Thermal hydrolysis as a pretreatment to anaerobic digestion to accelerate biogas production and decrease sludge volume at high loading rates

2020 ◽  
Author(s):  
Shirin Estahbanati ◽  
Krish Ramalingam ◽  
Roland Jezek ◽  
Natalia Perez ◽  
John Fillos ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
High Loading ◽  
Thermal Hydrolysis ◽  
Loading Rates

Study of thermal hydrolysis as a pretreatment to mesophilic anaerobic digestion of pig slurry

2001 ◽  
Vol 44 (4) ◽  
pp. 109-116 ◽  
Author(s):  
A. Bonmatí ◽  
X. Flotats ◽  
L. Mateu ◽  
E. Campos
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Limiting Factor ◽  
Pig Slurry ◽  
Thermal Hydrolysis ◽  
Organic Matter Degradation ◽  
Thermal Pretreatment ◽  
Digestion Process ◽  
Degradation Tests ◽  
Thermal Phenomena

Feasibility of anaerobic digestion of pig slurry is dependent, among other factors, on the biogas production rate, which is low compared with other organic wastes, and on the profitable uses of surplus thermal energy produced, a limiting factor in warm geographical areas. The objectives of this work are determining whether low temperature thermal pretreatment (<90°C) improves pig slurry anaerobic digestion, and determining whether organic matter degradation during the thermal pretreatment is due to thermal phenomena (80°C) or to enzymatic ones (60°C). The thermal degradation tests showed that hydrolysis occurring during the thermal pretreatment is due to thermal phenomena. The increase in soluble substances were significantly larger at 80°C than at 60°C (both during 3 h). Two types of slurry were used in the batch anaerobic digestion tests. The effect of thermal pretreatment differed with the type of slurry: it was positive with almost non-degraded slurries containing low NH4+-N concentration, and negative (inhibition of the anaerobic digestion process) when using degraded slurries with high NH4+-N content.

scholarly journals Performance of Anaerobic Digestion of Chicken Manure Under Gradually Elevated Organic Loading Rates

2019 ◽  
Vol 16 (12) ◽  
pp. 2239 ◽  
Author(s):  
Fei Wang ◽  
Mengfu Pei ◽  
Ling Qiu ◽  
Yiqing Yao ◽  
Congguang Zhang ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Poultry Manure ◽  
Ammonia Nitrogen ◽  
Methane Content ◽  
Chicken Manure ◽  
Continuous Stirred Tank Reactor ◽  
Organic Loading ◽  
Biogas Yield ◽  
Loading Rates

Poultry manure is the main source of agricultural and rural non-point source pollution, and its effective disposal through anaerobic digestion (AD) is of great significance; meanwhile, the high nitrogen content of chicken manure makes it a typical feedstock for anaerobic digestion. The performance of chicken-manure-based AD at gradient organic loading rates (OLRs) in a continuous stirred tank reactor (CSTR) was investigated herein. The whole AD process was divided into five stages according to different OLRs, and it lasted for 150 days. The results showed that the biogas yield increased with increasing OLR, which was based on the volatile solids (VS), before reaching up to 11.5 g VS/(L·d), while the methane content was kept relatively stable and maintained at approximately 60%. However, when the VS was further increased to 11.5 g VS/(L·d), the total ammonia nitrogen (TAN), pH, and alkalinity (CaCO3) rose to 2560 mg·L−1, 8.2, and 15,000 mg·L−1, respectively, while the volumetric biogas production rate (VBPR), methane content, and VS removal efficiency decreased to 0.30 L·(L·d)−1, 45%, and 40%, respectively. Therefore, the AD performance immediately deteriorated and ammonia inhibition occurred. Further analysis demonstrated that the microbial biomass yield and concentrations dropped dramatically in this period. These results indicated that the AD stayed steady when the OLR was lower than 11.5 g VS/(L·d); this also provides valuable information for improving the efficiency and stability of AD of a nitrogen-rich substrate.

