scholarly journals Enhancement anaerobic digestion and methane production from kitchen waste by thermal and thermo-chemical pretreatments in batch  leach bed reactor with down flow

2018 ◽  
Vol 64 (No. 3) ◽  
pp. 128-135 ◽  
Author(s):  
Radmard Seyed Abbas ◽  
Alizadeh Hossein Haji Agha ◽  
Seifi Rahman
Keyword(s):  
Anaerobic Digestion ◽  
Microwave Irradiation ◽  
Methane Production ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Lag Phase ◽  
Kitchen Waste ◽  
Gompertz Equation ◽  
Chemical Pretreatments ◽  
Pretreatment Conditions

The effects of thermal (autoclave and microwave irradiation (MW)) and thermo-chemical (autoclave and microwave irradiation – assisted NaOH 5N) pretreatments on the chemical oxygen demand (COD) solubilisation, biogas and methane production of anaerobic digestion kitchen waste (KW) were investigated in this study. The modified Gompertz equation was fitted to accurately assess and compare the biogas and methane production from KW under the different pretreatment conditions and to attain representative simulations and predictions. In present study, COD solubilisation was demonstrated as an effective effect of pretreatment. Thermo-chemical pretreatments could improve biogas and methane production yields from KW. A comprehensive evaluation indicated that the thermo-chemical pretreatments (microwave irradiation and autoclave- assisted NaOH 5N, respectively) provided the best conditions to increase biogas and methane production from KW. The most effective enhancement of biogas and methane production (68.37 and 36.92 l, respectively) was observed from MW pretreated KW along with NaOH 5N, with the shortest lag phase of 1.79  day, the max. rate of 2.38 l·day<sup>–1</sup> and ultimate biogas production of 69.8 l as the modified Gompertz equation predicted.

scholarly journals Pretreatment of Animal Manure Biomass to Improve Biogas Production: A Review

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3573 ◽  
Author(s):  
Meneses-Quelal Orlando ◽  
Velázquez-Martí Borja
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Biogas Production ◽  
Poultry Manure ◽  
Animal Manure ◽  
Methane Yield ◽  
Operational Parameters ◽  
Advantages And Disadvantages ◽  
Physical Chemical ◽  
Chemical Pretreatments

The objective of this research is to present a review of the current technologies and pretreatments used in the fermentation of cow, pig and poultry manure. Pretreatment techniques were classified into physical, chemical, physicochemical, and biological groups. Various aspects of these different pretreatment approaches are discussed in this review. The advantages and disadvantages of its applicability are highlighted since the effects of pretreatments are complex and generally depend on the characteristics of the animal manure and the operational parameters. Biological pretreatments were shown to improve methane production from animal manure by 74%, chemical pretreatments by 45%, heat pretreatments by 41% and physical pretreatments by 30%. In general, pretreatments improve anaerobic digestion of the lignocellulosic content of animal manure and, therefore, increase methane yield.

scholarly journals Addition of Different Biochars as Catalysts during the Mesophilic Anaerobic Digestion of Mixed Wastewater Sludge

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1094
Author(s):  
Marco Chiappero ◽  
Francesca Cillerai ◽  
Franco Berruti ◽  
Ondřej Mašek ◽  
Silvia Fiore
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Biogas Production ◽  
Chemical Properties ◽  
Principal Component ◽  
Gompertz Model ◽  
Wastewater Sludge ◽  
Total Carbon ◽  
Lag Phase ◽  
Working Volume

Biochar (BC) recently gained attention as an additive for anaerobic digestion (AD). This work aims at a critical analysis of the effect of six BCs, with different physical and chemical properties, on the AD of mixed wastewater sludge at 37 °C, comparing their influence on methane production and AD kinetics. AD batch tests were performed at the laboratory scale operating 48 reactors (0.25 L working volume) for 28 days with the addition of 10 g L−1 of BC. Most reactors supplemented with BCs exhibited higher (up to 22%) methane yields than the control reactors (0.15 Nm3 kgVS−1). The modified Gompertz model provided maximum methane production rate values, and in all reactors the lag-phase was equal to zero days, indicating a good adaptation of the inoculum to the substrate. The potential correlations between BCs’ properties and AD performance were assessed using principal component analysis (PCA). The PCA results showed a reasonable correlation between methane production and the BCs’ O–C and H–C molar ratios, and volatile matter, and between biogas production and BCs’ pore volume, specific surface area, and fixed and total carbon. In conclusion, the physic-chemical properties of BC (specifically, hydrophobicity and morphology) showed a key role in improving the AD of mixed wastewater sludge.

