Method for anaerobic fermentation and biogas production

DEFF Research Database (Denmark)

2013-01-01

The present invention relates to a method for biomass processing, anaerobic fermentation of the processed biomass, and the production biogas. In particular, the invention relates to a system and method for generating biogas from anaerobic fermentation of processed organic material that comprises...

Quantitative Metaproteomics Highlight the Metabolic Contributions of Uncultured Phylotypes in a Thermophilic Anaerobic Digester.

Science.gov (United States)

Hagen, Live H; Frank, Jeremy A; Zamanzadeh, Mirzaman; Eijsink, Vincent G H; Pope, Phillip B; Horn, Svein J; Arntzen, Magnus Ø

2017-01-15

In this study, we used multiple meta-omic approaches to characterize the microbial community and the active metabolic pathways of a stable industrial biogas reactor with food waste as the dominant feedstock, operating at thermophilic temperatures (60°C) and elevated levels of free ammonia (367 mg/liter NH 3 -N). The microbial community was strongly dominated (76% of all 16S rRNA amplicon sequences) by populations closely related to the proteolytic bacterium Coprothermobacter proteolyticus. Multiple Coprothermobacter-affiliated strains were detected, introducing an additional level of complexity seldom explored in biogas studies. Genome reconstructions provided metabolic insight into the microbes that performed biomass deconstruction and fermentation, including the deeply branching phyla Dictyoglomi and Planctomycetes and the candidate phylum "Atribacteria" These biomass degraders were complemented by a synergistic network of microorganisms that convert key fermentation intermediates (fatty acids) via syntrophic interactions with hydrogenotrophic methanogens to ultimately produce methane. Interpretation of the proteomics data also suggested activity of a Methanosaeta phylotype acclimatized to high ammonia levels. In particular, we report multiple novel phylotypes proposed as syntrophic acetate oxidizers, which also exert expression of enzymes needed for both the Wood-Ljungdahl pathway and β-oxidation of fatty acids to acetyl coenzyme A. Such an arrangement differs from known syntrophic oxidizing bacteria and presents an interesting hypothesis for future studies. Collectively, these findings provide increased insight into active metabolic roles of uncultured phylotypes and presents new synergistic relationships, both of which may contribute to the stability of the biogas reactor. Biogas production through anaerobic digestion of organic waste provides an attractive source of renewable energy and a sustainable waste management strategy. A comprehensive understanding

Evolution of microorganisms in thermophilic-dry anaerobic digestion.

Science.gov (United States)

Montero, B; Garcia-Morales, J L; Sales, D; Solera, R

2008-05-01

Microbial population dynamics were studied during the start-up and stabilization periods in thermophilic-dry anaerobic digestion at lab-scale. The experimental protocol was defined to quantify Eubacteria and Archaea using Fluorescent in situ hybridization (FISH) in a continuously stirred tank reactor (CSTR), without recycling solids. The reactor was subjected to a programme of steady-state operation over a range of the retention times from 40 to 25 days, with an organic loading rate between 4.42 and 7.50 kg volatile solid/m3/day. Changes in microbial concentrations were linked to traditional performance parameters such as biogas production and VS removal. The relations of Eubacteria:Archaea and H2-utilising methanogens:acetate-utilising methanogens were 88:12 and 11:1, respectively, during start-up stage. Hydrogenotrophic methanogens, although important in the initial phase of the reactor start-up, were displaced by acetoclastic methanogens at steady-state, thus their relation were 7:32, respectively. The methane yield coefficient, the methane content in the biogas and VS removal were stabilized around 0.30 LCH4/gCOD, 50% and 80%, respectively. Methanogenic population correlated well with performance measurements.

Thermophillic Sidestream Anaerobic Membrane Bioreactors: The Shear Rate Dilemma

NARCIS (Netherlands)

Jeison, D.A.; Telkamp, P.; Lier, van J.B.

2009-01-01

Anaerobic biomass retention under thermophilic conditions has proven difficult. Membrane filtration can be used as alternative way to achieve high sludge concentrations. This research studied the feasibility of anaerobic membrane bioreactors (AnMBRs) under thermophilic conditions. A sidestream MBR

Anaerobic co-digestion of municipal organic wastes and pre-treatment to enhance biogas production from waste.

Science.gov (United States)

Li, Chenxi; Champagne, Pascale; Anderson, Bruce C

2014-01-01

Co-digestion and pre-treatment have been recognized as effective, low-cost and commercially viable approaches to reduce anaerobic digestion process limitations and improve biogas yields. In our previous batch-scale study, fat, oil, and grease (FOG) was investigated as a suitable potential co-substrate, and thermo-chemical pre-treatment (TCPT) at pH = 10 and 55 °C improved CH4 production from FOG co-digestions. In this project, co-digestions with FOG were studied in bench-scale two-stage thermophilic semi-continuous flow co-digesters with suitable TCPT (pH = 10, 55 °C). Overall, a 25.14 ± 2.14 L/d (70.2 ± 1.4% CH4) biogas production was obtained, which was higher than in the two-stage system without pre-treatment. The results could provide valuable fundamental information to support full-scale investigations of anaerobic co-digestion of municipal organic wastes.

Thermophilic versus Mesophilic Anaerobic Digestion of Sewage Sludge: A Comparative Review

Directory of Open Access Journals (Sweden)

Getachew D. Gebreeyessus

2016-06-01

Full Text Available During advanced biological wastewater treatment, a huge amount of sludge is produced as a by-product of the treatment process. Hence, reuse and recovery of resources and energy from the sludge is a big technological challenge. The processing of sludge produced by Wastewater Treatment Plants (WWTPs is massive, which takes up a big part of the overall operational costs. In this regard, anaerobic digestion (AD of sewage sludge continues to be an attractive option to produce biogas that could contribute to the wastewater management cost reduction and foster the sustainability of those WWTPs. At the same time, AD reduces sludge amounts and that again contributes to the reduction of the sludge disposal costs. However, sludge volume minimization remains, a challenge thus improvement of dewatering efficiency is an inevitable part of WWTP operation. As a result, AD parameters could have significant impact on sludge properties. One of the most important operational parameters influencing the AD process is temperature. Consequently, the thermophilic and the mesophilic modes of sludge AD are compared for their pros and cons by many researchers. However, most comparisons are more focused on biogas yield, process speed and stability. Regarding the biogas yield, thermophilic sludge AD is preferred over the mesophilic one because of its faster biochemical reaction rate. Equally important but not studied sufficiently until now was the influence of temperature on the digestate quality, which is expressed mainly by the sludge dewateringability, and the reject water quality (chemical oxygen demand, ammonia nitrogen, and pH. In the field of comparison of thermophilic and mesophilic digestion process, few and often inconclusive research, unfortunately, has been published so far. Hence, recommendations for optimized technologies have not yet been done. The review presented provides a comparison of existing sludge AD technologies and the gaps that need to be filled so

