Assessment of the biochemical methane potential of mono- and co-digested dairy farm wastes

This study aimed to evaluate the methane potential of mono- and co-digested dairy farm wastes. The tested substrates included manure from lactating, dry, and young cows, as well as waste milk and feed waste. The highest methane yield was achieved from the lactating cow manure, which produced an average of 412 L of CH4 kg−1 volatile solids, followed by young and dry cow manures (332 and 273 L of CH4 kg−1 volatile solids, respectively). Feed and milk yielded an average of 325 and 212 L of CH4 kg−1 volatile solids, respectively. Co-digesting the manures from lactating and young cows with feed improved methane production by 7%. However, co-digesting the dry cow manure with feed achieved only 85% of the calculated methane yield. Co-digesting manure and milk at a ratio of 70:30 enhanced the methane potential from lactating, dry, and young cow manures by 19, 30, and 37%, respectively. Moreover, co-digesting lactating, dry, and young cow manures with milk at a ratio of 30:70 enhanced the methane yield by 60, 30, and 88%, respectively. The cumulative methane production of all samples was accurately described using the Gompertz model with a maximum error of 10%. Carbohydrates contributed the most to methane potential, while proteins and lipids were limiting.

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Biogas Production from Physicochemically Pretreated Grass Lawn Waste: Comparison of Different Process Schemes

Molecules ◽

10.3390/molecules25020296 ◽

2020 ◽

Vol 25 (2) ◽

pp. 296 ◽

Cited By ~ 2

Author(s):

Georgia Antonopoulou ◽

Dimitrios Vayenas ◽

Gerasimos Lyberatos

Keyword(s):

Biogas Production ◽

Economic Assessment ◽

Methane Yield ◽

Biochemical Methane Potential ◽

Naoh Pretreatment ◽

Volatile Solids ◽

Methane Potential ◽

Whole Slurry ◽

Almost All ◽

Pretreated Biomass

Various pretreatment methods, such as thermal, alkaline and acid, were applied on grass lawn (GL) waste and the effect of each pretreatment method on the Biochemical Methane Potential was evaluated for two options, namely using the whole slurry resulting from pretreatment or the separate solid and liquid fractions obtained. In addition, the effect of each pretreatment on carbohydrate solubilization and lignocellulossic content fractionation (to cellulose, hemicellulose, lignin) was also evaluated. The experimental results showed that the methane yield was enhanced with alkaline pretreatment and, the higher the NaOH concentration (20 g/100 gTotal Solids (TS)), the higher was the methane yield observed (427.07 L CH4/kg Volatile Solids (VS), which was almost 25.7% higher than the BMP of the untreated GL). Comparing the BMP obtained under the two options, i.e., that of the whole pretreatment slurry with the sum of the BMPs of both fractions, it was found that direct anaerobic digestion without separation of the pretreated biomass was favored, in almost all cases. A preliminary energy balance and economic assessment indicated that the process could be sustainable, leading to a positive net heat energy only when using a more concentrated pretreated slurry (i.e., 20% organic loading), or when applying NaOH pretreatment at a lower chemical loading.

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Optimisation of C:N Ratio for Co-Digested Processed Industrial Food Waste and Sewage Sludge Using the BMP Test

International Journal of Chemical Reactor Engineering ◽

10.1515/1542-6580.2327 ◽

2011 ◽

Vol 9 (1) ◽

Cited By ~ 5

Author(s):

Zuhaib Siddiqui ◽

N.J. Horan ◽

Kofi Anaman

Keyword(s):

