scholarly journals Effect of feed slurry dilution and total solids on specific biogas production by anaerobic digestion in batch and semi-batch reactors

2021 ◽  
Author(s):  
Gautham P. Jeppu ◽  
Jayalal Janardhan ◽  
Shivakumara Kaup ◽  
Anish Janardhanan ◽  
Shakeib Mohammed ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Substrate Inhibition ◽  
Cattle Dung ◽  
Cow Dung ◽  
Batch Reactors ◽  
Dilution Ratio ◽  
Total Solids ◽  
State Process ◽  
Wide Range

AbstractBiomass from various sources such as cow dung is a significant source of renewable energy (as biogas) in many regions globally, especially in India, Africa, Brazil, and China. However, biogas production from biomass such as cattle dung is a slow, inefficient biochemical process, and the specific biogas produced per kg of biomass is relatively small. The improvement of specific biogas production efficiency using various dilution ratios (and, hence, total solids [TS]) is investigated in this work. A wide range of feed dilution (FD) ratios of cow dung: water (CD: W) was tested in batch biogas digesters with total solids ranging from 1% to 12.5% and FD ratio ranging from 2:1 to 1:20. To further verify the results from the above batch experiments, semi-batch experiments representative of field-scale biodigesters were conducted. Semi-batch reactors have a steady-state process, unlike batch reactors, which have an unsteady state process. Our results suggested that specific biogas production (mL/g VS) increased continuously when the total solids decreased from 12.5% to 1% (or when dilution increased). Our experiments also indicate that the commonly used 1:1 feed dilution ratio (TS ~ 10% for cow dung) does not produce the maximum specific biogas production. The possible reason for this could be that anaerobic digestion at higher total solids is rate limited due to substrate inhibition, mass transfer limitations, and viscous mixing problems that arise at higher total solids concentration. Hence, a higher feed dilution ratio between 1:2 and 1:4 (TS between 4 and 6.7%) is recommended for a more efficient biomass utilization of cowdung. Empirical relationships were also developed for variation of specific biogas yield with the total solids content of the cow dung slurry. Graphic abstract

scholarly journals Evaluation of Biogas through Chemically Treated Cottonseed Hull in Anaerobic Digestion with/without Cow Dung: An Experimental Study

2021 ◽  
Author(s):  
Venkateshkumar R ◽  
Shanmugam S ◽  
Veerappan AR
Keyword(s):  
Anaerobic Digestion ◽  
Sodium Hydroxide ◽  
Calcium Hydroxide ◽  
Biogas Production ◽  
Cow Dung ◽  
Batch Reactors ◽  
Biogas Yield ◽  
Cottonseed Hull ◽  
Pre Treatment ◽  
Feedstock Material

Abstract Cow dung is generally used as the feedstock material for the anaerobic digestion to produce biogas. A selection of alternate biomass material is needed to reduce the consumption or to eliminate the use of cow dung. Recently, cottonseed hull has been considered as the primary substrate to produce biogas. In this paper, the effect of biogas production on anaerobic co-digestion of cow dung with pre-treated cottonseed hull using different concentrations of sulfuric acid, hydrochloric acid, hydrogen peroxide, and acetic acid is investigated. Sodium hydroxide and calcium hydroxide are used at different concentrations for pre-treatment of cottonseed hull. The enhancement of biogas production from the batch reactors at mesophilic temperature (35 ± 2 ℃) is observed for mono- and co-digestion of cow dung with treated cottonseed hull. Maximum biogas yield is achieved for the treated cottonseed hull at 6% sodium hydroxide during mono digestion and at 6% calcium hydroxide during co-digestion.

scholarly journals Effect of co-digestion of food waste and cow dung on biogas yield

2020 ◽  
Vol 181 ◽  
pp. 01005
Author(s):  
Makhura Emmanuel Pax ◽  
Edison Muzenda ◽  
Tumeletso Lekgoba
Keyword(s):  
Anaerobic Digestion ◽  
Moisture Content ◽  
Food Waste ◽  
Biogas Production ◽  
Cow Dung ◽  
Mixing Ratio ◽  
Total Solids ◽  
Biogas Yield ◽  
Volatile Solids ◽  
Thermophilic Conditions