Thermophilic versus Mesophilic Anaerobic Digestion of Sewage Sludge: A Comparative Review

Science.gov (United States)

Gebreeyessus, Getachew D.; Jenicek, Pavel

2016-01-01

During advanced biological wastewater treatment, a huge amount of sludge is produced as a by-product of the treatment process. Hence, reuse and recovery of resources and energy from the sludge is a big technological challenge. The processing of sludge produced by Wastewater Treatment Plants (WWTPs) is massive, which takes up a big part of the overall operational costs. In this regard, anaerobic digestion (AD) of sewage sludge continues to be an attractive option to produce biogas that could contribute to the wastewater management cost reduction and foster the sustainability of those WWTPs. At the same time, AD reduces sludge amounts and that again contributes to the reduction of the sludge disposal costs. However, sludge volume minimization remains, a challenge thus improvement of dewatering efficiency is an inevitable part of WWTP operation. As a result, AD parameters could have significant impact on sludge properties. One of the most important operational parameters influencing the AD process is temperature. Consequently, the thermophilic and the mesophilic modes of sludge AD are compared for their pros and cons by many researchers. However, most comparisons are more focused on biogas yield, process speed and stability. Regarding the biogas yield, thermophilic sludge AD is preferred over the mesophilic one because of its faster biochemical reaction rate. Equally important but not studied sufficiently until now was the influence of temperature on the digestate quality, which is expressed mainly by the sludge dewateringability, and the reject water quality (chemical oxygen demand, ammonia nitrogen, and pH). In the field of comparison of thermophilic and mesophilic digestion process, few and often inconclusive research, unfortunately, has been published so far. Hence, recommendations for optimized technologies have not yet been done. The review presented provides a comparison of existing sludge AD technologies and the gaps that need to be filled so as to optimize

Influence of initial pH on thermophilic anaerobic co-digestion of swine manure and maize stalk.

Science.gov (United States)

Zhang, Tong; Mao, Chunlan; Zhai, Ningning; Wang, Xiaojiao; Yang, Gaihe

2015-01-01

The contradictions between the increasing energy demand and decreasing fossil fuels are making the use of renewable energy the key to the sustainable development of energy in the future. Biogas, a renewable clean energy, can be obtained by the anaerobic fermentation of manure waste and agricultural straw. This study examined the initial pH value had obvious effect on methane production and the process in the thermophilic anaerobic co-digestion. Five different initial pH levels with three different manure ratios were tested. All digesters in different initial pH showed a diverse methane production after 35 days. The VFA/alkalinity ratio of the optimum reaction condition for methanogens activity was in the range of 0.1-0.3 and the optimal condition that at the 70% dung ratio and initial pH 6.81, was expected to achieve maximum total biogas production (146.32 mL/g VS). Copyright © 2014 Elsevier Ltd. All rights reserved.

Cassava Stillage Treatment by Thermophilic Anaerobic Continuously Stirred Tank Reactor (CSTR)

Science.gov (United States)

Luo, Gang; Xie, Li; Zou, Zhonghai; Zhou, Qi

2010-11-01

This paper assesses the performance of a thermophilic anaerobic Continuously Stirred Tank Reactor (CSTR) in the treatment of cassava stillage under various organic loading rates (OLRs) without suspended solids (SS) separation. The reactor was seeded with mesophilic anaerobic granular sludge, and the OLR increased by increments to 13.80 kg COD/m3/d (HRT 5d) over 80 days. Total COD removal efficiency remained stable at 90%, with biogas production at 18 L/d (60% methane). Increase in the OLR to 19.30 kg COD/m3/d (HRT 3d), however, led to a decrease in TCOD removal efficiency to 79% due to accumulation of suspended solids and incomplete degradation after shortened retention time. Reactor performance subsequently increased after OLR reduction. Alkalinity, VFA and pH levels were not significantly affected by OLR variation, indicating that no additional alkaline or pH adjustment is required. More than half of the SS in the cassava stillage could be digested in the process when HRT was 5 days, which demonstrated the suitability of anaerobic treatment of cassava stillage without SS separation.

Anaerobic digestion of spent mushroom substrate under thermophilic conditions: performance and microbial community analysis.

Science.gov (United States)

Xiao, Zheng; Lin, Manhong; Fan, Jinlin; Chen, Yixuan; Zhao, Chao; Liu, Bin

2018-01-01

Spent mushroom substrate (SMS) is the residue of edible mushroom production occurring in huge amounts. The SMS residue can be digested for biogas production in the mesophilic anaerobic digestion. In the present study, performance of batch thermophilic anaerobic digestion (TAD) of SMS was investigated as well as the interconnected microbial population structure changes. The analyzed batch TAD process lasted for 12 days with the cumulative methane yields of 177.69 mL/g volatile solid (VS). Hydrolytic activities of soluble sugar, crude protein, and crude fat in SMS were conducted mainly in the initial phase, accompanied by the excessive accumulation of volatile fatty acids and low methane yield. Biogas production increased dramatically from days 4 to 6. The degradation rates of cellulose and hemicellulose were 47.53 and 55.08%, respectively. The high-throughput sequencing of 16S rRNA gene amplicons revealed that Proteobacteria (56.7%-62.8%) was the dominant phylum in different fermentative stages, which was highly specific compared with other anaerobic processes of lignocellulosic materials reported in the literature. Crenarchaeota was abundant in the archaea. The most dominant genera of archaea were retrieved as Methanothermobacter and Methanobacterium, but the latter decreased sharply with time. This study shows that TAD is a feasible method to handle the waste SMS.

In situ Removal of Hydrogen Sulfide During Biogas Fermentation at Microaerobic Condition.

Science.gov (United States)

Wu, Mengmeng; Zhang, Yima; Ye, Yuanyuan; Lin, Chunmian

2016-11-01

In this paper, rice straw was used as a raw material to produce biogas by anaerobic batch fermentation at 35 °C (mesophilic) or 55 °C (thermophilic). The hydrogen sulfide in biogas can be converted to S 0 or sulfate and removed in-situ under micro-oxygen environment. Trace oxygen was conducted to the anaerobic fermentation tank in amount of 0.5, 1.0, 2.0, 3.0, 4.0, 5.0, or 10.0 times stoichiometric equivalence, respectively, and the control experiment without oxygen addition was carried out. The results showed that the initial H 2 S concentrations of biogas are about 3235 ± 185 mg/m 3 (mesophilic) or 3394 ± 126 mg/m 3 (thermophilic), respectively. The desulfurization efficiency is 72.3 % (mesophilic) or 65.6 % (thermophilic), respectively, with oxygen addition by stoichiometric relation. When the oxygen feeded in amount of 2∼4 times, theoretical quantity demanded the removal efficiency of hydrogen sulfide could be over 92 %, and the oxygen residue in biogas could be maintained less than 0.5 %, which fit the requirement of biogas used as vehicle fuel or combined to the grid. Though further more oxygen addition could promote the removal efficiency of hydrogen sulfide (about 93.6 %), the oxygen residue in biogas would be higher than the application limit concentration (0.5 %). Whether mesophilic or thermophilic fermentation with the extra addition of oxygen, there were no obvious changes in the gas production and methane concentration. In conclusion, in-situ desulfurization can be achieved in the anaerobic methane fermentation system under micro-oxygen environment. In addition, air could be used as a substitute oxygen resource on the situation without strict demand for the methane content of biogas.

