Development of a Modified Plug-Flow Anaerobic Digester for Biogas Production from Animal Manures

Traditional plug-flow anaerobic reactors (PFRs) are characterized by lacking a mixing system and operating at high total solid concentrations, which limits their applicability for several kinds of manures. This paper studies the performance of a novel modified PFR for the treatment of pig manure, characterized by having an internal sludge mixing system by biogas recirculation in the range of 0.270–0.336 m3 m−3 h−1. The influence on the methane yield of four operating parameters (recirculation rate, hydraulic retention time, organic loading rate, and total solids) was evaluated by running four modified PFRs at the pilot scale in mesophilic conditions. While the previous biodegradability of organic matter by biochemical methane potential tests were between 31% and 47% with a methane yield between 125 and 184 LCH4 kgVS−1, the PFRs showed a suitable performance with organic matter degradation between 25% and 51% and a methane yield of up to 374 LCH4 kgVS−1. Operational problems such as solid stratification, foaming, or scum generation were avoided.

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Anaerobic stabilisation of urine diverting dehydrating toilet faeces (UDDT-F) in urban poor settlements: biochemical energy recovery

Journal of Water Sanitation and Hygiene for Development ◽

10.2166/washdev.2019.099 ◽

2019 ◽

Vol 9 (2) ◽

pp. 289-299

Author(s):

Joy Riungu ◽

Mariska Ronteltap ◽

Jules B. van Lier

Keyword(s):

Methane Production ◽

Urban Poor ◽

Energy Recovery ◽

Biogas Production ◽

Plug Flow ◽

Pilot Scale ◽

Biochemical Methane Potential ◽

Two Stage ◽

One Stage ◽

Methane Potential

Abstract Biochemical energy recovery using digestion and co-digestion of faecal matter collected from urine diverting dehydrating toilet faeces (UDDT-F) and mixed organic market waste (OMW) was studied under laboratory- and pilot-scale conditions. Laboratory-scale biochemical methane potential (BMP) tests showed an increase in methane production with an increase in OMW fraction in the feed substrate. In subsequent pilot-scale experiments, one-stage and two-stage plug flow digester were researched, applying UDDT-F:OMW ratios of 4:1 and 1:0, at about 10 and 12% total solids (TS) slurry concentrations. Comparable methane production was observed in one-stage (Ro-4:1,12%) (314 ± 15 mL CH4/g VS added) and two-stage (Ram-4:1,12%) (325 ± 12 mL CH4/g VS added) digesters, when applying 12% TS slurry concentration. However, biogas production in Ram-4:1,12% digester (571 ± 25 mL CH4/g VS added) was about 12% higher than in Ro-4:1,12%, significantly more than the slight difference in methane production, i.e. 3–4%. The former was attributed to enhanced waste solubilisation and increased CO2 dissolution, resulting from mixing the bicarbonate-rich methanogenic effluent for neutralisation purposes with the low pH (4.9) influent acquired from the pre-acidification stage. Moreover, higher process stability was observed in the first parts of the plug flow two-stage digester, characterised by lower VFA concentrations.

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Performance evaluation of an anaerobic hybrid reactor treating petrochemical effluent

International Journal of Geology ◽

10.46300/9105.2020.14.10 ◽

2021 ◽

Vol 14 ◽

pp. 51-57

Author(s):

M.T. Jafarzadeh ◽

N. Jamshidi ◽

L. Talebiazar ◽

R. Aslaniavali

Keyword(s):

Loading Rate ◽

Biogas Production ◽

Dairy Wastewater ◽

Organic Loading Rate ◽

Hybrid Reactor ◽

Petrochemical Wastewater ◽

Anaerobic Reactors ◽

Anaerobic Hybrid Reactor ◽

Study Performance

Organic loading rate (OLR), Hydraulic Retention Time (HRT) and up flow velocity are important parameters significantly affecting microbial ecology and characteristics of anaerobic reactors. In this study, Performance of an anaerobic hybrid reactor (UASB/Filter) at mesophilic condition was evaluated in a 15.4 L reactor receiving petrochemical wastewater. The temperature of influent was adjusted by an inline heat exchanger at around 35 ˚C. The reactor was seeded with flocculent sludge from a UASB plant treating dairy wastewater. The sludge was acclimatized to petrochemical wastewater in twostage operation. After 39 weeks, a COD reduction of 70.3% was obtained at OLR=2.0 kg m-3 d-1 and HRT=18 h. Under steady state conditions, experiments were conducted at OLRs of between 0.5 and 24 kg TCOD m-3 d-1 , hydraulic retention times (HRT) of 4-48 h and up flow velocities 0.021-0.25 m h-1. Removal efficiencies in the range of 42-86% were achieved at feed TCOD concentrations of 1000- 4000 mg L-1 . The biogas production data used for determination of biogas production kinetics. The values of Gmax and GB estimated as 11.173 LL-1d -1 and 85.83 g L-1d -1 , respectively.

