scholarly journals Physical Properties of Dairy Manure Pre- and Post-Anaerobic Digestion

2019 ◽  
Vol 9 (13) ◽  
pp. 2703
Author(s):  
Hui Wang ◽  
Horacio A. Aguirre-Villegas ◽  
Rebecca A. Larson ◽  
Asli Alkan-Ozkaynak
Keyword(s):  
Anaerobic Digestion ◽  
Physical Properties ◽  
Linear Model ◽  
Food Waste ◽  
Dairy Farms ◽  
Dairy Manure ◽  
Biogas Yield ◽  
Volatile Solids ◽  
Anaerobically Digested Dairy Manure ◽  
Sand Bedding

Manure characteristics change through processing, including anaerobic digestion (AD). These changes can alter handling of manure during downstream operations. This study analyzed the density, total solids (TS) content, and volatile solids (VS) content of pre-digested and anaerobically digested dairy manure from seven dairy farms in Wisconsin. The density of pre-digested manure increased from 990 to 1065 kg m−3 as the TS level increased from 1.5% to 13.0%. Density and TS for pre-digested manure from facilities using separated solids as bedding were related with a linear model for TS ranging from 1.5% to 13.0% and with a polynomial model for TS ranging from 1.5% to 50%. The model shows that density decreases with an increasing TS content when TS is greater than 8.0%. Manure from dairy facilities that used sand bedding had a VS/TS ratio of 0.87. This ratio was higher than the ratio when manure solids were used as bedding (0.81) and when food waste was incorporated into the digester (0.77). This study also provides a simple methodology to estimate biogas yield by using the density of pre- and post-digested manure.

scholarly journals Effect of co-digestion of food waste and cow dung on biogas yield

2020 ◽  
Vol 181 ◽  
pp. 01005
Author(s):  
Makhura Emmanuel Pax ◽  
Edison Muzenda ◽  
Tumeletso Lekgoba
Keyword(s):  
Anaerobic Digestion ◽  
Moisture Content ◽  
Food Waste ◽  
Biogas Production ◽  
Cow Dung ◽  
Mixing Ratio ◽  
Total Solids ◽  
Biogas Yield ◽  
Volatile Solids ◽  
Thermophilic Conditions

This paper aims at finding the effect of co-digestion of cow dung and food waste on total biogas yield. Biogas production was improved through co-digestion of cow dung and food waste (FW) containing a small fraction of inoculum under mesophilic temperature (37ºC) over a retention time of 24 days. Co-digestion ratios of 1:1, 2:1 and 3:1 for cowdung/foodwaste were used for the study on anaerobic digestion on the co digested matter. Tests were carried out starting with the preparation of substrates, substrate characterization to determine the moisture content (MC), total solids (TS), volatile solids (VS) and ultimately batch anaerobic digestion experiments under thermophilic conditions (370C). The moisture content, volatile solids and total solids for food waste were 78, 22 and 90.7% respectively while the characteristics for cow dung were 67.2, 32.8 and 96.0 % respectively. From the study, a mixing ratio of cow dung: food waste of 1:2 was found to be the optimum substrate mixture for biogas production at 25595.7 Nml. The accumulated gas volumes of 18756.6, 14042.5, 13940.8 and 13839.1 Nml were recorded for cow dung: food waste ratios of 2:1, 1:1, 1:3 and 3:1 respectively. For a co-digestion containing more of the food waste than cow dung, a higher volume of biogas is produce.

scholarly journals Biogas potential of organic waste onboard cruise ships — a yet untapped energy source

2021 ◽  
Author(s):  
Kai Schumüller ◽  
Dirk Weichgrebe ◽  
Stephan Köster
Keyword(s):  
Energy Source ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Food Waste ◽  
Energy Demand ◽  
Organic Waste ◽  
Biogas Production ◽  
Biogas Yield ◽  
Cruise Ships ◽  
Detailed Presentation