Inhibitory effects on anaerobic digestion of swine manure

Energy Technology Data Exchange (ETDEWEB)

Cheung, P.W.S.; Zhou, H. [Univ. of Guelph, School of Engineering, Guelph, Ontario (Canada)]. E-mail: hzhou@uoguelph.ca; Hacker, R. [Univ. of Guelph, Dept. of Animal and Poultry Science, Guelph, Ontario (Canada)

2002-06-15

This paper presents a laboratory study using anaerobic digestion for swine manure under both mesophilic and thermophilic conditions, with emphasis on the effects of inhibitory chemicals on biogas production. A series of batch tests were conducted to examine the effects of various process parameters by varying temperature, pH, ammonia and hydrogen sulfide concentrations. As well, continuous anaerobic digestion tests were conducted using a completely stirred reactor system with a sludge retention time of 15 days. The results showed that at the initial stage, biogas was generated rapidly in the thermophilic reactor, but was more and more inhibited during the later stage with the presence of ammonia and hydrogen sulfide. In contrast, the biogas production was initially delayed in the mesophilic reactor but afterwards had an even higher total gas production. In order to take advantages of both temperature effects in each reactor, the dual-stage system that consists of a thermophilic reactor followed by a mesophilic reactor was suggested. (author)

Inhibitory effects on anaerobic digestion of swine manure

International Nuclear Information System (INIS)

Cheung, P.W.S.; Zhou, H.; Hacker, R.

2002-01-01

This paper presents a laboratory study using anaerobic digestion for swine manure under both mesophilic and thermophilic conditions, with emphasis on the effects of inhibitory chemicals on biogas production. A series of batch tests were conducted to examine the effects of various process parameters by varying temperature, pH, ammonia and hydrogen sulfide concentrations. As well, continuous anaerobic digestion tests were conducted using a completely stirred reactor system with a sludge retention time of 15 days. The results showed that at the initial stage, biogas was generated rapidly in the thermophilic reactor, but was more and more inhibited during the later stage with the presence of ammonia and hydrogen sulfide. In contrast, the biogas production was initially delayed in the mesophilic reactor but afterwards had an even higher total gas production. In order to take advantages of both temperature effects in each reactor, the dual-stage system that consists of a thermophilic reactor followed by a mesophilic reactor was suggested. (author)

Performance and kinetic study of semi-dry thermophilic anaerobic digestion of organic fraction of municipal solid waste

International Nuclear Information System (INIS)

Sajeena Beevi, B.; Madhu, G.; Sahoo, Deepak Kumar

2015-01-01

Highlights: • Performance of the reactor was evaluated by the degradation of volatile solids. • Biogas yield at the end of the digestion was 52.9 L/kg VS. • Value of reaction rate constant, k, obtained was 0.0249 day −1 . • During the digestion 66.7% of the volatile solid degradation was obtained. - Abstract: Anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW) is promoted as an energy source and waste disposal. In this study semi dry anaerobic digestion of organic solid wastes was conducted for 45 days in a lab-scale batch experiment for total solid concentration of 100 g/L for investigating the start-up performances under thermophilic condition (50 °C). The performance of the reactor was evaluated by measuring the daily biogas production and calculating the degradation of total solids and the total volatile solids. The biogas yield at the end of the digestion was 52.9 L/kg VS (volatile solid) for the total solid (TS) concentration of 100 g/L. About 66.7% of the volatile solid degradation was obtained during the digestion. A first order model based on the availability of substrate as the limiting factor was used to perform the kinetic studies of batch anaerobic digestion system. The value of reaction rate constant, k, obtained was 0.0249 day −1

Performance and kinetic study of semi-dry thermophilic anaerobic digestion of organic fraction of municipal solid waste

Energy Technology Data Exchange (ETDEWEB)

Sajeena Beevi, B., E-mail: sajeenanazer@gmail.com [Department of Chemical Engineering, Govt. Engineering College, Thrissur, Kerala 680 009 (India); Madhu, G., E-mail: profmadhugopal@gmail.com [Division of Safety & Fire Engineering, School of Engineering, Cochin University of Science and Technology, Cochin, Kerala 682 022 (India); Sahoo, Deepak Kumar, E-mail: dksahoo@gmail.com [Division of Safety & Fire Engineering, School of Engineering, Cochin University of Science and Technology, Cochin, Kerala 682 022 (India)

2015-02-15

Highlights: • Performance of the reactor was evaluated by the degradation of volatile solids. • Biogas yield at the end of the digestion was 52.9 L/kg VS. • Value of reaction rate constant, k, obtained was 0.0249 day{sup −1}. • During the digestion 66.7% of the volatile solid degradation was obtained. - Abstract: Anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW) is promoted as an energy source and waste disposal. In this study semi dry anaerobic digestion of organic solid wastes was conducted for 45 days in a lab-scale batch experiment for total solid concentration of 100 g/L for investigating the start-up performances under thermophilic condition (50 °C). The performance of the reactor was evaluated by measuring the daily biogas production and calculating the degradation of total solids and the total volatile solids. The biogas yield at the end of the digestion was 52.9 L/kg VS (volatile solid) for the total solid (TS) concentration of 100 g/L. About 66.7% of the volatile solid degradation was obtained during the digestion. A first order model based on the availability of substrate as the limiting factor was used to perform the kinetic studies of batch anaerobic digestion system. The value of reaction rate constant, k, obtained was 0.0249 day{sup −1}.