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Evaluation on the Methane Production Potential of Wood Waste Pretreated with NaOH and Co-Digested with Pig Manure

Catalysts ◽

10.3390/catal9060539 ◽

2019 ◽

Vol 9 (6) ◽

pp. 539 ◽

Cited By ~ 10

Author(s):

Renfei Li ◽

Wenbing Tan ◽

Xinyu Zhao ◽

Qiuling Dang ◽

Qidao Song ◽

...

Keyword(s):

Anaerobic Digestion ◽

Lignocellulosic Biomass ◽

Methane Production ◽

Biogas Production ◽

Untreated Wood ◽

Wood Waste ◽

Methane Yield ◽

Pig Manure ◽

Naoh Pretreatment ◽

Digestion Technique

Wood waste generated during the tree felling and processing is a rich, green, and renewable lignocellulosic biomass. However, an effective method to apply wood waste in anaerobic digestion is lacking. The high carbon to nitrogen (C/N) ratio and rich lignin content of wood waste are the major limiting factors for high biogas production. NaOH pre-treatment for lignocellulosic biomass is a promising approach to weaken the adverse effect of complex crystalline cellulosic structure on biogas production in anaerobic digestion, and the synergistic integration of lignocellulosic biomass with low C/N ratio biomass in anaerobic digestion is a logical option to balance the excessive C/N ratio. Here, we assessed the improvement of methane production of wood waste in anaerobic digestion by NaOH pretreatment, co-digestion technique, and their combination. The results showed that the methane yield of the single digestion of wood waste was increased by 38.5% after NaOH pretreatment compared with the untreated wood waste. The methane production of the co-digestion of wood waste and pig manure was higher than that of the single digestion of wood waste and had nonsignificant difference with the single-digestion of pig manure. The methane yield of the co-digestion of wood waste pretreated with NaOH and pig manure was increased by 75.8% than that of the untreated wood waste. The findings indicated that wood waste as a sustainable biomass source has considerable potential to achieve high biogas production in anaerobic digestion.

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The influence on biogas production of three slurry-handling systems in dairy farms

Journal of Agricultural Engineering ◽

10.4081/jae.2015.449 ◽

2015 ◽

Vol 46 (1) ◽

pp. 30 ◽

Cited By ~ 4

Author(s):

Damiano Coppolecchia ◽

Davide Gardoni ◽

Cecilia Baldini ◽

Federica Borgonovo ◽

Marcella Guarino

Keyword(s):

Organic Matter ◽

Biogas Production ◽

Dairy Farm ◽

Dairy Farms ◽

Organic Matter Concentration ◽

Deep Pit ◽

Volatile Solids ◽

Methane Potential ◽

Solid Liquid ◽

Solid Liquid Separation

Handling systems can influence the production of biogas and methane from dairy farm manures. A comparative work performed in three different Italian dairy farms showed how the most common techniques (scraper, slatted floor, flushing) can change the characteristics of collected manure. Scraper appears to be the most <em>neutral</em> choice, as it does not significantly affect the original characteristics of manure. Slatted floor produces a manure that has a lower methane potential in comparison with scraper, due to: a lower content of volatile solids caused by the biodegradation occurring in the deep pit, and a lower specific biogas production caused by the change in the characteristics of organic matter. Flushing can produce three different fluxes: diluted flushed manure, solid separated manure and liquid separated manure. The diluted fraction appears to be unsuitable for conventional anaerobic digestion in completely stirred reactors (CSTR), since its content of organic matter is too low to be worthwhile. The liquid separated fraction could represent an interesting material, as it appears to accumulate the most biodegradable organic fraction, but not as primary substrate in CSTR as the organic matter concentration is too low. Finally, the solid-liquid separation process tends to accumulate inert matter in the solid separated fraction and, therefore, its specific methane production is low.