Sewage Sludge ◽

Food Waste ◽

Biogas Production ◽

C:N Ratio ◽

Methane Yield ◽

Biochemical Methane Potential ◽

Volatile Solids ◽

Methane Potential ◽

Biomethane Production ◽

Bmp Test

Biomethane production from processed industrial food waste (IFW) in admixture with sewage sludge (primary and waste activated sludge: PS and WAS) was evaluated at a range of C:N ratios using a standard biochemical methane potential (BMP) test. IFW alone had a C:N of 30 whereas for WAS it was 5.4 and thus the C:N ratio of the blends fell in that range. Increasing the IFW content in mix improves the methane potential by increasing both the cumulative biogas production and the rate of methane production. Optimum methane yield 239 mL/g VSremoved occurred at a C:N ratio of 15 which was achieved with a blend containing 11 percent (w/w) IFW. As the fraction of IFW in the blend increased, volatile solids (VS) destruction was increased and this led to a reduction in methane yield and amount of production. The highest destruction of volatile solids of 93 percent was achieved at C:N of 20 followed by C:N 30 and 15. A shortened BMP test is adequate for evaluating optimum admixtures.

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In search of the optimal inoculum to substrate ratio during anaerobic co-digestion of spent coffee grounds and cow manure

Waste Management & Research ◽

10.1177/0734242x20914731 ◽

2020 ◽

Vol 38 (11) ◽

pp. 1278-1283

Author(s):

Çağrı Akyol

Keyword(s):

Operating Parameter ◽

Cow Manure ◽

Spent Coffee Grounds ◽

Biochemical Methane Potential ◽

Start Up ◽

Volatile Solids ◽

Coffee Grounds ◽

Wide Range ◽

Methane Potential ◽

Biogas Reactors

The inoculum to substrate (I:S) ratio is a crucial operating parameter during the start-up period of anaerobic digestion (AD) processes and this ratio shows high differentiation with respect to substrate composition. While spent coffee grounds (SCG) have started to gain attraction in AD as a co-substrate due to their vast production and promising methane potential, there is still not enough information on the operative environment of SCG-based biogas reactors. This study investigated the optimal I:S ratio during anaerobic co-digestion of SCG and cow manure. Biochemical methane potential tests were conducted at mesophilic conditions and the influence of I:S ratio on methane production and digestion stability was evaluated at a wide range of I:S ratios from 0.5:1 to 4:1 (volatile solids (VS) basis). Methane yields increased gradually starting from the I:S ratio of 0.5:1 up to 3:1 and the highest methane yield (225 mlCH4 gVS−1) was achieved at the I:S ratio of 3:1. Comparatively lower methane yields were obtained at the ratios of 3.5:1 and 4:1. Instable AD conditions were established at the lowest I:S ratio examined (0.5:1), which caused volatile fatty acid (VFA) accumulation. The results highlighted that anaerobic co-digestion of SCG and cow manure is a promising approach, while the I:S ratio should be well-maintained due to the high potential risk of rapid and/or excess VFA production of these feedstocks.

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Relationship of Substrate and Inoculum on Biochemical Methane Potential for Grass and Pig Manure Co-Digestion

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.512-515.444 ◽

2012 ◽

Vol 512-515 ◽

pp. 444-448 ◽

Cited By ~ 1

Author(s):

Sumeth Dechrugsa ◽

Sumate Chaiprapat

Keyword(s):

Methane Production ◽

Methane Yield ◽

Pig Manure ◽

Biochemical Methane Potential ◽

Production Potential ◽

Methane Potential ◽

Methane Production Rate ◽

Substrate Ratio ◽

Relationship Of ◽

Careful Investigation

The effects of substrate mix ratio and inoculum/substrate ratio (ISR) on biochemical methane potential of para-grass (PG) and pig manure (PM) were investigated in batch test that maintained temperature at 35±1 oC and continuously shaked at 120 rpm. Cumulative methane production data at different mix ratios and ISRs were evaluated and fitted with Gompertz equation to derive methane production potential (mL) and maximum methane production rate (mL/d). The maximum and average methane yields at each respective ISR of 1, 2, 3, and 4 were [413.0, 315.5], [539.7, 455.6], [590.3, 472.5], and [593.1, 473.5] mL/gVSadded. Relationship of ISR and PG mix ratio to specific methane yield were expressed in quadratic regression model. The generated response surface showed that methane yield was elevated at higher ISR and higher PG mix ratio. This suggests a careful investigation at different ISR and substrate mix ratios should be performed in order to develop a realistic biochemical methane potential of anaerobic co-digestion.