Dry thermophilic semi-continuous anaerobic digestion of food waste: Performance evaluation, modified Gompertz model analysis, and energy balance

International Nuclear Information System (INIS)

Nguyen, Dinh Duc; Chang, Soon Woong; Jeong, Seong Yeob; Jeung, Jaehoon; Kim, Sungsu; Guo, Wenshan; Ngo, Huu Hao

2016-01-01

Highlights: • Energy self-sufficiency/energy recovery with thermophilic DScAD of FW was evaluated. • The maximum biogas production rate was positively influenced by OLRs. • Maximum (average) electrical energy recoverable from a 1 tons of FW was 1050 kW h. • Thermophilic DScAD can substantially reduce the VS and recover energy to serve itself. • A modified Gompertz model fitted well with the experimental results for all phases. - Abstract: A thermophilic, dry semi-continuous anaerobic digestion (DScAD) method was used to effectively transform food waste (FW) into renewable energy. This study aims to thoroughly evaluate the system performance and model simulation to predict biogas production, intermediate products and their outcomes, energy recovery potential, and energy balance, while operating with organic loading rates ranging from 2.3 to 9.21 kg-TS/m"3 day. The results indicate that volatile solids (VS) reduction and biogas production both improved as the organic loading rates (OLR) increased, and the cost of FW valorization remained low. The greatest VS reduction achieved was 87.01%, associated with 170 m"3 of biogas yield per ton of sludge (69% methane) at an ORL of 9.21 ± 0.89 kg-TS/m"3 day (8.62 ± 0.34 kg-VS/m"3 day) although the amounts of ammonia (3700 mg/L), hydrogen sulfide (420 ppm), and total volatile fatty acids (7101 mg/L) during fermentation were relatively high. Furthermore, 75% of total energy requirement for the system could be recovered via biomethane production, resulting in a considerably reduced specific energy supply (kW h/ton of treating FW). The results suggest that a modified Gompertz model is suitable for estimating the biogas and methane production potential and rate. The results also reveal that the DScAD of FW at 55 °C is a reliable, stable, and robust option for both solids reduction and energy recovery via biogas generation.

Survival of weed seeds and animal parasites as affected by anaerobic digestion at meso- and thermophilic conditions.

Science.gov (United States)

Johansen, Anders; Nielsen, Henrik B; Hansen, Christian M; Andreasen, Christian; Carlsgart, Josefine; Hauggard-Nielsen, Henrik; Roepstorff, Allan

2013-04-01

Anaerobic digestion of residual materials from animals and crops offers an opportunity to simultaneously produce bioenergy and plant fertilizers at single farms and in farm communities where input substrate materials and resulting digested residues are shared among member farms. A surplus benefit from this practice may be the suppressing of propagules from harmful biological pests like weeds and animal pathogens (e.g. parasites). In the present work, batch experiments were performed, where survival of seeds of seven species of weeds and non-embryonated eggs of the large roundworm of pigs, Ascaris suum, was assessed under conditions similar to biogas plants managed at meso- (37°C) and thermophilic (55°C) conditions. Cattle manure was used as digestion substrate and experimental units were sampled destructively over time. Regarding weed seeds, the effect of thermophilic conditions (55°C) was very clear as complete mortality, irrespective of weed species, was reached after less than 2 days. At mesophilic conditions, seeds of Avena fatua, Sinapsis arvensis, Solidago canadensis had completely lost germination ability, while Brassica napus, Fallopia convolvulus and Amzinckia micrantha still maintained low levels (~1%) of germination ability after 1 week. Chenopodium album was the only weed species which survived 1 week at substantial levels (7%) although after 11 d germination ability was totally lost. Similarly, at 55°C, no Ascaris eggs survived more than 3h of incubation. Incubation at 37°C did not affect egg survival during the first 48 h and it took up to 10 days before total elimination was reached. In general, anaerobic digestion in biogas plants seems an efficient way (thermophilic more efficient than mesophilic) to treat organic farm wastes in a way that suppresses animal parasites and weeds so that the digestates can be applied without risking spread of these pests. Copyright © 2012 Elsevier Ltd. All rights reserved.

Biogas production from cattle manure by anaerobic digestion

International Nuclear Information System (INIS)

Chuen, S.C.; Tinia Idaty Mohd Ghazi; Rozita Omar; Azni Idris

2009-01-01

Full text: In order to deal with the energy shortage problem, we are searching for more alternative energy resources especially renewable or sustainable. Biogas is one of the solutions in dealing with the energy shortage problem. Biogas is a type of energy resources derives from organic matter during the process called anaerobic digestion. The biogas produced is mainly consisting of methane and carbon dioxide. In this research, diluted cattle manure (1:1 ration with water) was inoculated with palm oil mill (POME) activated sludge at the ratio of 1:5 and placed in a 10 liter bioreactor. The temperature and pH in the bioreactor was regulated at 6.95 and 53 degree Celsius, respectively to enhance the anaerobic digestion process. Parameters such as chemical oxygen demand, biochemical oxygen demand, total solid, volatile solid, ammonia nitrogen (NH 3 -N), methane (CH 4 ) and the volume of biogas generated was monitored for effectiveness of the treatment of cattle manure via anaerobic digestion. The total volume of biogas produced in this study is 80.25 liter in 29 days while being able to treat the COD content up to 52 %. (author)

Investigation of factors influencing biogas production in a large-scale thermophilic municipal biogas plant

Energy Technology Data Exchange (ETDEWEB)

Weiss, Agnes; Jerome, Valerie; Freitag, Ruth [Bayreuth Univ. (Germany). Chair for Process Biotechnology; Burghardt, Diana; Likke, Likke; Peiffer, Stefan [Bayreuth Univ. (Germany). Dept. of Hydrology; Hofstetter, Eugen M. [RVT Process Equipment GmbH, Steinwiesen (Germany); Gabler, Ralf [BKW Biokraftwerke Fuerstenwalde GmbH, Fuerstenwalde (Germany)

2009-10-15

A continuously operated, thermophilic, municipal biogas plant was observed over 26 months (sampling twice per month) in regard to a number of physicochemical parameters and the biogas production. Biogas yields were put in correlation to parameters such as the volatile fatty acid concentration, the pH and the ammonium concentration. When the residing microbiota was classified via analysis of the 16S rRNA genes, most bacterial sequences matched with unidentified or uncultured bacteria from similar habitats. Of the archaeal sequences, 78.4% were identified as belonging to the genus Methanoculleus, which has not previously been reported for biogas plants, but is known to efficiently use H{sub 2} and CO{sub 2} produced by the degradation of fatty acids by syntrophic microorganisms. In order to further investigate the influence of varied amounts of ammonia (2-8 g/L) and volatile fatty acids on biogas production and composition (methane/CO{sub 2}), laboratory scale satellite experiments were performed in parallel to the technical plant. Finally, ammonia stripping of the process water of the technical plant was accomplished, a measure through which the ammonia entering the biogas reactor via the mash could be nearly halved, which increased the energy output of the biogas plant by almost 20%. (orig.)

A comparative study of thermophilic and mesophilic anaerobic co-digestion of food waste and wheat straw: Process stability and microbial community structure shifts.