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Ultrasound pre-treatment for anaerobic digestion improvement

Water Science & Technology ◽

10.2166/wst.2009.484 ◽

2009 ◽

Vol 60 (6) ◽

pp. 1525-1532 ◽

Cited By ~ 51

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.

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Anaerobic digestion of sunflower oil cake: a current overview

Water Science & Technology ◽

10.2166/wst.2012.586 ◽

2013 ◽

Vol 67 (2) ◽

pp. 410-417 ◽

Cited By ~ 4

Author(s):

M. A. De la Rubia ◽

V. Fernández-Cegrí ◽

F. Raposo ◽

R. Borja

Keyword(s):

Anaerobic Digestion ◽

Sunflower Oil ◽

Physical Structure ◽

Methane Yield ◽

Organic Loading Rate ◽

Biochemical Methane Potential ◽

In Series ◽

Methane Potential ◽

Bmp Test ◽

Sunflower Oil Cake

Due to the chemical and physical structure of a lignocellulosic biomass, its anaerobic digestion (AD) is a slow and difficult process. In this paper, the results obtained from a batch biochemical methane potential (BMP) test and fed-batch mesophilic AD assays of sunflower oil cake (SuOC) are presented. Taking into account the low digestibility shown during one-stage experiments the methane yield decreased considerably after increasing the organic loading rate (OLR) from 2 to 3 g VS L−1 d−1, SuOC was subjected to a two-stage AD process (hydrolytic-acidogenic and methanogenic stages), in two separate reactors operating in series where the methanogenic stage became acidified (with >1,600 mg acetic acid L−1) at an OLR as low as 2 g VS L−1 d−1. More recently, BMP assays were carried out after mechanical, thermal, and ultrasonic pre-treatments to determine the best option on the basis of the methane yield obtained.

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Treatment of a chocolate industry wastewater in a pilot-scale low-temperature UASB reactor operated at short hydraulic and sludge retention time

Water Science & Technology ◽

10.2166/wst.2013.010 ◽

2013 ◽

Vol 67 (6) ◽

pp. 1353-1361 ◽

Cited By ~ 7

Author(s):

M. Esparza-Soto ◽

O. Arzate-Archundia ◽

C. Solís-Morelos ◽

C. Fall

Keyword(s):

Low Temperature ◽

Retention Time ◽

Biogas Production ◽

Pilot Scale ◽

Uasb Reactor ◽

Organic Loading Rate ◽

Anaerobic Sludge ◽

Processing Industry ◽

Sludge Retention Time ◽

Industry Wastewater

The aim of this work was to evaluate the performance of a 244-L pilot-scale upflow anaerobic sludge blanket (UASB) reactor during the treatment of chocolate-processing industry wastewater under low-temperature conditions (18 ± 0.6 °C) for approximately 250 d. The applied organic loading rate (OLR) was varied between 4 and 7 kg/m3/d by varying the influent soluble chemical oxygen demand (CODsol), while keeping the hydraulic retention time constant (6.4 ± 0.3 h). The CODsol removal efficiency was low (59–78%). The measured biogas production increased from 240 ± 54 to 431 ± 61 L/d during the experiments. A significant linear correlation between the measured biogas production and removed OLR indicated that 81.69 L of biogas were produced per kg/m3 of CODsol removed. Low average reactor volatile suspended solids (VSS) (2,700–4,800 mg/L) and high effluent VSS (177–313 mg/L) were derived in a short sludge retention time (SRT) (4.9 d). The calculated SRT was shorter than those reported in the literature, but did not affect the reactor's performance. Average sludge yield was 0.20 kg-VSS/kg-CODsol. The low-temperature anaerobic treatment was a good option for the pre-treatment of chocolate-processing industry wastewater.

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Biogas Production by Pilot-Scale Anaerobic Co-Digestion and Life Cycle Assessment Using a Real Scale Scenario: Independent Parameters and Co-Substrates Influence

Processes ◽

10.3390/pr9111875 ◽

2021 ◽

Vol 9 (11) ◽

pp. 1875

Author(s):

Jhessica Mosquera ◽

Carol Rangel ◽

Jogy Thomas ◽

Angelica Santis ◽

Paola Acevedo ◽

...

