scholarly journals Biogas and volatile fatty acid production during anaerobic digestion of straw, cellulose, and hemicellulose with analysis of microbial communities and functions

2020 ◽  
Author(s):  
Jie Liu ◽  
Xiaoyu Zuo ◽  
Ke Peng ◽  
Rui He
Keyword(s):  
Acetic Acid ◽  
Fatty Acid ◽  
Anaerobic Digestion ◽  
Volatile Fatty Acid ◽  
Biogas Production ◽  
Raw Materials ◽  
Methane Content ◽  
Production Potential ◽  
Aceticlastic Methanogenesis ◽  
Stable Stage

Abstract Background Anaerobic digestion (AD) is a promising method for straw treatment, but the complex composition and structure of straw limit AD efficiency and methane production. The main biodegradable components of straw are cellulose and hemicellulose. Because of the different chemical structures and physicochemical properties, the performance of AD of cellulose and hemicellulose is different, thus it’s also different from that of straw. Research on the similarities and differences of AD of straw, cellulose and hemicellulose is helpful to clarify the law of anaerobic digestion of straw and provide theoretical basis for further improving the efficiency of anaerobic digestion. However, there are very few studies on AD using cellulose and hemicellulose as raw materials. Results Rice straw (RS), cellulose, and hemicellulose were used as raw materials to study biogas production performance and changes in the volatile fatty acids (VFAs). Further, microbial communities and genetic functions were analyzed separately for each material. The biogas production potential of RS, cellulose, and hemicellulose was different, with cumulative biogas production of 620.64, 412.50, and 283.75 mL/g·VS− 1, respectively. The methane content of the biogas produced from cellulose and hemicellulose was approximately 10% higher than that produced from RS after the methane content stabilized. Biogas production and the methane content of RS stabilized more quickly than that of cellulose and hemicellulose. The accumulation of VFAs occurred in the early stage of anaerobic digestion in all the three materials, and the main volatile fatty acid component of RS was acetic acid, whereas that of cellulose and hemicellulose was propionic acid. The cumulative amount of VFAs in both cellulose and hemicellulose was relatively higher than that in RS, and the accumulation time was 12 and 14 days longer, respectively. When anaerobic digestion progressed to a stable stage, Clostridium was the dominant bacterial genus in all three AD systems, and the abundance of Ruminofilibacter was higher during anaerobic digestion of RS. Genetically, AD of all the three materials proceeded mainly via aceticlastic methanogenesis, with similar functional components. Conclusion The biogas and VFAs production during AD of RS, cellulose, and hemicellulose showed marked differences. But when the AD progressed to the stable stage, there was no significant difference in microbial community and genetic function. Specifically, the biogas production potential of cellulose and hemicellulose was greater than that of RS. The accumulation of VFAs in the three AD systems occurred in the early stages. The main component of VFA that accumulated in RS was acetic acid, while the major component of VFAs accumulated in cellulose and hemicellulose digestions was propionic acid. At the stable stage, Clostridium was the dominant bacterial genus in all three AD systems. The AD of all the three materials proceeded mainly via aceticlastic methanogenesis, with similar components of gene functions.

Rumen Metabolite of Balinese Cows that Being Given Stewed Water of Lannea coromandelica Peel as Feed Additive

2017 ◽  
Vol 3 (5) ◽  
pp. 24 ◽  
Author(s):  
Sio Stefanus ◽  
I.G. Mahardika ◽  
I.B.G Partama ◽  
N.N. Suryani
Keyword(s):  
Acetic Acid ◽  
Fatty Acid ◽  
Rice Bran ◽  
Volatile Fatty Acid ◽  
Gliricidia Sepium ◽  
Feed Additive ◽  
Random Design ◽  
Lannea Coromandelica

The research has been conducted to find out rumen metabolite of Balinese cows that being given stewed water of Lannea coromandelica peel as a feed additive. The research used group random design (RAK) with 4 treatments of rations and 3 times repetition. Each repetition used three Balinese cows. The weight of cows being used ranging between 137.5 – 235 kg. Basic rations being given were equal, arranged based on a percentage of dry material (% DM) namely: 50% of arrow grass, 20% of gamal leaves (Gliricidia sepium), 1% of urea and 29% of rice bran. Whereas for treatment was feed additive level. The basic ratio of +0 was feed additive (A). The basic ration of +1000 ml was feed additive (B). The basic ration of +1500 ml was feed additive (C) and a basic ration of +2000 ml was feed additive (D). Variables being observed were: N-NH3, volatile fatty acid total and volatile fatty acid partial (acetic acid, propionate acid and butyrate acid). The result of research showed that the administration of 1000 ml-2000 ml of feed additive of stewed water of Lannea coromandelica peel in basic ration differed markedly (P<0.05) to increase the concentration of N-NH3, volatile fatty acid total and volatile fatty acid partial. The utilization of stewed water of Lannea coromandelica peel as a feed additive in basic ration was increasing rumen metabolite of Balinese cows.