AbstractTo tap the organic waste generated onboard cruise ships is a very promising approach to reduce their adverse impact on the maritime environment. Biogas produced by means of onboard anaerobic digestion offers a complementary energy source for ships’ operation. This report comprises a detailed presentation of the results gained from comprehensive investigations on the gas yield from onboard substrates such as food waste, sewage sludge and screening solids. Each person onboard generates a total average of about 9 kg of organic waste per day. The performed analyses of substrates and anaerobic digestion tests revealed an accumulated methane yield of around 159 L per person per day. The anaerobic co-digestion of sewage sludge and food waste (50:50 VS) emerged as particularly effective and led to an increased biogas yield by 24%, compared to the mono-fermentation. In the best case, onboard biogas production can provide an energetic output of 82 W/P, on average covering 3.3 to 4.1% of the total energy demand of a cruise ship.

Application of the IWA Anaerobic Digestion Model (ADM1) for simulating full-scale anaerobic sewage sludge digestion

2005 ◽  
Vol 52 (1-2) ◽  
pp. 487-492 ◽  
Author(s):  
Y. Shang ◽  
B.R. Johnson ◽  
R. Sieger
Keyword(s):  
Wastewater Treatment ◽  
Steady State ◽  
Anaerobic Digestion ◽  
Biogas Production ◽  
Treatment Plant ◽  
Biochemical Parameter ◽  
Full Scale ◽  
Anaerobic Digesters ◽  
Biogas Yield ◽  
Volatile Solids

A steady-state implementation of the IWA Anaerobic Digestion Model No. 1 (ADM1) has been applied to the anaerobic digesters in two wastewater treatment plants. The two plants have a wastewater treatment capacity of 76,000 and 820,000 m3/day, respectively, with approximately 12 and 205 dry metric tons sludge fed to digesters per day. The main purpose of this study is to compare the ADM1 model results with full-scale anaerobic digestion performance. For both plants, the prediction of the steady-state ADM1 implementation using the suggested physico-chemical and biochemical parameter values was able to reflect the results from the actual digester operations to a reasonable degree of accuracy on all parameters. The predicted total solids (TS) and volatile solids (VS) concentration in the digested biosolids, as well as the digester volatile solids destruction (VSD), biogas production and biogas yield are within 10% of the actual digester data. This study demonstrated that the ADM1 is a powerful tool for predicting the steady-state behaviour of anaerobic digesters treating sewage sludges. In addition, it showed that the use of a whole wastewater treatment plant simulator for fractionating the digester influent into the ADM1 input parameters was successful.

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.

scholarly journals Effect of yeast addition on the biogas production performance of a food waste anaerobic digestion system

2020 ◽  
Vol 7 (8) ◽  
pp. 200443
Author(s):  
Ming Gao ◽  
Shuang Zhang ◽  
Xinxin Ma ◽  
Weijie Guan ◽  
Na Song ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Food Waste ◽  
Biogas Production ◽  
Gas Production ◽  
Production Performance ◽  
Organic Load ◽  
Control Group ◽  
Volatile Solids ◽  
Volatile Organic ◽  
The Stability

Food waste contains numerous easily degradable components, and anaerobic digestion is prone to acidification and instability. This work aimed to investigate the effect of adding yeast on biogas production performance, when substrate is added after biogas production is reduced. The results showed that the daily biogas production increased 520 and 550 ml by adding 2.0% (volatile solids; VS) of activated yeast on the 12th and 37th day of anaerobic digestion, respectively, and the gas production was relatively stable. In the control group without yeast, the increase of gas production was significantly reduced. After the second addition of substrate and yeast, biogas production only increased 60 ml compared with that before the addition. After fermentation, the biogas production of yeast group also increased by 33.2% compared with the control group. Results of the analysis of indicators, such as volatile organic acids, alkalinity and propionic acid, showed that the stability of the anaerobic digestion system of the yeast group was higher. Thus, the yeast group is highly likely to recover normal gas production when the biogas production is reduced, and substrate is added. The results provide a reference for experiments on the industrialization of continuous anaerobic digestion to take tolerable measures when the organic load of the feed fluctuates dramatically.

