Effect of Different Ensiling Conditions on the Anaerobic Digestion of Corn Stalks Pretreated with NaOH

2021 ◽  
Vol 15 (3) ◽  
pp. 342-346
Author(s):  
Xiaofei Zhen ◽  
Miao Luo ◽  
Zhenggui Li
Keyword(s):  
Anaerobic Digestion ◽  
Sodium Hydroxide ◽  
Methane Production ◽  
Low Ph ◽  
Utilization Rate ◽  
Corn Straw ◽  
Slow Start ◽  
Start Up ◽  
Overall Performance ◽  
Experimental Group

When ensiled corn straw is used for anaerobic digestion to produce biogas, it usually has problems such as slow start and long fermentation cycle due to low pH. To solve these problems, improving the utilization rate of silage straw, this study analyzed the methanogenic properties of different ensiled corn straw pretreated with sodium hydroxide. The experimental results showed that the methane-producing ability of the experimental group (CB) with cellulase was the best and reached 10.91 L in total methane production. It can be seen from the parameter performance of pH, VFAs, FAN and COD that NaOH can significantly shorten the experiment start-up period and make the system run stably. The overall trend of each group was basically the same, however, there are slight differences due to different ensiling additives. In general, the overall performance of the experiment was better after adding NaOH.

Sludge accumulation and methanogenic activity in an anaerobic lagoon

2000 ◽  
Vol 42 (10-11) ◽  
pp. 247-255 ◽  
Author(s):  
J. Paing ◽  
B. Picot ◽  
J. P. Sambuco ◽  
A. Rambaud
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Anaerobic Degradation ◽  
Volatile Fatty Acids ◽  
Anaerobic Fermentation ◽  
Methanogenic Activity ◽  
Start Up ◽  
Anaerobic Lagoon ◽  
Methane Production Rate ◽  
Sludge Accumulation

Sludge accumulation and the characteristics of anaerobic digestion in sludge had been investigated in a primary anaerobic lagoon. Methanogenic potential of sludge was evaluated by an anaerobic digestion test which measured the methane production rate. Sludge was sampled at several points in the lagoon to determine spatial variations and with a monthly frequency from the start-up of the lagoon to observe the development of anaerobic degradation. Maximum amounts of sludge accumulated near the inlet. The mean methane production of sludge was 2.9 ml gVS–1 d–1. Sludge near the outlet presented a greater methanogenic activity and a lesser concentration of volatile fatty acids than near the inlet. The different stages of anaerobic degradation were spatially separated, acidogenesis near the inlet and methanogenesis near the outlet. This staged distribution seemed to increase efficiency of anaerobic fermentation compared with septic tanks. Methane release at the surface of the lagoon was estimated to be very heterogeneous with a mean of 25 l m–2 d–1. The development of performance and sludge characteristics showed the rapid beginning of methanogenesis, three months after the start-up of the anaerobic lagoon. Considering the volume of accumulated sludge, it could however be expected that methanogenic activity would further increase.

Control of sulfate reduction by molybdate in anaerobic digestion

1997 ◽  
Vol 36 (12) ◽  
pp. 143-150 ◽  
Author(s):  
Shuzo Tanaka ◽  
Young-Ho Lee
Keyword(s):  
Anaerobic Digestion ◽  
Sulfate Reduction ◽  
Methane Production ◽  
Phase 1 ◽  
Continuous Operation ◽  
Phase 2 ◽  
Sulfate Reducing ◽  
Start Up ◽  
Reducing Bacteria ◽  
Control Batch

Control of sulfate reduction by adding molybdate was investigated to enhance the methane production under batch and continuous operation in the anaerobic digestion of a sulfate-rich lysine wastewater. In phase 1 of the continuous operation, four anaerobic filters were fed with the lysine wastewater and then added with molybdate at 1,3,5 and 10 mM just after methane producing bacteria (MPB) were completely inhited by H2S produced by sulfate reducing bacteria (SRB). In phase 2, three anaerobic filters were operated with continuous or intermittent addition of 3 mM molybdate from the beginning of operation, including one with no molybdate as a control. Batch experiments revealed that the sulfate reduction was strongly inhibited and finally ceased by adding 3 mM or more of molybdate, resulting in great enhancement of the methane production. In phase 1 of the continuous experiments, all reactors showed the cessation of the methane production when the content of H2S reached 9–10 % in biogas, but the MPB activity was gradually recovered after initiating the molybdate addition at 3 or 5 mM. The 10 mM dosage of molybdate, however, had an inhibiting effect to MPB as well as SRB, resulting in the accumulation of acetate within the reactor. In phase 2, the control reactor continued to decrease the methane production, and a methane conversion rate was only 3 % in the control, while 35 and 10 % in continuously-added and intermittently-added reactors, respectively. Thus, it was confirmed that the MPB activity was greatly enhanced under control of the SRB activity by the continuous addition of molybdate. Comparing phase 2 with phase 1, addition from the start-up of the process is considered more effective than addition after the methane production dropped in the control of the sulfate reduction by molybdate.