Science.gov (United States)

Shi, Xuchuan; Guo, Xianglin; Zuo, Jiane; Wang, Yajiao; Zhang, Mengyu

2018-05-01

Renewable energy recovery from organic solid waste via anaerobic digestion is a promising way to provide sustainable energy supply and eliminate environmental pollution. However, poor efficiency and operational problems hinder its wide application of anaerobic digestion. The effects of two key parameters, i.e. temperature and substrate characteristics on process stability and microbial community structure were studied using two lab-scale anaerobic reactors under thermophilic and mesophilic conditions. Both the reactors were fed with food waste (FW) and wheat straw (WS). The organic loading rates (OLRs) were maintained at a constant level of 3 kg VS/(m 3 ·d). Five different FW:WS substrate ratios were utilized in different operational phases. The synergetic effects of co-digestion improved the stability and performance of the reactors. When FW was mono-digested, both reactors were unstable. The mesophilic reactor eventually failed due to volatile fatty acid accumulation. The thermophilic reactor had better performance compared to mesophilic one. The biogas production rate of the thermophilic reactor was 4.9-14.8% higher than that of mesophilic reactor throughout the experiment. The shifts in microbial community structures throughout the experiment in both thermophilic and mesophilic reactors were investigated. With increasing FW proportions, bacteria belonging to the phylum Thermotogae became predominant in the thermophilic reactor, while the phylum Bacteroidetes was predominant in the mesophilic reactor. The genus Methanosarcina was the predominant methanogen in the thermophilic reactor, while the genus Methanothrix remained predominant in the mesophilic reactor. The methanogenesis pathway shifted from acetoclastic to hydrogenotrophic when the mesophilic reactor experienced perturbations. Moreover, the population of lignocellulose-degrading microorganisms in the thermophilic reactor was higher than those in mesophilic reactor, which explained the better

Biogas Upgrading via Hydrogenotrophic Methanogenesis in Two-Stage Continuous Stirred Tank Reactors at Mesophilic and Thermophilic Conditions

DEFF Research Database (Denmark)

Bassani, Ilaria; Kougias, Panagiotis; Treu, Laura

2015-01-01

This study proposes an innovative setup composed by two stage reactors to achieve biogas upgrading coupling the CO2 in the biogas with external H2 and subsequent conversion into CH4 by hydrogenotrophic methanogenesis. In this configuration, the biogas produced in the first reactor was transferred...... production and CO2 conversion was recorded. The consequent increase of pH did not inhibit the process indicating adaptation of microorganisms to higher pH levels. The effects of H2 on the microbial community were studied using high-throughput Illumina random sequences and full-length 16S rRNA genes extracted...... to the second one, where H2 was injected. This configuration was tested at both mesophilic and thermophilic conditions. After H2 addition, the produced biogas was upgraded to average CH4 content of 89% in the mesophilic reactor and 85% in the thermophilic. At thermophilic conditions, a higher efficiency of CH4...

Anaerobic thermophilic culture-system

Energy Technology Data Exchange (ETDEWEB)

Ljungdahl, L G; Wiegel, J K.W.

1981-04-14

A mixed culture system of Thermoanaerobacter ethanolicus and Clostridium thermocellum is employed for anaerobic, thermophilic ethanol fermentation of cellulose. By cellulase action, monosaccharides are formed which inhibit the growth of C. thermocellum, but are fermented by T. ethanolicus. Thus, at a regulated pH-value of 7.5, this mixed culture system of micro organisms results in a cellulose fermentation with a considerably higher ethanol yield.

International scientific conference biogas science 2009. Vol. 2. Lectures; Internationale Wissenschaftstagung Biogas Science 2009. Bd. 2. Vortraege

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-12-15

Within the international conference of the Bavarian State Research Center for Agriculture (Munich, Federal Republic of Germany) at 2nd to 4th December, 2009, in Erding (Federal Republic of Germany), the following lectures were held: (1) Design and application of a functional oligonucleotide microarray for the identification of cellulose genes and their expression in (different) biogas Fermenters (M. Engel et al.); (2) Evaluation of the potential of hygienisation of the biogas process with regard to phytogenic damage exciter (R. Friedrich et al.); (3) Prevalence and role of hydrolytic bacteria in mesophilic and thermophilic biogas reactors (V.V. Zverlov et al.); (4) System analysis of biogas plants by means of microbiologic and molecular biologic methods: Comparison of hyperthermophilic (60 C) and thermophilic (55 C) (P. Scherer et al.); (5) Methanogenic archaea in agricultural biogas plants (E. Nettmann et al.); (6) Population dynamics of methanogens during acidification of biogas Fermenters fed with maize silage - a causal analysis (M. Lebuhn et al.); (7) Advanced interpretation of anaerobic batch tests - Conclusions for the practical operation (S. Meier et al.); (8) Development of a NIRS calibration for the determination of the biogas yield of maize (B. Darnhofer et al.); (9) Hydrogen and methane: Enhanced methane as well as hydrogen production and increased process stability by Sensorik control (N. Weran); (10) Stable carbon isotopes: A new laser method for the process analysis and identification of microbiologic reactions in the biogas process (S. Laukenmann et al.); (11) Biogas from grass silage - measurements and modelling (K. Koch et al.); (12) Mathematical modelling of the mesophilic and thermophilic anaerobe fermentation of maize silage (M. Luebken et al.); (13) The basket of benefit methodology as a tool for the comparison of electricity, heat, and fuel production from energy crops, exemplified by different utilization pathways for biogas (M. Bystricky et

Long-term stability of thermophilic co-digestion submerged anaerobic membrane reactor encountering high organic loading rate, persistent propionate and detectable hydrogen in biogas.

Science.gov (United States)

Qiao, Wei; Takayanagi, Kazuyuki; Niu, Qigui; Shofie, Mohammad; Li, Yu You

2013-12-01

The performance of thermophilic anaerobic co-digestion of coffee grounds and sludge using membrane reactor was investigated for 148 days, out of a total research duration of 263 days. The OLR was increased from 2.2 to 33.7 kg-COD/m(3)d and HRT was shortened from 70 to 7 days. A significant irreversible drop in pH confirmed the overload of reactor. Under a moderately high OLR of 23.6 kg-COD/m(3)d, and with HRT and influent total solids of 10 days and 150 g/L, respectively, the COD removal efficiency was 44.5%. Hydrogen in biogas was around 100-200 ppm, which resulted in the persistent propionate of 1.0-3.2g/L. The VFA consumed approximately 60% of the total alkalinity. NH4HCO3 was supplemented to maintain alkalinity. The stability of system relied on pH management under steady state. The 16SrDNA results showed that hydrogen-utilizing methanogens dominates the archaeal community. The propionate-oxidizing bacteria in bacterial community was insufficient. Copyright © 2013 Elsevier Ltd. All rights reserved.

Diversity of Cultured Thermophilic Anaerobes in Hot Springs of Yunnan Province, China

Science.gov (United States)

Lin, L.; Lu, Y.; Dong, X.; Liu, X.; Wei, Y.; Ji, X.; Zhang, C.