Effect of sodium salt on anaerobic digestion of kitchen waste

2016 ◽  
Vol 73 (8) ◽  
pp. 1865-1871 ◽  
Author(s):  
Naveed Anwar ◽  
Wen Wang ◽  
Jie Zhang ◽  
Yeqing Li ◽  
Chang Chen ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Sodium Salt ◽  
Salt Concentration ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Production Performance ◽  
Methane Yield ◽  
Production Model ◽  
Lag Phase ◽  
Kitchen Waste

The effect of different sodium salt concentration on anaerobic digestion of kitchen waste was investigated. The methane production performance, the corresponding methane production model and sodium salt inhibition model were studied, and the degradation efficiency was analyzed. With the increase of sodium salt concentration, the methane yield and the maximal methane production rate decreased along with the increase of lag phase time. The highest methane yield of 594 mL/g-VSadded (VS: volatile solids) was found with no sodium salt addition while the lowest was obtained with addition of 16 g/L NaCl. The declines of the methane yield were negligible when the sodium salt concentration was below 8 g/L, which corresponded to &lt;10% inhibiting efficiency. In contrast, a sharp decrease of methane yield was observed with addition of &gt;8 g/L NaCl (causing 17–80% inhibition). Five kinds of regression models were developed to describe the sodium salt inhibition efficiency, and the cubic regression model of y = 0.508 + 2.401x − 0.369x2 + 0.033x3 showed the best fitting. The volatile fatty acids/ethanol gradually accumulated along with the increase of the sodium salt concentration, and the volatile solid removal efficiency represented a gradual decline accordingly. It is recommended that the sodium salt concentration in the anaerobic digesters should be controlled below 8 g/L in order to avoid intense methane inhibition.

scholarly journals Inter-stage thermophilic aerobic digestion may increase organic matter removal from wastewater sludge without decreasing biogas production

2017 ◽  
Vol 77 (3) ◽  
pp. 721-726
Author(s):  
Sasha D. Hafner ◽  
Johan T. Madsen ◽  
Johanna M. Pedersen ◽  
Charlotte Rennuit
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Wastewater Sludge ◽  
Aerobic Digestion ◽  
Anaerobic Digesters ◽  
Stage System ◽  
Thermophilic Aerobic Digestion ◽  
Pre Treatment

Abstract Combining aerobic and anaerobic digestion in a two-stage system can improve the degradation of wastewater sludge over the use of either technology alone. But use of aerobic digestion as a pre-treatment before anaerobic digestion generally reduces methane production due to loss of substrate through oxidation. An inter-stage configuration may avoid this reduction in methane production. Here, we evaluated the use of thermophilic aerobic digestion (TAD) as an inter-stage treatment for wastewater sludge using laboratory-scale semi-continuous reactors. A single anaerobic digester was compared to an inter-stage system, where a thermophilic aerobic digester (55 °C) was used between two mesophilic anaerobic digesters (37 °C). Both systems had retention times of approximately 30 days, and the comparison was based on measurements made over 97 days. Results showed that the inter-stage system provided better sludge destruction (52% volatile solids (VS) removal vs. 40% for the single-stage system, 44% chemical oxygen demand (COD) removal vs. 34%) without a decrease in total biogas production (methane yield per g VS added was 0.22–0.24 L g−1 for both systems).

