Design and Validation of Field-Scale Anaerobic Digesters Treating Dairy Manure for Small Farms

2015 ◽  
pp. 441-449
Keyword(s):  
Dairy Manure ◽  
Small Farms ◽  
Field Scale ◽  
Anaerobic Digesters

Effect of Solids Removal From Dairy Manure Feedstock on Biogas Production in Anaerobic Digesters

2010 ◽  
Author(s):  
Peter E. Zemke ◽  
Byard D. Wood ◽  
Christopher R. Rohleder
Keyword(s):  
Elevated Temperatures ◽  
Biogas Production ◽  
Developed Countries ◽  
Dairy Manure ◽  
Dairy Wastewater ◽  
Anaerobic Digesters ◽  
Biogas Yield ◽  
Volatile Solids ◽  
Mechanical Separation ◽  
Separation Equipment

Many modern anaerobic digesters in developed countries consist of a digestion process in which solids are reduced to biogas, followed by mechanical separation that removes the majority of the remaining solids from the effluent. Experience has shown that such systems are often plagued with plugging due to excessive solids in the digester influent. Moreover, the mechanical separation equipment is prematurely degraded due to the elevated temperatures and corrosive compounds in the digester effluent. Reversing the order of separation and digestion offers a proven method of eliminating these problems, but at the expense of lower biogas production. The work presented in this paper quantifies this difference in biogas production by comparing the biogas yields of dairy wastewater feedstocks with and without prior mechanical solids separation through a 0.75-mm screen. Laboratory-scale batch digesters were operated up to 40 days at 35–40 °C and monitored for mass of volatile solids consumed and biogas production. Although the initially separated influent contained only half as much volatile solids, the ultimate biogas yield was only 25% less than that obtained with non-separated influent, demonstrating some tradeoff between higher energy production and system reliability.

Dewatering considerations for effluent from dairy manure anaerobic digesters

1981 ◽  
Vol 3 (4) ◽  
pp. 297-310 ◽  
Author(s):  
David J. Hills ◽  
Robert L. Kemmerle
Keyword(s):  
Dairy Manure ◽  
Anaerobic Digesters

Performance and Microbial Analysis of Anaerobic Digesters Treating Food Waste and Dairy Manure

2008 ◽  
Vol 1 (3) ◽  
pp. 233-242 ◽  
Author(s):  
H. M. El-Mashad ◽  
J. A. McGarvey ◽  
R. Zhang
Keyword(s):  
Food Waste ◽  
Dairy Manure ◽  
Anaerobic Digesters ◽  
Microbial Analysis

scholarly journals Response of Microbial Community to Induced Failure of Anaerobic Digesters Through Overloading With Propionic Acid Followed by Process Recovery

2020 ◽  
Vol 8 ◽  
Author(s):  
Azin Khafipour ◽  
Elsie M. Jordaan ◽  
Daniel Flores-Orozco ◽  
Ehsan Khafipour ◽  
David B. Levin ◽  
...  
Keyword(s):  
Microbial Community ◽  
Propionic Acid ◽  
Relative Abundance ◽  
Microbial Community Composition ◽  
Dairy Manure ◽  
Rrna Gene ◽  
Operational Parameters ◽  
Anaerobic Digesters ◽  
Recovery Potential ◽  
And Shifts

In order to effectively use microbial-based strategies to manage anaerobic digesters, it is necessary to distinguish between community shifts that are part of the natural dynamic of the system and shifts caused by environmental or operational disturbances. The objective of this research study was to evaluate the significance of changes in the microbial community of anaerobic digesters during failure in correlation to operational parameters such as an organic acid overload. Five continuously stirred 0.5 L reactors were set-up as semi-continuously-fed, mesophilic dairy manure digesters with a 30-day hydraulic retention time. After a 120-day stabilization period, two digesters were kept as controls, while the organic loading rates in the triplicate set were increased step-wise to ultimately provide a shock-load leading to failure using propionic acid spikes. Acidosis resulting in near cessation of biogas and termination of methane production occurred between 4 and 7 weeks, after which all the digesters continued to be fed only dairy manure. The shock loading of propionic acid led to an accumulation of mainly acetate and propionate, with low levels of iso-butyrate, butyrate, iso-valerate, and valerate. High-throughput Illumina sequencing of the V4 region of the bacterial and archaeal 16S rRNA gene in digester samples showed a significant change in the microbial community composition during propionic acid overload, followed by a return to the original composition with regular feedstock. Bacterial genera whose relative abundance decreased during the inhibition stage included Sedimentibacter, Syntrophomonas, TSCOR003.O20, and Marinilabiaceae, while the relative abundance of Lachnospiraceae, Ruminococcus, Mogibacteriaceae, Pyramidobacter, and Bacteroides increased. The relative abundance of dominant methanogens, Methanosarcina and Methanobacterium, although initially resistant, were decreased (from 91.71 to 12.14% and from 2.98 to 0.73%, respectively) during inhibition, while Methanobrevibacter and Methanosphaera that were prominent in the manure feedstock increased from 17.36 to 79.45% and from 0.14 to 1.12%, respectively. Shifts in bacterial and archaeal compositions, back to their pre-shock steady state after failure, highlight the digester’s microbial resilience and recovery potential.

Solar energy heating of dairy-manure anaerobic digesters

1980 ◽  
Vol 2 (2) ◽  
pp. 103-118 ◽  
Author(s):  
David J. Hills ◽  
John R. Stephens
Keyword(s):  
Solar Energy ◽  
Dairy Manure ◽  
Anaerobic Digesters

scholarly journals Design of a Centralized Bioenergy Unit at Comarca Lagunera, Mexico: Modeling Strategy to Optimize Bioenergy Production and Reduce Methane Emissions

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1350
Author(s):  
José Alberto Silva-González ◽  
Inty Omar Hernández-De Lira ◽  
Antonio Rodríguez-Martínez ◽  
Grace Aileen Ruiz-Santoyo ◽  
Berenice Juárez-López ◽  
...  
Keyword(s):  
Production Cost ◽  
Organic Fertilizer ◽  
Dairy Manure ◽  
Anaerobic Digesters ◽  
Net Production ◽  
Biomethane Production ◽  
Centralized Biogas Plant ◽  
Environmental Feasibility ◽  
Economic Analyses ◽  
Modeling Strategy

A centralized bioenergy unit was simulated, focusing on optimizing the manure transport chain, installing a centralized biogas plant, operation costs of the process, biogas upgrading, organic fertilizer production, and economic analyses. Comarca Lagunera from northeast Mexico was chosen as a study zone due to the existing number of dairy farms and livestock population (64,000 cattle heads). Two scenarios were analyzed: The first centralized scenario consisted of selecting one unique location for the anaerobic digesters for the 16 farms; the second decentralized scenario consisted of distributing the anaerobic digesters in three locations. Optimal locations were determined using mathematical modeling. The bioenergy unit was designed to process 1600 t/day of dairy manure. Results indicated that biomethane production was a more profitable option than generating electricity with non-purified methane. The amount of biomethane production was 58,756 m3/day. Economic analysis for centralized bioenergy unit scenario showed a net production cost of USD $0.80 per kg of biomethane with a profit margin of 14.4% within 10.7 years. The decentralized bioenergy unit scenario showed a net production cost of USD $0.80 per kg of biomethane with a profit of 12.9% within 11.4 years. This study demonstrated the techno-economical and environmental feasibility for centralized and decentralized bioenergy units.

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