Effect of Oil Content on Dry Anaerobic Digestion of Food Waste under Mesophilic Conditions

2015 ◽  
Vol 768 ◽  
pp. 281-288
Author(s):  
Lian Hai Ren ◽  
Yan Bing Huang ◽  
Pan Wang
Keyword(s):  
Anaerobic Digestion ◽  
Food Waste ◽  
Oil Content ◽  
Continuous Fermentation ◽  
Biogas Production ◽  
Removal Rate ◽  
Gas Production ◽  
Composition Analysis ◽  
Volatile Solids ◽  
Dry Anaerobic Digestion

The variations of daily biogas yields, cumulative biogas yields, biogas composition analysis, total solids (TS) and volatile solids (VS) were studied in the process of mesophilic and dry anaerobic digestion of food waste under different oil contents (0%, 2%, 4%, 6%, 8%, 10%) at 35 °C. The gas production raised and then went down with the oil content, followed by 243.14, 245.64, 256.09, 269.25, 276.54, 284.22mL /g TS respectively. The research provided a reference for the pretreatment of food waste in follow-up continuous fermentation. Results showed that the period of the process of mesophilic dry anaerobic digestion under oil content of 0% was the shortest, with the total biogas production of 1275.5mL. During the process of the digestion, methane content of the biogas raised and then went down, up to a maximum of 77.62%. The removal rate of TS and VS in food waste with the oil content of 6% was the highest, obtained as 11.2% and 13.2%, respectively.

scholarly journals A pilot-scale comparison of mesophilic and thermophilic digestion of source segregated domestic food waste

2008 ◽  
Vol 58 (7) ◽  
pp. 1475-1481 ◽  
Author(s):  
Charles J. Banks ◽  
Michael Chesshire ◽  
Anne Stringfellow
Keyword(s):  
Food Waste ◽  
Pilot Scale ◽  
Gas Production ◽  
Average Weight ◽  
Anaerobic Digesters ◽  
Biogas Yield ◽  
Volatile Solids ◽  
Thermophilic Conditions ◽  
High Alkalinity ◽  
Thermophilic Digestion

Source segregated food waste was collected from domestic properties and its composition determined together with the average weight produced per household, which was 2.91 kg per week. The waste was fed over a trial period lasting 58 weeks to an identical pair of 1.5 m3 anaerobic digesters, one at a mesophilic (36.5°C) and the other at a thermophilic temperature (56°C). The digesters were monitored daily for gas production, solids destruction and regularly for digestate characteristics including alkalinity, pH, volatile fatty acid (VFA) and ammonia concentrations. Both digesters showed high VFA and ammonia concentrations but in the mesophilic digester the pH remained stable at around 7.4, buffered by a high alkalinity of 13,000 mg l−1; whereas in the thermophilic digester VFA levels reached 45,000 mg l−1 causing a drop in pH and digester instability. In the mesophilic digester volatile solids (VS) destruction and specific gas yield were favourable, with 67% of the organic solids being converted to biogas at a methane content of 58% giving a biogas yield of 0.63 m3 kg−1 VSadded. Digestion under thermophilic conditions showed potentially better VS destruction at 70% VS and a biogas yield of 0.67 m3 kg−1 VSadded, but the shifts in alkalinity and the high VFA concentrations required a reduced loading to be applied. The maximum beneficial loading that could be achieved in the mesophilic digester was 4.0 kg VS m−3 d−1.

scholarly journals Monitoring of Food Waste Anaerobic Digestion Performance: Conventional Co-Substrates vs. Unmarketable Biochar Additions

Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2353
Author(s):  
Nour El Houda Chaher ◽  
Abdallah Nassour ◽  
Moktar Hamdi ◽  
Michael Nelles
Keyword(s):  
Anaerobic Digestion ◽  
Food Waste ◽  
Agricultural Waste ◽  
Cost Effective ◽  
Organic Loading Rate ◽  
Experimental Conditions ◽  
Biogas Yield ◽  
Effluent Quality ◽  
Start Up ◽  
Technical Details