Keyword(s):

Life Cycle Assessment ◽

Life Cycle ◽

Biogas Production ◽

Scale Up ◽

Pilot Scale ◽

Industrial Sector ◽

Potential Effect ◽

Organic Loading Rate ◽

Environmentally Sustainable ◽

Real Scale

This study evaluates the performance of different agricultural by-products to identify the potential effect of independent variables, using as the dependent variable the biogas production. A Box–Behnken experimental design was carried out in a pilot-scale plant of four stirred stainless-steel digesters under mesophilic semi-continuous digestion. The results obtained support the creation of a technical framework to scale up the process and further evaluation of the potential environmental impacts through life cycle assessment (LCA) methodology. A stable behaviour was achieved in 12 of the 13 experiments proposed. The highest value of daily biogas production was 2200.15 mL day−1 with a stabilization time of 14 days, an organic loading rate of 4 g VS feed daily, low C/N ratio and a 1:1 relation of nitrogen providers. The concentrations of CH4 remained stable after the production stabilization and an average biogas composition of 60.6% CH4, 40.1% CO2 and 0.3% O2 was obtained for the conditions mentioned above. Therefore, the real scale plant was estimated to manage 2.67 tonnes of residual biomass per day, generating 369.69 kWh day−1 of electricity. The LCA analysis confirms that the co-digestion process evaluated is a feasible and environmentally sustainable option for the diversification of the Colombian energy matrix and the development of the agro-industrial sector.

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Phosphorus forms and lability of organic matter during anaerobic digestion of swine manure

Semina Ciências Agrárias ◽

10.5433/1679-0359.2019v40n5supl1p2107 ◽

2019 ◽

Vol 40 (5Supl1) ◽

pp. 2107 ◽

Cited By ~ 1

Author(s):

José de Souza Oliveira Filho ◽

Thales Vinicius de Araújo Viana ◽

Benito Moreira de Azevedo ◽

Geocleber Gomes de Sousa ◽

Marcos Gervasio Pereira

Keyword(s):

Organic Matter ◽

Anaerobic Digestion ◽

Swine Manure ◽

Pig Manure ◽

Digestion Time ◽

Anaerobic Reactors ◽

Phosphorus Forms ◽

Extractable P ◽

P Content ◽

Total P

Understanding the dynamics of the organic matter and nutrients in pig manure submitted to anaerobic digestion is important to assist in decision-making regarding the use of anaerobic biofertilizer in agriculture. Accordingly, this study was carried out with the objective of evaluating the changes in organic matter, quantified as the content of carbon in the humic and oxidizable fractions, and in the content of the organic and inorganic forms of phosphorus in the solid fraction of the manure, as a function of digestion time in anaerobic reactors. Evaluations were carried out after 7, 14, 21, 28, 35, 42, and 49 days of digestion, and the results were compared to the raw manure. Changes in organic matter occurred mostly in the labile fractions (fulvic acid and the F1 fraction), the content of which underwent a reduction, favoring the accumulation of more recalcitrant fractions in the final biofertilizer (humic acid and the F2, F3, and F4 fractions). Total P content did not change throughout the digestion process. However, the size of inorganic fraction of water-extractable P decreased by 16.7% after 49 days of digestion, as it was consumed by the decomposing microbiota to form stabilized organic matter, which accumulated along with the more recalcitrant fractions of P in the final biofertilizer. Therefore, the use of swine manure-derived anaerobic biofertilizer has less risk of environmental contamination with excessive P than the direct application of raw manure to the soil.

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Production of Biogas from Cattle Paunch Manure

European Journal of Engineering Research and Science ◽

10.24018/ejers.2019.4.4.1140 ◽

2019 ◽

Vol 4 (4) ◽

pp. 1-3

Author(s):

Mona Khidir Mohammed ◽

G. A. Gasmelseed ◽

Mohammed H. Abuuznien

Keyword(s):

Public Health ◽

Organic Matter ◽

Biological Treatment ◽

Room Temperature ◽

Biogas Production ◽

Batch Process ◽

Total Solid ◽

Solid Concentration ◽

Slaughter House ◽

Control Units

Slaughter house waste contains high levels of organic matter and pollutants. These pollutants can affect the ecosystem and public health negatively, to minimize the effects of these pollutants many treatments are used, one of these is biological treatment methods. In this study potential of biogas production from cattle paunch manure (stomach digestion content) was investigated using a batch process laboratory scale of liters digester size. Three replicate of total solid concentration of (5%, 7%) of cattle paunch manure were mixed with (10%v/v) inoculums with control units for each concentrations at room temperature. The total amount of biogas produced after 49 days of experiments were, 12.678 L, 11.544 L, 8.154 and 5.724 L for, 7% ,5% TS seeded sample, 7% and 5% total solid control respectively.

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