Comparison of One-Phase and Two-Phase Anaerobic Digestion of Swine Manure

2013 ◽  
Vol 726-731 ◽  
pp. 2875-2880
Author(s):  
Wen Hao Liu ◽  
Shi Jie Tian ◽  
Shu Biao Wu ◽  
Xiao Qian Zhang ◽  
Chang Le Pang ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Swine Manure ◽  
Continuous Stirred Tank Reactor ◽  
Organic Loading ◽  
Two Phase ◽  
Biogas Yield ◽  
Loading Rates ◽  
Significant Difference ◽  
The One

The possible exploitation of two-phase anaerobic digestion for swine manure was investigated in this study. One-phase and two-phase anaerobic digestion process were investigated in continuous stirred-tank reactor with hydraulic retention times 15 days (hydrolysis and acidification for 3 days and methanogenic12 days in two-phase). When the organic loading rates were equal to or less than 4 g VS/L day, the biogas yield and volumetric production of two processes were no significant difference. However, in the case of organic loading rates being equal to or higher than 5.0 g VS/L day, two-phase biogas yield and volumetric biogas production averaged 0.294 L CH4/g VS added and 2.218 L/L day, compared with one-phase averaged 0.255L CH4/g VS added and 2.168 L/L day, respectively. Significant advantages in saving cost of biogas project were indicated by the comparison of biogas production and COD degradation in the one-phase and two-phase processes.

Biogas production from chicken manure at different organic loading rates in a mesophilic full scale anaerobic digestion plant

2020 ◽  
Vol 141 ◽  
pp. 105693 ◽  
Author(s):  
Linas Jurgutis ◽  
Alvyra Slepetiene ◽  
Jonas Volungevicius ◽  
Kristina Amaleviciute-Volunge
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Full Scale ◽  
Chicken Manure ◽  
Organic Loading ◽  
Loading Rates

scholarly journals Methane conversion efficiency as a simple control parameter for an anaerobic digester at high loading rates

2011 ◽  
Vol 64 (2) ◽  
pp. 534-540 ◽  
Author(s):  
W. Charles ◽  
N. P. Carnaje ◽  
R. Cord-Ruwisch
Keyword(s):  
Anaerobic Digestion ◽  
Production Rate ◽  
Conversion Efficiency ◽  
Methane Conversion ◽  
Control Parameter ◽  
Loading Rate ◽  
High Loading ◽  
Loading Rates ◽  
Ch4 Production ◽  
On Line

The anaerobic digestion process is globally applied to the treatment of highly concentrated wastes such as industrial and rural effluents, and sewage sludge. However, it is known to be relatively unstable. When loaded with high concentrations of organic material, unwanted volatile fatty acids (VFA) are often produced rather than methane (CH4) gas which can lead to digester acidification and failure. This study investigated digester behaviour under high loading rates, testing the usefulness of stoichiometric methane conversion efficiency as a digester control parameter at high loading rates. Our results show that, in general, the CH4 production rate was proportional to the feed rate (loading rate). However, at very high loading rates, the CH4 production rate was not proportional to the increase in the feeding rate. Consequently, VFA accumulated and the H2 partial pressure increased. The proportionality of the loading rate and gas production rate is stoichiometrically expressed as the conversion efficiency. We found that conversion efficiency was a useful indicator as an early warning of digester imbalance. The digester remained stable at conversion efficiencies above 75%. Dropping below 70% signified the onset of digester failure. As loading rate and methane production data are readily available on-line in most anaerobic digestion plants, the conversion efficiency can be monitored on-line and used as an efficient control technique to maintain safe operation of anaerobic digesters at high loading rates.

Biogas production by encased bacteria in synthetic membranes: protective effects in toxic media and high loading rates

2013 ◽  
Vol 34 (13-14) ◽  
pp. 2077-2084 ◽  
Author(s):  
Supansa Youngsukkasem ◽  
Julius Akinbomi ◽  
Sudip K. Rakshit ◽  
Mohammad J. Taherzadeh
Keyword(s):  
Biogas Production ◽  
High Loading ◽  
Protective Effects ◽  
Synthetic Membranes ◽  
Loading Rates
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