2010-12-01

Thermophilic anaerobes including Archaea and Bacteria refer to those growing optimally at temperatures above 50°C and do not use oxygen as the terminal electron acceptor for growth. Study on thermophilic anaerobes will help to understand how life thrives under extreme conditions. Meanwhile thermophilic anaerobes are of importance in potential application and development of thermophilic biotechnology. We have surveyed culturable thermophilic anaerobes in hot springs (pH6.5-7.5; 70 - 94°C) in Rehai of Tengchong, Bangnazhang of Longlin, Eryuan of Dali,Yunnan, China. 50 strains in total were cultured from the hot springs water using Hungate anaerobic technique, and 30 strains were selected based on phenotypic diversity for analysis of 16S rDNA sequences. Phylogenetic analysis showed that 28 strains belonged to the members of five genera: Caldanaerobacter, Calaramator, Thermoanaerobacter, Dictyoglomus and Fervidobacterium, which formed five branches on the phylogenetic tree. Besides, 2 strains of methanogenic archaea were obtained. The majority of the isolates were the known species, however, seven strains were identified as novel species affiliated to the five genera based on the lower 16S rDNA sequence similarities (less than 93 - 97%) with the described species. This work would provide the future study on their diversity, distribution among different regions and the potential application of thermophilic enzyme. Supported by State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences(SKLMR-080605)and the Foundation of State Natural Science (30660009, 30960022, 31081220175).

Thermophilic anaerobic digestion of Lurgi coal gasification wastewater in a UASB reactor

Energy Technology Data Exchange (ETDEWEB)

Wang, W.; Ma, W.C.; Han, H.J.; Li, H.Q.; Yuan, M. [Harbin Institute of Technology, Harbin (China)

2011-02-15

Lurgi coal gasification wastewater (LCGW) is a refractory wastewater, whose anaerobic treatment has been a severe problem due to its toxicity and poor biodegradability. Using a mesophilic (35 {+-} 2{sup o}C) reactor as a control, thermophilic anaerobic digestion (55 {+-} 2{sup o}C) of LCGW was investigated in a UASB reactor. After 120 days of operation, the removal of COD and total phenols by the thermophilic reactor could reach 50-55% and 50-60% respectively, at an organic loading rate of 2.5 kg COD/(m{sup 3} d) and HRT of 24h: the corresponding efficiencies were both only 20-30% in the mesophilic reactor. After thermophilic digestion, the wastewater concentrations of the aerobic effluent COD could reach below 200 mg/L compared with around 294 mg/L if mesophilic digestion was done and around 375 mg/L if sole aerobic pre-treatment was done. The results suggested that thermophilic anaerobic digestion improved significantly both anaerobic and aerobic biodegradation of LCGW.

Enhanced biogas yield from energy crops with rumen anaerobic fungi

Energy Technology Data Exchange (ETDEWEB)

Prochazka, Jindrich; Zabranska, Jana; Dohanyos, Michal [Department of Water Technology and Environmental Engineering, Faculty of Environmental Technology, Institute of Chemical Technology in Prague, Prague (Czech Republic); Mrazek, Jakub; Strosova, Lenka; Fliegerova, Katerina [Laboratory of Anaerobic Microbiology, Institute of Animal Physiology and Genetics, CAS, v.v.i., Prague (Czech Republic)

2012-06-15

Anaerobic fungi (AF) are able to degrade crop substrates with higher efficiency than commonly used anaerobic bacteria. The aim of this study was to investigate ways of use of rumen AF to improve biogas production from energy crops under laboratory conditions. In this study, strains of AF isolated from feces or rumen fluid of cows and deer were tested for their ability to integrate into the anaerobic bacterial ecosystem used for biogas production, in order to improve degradation of substrate polysaccharides and consequently the biogas yield. Batch culture, fed batch culture, and semicontinuous experiments have been performed using anaerobic sludge from pig slurry fermentation and different kinds of substrates (celluloses, maize, and grass silage) inoculated by different genera of AF. All experiments showed a positive effect of AF on the biogas yield and quality. AF improved the biogas production by 4-22%, depending on the substrate and AF species used. However, all the cultivation experiments indicated that rumen fungi do not show long-term survival in fermenters with digestate from pig slurry. The best results were achieved during fed batch experiment with fungal culture Anaeromyces (KF8), in which biogas production was enhanced during the whole experimental period of 140 days. This result has not been achieved in semicontinuous experiment, where increment in biogas production in fungal enriched reactor was only 4% after 42 days. (copyright 2012 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Can anaerobic digestion of sugar beet pulp support the circular economy? a study of biogas and nutrient potential

Science.gov (United States)

Suhartini, S.; Heaven, S.; Banks, C. J.

2018-03-01

Anaerobic digestion (AD), known as a biological process without oxygen to convert complex organic materials into biogas, is capable of processing large tonnage quantities of biomass, such as sugar beet pulp (SBP). In addition to biogas production, its use allows nutrients and organic carbon recycle back to agriculture through the spreading of digestate. Digestate still contains high amount of nutrients (N, P, K) for use as biofertiliser. The aims of this research were to determine biogas/methane potential as a baseline for comparison with performance in semi-continuous digestion, and to determine nutrient and potentially toxic elements (PTE) of digestate fractions with respect to their potential for utilisation in agriculture. The Biochemical Methane Potential (BMP) test was performed in triplicate against blank and positive controls over a period of 28 days with gas measured at regular intervals. Semi-continuous AD of SBP was operated under mesophilic and thermophilic condition for 206 and 165 days. The results indicated that SBP is a very promising feedstock for AD, with the average BMP of 0.321 l CH4 g-1 VS and biogas potential of 0.605 l g-1 VS. Under semi-continuous operation, SBP also demonstrated positive results. Digestates from mesophilic and thermophilic AD of SBP contained useful quantities of N, P and K, with an acceptable Ni concentration in accordance to limits for PTE. These results suggest that digestate has the potential to be utilised on agricultural and arable land. This study illustrated the positive effects of applying AD to the achievement of economic savings and environmental-friendly performance.

Hybrid biogas upgrading in a two-stage thermophilic reactor

DEFF Research Database (Denmark)

Corbellini, Viola; Kougias, Panagiotis; Treu, Laura

2018-01-01

The aim of this study is to propose a hybrid biogas upgrading configuration composed of two-stage thermophilic reactors. Hydrogen is directly injected in the first stage reactor. The output gas from the first reactor (in-situ biogas upgrade) is subsequently transferred to a second upflow reactor...... (ex-situ upgrade), in which enriched hydrogenotrophic culture is responsible for the hydrogenation of carbon dioxide to methane. The overall objective of the work was to perform an initial methane enrichment in the in-situ reactor, avoiding deterioration of the process due to elevated pH levels......, and subsequently, to complete the biogas upgrading process in the ex-situ chamber. The methane content in the first stage reactor reached on average 87% and the corresponding value in the second stage was 91%, with a maximum of 95%. A remarkable accumulation of volatile fatty acids was observed in the first...

Anaerobic digestion of whole stillage from dry-grind corn ethanol plant under mesophilic and thermophilic conditions.