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.

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.

Enhancement of methane production by anaerobic digestion of corn straw with hydrogen-nanobubble water

2021 ◽  
pp. 126220
Author(s):  
Chao He ◽  
Hao Song ◽  
Liang Liu ◽  
Panpan Li ◽  
Mukesh Kumar Awasthi ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Corn Straw

High-solid anaerobic digestion of corn straw for methane production and pretreatment of bio-briquette

2018 ◽  
Vol 250 ◽  
pp. 741-749 ◽  
Author(s):  
Yeqing Li ◽  
Fang Yan ◽  
Tao Li ◽  
Ying Zhou ◽  
Hao Jiang ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Corn Straw ◽  
High Solid

Computer simulation of control strategies for optimal anaerobic digestion

2013 ◽  
Vol 67 (3) ◽  
pp. 594-603 ◽  
Author(s):  
S. Strömberg ◽  
M. O. Possfelt ◽  
J. Liu
Keyword(s):  
Anaerobic Digestion ◽  
Control Strategies ◽  
Extremum Seeking ◽  
Reference Case ◽  
Variable Gain ◽  
Start Up ◽  
Different Types ◽  
Overall Performance ◽  
Ph Level ◽  
Proportional Feedback

Three previously published control strategies for anaerobic digestion were implemented in Simulink/Matlab using Anaerobic Digestion Model No. 1 (ADM1) to model the biological process. The controllers’ performance were then simulated and evaluated based on their responses from five different types of process scenarios i.e. start-up and steady state performance as well as disturbances from concentration, pH and ammonia in the inflow. Of the three evaluated control strategies, the extremum-seeking variable gain controller gave the best overall performance. However, a proportional feedback controller based on the pH-level, used as a reference case in the evaluation, proved to give as good results as the extremum-seeking variable gain controller but with a lower wear on the pump. It was therefore concluded that a fast proportional control of the reactor pH is a key element for optimally controlling a low-buffering anaerobic digestion process.

scholarly journals Effect of Biochar Addition on the Microbial Community and Methane Production in the Rapid Degradation Process of Corn Straw

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2223
Author(s):  
Zhi Wang ◽  
Ying Guo ◽  
Weiwei Wang ◽  
Liumeng Chen ◽  
Yongming Sun ◽  
...  
Keyword(s):  
Microbial Community ◽  
Anaerobic Digestion ◽  
Methane Production ◽  
Biogas Production ◽  
Degradation Process ◽  
Hydrolysis Rate ◽  
Control Group ◽  
Corn Straw ◽  
High Concentration ◽  
Fermentation Time

Anaerobic digestion with corn straw faces the problems of difficult degradation, long fermentation time and acid accumulation in the high concentration of feedstocks. In order to speed up the process of methane production, corn straw treated with sodium hydroxide was used in thermophilic (50 °C) anaerobic digestion, and the effects of biochar addition on the performance of methane production and the microbial community were analyzed. The results showed that the cumulative methane production of all treatment groups reached over 75% of the theoretical methane yield in 7 days and the addition of 4% biochar increased the cumulative methane production by 6.75% compared to the control group. The addition of biochar also decreased the number of biogas and methane production peaks from 2 to 1, and had a positive effect on shortening the digestion start-up period and reducing the fluctuation of biogas production during the digestion process. The addition of 4% biochar increased the abundance of the bacterial family Peptococcaceae throughout the digestion period, promoting the hydrolysis rate of corn straw. The dominant archaeal genus Methanosarcina was significantly more abundant at the peak stage and the end of methane production with 4% biochar added compared to the control group.

Improving anaerobic digestion of sugarcane straw for methane production: Combined benefits of mechanical and sodium hydroxide pretreatment for process designing

2017 ◽  
Vol 141 ◽  
pp. 378-389 ◽  
Author(s):  
Leandro Janke ◽  
Sören Weinrich ◽  
Athaydes F. Leite ◽  
Filippi K. Terzariol ◽  
Marcell Nikolausz ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Sodium Hydroxide ◽  
Methane Production ◽  
Sugarcane Straw
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