This paper aims at finding the effect of co-digestion of cow dung and food waste on total biogas yield. Biogas production was improved through co-digestion of cow dung and food waste (FW) containing a small fraction of inoculum under mesophilic temperature (37ºC) over a retention time of 24 days. Co-digestion ratios of 1:1, 2:1 and 3:1 for cowdung/foodwaste were used for the study on anaerobic digestion on the co digested matter. Tests were carried out starting with the preparation of substrates, substrate characterization to determine the moisture content (MC), total solids (TS), volatile solids (VS) and ultimately batch anaerobic digestion experiments under thermophilic conditions (370C). The moisture content, volatile solids and total solids for food waste were 78, 22 and 90.7% respectively while the characteristics for cow dung were 67.2, 32.8 and 96.0 % respectively. From the study, a mixing ratio of cow dung: food waste of 1:2 was found to be the optimum substrate mixture for biogas production at 25595.7 Nml. The accumulated gas volumes of 18756.6, 14042.5, 13940.8 and 13839.1 Nml were recorded for cow dung: food waste ratios of 2:1, 1:1, 1:3 and 3:1 respectively. For a co-digestion containing more of the food waste than cow dung, a higher volume of biogas is produce.

scholarly journals Elevated biogas production from the anaerobic co-digestion of farmhouse waste: Insight into the process performance and kinetics

2019 ◽  
Vol 37 (12) ◽  
pp. 1240-1249 ◽  
Author(s):  
Spyridon Achinas ◽  
Gerrit Jan Willem Euverink
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Ternary Mixtures ◽  
Batch Reactors ◽  
Process Performance ◽  
Mixing Ratios ◽  
Batch Tests ◽  
Biogas Plants ◽  
The Impact ◽  
Insight Into

The biodegradable portion of solid waste generated in farmhouses can be treated for energy recovery with small portable biogas plants. This action can be done across the Netherlands and all around the planet. This study aims to appraise the performance of anaerobic digestion of different wastes (cow manure, food waste and garden waste) obtained from a regional farmhouse. Batch reactors were established under mesophilic conditions in order to investigate the impact of ternary mixtures on the anaerobic digestion process performance. Different mixing ratios were set in the batch tests. The upshots from the experiments connoted that ternary digestion with cow manure:food waste:garden waste mixing ratio of 40:50:10 yielded higher biogas amount. The kinetics’ results showed quite good congruence with the experimental study. The results from the kinetic analysis appeared to be in line with the experimental one.

Solid-State Anaerobic Digestion for Methane Production from Corn Stalks with Stack-Pretreated

2011 ◽  
Vol 697-698 ◽  
pp. 326-330 ◽  
Author(s):  
S.X. Zhou ◽  
Y.P. Dong ◽  
Y.L. Zhang
Keyword(s):  
Anaerobic Digestion ◽  
Solid State ◽  
Methane Production ◽  
Biogas Production ◽  
Cow Dung ◽  
Cow Manure ◽  
Pretreatment Method ◽  
Biogas Yield ◽  
Microbial Pretreatment ◽  
Microbial Strains

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。

Ultrasound pre-treatment for anaerobic digestion improvement

2009 ◽  
Vol 60 (6) ◽  
pp. 1525-1532 ◽  
Author(s):  
S. Pérez-Elvira ◽  
M. Fdz-Polanco ◽  
F. I. Plaza ◽  
G. Garralón ◽  
F. Fdz-Polanco
Keyword(s):  
Anaerobic Digestion ◽  
Energy Balance ◽  
Specific Energy ◽  
Biogas Production ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Net Generation ◽  
Batch Reactors ◽  
Anaerobic Reactors ◽  
Pre Treatment

Prior research indicates that ultrasounds can be used in batch reactors as pre-treatment before anaerobic digestion, but the specific energy required at laboratory-scale is too high. This work evaluates both the continuous ultrasound device performance (efficiency and solubilisation) and the operation of anaerobic digesters continuously fed with sonicated sludge, and presents energy balance considerations. The results of sludge solubilisation after the sonication treatment indicate that, applying identical specific energy, it is better to increase the power than the residence time. Working with secondary sludge, batch biodegradability tests show that by applying 30 kWh/m3 of sludge, it is possible to increase biogas production by 42%. Data from continuous pilot-scale anaerobic reactors (V=100 L) indicate that operating with a conventional HRT = 20 d, a reactor fed with pre-treated sludge increases the volatile solids removal and the biogas production by 25 and 37% respectively. Operating with HRT = 15 d, the removal efficiency is similar to the obtained with a reactor fed with non-hydrolysed sludge at HTR = 20 d, although the specific biogas productivity per volume of reactor is higher for the pretreated sludge. Regarding the energy balance, although for laboratory-scale devices it is negative, full-scale suppliers state a net generation of 3–10 kW per kW of energy used.

scholarly journals Kinetic Study on Biogas Production from Cabbage (Brassica oleracea) Waste and Its Blend with Animal Manure Using Logistic Function Model

2021 ◽  
pp. 34-43
Author(s):  
Christian C. Opurum
Keyword(s):  
Anaerobic Digestion ◽  
Kinetic Parameters ◽  
Goodness Of Fit ◽  
Biogas Production ◽  
Logistic Function ◽  
Gas Production ◽  
Cow Dung ◽  
Function Model ◽  
Biogas Yield ◽  
Significant Difference

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.

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