhornia crassipes) causes ecological and economic problems because it grows very fast and quickly consumes nutrients and oxygen in water bodies, affecting both the flora and fauna; besides, it can form blockages in the waterways, hindering fishing and boat use. However, this plant contains bioactive compounds that can be used to produce biofuels. This study investigated the effect of various substrates as feedstock for biogas production. A 125-l plug-flow anaerobic digester was utilized and the hydraulic retention time was 14 days; cow dung was inoculated into water hyacinth at a 2:1 mass ratio over 7 days. The maximum biogas yield, achieved using a mixture of natural water hyacinth and water (NWH-W), was 0.398 l/g volatile solids (VS). The cow dung/water (CD-W), hydrothermally pretreated water hyacinth/digestate, and hydrothermally pretreated water hyacinth/water (TWH-W) mixtures reached biogas yields of 0.239, 0.2198, and 0.115 l/g VS, respectively. The NWH-W composition was 70.57% CH4, 12.26% CO2, 1.32% H2S, and 0.65% NH3. The modified Gompertz kinetic model provided data satisfactorily compatible with the experimental one to determine the biogas production from various substrates. TWH-W and NWH-W achieved, respectively, the shortest and (6.561 days) and the longest (7.281 days) lag phase, the lowest (0.133 (l/g VS)/day) and the highest (0.446 (l/g VS)/day) biogas production rate, and the maximum and (15.719 l/g VS) and minimum (4.454 l/g VS) biogas yield potential.


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