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 ◽  
...  

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.

2015 ◽  
Vol 768 ◽  
pp. 281-288
Author(s):  
Lian Hai Ren ◽  
Yan Bing Huang ◽  
Pan Wang

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.


2014 ◽  
Vol 6 (2) ◽  
pp. 347-357 ◽  
Author(s):  
K. Iqbal ◽  
T. Aftab ◽  
J. Iqbal ◽  
S. Aslam ◽  
R. Ahmed

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)


2012 ◽  
Vol 518-523 ◽  
pp. 3358-3362 ◽  
Author(s):  
De Dong Sun ◽  
Hua Mei Liang ◽  
Chun Ma

The effect of sulfate radical(SO4−•) pretreatment on mesophilic anaerobic digestion of sewage sludge was investigated and compared with a control group. The results showed that pretreatment can effectively improve sludge anaerobic digestion performance. After sulfate radical pretreatment, the removal rate of TCOD during the digestion was increased by 11.5% , the cumulative gas production was increased by 44.9%.The VFA concentration increased in the supernatant after pretreatment, but the alkalinity was also increased at the same time, so as to ensure the stability of whole system. The highest methane yield under pretreatment condition was 0.27m3 CH4/kgVSremoval, 180.0% of the control. The results indicated that persulfate /K2S2O8 pretreatment could be an effective method for improving methane yield.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Abeer Al-Wahaibi ◽  
Ahmed I. Osman ◽  
Ala’a H. Al-Muhtaseb ◽  
Othman Alqaisi ◽  
Mahad Baawain ◽  
...  

Abstract Food waste is a major constituent in municipal solid wastes and its accumulation or disposal of in landfills is problematic, causing environmental issues. Herein, a techno-economic study is carried out on the potential of biogas production from different types of food waste generated locally. The biogas production tests were at two-time sets; 24-h and 21-day intervals and results showed a good correlation between those two-time sets. Thus, we propose to use the 24-h time set to evaluate feedstock fermentation capacity that is intended for longer periods. Our approach could potentially be applied within industry as the 24-h test can give a good indication of the potential substrate gas production as a quick test that saves time, with minimal effort required. Furthermore, polynomial models were used to predict the production of total gas and methane during the fermentation periods, which showed good matching between the theoretical and practical values with a coefficient of determination R2 = 0.99. At day 21, the accumulative gas production value from mixed food waste samples was 1550 mL per 1 g of dry matter. An economic evaluation was conducted and showed that the case study breaks-even at $0.2944 per cubic metre. Any prices above this rate yield a positive net present value (NPV); at $0.39/m3 a discounted payback period of six years and a positive NPV of $3108 were calculated. If waste management fee savings are to be incorporated, the total savings would be higher, increasing annual cash flows and enhancing financial results. This economic evaluation serves as a preliminary guide to assess the economic feasibility based on the fluctuating value of methane when producing biogas from food waste via anaerobic digestion, thus could help biogas project developers investigate similar scale scenarios .


2021 ◽  
Vol 42 ◽  
pp. e52
Author(s):  
Joseane Bortolini ◽  
Maria Hermínia Ferreira Tavares ◽  
Ana Claudia Guedes Silva ◽  
Dayane Taine Freitag ◽  
Leandro Fleck ◽  
...  

The present study aimed to analyze the use of different digestates as inocula for the anaerobic digestion of poultry litter, evaluating the biogas and methane production. The inocula used were: bovine and porcine biofertilizer; with feeding loads of 0.67, 1.00 and 1.67 gVS L-1 day-1. Statistical analyses followed a split-plot design, where the main plot being inoculum and the feeding load as secondary. The experimental data were submitted to analysis of variance, at the level of 5% of significance. The following variable responses were considered: biogas production, specific biogas production as a function of volatile solids (VS) added to the biodigester, specific biogas production as a function of organic load, in terms of COD, and methane production. The highest rates of average biogas production, specific biogas production by VS added, specific production of biogas as a function of COD, and average methane production occurred with the use of bovine inoculum. Through the analysis of the total average percentage of methane production, productions of 63.0% and 54.5% for bovine and swine inoculum. Considering the results obtained, the use of bovine inoculum for the process of anaerobic digestion of poultry litter is recommended vinculado a produção de biogás e metano.