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Effects of Lipase Addition, Hydrothermal Processing, Their Combination, and Co-Digestion with Crude Glycerol on Food Waste Anaerobic Digestion

Fermentation ◽

10.3390/fermentation7040284 ◽

2021 ◽

Vol 7 (4) ◽

pp. 284

Author(s):

Xiaojue Li ◽

Naoto Shimizu

Keyword(s):

Anaerobic Digestion ◽

Food Waste ◽

Methane Production ◽

Crude Glycerol ◽

Anaerobic Fermentation ◽

Gompertz Model ◽

Volatile Solids ◽

Methane Potential ◽

Better Than ◽

Modified Gompertz Model

To enhance anaerobic fermentation during food waste (FW) digestion, pretreatments can be applied or the FW can be co-digested with other waste. In this study, lipase addition (LA), hydrothermal pretreatment (HTP), and a combination of both methods (HL) were applied to hydrolyze organic matter in FW. Furthermore, the effects of crude glycerol (CG), which provided 5%, 10%, and 15% of the volatile solids (VS) as co-substrate (denoted as CG5, CG10, and CG15, respectively), on the anaerobic digestion of FW were assessed. With an increasing proportion of CG in the co-digestion experiment, CG10 showed higher methane production, while CG15 negatively affected the anaerobic digestion (AD) performance owing to propionic acid accumulation acidifying the reactors and inhibiting methanogen growth. As the pretreatments partially decomposed hard-to-degrade substances in advance, pretreated FW showed a stronger methane production ability compared with raw FW, especially using the HL method, which was significantly better than co-digestion. HL pretreatment was shown to be a promising option for enhancing the methane potential value (1.773 NL CH4/g VS) according to the modified Gompertz model.

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Prediction of the Long-Term Effect of Iron on Methane Yield in an Anaerobic Membrane Bioreactor Using Bayesian Network Meta-Analysis

Membranes ◽

10.3390/membranes11020100 ◽

2021 ◽

Vol 11 (2) ◽

pp. 100

Author(s):

Dawei Yu ◽

Yushuai Liang ◽

Rathmalgodagei Thejani Nilusha ◽

Tharindu Ritigala ◽

Yuansong Wei

Keyword(s):

Bayesian Network ◽

Methane Production ◽

Membrane Bioreactor ◽

Meta Analysis ◽

Methane Yield ◽

Long Term Effects ◽

Biochemical Methane Potential ◽

Anaerobic Membrane Bioreactor ◽

Methane Potential

A method for predicting the long-term effects of ferric on methane production was developed in an anaerobic membrane bioreactor treating food processing wastewater to provide management tools for maximizing methane recovery using ferric based on a batch test. The results demonstrated the accuracy of the predictions for both batch and long-term continuous operations using a Bayesian network meta-analysis based on the Gompertz model. The prediction bias of methane production for batch and continuous operations was minimized, from 11~19% to less than 0.5%. A biochemical methane potential-based Bayesian network meta-analysis suggested a maximum 2.55% ± 0.42% enhancement for Fe2.25. An anaerobic membrane bioreactor improved the methane yield by 2.27% and loading rate by 4.57% for Fe2.25, operating in the sequenced batch mode. The method allowed for a predictable methane yield enhancement based on the biochemical methane potential. Ferric enhanced the biochemical methane potential in batch tests and the methane yield in a continuously operated reactor by a maximum of 8.20% and 7.61% for Fe2.25, respectively. Copper demonstrated a higher methane (18.91%) and sludge yield (17.22%) in batch but faded in the continuous operation (0.32% of methane yield). The enhancement was primarily due to changing the kinetic patterns for the last period, i.e., increasing the second methane production peak (k71), bringing forward the second peak (λ7, λ8), and prolonging the second period (k62). The dual exponential function demonstrated a better fit in the last three stages (after the first peak), which implied that syntrophic methanogenesis with a ferric shuttle played a primary role in the last three methane production periods, in which long-term effects were sustained, as the Bayesian network meta-analysis predicted.