Study on Solid-State Anaerobic Co-Digestion with Distiller’s Grains and Food Waste for Methane Production

2012 ◽  
Vol 485 ◽  
pp. 306-309
Author(s):  
Li Hong Wang ◽  
Qun Hui Wang ◽  
Wei Wei Cai
Keyword(s):  
Anaerobic Digestion ◽  
Solid State ◽  
Synergistic Effect ◽  
Food Waste ◽  
Methane Production ◽  
Waste Treatment ◽  
Biogas Production ◽  
Methane Yield ◽  
Kitchen Waste ◽  
Distiller's Grains

Solid-state anaerobic digestion (SSAD) of distiller’s grains (DG) and kitchen waste (KW) for biogas was investigated. Six DG to KW ratios of 10/1, 8/1, 6/1, 4/1, 1/0, and 0/1 was used. The results showed that in 48 digestion days the co-digestion with DG to KW ratio of 8:1 obtained the highest methane yield of 159.74mL/gTS, TS and VS reductions of 58.7% and 71.8%, hemicellulase, cellulose and lignin reductions of 46.7%, 45.4% and 4.0%. Compared to mono-digestions of DG or KW, co-digestion of DG and FW had a good synergistic effect. It indicated that SSAD of cellulosic-based waste and food waste could be one of the options for efficient biogas production and waste treatment

Experimental and Modelling Approach of Biogas Production by Anaerobic Digestion of Agricultural Resources

2017 ◽  
Vol 68 (6) ◽  
pp. 1294-1297 ◽  
Author(s):  
Gabriela Alina Dumitrel ◽  
Adrian Eugen Cioabla ◽  
Ioana Ionel ◽  
Lucia Ana Varga
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Biogas Production ◽  
Batch Reactor ◽  
Pilot Scale ◽  
Lag Phase ◽  
Biogas Yield ◽  
Agricultural Resources ◽  
Methane Production Rate ◽  
Modelling Approach

Anaerobic digestion processes of agricultural resources, as single substrates (wheat bran and barley) or as combination of substrates (75 % corn&25% corn cob � named MIX1 and 40 % corn & 40 % wheat&20 % sunflower husks � named MIX2), were performed, at a mesophilic temperature in a batch reactor, at pilot scale. The results proved that the higher quantity of biogas yield was achieved for barley, followed by MIX1, and finally MIX2. The same order was obtained when the total methane production was evaluated. The performances of digesters were mathematically evaluated by using the modified Gompertz equation. The kinetic parameters, such as the methane production potential (MP), the maximum methane production rate (Rm) and the extent of lag phase (l) were calculated, for each experimental case. The values of the performance indicators confirmed that all the models fitted well with the experimental data.

Effect of CaCO3 Pretreatment on Methane Production from Anaerobic Digestion of Rice Straw

2014 ◽  
Vol 587-589 ◽  
pp. 208-211 ◽  
Author(s):  
Ben Lin Dai ◽  
An Feng Zhu ◽  
Fei Hu Mu ◽  
Ning Xu ◽  
Zhen Wu
Keyword(s):  
Anaerobic Digestion ◽  
Rice Straw ◽  
Methane Production ◽  
Liquid State ◽  
Biogas Production ◽  
Chemical Pretreatment ◽  
Pretreatment Effects ◽  
Pretreatment Conditions ◽  
Anaerobic Production ◽  
Peak Value

The chemical pretreatment of rice straw was achieved via the liquid-state dissolution of CaCO3. Pretreatment effects on the biodegradability and subsequent anaerobic production of methane were investigated. The results showed that the peak value of biogas production was attained of 4% CaCO3 pretreatment on the 20th day, which is 1 589 mL. The test daily methane content of different pretreatment conditions mainly ranges from 3.4% to 47.4%. The cumulative biogas production of 6% CaCO3 pretreatment was the highest, about 19 917 mL.

The impacts of red mud dosing on methane production and reduction of CO2: Activity of granules and formation

2021 ◽  
pp. 0958305X2098689
Author(s):  
Anwar Ahmad ◽  
Fatima Shahitha
Keyword(s):  
Production Rate ◽  
Methane Production ◽  
Red Mud ◽  
Extracellular Polymeric Substances ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Hydrolysis Rate ◽  
Lag Phase ◽  
Optimal Dosage ◽  
Mixing Ratio