2020 ◽  
Vol 42 ◽  
pp. e73
Author(s):  
Joseane Bortolini ◽  
Ana Claudia Guedes Silva ◽  
Maria Hermínia Ferreira Tavares ◽  
Dayane Taine Freitag ◽  
Leandro Fleck ◽  
...  

The present study aimed to analyze the use of different digestates as inocula for the anaerobic digestion of poultry litter, evaluating the biogas and methane production. The inocula used were: bovine and porcine biofertilizer; with feeding loads of 0.67, 1.00 and 1.67 gVS L-1 day-1. Statistical analyses followed a split-plot design, where the main plot being inoculum and the feeding load as secondary. The experimental data were submitted to analysis of variance, at the level of 5% of significance. The following variable responses were considered: biogas production, specific biogas production as a function of volatile solids (VS) added to the biodigester, specific biogas production as a function of organic load, in terms of COD, and methane production. The highest rates of average biogas production, specific biogas production by VS added, specific production of biogas as a function of COD, and average methane production occurred with the use of bovine inoculum. Through the analysis of the total average percentage of methane production, productions of 63.0% and 54.5% for bovine and swine inoculum. Considering the results obtained, the use of bovine inoculum for the process of anaerobic digestion of poultry litter is recommended vinculado a produção de biogás e metano.


Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5971 ◽  
Author(s):  
Cristian Bernabé Arenas Sevillano ◽  
Marco Chiappero ◽  
Xiomar Gomez ◽  
Silvia Fiore ◽  
E. Judith Martínez

Wine lees have a great potential to obtain clean energy in the form of biogas through anaerobic digestion due to their high organic load. However, wine lees are a complex substrate and may likely give rise to instabilities leading to failure of the biological process. This work analysed the digestion of wine lees using two different approaches. First, electro-oxidation was applied as pre-treatment using boron-doped diamond-based electrodes. The voltage was 25 V and different treatment times were tested (ranging from 0.08 to 1.5 h) at 25 °C. Anaerobic digestion of wine lees was evaluated in batch tests to investigate the effect of electro-oxidation on biogas yield. Electro-oxidation exhibited a significant positive effect on biogas production increasing its value up to 330 L kg−1 of volatile solids after 1.5 h of treatment, compared to 180 L kg−1 of volatile solids measured from raw wine lees. As a second approach, the addition of biochar to the anaerobic digestion of wine lees was investigated; in the experimental conditions considered in the present study, the addition of biochar did not show any positive effect on anaerobic digestion performance.


2018 ◽  
Vol 913 ◽  
pp. 887-892
Author(s):  
Run Zhuan ◽  
Guang Yang ◽  
Guang Ming Zhang ◽  
Wei Wang

The treatment and disposal of excess sludge is a great challenge. Anaerobic digestion can achieve sludge reduction and harmless. However, its application is largely limited due to the low biogas production, low organic matters removal rate, odor gas production, corrosive gas destroying equipment. Sulfur is a key element resulting in these problems. In this research, potassium ferrate and ferric chloride were added to enhance anaerobic digestion. The research investigated the effects on biogas production, H2S content, microbial diversity with the addition of potassium ferrate and ferric chloride. We found that with 2.5 mg/g TS potassium ferrate, the enhancement was the highest, the total biogas production improved 18% compared with control group and organic removal rate reached 30.66%. Considering the effect of sulfur removal, 5 mg/g TS potassium ferrate resulted in the best effect, the content of H2S gas decreased 139.4%. With 2.5 mg/g TS ferric chloride, total biogas production improved 8% comparing with the control group, the content of H2S gas decreased 46%, no remarkable effect was found on the content of nitrogen and phosphorus in slurry.


2020 ◽  
Vol 181 ◽  
pp. 01005
Author(s):  
Makhura Emmanuel Pax ◽  
Edison Muzenda ◽  
Tumeletso Lekgoba

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.


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