Science.gov (United States)

Eskicioglu, Cigdem; Kennedy, Kevin J; Marin, Juan; Strehler, Benjamin

2011-01-01

Anaerobic digestion of whole stillage from a dry-grind corn-based ethanol plant was evaluated by batch and continuous-flow digesters under thermophilic and mesophilic conditions. At whole corn stillage concentrations of 6348 to 50,786 mg total chemical oxygen demand (TCOD)/L, at standard temperature (0 °C) and pressure (1 atm), preliminary biochemical methane potential assays produced 88±8 L (49±5 L CH4) and 96±19 L (65±14 L CH4) biogas per L stillage from mesophilic and thermophilic digesters, respectively. Continuous-flow studies for the full-strength stillage (TCOD=254 g/L) at organic loadings of 4.25, 6.30 and 9.05 g TCOD/L days indicated unstable performance for the thermophilic digester. Among the sludge retention times (SRTs) of 60, 45 and 30 days tested, the mesophilic digestion was successful only at 60 days-SRT which does not represent a practical operation time for a large scale bioethanol plant. Future laboratory studies will focus on different reactor configurations to reduce the SRT needed in the digesters. Copyright © 2010 Elsevier Ltd. All rights reserved.

ANAEROBIC BIODEGRADATION OF A BIODEGRADABLE MATERIAL UNDER ANAEROBIC - THERMOPHILIC DIGESTION

Directory of Open Access Journals (Sweden)

RICARDO CAMACHO-MUÑOZ

2014-12-01

Full Text Available This paper dertermined the anaerobic biodegradation of a polymer obtained by extrusion process of native cassava starch, polylactic acid and polycaprolactone. Initially a thermophilic - methanogenic inoculum was prepared from urban solid waste. The gas final methane concentration and medium’s pH reached values of 59,6% and 7,89 respectively. The assay assembly was carried out according ASTM D5511 standard. The biodegradation percent of used materials after 15 day of digestion were: 77,49%, 61,27%, 0,31% for cellulose, sample and polyethylene respectively. Due cellulose showed biodegradation levels higher than 70% it’s deduced that the inoculum conditions were appropriate. A biodegradation level of 61,27%, 59,35% of methane concentration in sample’s evolved gas and a medium’s finale pH of 7,71 in sample’s vessels, reveal the extruded polymer´s capacity to be anaerobically degraded under thermophilic- high solid concentration conditions.

Biogas generation from in-storage psychrophilic anaerobic digestion.

Science.gov (United States)

Giard, David; Choiniere, Denis; Cordeau, Sébastien; Barrington, Suzelle

2013-01-01

In-storage psychrophilic anaerobic digestion (ISPAD) is a technology allowing livestock producers to operate an anaerobic digester with minimum technological know-how and for the cost of a conventional storage cover. Nevertheless, the system is exposed to ambient temperatures and biogas production is expected to vary with climatic conditions. The objective of the project was therefore to measure ISPAD biogas production during the winter and fall seasons for a region east of Montreal, Canada. A calibrated biogas monitoring system was used to monitor biogas methane and carbon dioxide concentrations inside a two-year-old field installation with a 1000 m3 storage capacity. Despite a leaking pumping hatch, winter 2010 (January to March) methane concentrations varied directly with solar radiation and maximum exterior temperature, rather than with manure temperature at 2.4 and 1.2 m depths which remained relatively constant between 1 and 5 degrees C. During a six-month-period from November 2009 to April 2010, inclusively, the field ISPAD degraded 34% of the manure volatile solids corresponding to an average methane production of 40 m3/d. The ISPAD biogas production could be further increased by improving its air tightness and intrusion and by regularly pumping out the biogas.

Thermotoga lettingae sp. nov. : a novel thermophilic, methanol-degrading bacterium isolated from a thermophilic anaerobic reactor

NARCIS (Netherlands)

Balk, M.; Weijma, J.; Stams, A.J.M.

2002-01-01

A novel, anaerobic, non-spore-forming, mobile, Gram-negative, thermophilic bacterium, strain TMO(T), was isolated from a thermophilic sulfate-reducing bioreactor operated at 65 degrees C with methanol as the sole substrate. The G C content of the DNA of strain TMO(T) was 39.2 molÐThe optimum pH,

Anaerobic digestion of nitrogen rich poultry manure: Impact of thermophilic biogas process on metal release and microbial resistances.

Science.gov (United States)

Anjum, Reshma; Grohmann, Elisabeth; Krakat, Niclas

2017-02-01

Poultry manure is a nitrogen rich fertilizer, which is usually recycled and spread on agricultural fields. Due to its high nutrient content, chicken manure is considered to be one of the most valuable animal wastes as organic fertilizer. However, when chicken litter is applied in its native form, concerns are raised as such fertilizers also include high amounts of antibiotic resistant pathogenic Bacteria and heavy metals. We studied the impact of an anaerobic thermophilic digestion process on poultry manure. Particularly, microbial antibiotic resistance profiles, mobile genetic elements promoting the resistance dissemination in the environment as well as the presence of heavy metals were focused in this study. The initiated heat treatment fostered a community shift from pathogenic to less pathogenic bacterial groups. Phenotypic and molecular studies demonstrated a clear reduction of multiple resistant pathogens and self-transmissible plasmids in the heat treated manure. That treatment also induced a higher release of metals and macroelements. Especially, Zn and Cu exceeded toxic thresholds. Although the concentrations of a few metals reached toxic levels after the anaerobic thermophilic treatment, the quality of poultry manure as organic fertilizer may raise significantly due to the elimination of antibiotic resistance genes (ARG) and self-transmissible plasmids. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterization of microbial biofilms in a thermophilic biogas system by high-throughput metagenome sequencing.

Science.gov (United States)

Rademacher, Antje; Zakrzewski, Martha; Schlüter, Andreas; Schönberg, Mandy; Szczepanowski, Rafael; Goesmann, Alexander; Pühler, Alfred; Klocke, Michael

2012-03-01

DNAs of two biofilms of a thermophilic two-phase leach-bed biogas reactor fed with rye silage and winter barley straw were sequenced by 454-pyrosequencing technology to assess the biofilm-based microbial community and their genetic potential for anaerobic digestion. The studied biofilms matured on the surface of the substrates in the hydrolysis reactor (HR) and on the packing in the anaerobic filter reactor (AF). The classification of metagenome reads showed Clostridium as most prevalent bacteria in the HR, indicating a predominant role for plant material digestion. Notably, insights into the genetic potential of plant-degrading bacteria were determined as well as further bacterial groups, which may assist Clostridium in carbohydrate degradation. Methanosarcina and Methanothermobacter were determined as most prevalent methanogenic archaea. In consequence, the biofilm-based methanogenesis in this system might be driven by the hydrogenotrophic pathway but also by the aceticlastic methanogenesis depending on metabolite concentrations such as the acetic acid concentration. Moreover, bacteria, which are capable of acetate oxidation in syntrophic interaction with methanogens, were also predicted. Finally, the metagenome analysis unveiled a large number of reads with unidentified microbial origin, indicating that the anaerobic degradation process may also be conducted by up to now unknown species. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Evaluation of biogas production potential by dry anaerobic digestion of switchgrass--animal manure mixtures.