This study proposed the selection of cost-effective additives generated from different activity sectors to enhance and stabilize the start-up, as well as the transitional phases, of semi-continuous food waste (FW) anaerobic digestion. The results showed that combining agricultural waste mixtures including wheat straw (WS) and cattle manure (CM) boosted the process performance and generated up to 95% higher methane yield compared to the control reactors (mono-digested FW) under an organic loading rate (OLR) range of 2 to 3 kg VS/m3·d. Whereas R3 amended with unmarketable biochar (UBc), to around 10% of the initial fresh mass inserted, showed a significant process enhancement during the transitional phase, and more particularly at an OLR of 4 kg VS/m3·d, it was revealed that under these experimental conditions, FW reactors including UBc showed an increase of 144% in terms of specific biogas yield (SBY) compared to FW reactors fed with agricultural residue. Hence, both agricultural and industrial waste were efficacious when it came to boosting either FW anaerobic performance or AD effluent quality. Although each co-substrate performed under specific experimental conditions, this feature provides decision makers with diverse alternatives to implement a sustainable organic waste management system, conveying sufficient technical details to draw up appropriate designs for the recovery of various types of organic residue.

Effect of Dry Matter Concentration on Dry Anaerobic Digestion of Animal Manure and Straw

2012 ◽  
Vol 253-255 ◽  
pp. 897-902
Author(s):  
Li Jun Shi ◽  
Miao Huang ◽  
Wei Yu Zhang ◽  
Hui Fen Liu
Keyword(s):  
Anaerobic Digestion ◽  
Dry Matter ◽  
Biogas Production ◽  
Engineering Application ◽  
Dairy Manure ◽  
Organic Loading Rate ◽  
Biogas Yield ◽  
Dry Matter Concentration ◽  
Matter Concentration ◽  
Dry Anaerobic Digestion

In this paper anaerobic digestion of dairy manure and straw was conducted to produce biogas. Under the conditions of C/N=25-30 and T=36°C, five kinds of dry matter concentration of 20%, 15%, 10%, 5% and 2.5% were tested to investigate the effect of dry matter concentration on anaerobic digestion. The result showed that first 30 days was the biogas production peak phase and VFA concentrations in the leachate were also high during the same period. When dry matter concentration increased, biogas production appeared larger fluctuation, and alkalinity and NH4+-N concentration in the leachate also increased with higher organic loading rate. Among five kinds of dry matter concentration, 10% was more suitable for anaerobic digestion to produce biogas with total biogas production amount of 4710 mL after 30 days and volumetric biogas yield of 0.313 m3•m-3•d-1. These results could provide instructive meaning to the engineering application of dry anaerobic digestion.

scholarly journals Production of Biogas from an Agro-industrial Waste and its Characteristics

2014 ◽  
Vol 6 (2) ◽  
pp. 347-357 ◽  
Author(s):  
K. Iqbal ◽  
T. Aftab ◽  
J. Iqbal ◽  
S. Aslam ◽  
R. Ahmed
Keyword(s):  
Anaerobic Digestion ◽  
Industrial Waste ◽  
Biogas Production ◽  
Sugar Industry ◽  
Gas Production ◽  
Anaerobic Conditions ◽  
Water Displacement ◽  
Biogas Yield ◽  
Batch Bioreactor ◽  
Volatile Solids

Molasses is a significant by-product of sugar industry and can be used as substrate in anaerobic digestion process for biogas production. Molasses was diluted ten time; inoculated by methane producing bacteria, mixed thoroughly in 2 liter batch bioreactor, kept at 370C for 15 days under anaerobic conditions for biogas yield. pH in the process was monitored three times a day. Total solids, volatile solids and COD were measured at alternate days. The gas production was measured by water displacement method. Ten times diluted molasses under anaerobic conditions, in the presence of methane producing bacteria was converted to 6.55 dm3/kg of biogas or 3.93 dm3/kg CH4 and 0.144 kWh electricity.  Keywords: Agro industrial waste; Molasses; Methanogen; Anaerobic digestion; Biogas production. © 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v6i2.17320 J. Sci. Res. 6 (2), 347-357 (2014)

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