Effects of volatile fatty acids, ammonium and agitation on thermophilic methane production from biogas plant sludge in lab-scale experiments

2012 ◽  
Vol 57 (4) ◽  
pp. 313-316 ◽  
Author(s):  
Philipp Lins ◽  
Paul Illmer
Keyword(s):  
Fatty Acids ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Biogas Plant

Application of Methanobrevibacter acididurans in anaerobic digestion

2004 ◽  
Vol 50 (6) ◽  
pp. 109-114 ◽  
Author(s):  
D.V. Savant ◽  
D.R. Ranade
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Low Ph ◽  
Anaerobic Digesters ◽  
Hydrogenotrophic Methanogen ◽  
Distillery Wastewater ◽  
Acid Tolerant ◽  
Acidic Conditions

To operate anaerobic digesters successfully under acidic conditions, hydrogen utilizing methanogens which can grow efficiently at low pH and tolerate high volatile fatty acids (VFA) are desirable. An acid tolerant hydrogenotrophic methanogen viz. Methanobrevibacter acididurans isolated from slurry of an anaerobic digester running on alcohol distillery wastewater has been described earlier by this lab. This organism could grow optimally at pH 6.0. In the experiments reported herein, M. acididurans showed better methanogenesis under acidic conditions with high VFA, particularly acetate, than Methanobacterium bryantii, a common hydrogenotrophic inhabitant of anaerobic digesters. Addition of M. acididurans culture to digesting slurry of acidogenic as well as methanogenic digesters running on distillery wastewater showed increase in methane production and decrease in accumulation of volatile fatty acids. The results proved the feasibility of application of M. acididurans in anaerobic digesters.

scholarly journals Development of an Optimised Chinese Dome Digester Enables Smaller Reactor Volumes; Pilot Scale Performance

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2213 ◽  
Author(s):  
Abiodun O. Jegede ◽  
Grietje Zeeman ◽  
Harry Bruning
Keyword(s):  
Fatty Acids ◽  
Ambient Temperature ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Pilot Scale ◽  
High Loading ◽  
Treatment Efficiency ◽  
Total Solids ◽  
Loading Rates ◽  
Volatile Solids

Chinese dome digesters are usually operated at long hydraulic retention times (HRT) and low influent total solids (TS) concentration because of limited mixing. In this study, a newly optimised Chinese dome digester with a self-agitating mechanism was investigated at a pilot scale (digester volume = 500 L) and compared with a conventional Chinese dome digester (as blank) at 15% influent TS concentration at two retention times (30 and 40 days). The reactors were operated at ambient temperature: 27–33 °C. The average specific methane production, volatile fatty acids and percentage of volatile solids (VS) reduction are 0.16 ± 0.13 and 0.25 ± 0.05L CH4/g VS; 1 ± 0.5 and 0.7 ± 0.3 g/L; and 51 ± 14 and 57 ± 10% at 40 days HRT (day 52–136) for the blank and optimised digester, respectively. At 30 days HRT (day 137–309) the results are 0.19 ± 0.12 and 0.23 ± 0.04 L CH4/g VS; 1.2 ± 0.6 and 0.7 ± 0.3 g/L; and 51 ± 9 and 58 ± 11.6%. Overall, the optimised digester produced 40% more methane than the blank, despite the high loading rates applied. The optimised digester showed superior digestion treatment efficiency and was more stable in terms of VFA concentration than the blank digester, can be therefore operated at high influent TS (15%) concentration.

Effect of banana flower powder on rumen fermentation, synthesis of microbial protein and nutrient digestibility in swamp buffaloes

2019 ◽  
Vol 59 (9) ◽  
pp. 1674 ◽  
Author(s):  
Metha Wanapat ◽  
Thiwakorn Ampapon ◽  
Kampanat Phesatcha ◽  
Sungchhang Kang
Keyword(s):  
Fatty Acids ◽  
Protein Synthesis ◽  
Rice Straw ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Nutrient Digestibility ◽  
Microbial Protein ◽  
Microbial Protein Synthesis ◽  
Ruminal Ph ◽  
Banana Flower

Replacement of chemical compounds by dietary sources as rumen enhancers have been of great interest and concern by researchers. Four, rumen-fistulated swamp buffalo bulls with average liveweight of 365 ± 15.0 kg were randomly assigned to treatments, to investigate the impact of banana flower powder (BAFLOP) as a rumen modifier on pH, rumen fermentation, nutrient digestibility, microbial protein synthesis and volatile fatty acids. All buffaloes were allotted according to a 4 × 4 Latin square design. Dietary supplementation treatments were as follows: 2 g concentrate/kg bodyweight (BW; T1), 15 g concentrate/kg BW (T2), 15 g concentrate/kg BW plus BAFLOP 300 g/head.day (T3) and 15 g concentrate/kg BW plus BAFLOP 600 g/head.day (T4). Untreated rice straw was fed ad libitum. The findings showed that total feed intake was increased in buffaloes fed a diet supplemented with concentrate at 2 g/kg BW, while rice straw intake was reduced. Nutrient digestibility was increased by BAFLOP supplementation at both levels (T3 and T4; P < 0.05). Ruminal pH dropped (5.9) in buffaloes fed with concentrate at 15 g/kg BW, while buffaloes with BAFLOP supplementation could maintain ruminal pH when fed with high-concentrate diet. Ruminal ammonia-nitrogen increased in the buffaloes fed concentrate at 15 g/kg BW, especially with BAFLOP supplementation. Feeding high-concentrate diet increased the concentrations of ruminal total volatile fatty acids and propionic acid (C3), while the concentration of acetic acid and the acetic acid:C3 ratio and methane production were subsequently reduced (P < 0.05). In addition, efficiency of microbial protein synthesis was increased by the BAFLOP feeding (P < 0.05). In the present study, using BAFLOP as a dietary rumen enhancer at 300–600 g/head.day resulted in an increased rumen pH, C3 concentration, nutrient digestibility and microbial protein synthesis, while mitigating ruminal methane production. Higher nutrient digestibility and lower ruminal methane production, more dietary energy and production efficiency are expected.