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Batch Anaerobic Co-Digestion and Biochemical Methane Potential Analysis of Goat Manure and Food Waste

Energies ◽

10.3390/en14071952 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1952

Author(s):

Ayobami Orangun ◽

Harjinder Kaur ◽

Raghava R. Kommalapati

Keyword(s):

Food Waste ◽

Gompertz Model ◽

Water Displacement ◽

Biochemical Methane Potential ◽

Greenhouse Gasses ◽

Nonlinear Regression Models ◽

The Us ◽

Methane Potential ◽

Goat Manure ◽

Modified Gompertz Model

The improper management of goat manure from concentrated goat feeding operations and food waste leads to the emission of greenhouse gasses and water pollution in the US. The wastes were collected from the International Goat Research Center and a dining facility at Prairie View A&M University. The biochemical methane potential of these two substrates in mono and co-digestion at varied proportions was determined in triplicates and processes were evaluated using two nonlinear regression models. The experiments were conducted at 36 ± 1 °C with an inoculum to substrate ratio of 2.0. The biomethane was measured by water displacement method (pH 10:30), absorbing carbon dioxide. The cumulative yields in goat manure and food waste mono-digestions were 169.7 and 206.0 mL/gVS, respectively. Among co-digestion, 60% goat manure achieved the highest biomethane yields of 380.5 mL/gVS. The biodegradabilities of 33.5 and 65.7% were observed in goat manure and food waste mono-digestions, while 97.4% were observed in the co-digestion having 60% goat manure. The modified Gompertz model is an excellent fit in simulating the anaerobic digestion of food waste and goat manure substrates. These findings provide useful insights into the co-digestion of these substrates.

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Co-Digestion of Rice Straw with Cow Manure in an Innovative Temperature Phased Anaerobic Digestion Technology: Performance Evaluation and Trace Elements

Energies ◽

10.3390/en14092561 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2561

Author(s):

Furqan Muhayodin ◽

Albrecht Fritze ◽

Oliver Christopher Larsen ◽

Marcel Spahr ◽

Vera Susanne Rotter

Keyword(s):

Trace Elements ◽

Anaerobic Digestion ◽

Greenhouse Gas ◽

Rice Straw ◽

Methane Yield ◽

Methane Formation ◽

Cow Manure ◽

Volatile Solids ◽

Mass Fractions ◽

Cu And Zn

Rice straw is an agricultural residue produced in abundant quantities. Open burning and plowing back the straw to the fields are common practices for its disposal. In-situ incorporation and burning cause emissions of greenhouse gas and particulate matter. Additionally, the energy potential of rice straw is lost. Anaerobic digestion is a technology that can be potentially used to utilize the surplus rice straw, provide renewable energy, circulate nutrients available in the digestate, and reduce greenhouse gas emissions from rice paddies. An innovative temperature phased anaerobic digestion technology was developed and carried out in a continuous circulating mode of mesophilic and hyperthermophilic conditions in a loop digester (F1). The performance of the newly developed digester was compared with the reference digester (F2) working at mesophilic conditions. Co-digestion of rice straw was carried out with cow manure to optimize the carbon to nitrogen ratio and to provide the essential trace elements required by microorganisms in the biochemistry of methane formation. F1 produced a higher specific methane yield (189 ± 37 L/kg volatile solids) from rice straw compared to F2 (148 ± 36 L/kg volatile solids). Anaerobic digestion efficiency was about 90 ± 20% in F1 and 70 ± 20% in F2. Mass fractions of Fe, Ni, Co, Mo, Cu, and Zn were analyzed over time. The mass fractions of Co, Mo, Cu, and Zn were stable in both digesters. While mass fractions of Fe and Ni were reduced at the end of the digestion period. However, no direct relationship between specific methane yield and reduced mass fraction of Fe and Ni was found. Co-digestion of rice straw with cow manure seems to be a good approach to provide trace elements except for Se.