A Techno-Economic case for Volatile Fatty Acid Production for Increased Sustainability in the Wastewater Treatment Industry

2021 ◽  
Author(s):  
Ganesh K Veluswamy ◽  
Andy Ball ◽  
Richard Dinsdale ◽  
Alan Guwy ◽  
Kalpit Shah
Keyword(s):  
Wastewater Treatment ◽  
Fatty Acid ◽  
Anaerobic Digestion ◽  
Acid Production ◽  
Volatile Fatty Acid ◽  
Fugitive Emissions ◽  
Fatty Acid Production

Methane, the final product of methanogenesis during anaerobic digestion is a low value product (0.1$/m3). Concerns over fugitive emissions from methane coupled with recent reduction in costs of solar and...

scholarly journals Innovations in anaerobic digestion: a model-based study

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Karol Postawa ◽  
Jerzy Szczygieł ◽  
Marek Kułażyński
Keyword(s):  
Mathematical Model ◽  
Anaerobic Digestion ◽  
Production Efficiency ◽  
Biogas Production ◽  
Biogas Plant ◽  
Methane Content ◽  
Pig Manure ◽  
Pig Slurry ◽  
Production Chain ◽  
The Impact

Abstract Background Increasing the efficiency of the biogas production process is possible by modifying the technological installations of the biogas plant. In this study, specific solutions based on a mathematical model that lead to favorable results were proposed. Three configurations were considered: classical anaerobic digestion (AD) and its two modifications, two-phase AD (TPAD) and autogenerative high-pressure digestion (AHPD). The model has been validated based on measurements from a biogas plant located in Poland. Afterward, the TPAD and AHPD concepts were numerically tested for the same volume and feeding conditions. Results The TPAD system increased the overall biogas production from 9.06 to 9.59%, depending on the feedstock composition, while the content of methane was slightly lower in the whole production chain. On the other hand, the AHPD provided the best purity of the produced fuel, in which a methane content value of 82.13% was reached. At the same time, the overpressure leads to a decrease of around 7.5% in the volumetric production efficiency. The study indicated that the dilution of maize silage with pig manure, instead of water, can have significant benefits in the selected configurations. The content of pig slurry strengthens the impact of the selected process modifications—in the first case, by increasing the production efficiency, and in the second, by improving the methane content in the biogas. Conclusions The proposed mathematical model of the AD process proved to be a valuable tool for the description and design of biogas plant. The analysis shows that the overall impact of the presented process modifications is mutually opposite. The feedstock composition has a moderate and unsteady impact on the production profile, in the tested modifications. The dilution with pig manure, instead of water, leads to a slightly better efficiency in the classical configuration. For the TPAD process, the trend is very similar, but the AHPD biogas plant indicates a reverse tendency. Overall, the recommendation from this article is to use the AHPD concept if the composition of the biogas is the most important. In the case in which the performance is the most important factor, it is favorable to use the TPAD configuration.

scholarly journals Sugarcane Bagasse as a Co-Substrate with Oil-Refinery Biological Sludge for Biogas Production Using Batch Mesophilic Anaerobic Co-Digestion Technology: Effect of Carbon/Nitrogen 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 ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Sugarcane Bagasse ◽  
Organic Waste ◽  
Wastewater Treatment Plants ◽  
Biogas Production ◽  
Raw Materials ◽  
Oil Refinery ◽  
Methane Yield ◽  
Oil Refineries ◽  
Biological Sludge

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.

scholarly journals Evaluation of Anaerobic Digestion of Dairy Wastewater in an Innovative Multi-Section Horizontal Flow Reactor

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2392 ◽  
Author(s):  
Marcin Dębowski ◽  
Marcin Zieliński ◽  
Marta Kisielewska ◽  
Joanna Kazimierowicz
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Flow Reactor ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Methane Content ◽  
Dairy Wastewater ◽  
Horizontal Flow ◽  
Organic Loading Rate ◽  
Biogas Yield

The aim of this study was the performance evaluation of anaerobic digestion of dairy wastewater in a multi-section horizontal flow reactor (HFAR) equipped with microwave and ultrasonic generators to stimulate biochemical processes. The effects of increasing organic loading rate (OLR) ranging from 1.0 g chemical oxygen demand (COD)/L·d to 4.0 g COD/L·d on treatment performance, biogas production, and percentage of methane yield were determined. The highest organic compounds removals (about 85% as COD and total organic carbon—TOC) were obtained at OLR of 1.0–2.0 g COD/L·d. The highest biogas yield of 0.33 ± 0.03 L/g COD removed and methane content in biogas of 68.1 ± 5.8% were recorded at OLR of 1.0 g COD/L·d, while at OLR of 2.0 g COD/L·d it was 0.31 ± 0.02 L/COD removed and 66.3 ± 5.7%, respectively. Increasing of the OLR led to a reduction in biogas productivity as well as a decrease in methane content in biogas. The best technological effects were recorded in series with an operating mode of ultrasonic generators of 2 min work/28 min break. More intensive sonication reduced the efficiency of anaerobic digestion of dairy wastewater as well as biogas production. A low nutrient removal efficiency was observed in all tested series of the experiment, which ranged from 2.04 ± 0.38 to 4.59 ± 0.68% for phosphorus and from 9.67 ± 3.36 to 20.36 ± 0.32% for nitrogen. The effects obtained in the study (referring to the efficiency of wastewater treatment, biogas production, as well as to the results of economic analysis) proved that the HFAR can be competitive to existing industrial technologies for food wastewater treatment.

scholarly journals Will Membranes Break Barriers on Volatile Fatty Acid Recovery from Anaerobic Digestion?

2020 ◽  
Author(s):  
Xiaobo Zhu ◽  
Aaron Leininger ◽  
David Jassby ◽  
Nicolas Tsesmetzis ◽  
Zhiyong Jason Ren
Keyword(s):  
Fatty Acid ◽  
Anaerobic Digestion ◽  
Volatile Fatty Acid ◽  
Acid Recovery
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