Effect of a Cellulose-Degrading Strain on Anaerobic Fermentation of Corn Straw

2011 ◽  
Vol 356-360 ◽  
pp. 2510-2514 ◽  
Author(s):  
Ming Fen Niu ◽  
Sai Yue Wang ◽  
Wen Di Xu ◽  
An Dong Ge ◽  
Hao Wang
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Anaerobic Fermentation ◽  
Biogas Production ◽  
Corn Straw ◽  
High Efficient ◽  
Important Significance ◽  
Strong Capacity

In order to improve the rate of degradation of cellulose in corn straw, the study has an important significance that compost corn straw with inoculating high-efficient microbe agents. The experiment inoculated a cellulose-degrading strain F2 which was screened from compost into compost pretreatment, the VS of corn straw reduced from 93.14% to 71.69% after 15 days, the content of cellulose reduced from 34.12g·kg-1 to 25.66g·kg-1, the rate of degradation was 24.79% which was 10.60% higher than those without the strain. An anaerobic fermentation experiment was carried out with the two groups of composted corn straw and mixed pig feces with a certain ratio, and investigations of biogas production, pH, content of volatile fatty acids(VFA) and rate of methane production were conducted. The results were that the corn straw composted with the cellulose-degrading strain peaked 4 days earlier, the maximal daily biogas production was 1470mL, the cumulative biogas production reached 23641mL which was 16.87% higher and operated stably earlier. The study showed that the cellulose-degrading strain had a strong capacity to degrade cellulose in corn straw, and then improved the performance of anaerobic digestion.

Separation of volatile fatty acids from biogas plant hydrolysates

2019 ◽  
Vol 223 ◽  
pp. 264-273 ◽  
Author(s):  
T. Jänisch ◽  
S. Reinhardt ◽  
U. Pohsner ◽  
S. Böringer ◽  
R. Bolduan ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Biogas Plant

scholarly journals Magnetite nanoparticles enable a rapid conversion of volatile fatty acids to methane

RSC Advances ◽  
2016 ◽  
Vol 6 (31) ◽  
pp. 25662-25668 ◽  
Author(s):  
Zhiman Yang ◽  
Rongbo Guo ◽  
Xiaoshuang Shi ◽  
Chuanshui Wang ◽  
Lin Wang ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Magnetite Nanoparticles ◽  
Paddy Soil ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Rapid Conversion

Evaluation of whether paddy soil enrichments obtained in the presence of magnetite and propionate can accelerate methane production from mixed volatile fatty acids.

scholarly journals Insects as Novel Ruminant Feed and a Potential Mitigation Strategy for Methane Emissions

Animals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2648
Author(s):  
Eslam Ahmed ◽  
Naoki Fukuma ◽  
Masaaki Hanada ◽  
Takehiro Nishida
Keyword(s):  
Fatty Acids ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Ammonia Nitrogen ◽  
Nutrient Digestibility ◽  
Acheta Domesticus ◽  
Environmental Benefit ◽  
Grass Hay

This study is the first to evaluate the chemical composition and impacts of four different edible insects, Acheta domesticus (A.d), Brachytrupes portentosus (B.p), Gryllus bimaculatus (G.b), and Bombyx mori (B.m), on the digestibility, rumen fermentation, and methane production when used as a substitute for 25% of the soybean meal (SBM) in a ruminant diet through in vitro incubation. The dietary treatments were 100% grass hay, 60% grass hay + 40% SBM, 60% grass hay + 30% SBM + 10% A.d, 60% grass hay + 30% SBM + 10% B.p, 60% grass hay + 30% SBM + 10% G.b, and 60% grass hay + 30% SBM + 10% B.m. The experiment was conducted as a short-term batch culture for 24 h at 39 °C, and the incubation was repeated in 3 consecutive runs. Chemical analysis of the insects showed that they were rich in fat (14–26%) with a high proportion of unsaturated fatty acids (60–70%). Additionally, the insects were rich in protein (48–61%) containing all essential amino acids and the amino acid profiles of the insects were almost the same as that of SBM. The inclusion of insects did not affect nutrient digestibility or the production of volatile fatty acids but did increase the production of ammonia-nitrogen. The addition of G.b and B.m led to decrease in methane production by up to 18% and 16%, respectively. These results reveal that substitution of 25% SBM in the diet with the tested insects had no negative impacts, and their potential to reduce methane production is an environmental benefit.

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