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Biomethane Potential of Sludges from a Brackish Water Fish Hatchery

Applied Sciences ◽

10.3390/app11020552 ◽

2021 ◽

Vol 11 (2) ◽

pp. 552

Author(s):

Francesco da Borso ◽

Alessandro Chiumenti ◽

Giulio Fait ◽

Matia Mainardis ◽

Daniele Goi

Keyword(s):

Brackish Water ◽

Gompertz Model ◽

Experimental Tests ◽

Lag Phase ◽

Phase Duration ◽

Fish Hatchery ◽

Volatile Solids ◽

Water Recirculation ◽

Methane Potential ◽

Intensive Aquaculture

The development of intensive aquaculture is facing the challenge of the sustainable management of effluents. The reproductive sectors (i.e., hatcheries) mainly use water recirculation systems (RAS), which discharge a portion of wastewater. Anaerobic digestion (AD) could reduce the environmental impact of this waste stream while producing biogas. The study is focused on the biochemical methane potential (BMP) of brackish fish hatchery sludges. Wastewater was concentrated by microfiltration and sedimentation and thickened sludges were treated in a BMP system with different inoculum/substrate (I/S) volatile solids ratios (from 50:1 to no inoculum). The highest I/S ratio showed the highest BMP (564.2 NmL CH4/g VS), while different I/S ratios showed a decreasing trend (319.4 and 127.7 NmL CH4/g VS, for I/S = 30 and I/S = 3). In absence of inoculum BMP resulted of 62.2 NmL CH4/g VS. The kinetic analysis (modified Gompertz model) showed a good correlation with the experimental data, but with a long lag-phase duration (from 14.0 to 5.5 days) in particular with the highest I/S. AD applied to brackish water sludges can be a promising treatment with interesting methane productions. For a continuous, full-scale application further investigation on biomass adaptation to salinity and on retention times is needed. Further experimental tests are ongoing.

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Biochemical Methane Potential of Cork Boiling Wastewater at Different Inoculum to Substrate Ratios

Applied Sciences ◽

10.3390/app11073064 ◽

2021 ◽

Vol 11 (7) ◽

pp. 3064

Author(s):

Roberta Mota-Panizio ◽

Manuel Jesús Hermoso-Orzáez ◽

Luis Carmo-Calado ◽

Gonçalo Lourinho ◽

Paulo Sérgio Duque de Brito

Keyword(s):

Anaerobic Digestion ◽

Biogas Production ◽

Treatment Plant ◽

Organic Substrates ◽

Biochemical Methane Potential ◽

Volatile Solids ◽

Working Volume ◽

Methane Potential ◽

Bmp Test ◽

Cork Industry

The present study evaluates the digestion of cork boiling wastewater (CBW) through a biochemical methane potential (BMP) test. BMP assays were carried out with a working volume of 600 mL at a constant mesophilic temperature (35 °C). The experiment bottles contained CBW and inoculum (digested sludge from a wastewater treatment plant (WWTP)), with a ratio of inoculum/substrate (Ino/CBW) of 1:1 and 2:1 on the basis of volatile solids (VSs); the codigestion with food waste (FW) had a ratio of 2/0.7:0.3 (Ino/CBW:FW) and the codigestion with cow manure (CM) had a ratio of 2/0.5:0.5 (Ino/CBW:CM). Biogas and methane production was proportional to the inoculum substrate ratio (ISR) used. BMP tests have proved to be valuable for inferring the adequacy of anaerobic digestion to treat wastewater from the cork industry. The results indicate that the biomethane potential of CBWs for Ino/CBW ratios 1:1 and 2:1 is very low compared to other organic substrates. For the codigestion tests, the test with the Ino/CBW:CM ratio of 2/0.7:0.3 showed better biomethane yields, being in the expected values. This demonstrated that it is possible to perform the anaerobic digestion (AD) of CBW using a cosubstrate to increase biogas production and biomethane and to improve the quality of the final digestate.

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