Enhanced Biogas Production in the Duckweed Anaerobic Digestion Process

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Hongyan Ren ◽  
Nan Jiang ◽  
Tao Wang ◽  
M. Mubashar Omar ◽  
Wenquan Ruan ◽  
...  

In order to enhance biogas production in the anaerobic digestion of duckweed, and duckweed with excess sludge as single and mixed substrates, the effects of hot alkali pretreatment and variation of the ratio of substrate to inoculum were investigated. The results showed that the delayed stage of anaerobic gas generation could be shortened when the two substrates were mixed during methane production, to give a cumulative gas yield of 2963 mL, which was 11% higher than the calculated value for the complementary substrate. The methane content was 57%, which was 13% higher than that from the duckweed group and 9% higher than from the excess sludge group. Furthermore, the methane yield was improved by 8% after the duckweed was pretreated with hot alkali. When the substrate to inoculum ratio was 1:1, the maximum biogas production of 3309 mL was achieved, with a methane yield of 1883 mL which, respectively, increases of 151 mL and 304 mL compared with the worst group (1:2.5).

2018 ◽  
Vol 67 ◽  
pp. 02047 ◽  
Author(s):  
Reigina Sandriaty ◽  
Cindy Priadi ◽  
Septiana Kurnianingsih ◽  
Ayik Abdillah

The generation of fat, oil and grease (FOG) waste can be a nuisance hazard, but also a potential for resource recovery. FOG waste can be utilized as nutrient and energy source through anaerobic digestion which may increase methane yield but also increase presence of inhibitors. Using the biochemical methane potential method, this research is aimed to determine the effect of FOG waste in the co-digestion process of food waste (FW) to produce biogas. The research was conducted for 42 days at 37°C using FOG waste codigested with FW of 3 different volatile solid (VS) rasio which are 0.125, 0.3, and 0.5. The results showed that FOG waste combined with FW has a methane yield that may reach up to 485 ± 36.8 mL CH4/gr VS, the highest one produced by the 0.125 VS rasio mix. While the ratio of FOG waste with FW at 0.3 and 0.5 only produce 128 ± 195 and 4 ± 1.45 mL CH4/gr VS, respectively. The ratio of 0.125 also demonstrates the highest COD reduction of 56% compared to the other ratio which indicates the 0.125 FOG and FW ratio can be implemented to utilize FOG waste and increase methane yield during anaerobic digestion process.


2006 ◽  
Vol 54 (5) ◽  
pp. 77-84 ◽  
Author(s):  
C.M. Braguglia ◽  
G. Mininni ◽  
M.C. Tomei ◽  
E. Rolle

In recent years, relevant interest has been devoted to activated sludge disintegration and solubilisation techniques in order to cope with the biological limitations related to particulate degradation. Mechanical disintegration with ultrasound can efficiently transform insoluble organics into a soluble form: the solubilised organic matter is released from the cells to the bulk phase, thus accelerating the hydrolysis step in the digestion process. Experiments were carried out on bench scale anaerobic reactors fed with either untreated or disintegrated excess sludge, added with a biomass inoculum taken from a full scale anaerobic digester. Digestion tests have been carried out at different feed/inoculum ratios (F/I) in the range of 0.1–2, kinetics of VS reduction has been investigated and a beneficial effect of sonication is observed for all the experimental conditions. Similar beneficial results have also been found for biogas production with a maximum gain of 25% at 0.5 F/I ratio.


Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 590
Author(s):  
Aiban Abdulhakim Saeed Ghaleb ◽  
Shamsul Rahman Mohamed Kutty ◽  
Gasim Hayder Ahmed Salih ◽  
Ahmad Hussaini Jagaba ◽  
Azmatullah Noor ◽  
...  

Man-made organic waste leads to the rapid proliferation of pollution around the globe. Effective bio-waste management can help to reduce the adverse effects of organic waste while contributing to the circular economy at the same time. The toxic oily-biological sludge generated from oil refineries’ wastewater treatment plants is a potential source for biogas energy recovery via anaerobic digestion. However, the oily-biological sludge’s carbon/nitrogen (C/N) ratio is lower than the ideal 20–30 ratio required by anaerobic digestion technology for biogas production. Sugarcane bagasse can be digested as a high C/N co-substrate while the oily-biological sludge acts as a substrate and inoculum to improve biogas production. In this study, the best C/N with co-substrate volatile solids (VS)/inoculum VS ratios for the co-digestion process of mixtures were determined empirically through batch experiments at temperatures of 35–37 °C, pH (6–8) and 60 rpm mixing. The raw materials were pre-treated mechanically and thermo-chemically to further enhance the digestibility. The best condition for the sugarcane bagasse delignification process was 1% (w/v) sodium hydroxide, 1:10 solid-liquid ratio, at 100 °C, and 150 rpm for 1 h. The results from a 33-day batch anaerobic digestion experiment indicate that the production of biogas and methane yield were concurrent with the increasing C/N and co-substrate VS/inoculum VS ratios. The total biogas yields from C/N 20.0 with co-substrate VS/inoculum VS 0.06 and C/N 30.0 with co-substrate VS/inoculum VS 0.18 ratios were 2777.0 and 9268.0 mL, respectively, including a methane yield of 980.0 and 3009.3 mL, respectively. The biogas and methane yield from C/N 30.0 were higher than the biogas and methane yields from C/N 20.0 by 70.04 and 67.44%, respectively. The highest biogas and methane yields corresponded with the highest C/N with co-substrate VS/inoculum VS ratios (30.0 and 0.18), being 200.6 mL/g VSremoved and 65.1 mL CH4/g VSremoved, respectively.