Experiments were conducted to investigate the effect of red mud (RM) dosing on granular sludge formation, biogas production and carbon dioxide reduction from palm oil mill effluent (POME) digestion. The results show that dosing RM adversely affected sludge granulation due to the formation of precipitates and hydrolyzates with poor settleability. However, at the optimal dosage (4.5 g RM/L), it could benefit granules formation and stability by improving the in extracellular polymeric substances and biogas production rate was 87.9 l g-VSadded/d at 4.5:30 mixing ratio. The ratio of 0.5:80–2.5:50 g-VS did not affect methane production and the highest methane yield average 79.9 l/g-VS added for RM:POME of 4.5:30, 14.5 higher respective to that of POME alone only. A CO2 reduction of 89.6% was obtained at RM of 4.5:30 ( r = 0.998). The chemical oxygen demand (COD) removal was 87% obtained at 30 g COD/l and 4.5:30 g-VS with growth of sp. Methanosarcina. The process evaluation was found model cone best fitted and actual production of CH4. The evidence by low root mean square prediction error (RMSPE) showed high correlation difference (Dif. %) with predicted value and actual values. Analyses were evaluated that the POME degradation with RM utilization, substantially enhanced the hydrolysis rate (khyd), lag phase time h (λ) and methane production rate ( Rm) of mixing ratio of RM:POME. Furthermore, the system showed solid reduction with the increased production of methane.

Evaluation of thermal steam-explosion key operation factors to optimize biogas production from biological sludge

2015 ◽  
Vol 72 (6) ◽  
pp. 937-945 ◽  
Author(s):  
S. I. Pérez-Elvira ◽  
I. Sapkaite ◽  
F. Fdz-Polanco
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Steam Explosion ◽  
Treatment Time ◽  
Biogas Production ◽  
Negative Influence ◽  
Point Of View ◽  
Lag Phase ◽  
Biological Sludge ◽  
The One

Thermal steam-explosion is the most extended hydrolysis pretreatment to enhance anaerobic digestion of sludge. Thermal hydrolysis key parameters are temperature (T) and time (t), and the generally accepted values reported from full-scale information are: 150–230 °C and 20–60 min. This study assesses the influence of different temperature–time–flash combinations (110–180 °C, 5–60 min, 1–3 re-flashing) on the anaerobic degradation of secondary sludge through biochemical methane potential (BMP) tests. All the conditions tested presented higher methane production compared to the untreated sludge, and both solubilization (after the hydrolysis) and degradation (by anaerobic digestion) increased linearly when increasing the severity (T–t) of the pretreatment, reaching 40% solubilization and degradation of the particulate matter at 180° C–60 min. However, for the 180 °C temperature, the treatment time impacted negatively on the lag phase. No influence of re-flashing the pretreated matter was observed. In conclusion, thermal steam-explosion at short operation times (5 min) and moderate temperatures (145 °C) seems to be very attractive from a degradation point of view thus presenting a methane production enhancement similar to the one obtained at 180°C and without negative influence of the lag phase.

scholarly journals Optimization of the Biomethane Production Process by Anaerobic Digestion of Wheat Straw Using Chemical Pretreatments Coupled with Ultrasonic Disintegration

2021 ◽  
Vol 13 (13) ◽  
pp. 7202
Author(s):  
Yasmine Ryma Ouahabi ◽  
Kenza Bensadok ◽  
Abdeldjalil Ouahabi
Keyword(s):  
Anaerobic Digestion ◽  
Wheat Straw ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Large Contribution ◽  
Solids Concentration ◽  
Soluble Chemical Oxygen Demand ◽  
Chemical Pretreatments ◽  
Waste Particles ◽  
Improved Characteristics

Biomass is an attractive energy source that can be used for production of heat, power, and transport fuels and when produced and used on a sustainable basis, can make a large contribution to reducing greenhouse gas emissions. Anaerobic digestion (AD) is a suitable technology for reducing organic matter and generating bioenergy in the form of biogas. This study investigated the factors allowing the optimization of the process of biogas production from the digestion of wheat straw (WS). The statistical analysis of the experiments carried out showed that ultrasonic processing plays a fundamental role with the sonication density and solids concentration leading to improved characteristics of WS, reducing particle size, and increasing concentration of soluble chemical oxygen demand. The higher the sonicating power used, the more the waste particles are disrupted. The optimality obtained under mesophilic conditions for WS pretreated with 4% w/w (weight by weight) H2O2 at temperature 36 °C under 10 min of ultrasonication at 24 kHz with a power of 200 W improves the methane yield by 64%.

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