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

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.

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

Bioresource Technology ◽

10.1016/j.biortech.2017.11.083 ◽

2018 ◽

Vol 250 ◽

pp. 741-749 ◽

Cited By ~ 12

Author(s):

Yeqing Li ◽

Fang Yan ◽

Tao Li ◽

Ying Zhou ◽

Hao Jiang ◽

...

Keyword(s):

Anaerobic Digestion ◽

Methane Production ◽

Corn Straw ◽

High Solid

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

Energies ◽

10.3390/en14082223 ◽

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.

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Effect of combined addition amount of nano zero-valent iron and biochar on methane production by anaerobic digestion of corn straw

Environment Development and Sustainability ◽

10.1007/s10668-021-01629-0 ◽

2021 ◽

Author(s):

Youzhou Jiao ◽

Huizan Xue ◽

Chao He ◽

Zigang Wang ◽

Xiaoran Ma ◽

...

Keyword(s):

Anaerobic Digestion ◽

Methane Production ◽

Zero Valent Iron ◽

Corn Straw ◽

Nano Zero Valent Iron ◽

Addition Amount

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

Journal of Biobased Materials and Bioenergy ◽

10.1166/jbmb.2021.2064 ◽

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.

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Impacts of Cellulase and Amylase on Enzymatic Hydrolysis and Methane Production in the Anaerobic Digestion of Corn Straw

Sustainability ◽

10.3390/su12135453 ◽

2020 ◽

Vol 12 (13) ◽

pp. 5453 ◽

Cited By ~ 1

Author(s):

Xuemei Wang ◽

Shikun Cheng ◽

Zifu Li ◽

Yu Men ◽

Jiajun Wu

Keyword(s):

Comparative Analysis ◽

Anaerobic Digestion ◽

Enzymatic Hydrolysis ◽

Methane Production ◽

Methane Yield ◽

Corn Straw ◽

Enzymatic Hydrolysis Of Cellulose ◽

Hydrolysis Of Cellulose ◽

Pre Treatment ◽

Hydrolysis Of

The impacts of enzyme pre-treatments on anaerobic digestion of lignocellulosic biomass were explored by using corn straw as a substrate for enzyme pre-treatment and anaerobic digestion and by utilizing starch and microcrystalline cellulose as substrates for comparative analysis. The cellulase pre-treatment effectively improved the enzymatic hydrolysis of cellulose, decreased the crystallinity, and consequently showed 33.2% increase in methane yield. The methane yield of starch increased by 16.0% through amylase pre-treatment. However, when the substrate was corn straw, both the efficiencies of enzymes and methane production were markedly reduced by the lignocellulosic structure. The corn straw’s methane yields were 277.6 and 242.4 mL·CH4/g·VS with cellulase and amylase pre-treatment, respectively, which was 11.7% and 27.9% higher than that of the untreated corn straw. It may imply that the lignocellulose should be broken up firstly, enzyme pre-treatments could have great potentials when combined with other methods.

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Enhancing methane production from the invasive macroalga Rugulopteryx okamurae through anaerobic co-digestion with olive mill solid waste: process performance and kinetic analysis

Journal of Applied Phycology ◽

10.1007/s10811-021-02548-3 ◽

2021 ◽

Author(s):

D. de la Lama-Calvente ◽

M. J. Fernández-Rodríguez ◽

J. Llanos ◽

J. M. Mancilla-Leytón ◽

R. Borja

Keyword(s):

Anaerobic Digestion ◽

Solid Waste ◽

Methane Production ◽

Methane Yield ◽

Specific Rate ◽

Order Kinetic ◽

Two Phase ◽

First Order ◽

Olive Mill Solid Waste ◽

Olive Mill

AbstractThe biomass valorisation of the invasive brown alga Rugulopteryx okamurae (Dictyotales, Phaeophyceae) is key to curbing the expansion of this invasive macroalga which is generating tonnes of biomass on southern Spain beaches. As a feasible alternative for the biomass management, anaerobic co-digestion is proposed in this study. Although the anaerobic digestion of macroalgae barely produced 177 mL of CH4 g−1 VS, the co-digestion with a C-rich substrate, such as the olive mill solid waste (OMSW, the main waste derived from the two-phase olive oil manufacturing process), improved the anaerobic digestion process. The mixture improved not only the methane yield, but also its biodegradability. The highest biodegradability was found in the mixture 1 R. okamurae—1 OMSW, which improved the biodegradability of the macroalgae by 12.9% and 38.1% for the OMSW. The highest methane yield was observed for the mixture 1 R. okamurae—3 OMSW, improving the methane production of macroalgae alone by 157% and the OMSW methane production by 8.6%. Two mathematical models were used to fit the experimental data of methane production time with the aim of assessing the processes and obtaining the kinetic constants of the anaerobic co-digestion of different combination of R. okamurae and OMSW and both substrates independently. First-order kinetic and the transference function models allowed for appropriately fitting the experimental results of methane production with digestion time. The specific rate constant, k (first-order model) for the mixture 1 R. okamurae- 1.5 OMSW, was 5.1 and 1.3 times higher than that obtained for the mono-digestion of single OMSW and the macroalga, respectively. In the same way, the transference function model revealed that the maximum methane production rate (Rmax) was also found for the mixture 1 R. okamurae—1.5 OMSW (30.4 mL CH4 g−1 VS day−1), which was 1.6 and 2.2 times higher than the corresponding to the mono-digestions of the single OMSW and sole R. okamurae (18.9 and 13.6 mL CH4 g−1 VS day−1), respectively.