2001 ◽  
Vol 44 (4) ◽  
pp. 109-116 ◽  
Author(s):  
A. Bonmatí ◽  
X. Flotats ◽  
L. Mateu ◽  
E. Campos

Feasibility of anaerobic digestion of pig slurry is dependent, among other factors, on the biogas production rate, which is low compared with other organic wastes, and on the profitable uses of surplus thermal energy produced, a limiting factor in warm geographical areas. The objectives of this work are determining whether low temperature thermal pretreatment (<90°C) improves pig slurry anaerobic digestion, and determining whether organic matter degradation during the thermal pretreatment is due to thermal phenomena (80°C) or to enzymatic ones (60°C). The thermal degradation tests showed that hydrolysis occurring during the thermal pretreatment is due to thermal phenomena. The increase in soluble substances were significantly larger at 80°C than at 60°C (both during 3 h). Two types of slurry were used in the batch anaerobic digestion tests. The effect of thermal pretreatment differed with the type of slurry: it was positive with almost non-degraded slurries containing low NH4+-N concentration, and negative (inhibition of the anaerobic digestion process) when using degraded slurries with high NH4+-N content.


Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3761 ◽  
Author(s):  
Abdullah Nsair ◽  
Senem Onen Cinar ◽  
Ayah Alassali ◽  
Hani Abu Qdais ◽  
Kerstin Kuchta

The biogas production technology has improved over the last years for the aim of reducing the costs of the process, increasing the biogas yields, and minimizing the greenhouse gas emissions. To obtain a stable and efficient biogas production, there are several design considerations and operational parameters to be taken into account. Besides, adapting the process to unanticipated conditions can be achieved by adequate monitoring of various operational parameters. This paper reviews the research that has been conducted over the last years. This review paper summarizes the developments in biogas design and operation, while highlighting the main factors that affect the efficiency of the anaerobic digestion process. The study’s outcomes revealed that the optimum operational values of the main parameters may vary from one biogas plant to another. Additionally, the negative conditions that should be avoided while operating a biogas plant were identified.


Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2311 ◽  
Author(s):  
Spyridon Achinas ◽  
Yu Li ◽  
Vasileios Achinas ◽  
Gerrit Jan Willem Euverink

This article intends to promote the usage of potato peels as efficient substrate for the anaerobic digestion process for energy recovery and waste abatement. This study examined the performance of anaerobic digestion of potato peels in different inoculum-to-substrate ratios. In addition, the impact of combined treatment with cow manure and pretreatment of potato peels was examined. It was found that co-digestion of potato peel waste and cow manure yielded up to 237.4 mL CH4/g VSadded, whereas the maximum methane yield from the mono-digestion of potato peels was 217.8 mL CH4/g VSadded. Comparing the co-digestion to mono-digestion of potato peels, co-digestion in PPW/CM ratio of 60:40 increased the methane yield by 10%. In addition, grinding and acid hydrolysis applied to potato peels were positively effective in increasing the methane amount reaching 260.3 and 283.4 mL CH4/g VSadded respectively. Likewise, compared to untreated potato peels, pretreatment led to an elevation of the methane amount by 9% and 17% respectively and alleviated the kinetics of biogas production.


Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3573 ◽  
Author(s):  
Meneses-Quelal Orlando ◽  
Velázquez-Martí Borja

The objective of this research is to present a review of the current technologies and pretreatments used in the fermentation of cow, pig and poultry manure. Pretreatment techniques were classified into physical, chemical, physicochemical, and biological groups. Various aspects of these different pretreatment approaches are discussed in this review. The advantages and disadvantages of its applicability are highlighted since the effects of pretreatments are complex and generally depend on the characteristics of the animal manure and the operational parameters. Biological pretreatments were shown to improve methane production from animal manure by 74%, chemical pretreatments by 45%, heat pretreatments by 41% and physical pretreatments by 30%. In general, pretreatments improve anaerobic digestion of the lignocellulosic content of animal manure and, therefore, increase methane yield.


Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 539 ◽  
Author(s):  
Renfei Li ◽  
Wenbing Tan ◽  
Xinyu Zhao ◽  
Qiuling Dang ◽  
Qidao Song ◽  
...  

Wood waste generated during the tree felling and processing is a rich, green, and renewable lignocellulosic biomass. However, an effective method to apply wood waste in anaerobic digestion is lacking. The high carbon to nitrogen (C/N) ratio and rich lignin content of wood waste are the major limiting factors for high biogas production. NaOH pre-treatment for lignocellulosic biomass is a promising approach to weaken the adverse effect of complex crystalline cellulosic structure on biogas production in anaerobic digestion, and the synergistic integration of lignocellulosic biomass with low C/N ratio biomass in anaerobic digestion is a logical option to balance the excessive C/N ratio. Here, we assessed the improvement of methane production of wood waste in anaerobic digestion by NaOH pretreatment, co-digestion technique, and their combination. The results showed that the methane yield of the single digestion of wood waste was increased by 38.5% after NaOH pretreatment compared with the untreated wood waste. The methane production of the co-digestion of wood waste and pig manure was higher than that of the single digestion of wood waste and had nonsignificant difference with the single-digestion of pig manure. The methane yield of the co-digestion of wood waste pretreated with NaOH and pig manure was increased by 75.8% than that of the untreated wood waste. The findings indicated that wood waste as a sustainable biomass source has considerable potential to achieve high biogas production in anaerobic digestion.


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