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Biochar promotes methane production during anaerobic digestion of organic waste

Environmental Chemistry Letters ◽

10.1007/s10311-021-01251-6 ◽

2021 ◽

Author(s):

Leilei Xiao ◽

Eric Lichtfouse ◽

P. Senthil Kumar ◽

Quan Wang ◽

Fanghua Liu

Keyword(s):

Anaerobic Digestion ◽

Methane Production ◽

Organic Waste

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Pretreatment, Anaerobic Codigestion, or Both? Which Is More Suitable for the Enhancement of Methane Production from Agricultural Waste?

Molecules ◽

10.3390/molecules26144175 ◽

2021 ◽

Vol 26 (14) ◽

pp. 4175

Author(s):

Lütfiye Dumlu ◽

Asli Seyhan Ciggin ◽

Stefan Ručman ◽

N. Altınay Perendeci

Keyword(s):

Anaerobic Digestion ◽

Methane Production ◽

Agricultural Waste ◽

Kinetic Studies ◽

Antagonistic Effect ◽

Hydrolysis Rate ◽

Order Kinetic ◽

Maximum Enhancement ◽

Mixing Ratios ◽

Anaerobic Codigestion

Pretreatment and codigestion are proven to be effective strategies for the enhancement of the anaerobic digestion of lignocellulosic residues. The purpose of this study is to evaluate the effects of pretreatment and codigestion on methane production and the hydrolysis rate in the anaerobic digestion of agricultural wastes (AWs). Thermal and different thermochemical pretreatments were applied on AWs. Sewage sludge (SS) was selected as a cosubstrate. Biochemical methane potential tests were performed by mixing SS with raw and pretreated AWs at different mixing ratios. Hydrolysis rates were estimated by the best fit obtained with the first-order kinetic model. As a result of the experimental and kinetic studies, the best strategy was determined to be thermochemical pretreatment with sodium hydroxide (NaOH). This strategy resulted in a maximum enhancement in the anaerobic digestion of AWs, a 56% increase in methane production, an 81.90% increase in the hydrolysis rate and a 79.63% decrease in the technical digestion time compared to raw AWs. On the other hand, anaerobic codigestion (AcoD) with SS was determined to be ineffective when it came to the enhancement of methane production and the hydrolysis rate. The most suitable mixing ratio was determined to be 80:20 (Aws/SS) for the AcoD of the studied AWs with SS in order to obtain the highest possible methane production without any antagonistic effect.

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Efficiency of integrated electrooxidation and anaerobic digestion of waste activated sludge

Biotechnology for Biofuels ◽

10.1186/s13068-021-01929-7 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

J. A. Barrios ◽

A. Cano ◽

F. F. Rivera ◽

M. E. Cisneros ◽

U. Durán

Keyword(s):

Anaerobic Digestion ◽

Current Density ◽

Methane Production ◽

Energy Recovery ◽

Energy Analysis ◽

Mathematical Optimization ◽

Waste Activated Sludge ◽

Bdd Electrode ◽

Vs Removal ◽

Pre Treatment

Abstract Background Most of the organic content of waste activated sludge (WAS) comprises microbial cells hard to degrade, which must be pre-treated for energy recovery by anaerobic digestion (AD). Electrooxidation pre-treatment (EOP) with boron-doped diamond (BDD) electrode have been considered a promising novel technology that increase hydrolysis rate, by the disintegrating cell walls from WAS. Although electrochemical oxidation could efficiently solubilize organic substances of macromolecules, limited reports are available on EOP of WAS for improving AD. In this endeavour, the mathematical optimization study and the energy analysis of the effects of initial total solids concentrations [TS] of WAS and current density (CD) during EOP on the methane production and removal of chemical oxygen demand (COD) and volatile solids (VS) were investigated. Because limited reports are available on EOP of WAS for improving biogas production, it is not well understood; however, it has started to attract interest of scientists and engineers. Results In the present work, the energy recovery as biogas and WAS conversion were comprehensively affected by CD and [TS], in an integrated EOP and AD system. When working with WAS at 3% of [TS] pre-treated at current density of 24.1 mA/cm2, the highest COD and VS removal were achieved, making it possible to obtain the maximum methane (CH4) production of 305 N-L/kg VS and a positive energy balance of 1.67 kWh/kg VS. Therefore, the current densities used in BDD electrode are adequate to produce the strong oxidant (hydroxyl radical, ·OH) on the electrode surface, allow the oxidation of organic compounds that favours the solubilization of particulate matter and VS from WAS. Conclusions The improvement of VS removal and COD solubilization were due to the effects of pre-treatments, which help to break down the microbial cells for faster subsequent degradation; this allows a decomposition reaction that leads to biodegrade more compounds during AD. The balance was positive, suggesting that even without any optimization the energy used as electricity could be recovered from the increased methane production. It is worth noting that this kind of analysis have not been sufficiently studied so far. It is therefore important to understand how operational parameters can influence the pre-treatment and AD performances. The current study highlights that the mathematical optimization and energy analysis can make the whole process more convenient and feasible.

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