Science.gov (United States)

Ahn, H K; Smith, M C; Kondrad, S L; White, J W

2010-02-01

Anaerobic digestion is a biological method used to convert organic wastes into a stable product for land application with reduced environmental impacts. The biogas produced can be used as an alternative renewable energy source. Dry anaerobic digestion [>15% total solid (TS)] has an advantage over wet digestion (anaerobic digestion of animal manure-switchgrass mixture was evaluated under dry (15% TS) and thermophilic conditions (55 degrees C). Three different mixtures of animal manure (swine, poultry, and dairy) and switchgrass were digested using batch-operated 1-L reactors. The swine manure test units showed 52.9% volatile solids (VS) removal during the 62-day trial, while dairy and poultry manure test units showed 9.3% and 20.2%, respectively. Over the 62 day digestion, the swine manure test units yielded the highest amount of methane 0.337 L CH4/g VS, while the dairy and poultry manure test units showed very poor methane yield 0.028 L CH4/g VS and 0.002 L CH4/g VS, respectively. Although dairy and poultry manure performed poorly, they may still have high potential as biomass for dry anaerobic digestion if appropriate designs are developed to prevent significant volatile fatty acid (VFA) accumulation and pH drop.

Mesophilic and thermophilic anaerobic co-digestion of winery wastewater sludge and wine lees: An integrated approach for sustainable wine production.

Science.gov (United States)

Da Ros, C; Cavinato, C; Pavan, P; Bolzonella, D

2017-12-01

In this work, winery wastes generated by a cellar producing approximately 300,000 hL of wine per year was monitored for a period of one year. On average, 196 L of wastewater, 0.1 kg of waste activated sludge (dry matter) and 1.6 kg of wine lees were produced per hectoliter of wine produced. Different winery wastes, deriving from different production steps, namely waste activated sludge from wastewater treatment and wine lees, were co-treated using an anaerobic digestion process. Testing was conducted on a pilot scale for both mesophilic and thermophilic conditions. The process was stable for a long period at 37 °C, with an average biogas production of 0.386 m 3 /kg COD fed . On the other hand, for thermophilic conditions, volatile fatty acids accumulated in the reactor and the process failed after one hydraulic retention time (23 days). In order to fix the biological process, trace elements (iron, cobalt and nickel) were added to the feed of the thermophilic reactor. Metals augmentation improved process stability and yields at 55 °C. The pH ranged between 7.8 and 8.0, and specific gas production was 0.450 m 3 /kg COD fed , which corresponded to dry matter and COD removals of 34% and 88%, respectively. Although the observed performances in terms of biogas production were good, the thermophilic process exhibited some limitations related to both the necessity of metals addition and the worse dewaterability properties. In fact, while the mesophilic digestates reached a good dewatering quality via the addition of 6.5 g of polymer per kg of dry matter, the required dosage for the thermophilic sludge was greater than 10 g/kg of dry matter. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quantifying Contribution of Synthrophic Acetate Oxidation to Methane Production in Thermophilic Anaerobic Reactors by Membrane Inlet Mass Spectrometry

DEFF Research Database (Denmark)

Mulat, Daniel Girma; Ward, Alastair James; Adamsen, Anders Peter S.

2014-01-01

A unique method was developed and applied for monitoring methanogenesis pathways based on isotope labeled substrates combined with online membrane inlet quadrupole mass spectrometry (MIMS). In our study, a fermentation sample from a full-scale biogas plant fed with pig and cattle manure, maize...... silage, and deep litter was incubated with 100 mM of [2-13C] sodium acetate under thermophilic anaerobic conditions. MIMS was used to measure the isotopic distribution of dissolved CO2 and CH4 during the degradation of acetate, while excluding interference from water by applying a cold trap. After 6 days...... a new approach for online quantification of the relative contribution of methanogenesis pathways to methane production with a time resolution shorter than one minute. The observed contribution of SAO-HM to methane production under the tested conditions challenges the current widely accepted anaerobic...

Anaerobic digestion technology in livestock manure treatment for biogas production: a review

Energy Technology Data Exchange (ETDEWEB)

Nasir, Ismail M. [Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia, Selangor (Malaysia); Mohd Ghazi, Tinia I.; Omar, Rozita

2012-06-15

This article reviews the potential of anaerobic digestion (AD) for biogas production from livestock manure wastes and compares the operating and performance data for various anaerobic process configurations. It examines different kinds of manure waste treatment techniques and the influence of several parameters on biogas and methane yield. The comparison indicates that a variety of different operational conditions, various reactor configurations such as batch reactors, continuously stirred tank reactor (CSTR), plug flow reactor (PFR), up-flow anaerobic sludge blanket (UASB), anaerobic sequencing batch reactor (ASBR), temperature phased anaerobic digestion (TPAD), and continuous one- and two-stage systems, present a suitable technology for the AD of livestock manure waste. Main performance indicators are biogas and methane yield, degradation of volatile solids (VS), higher loading, and process stability with a short retention time. (copyright 2012 WILEY-VCH Verlag GmbH 8 Co. KGaA, Weinheim)

Improvement of Biogas Production by Bioaugmentation

Directory of Open Access Journals (Sweden)

K. L. Kovács

2013-01-01

Full Text Available Biogas production technologies commonly involve the use of natural anaerobic consortia of microbes. The objective of this study was to elucidate the importance of hydrogen in this complex microbial food chain. Novel laboratory biogas reactor prototypes were designed and constructed. The fates of pure hydrogen-producing cultures of Caldicellulosiruptor saccharolyticus and Enterobacter cloacae were followed in time in thermophilic and mesophilic natural biogas-producing communities, respectively. Molecular biological techniques were applied to study the altered ecosystems. A systematic study in 5-litre CSTR digesters revealed that a key fermentation parameter in the maintenance of an altered population balance is the loading rate of total organic solids. Intensification of the biogas production was observed and the results corroborate that the enhanced biogas productivity is associated with the increased abundance of the hydrogen producers. Fermentation parameters did not indicate signs of failure in the biogas production process. Rational construction of more efficient and sustainable biogas-producing microbial consortia is proposed.

Improvement of Biogas Production by Bioaugmentation

Science.gov (United States)

Kovács, K. L.; Ács, N.; Kovács, E.; Wirth, R.; Rákhely, G.; Strang, Orsolya; Herbel, Zsófia; Bagi, Z.

2013-01-01

Biogas production technologies commonly involve the use of natural anaerobic consortia of microbes. The objective of this study was to elucidate the importance of hydrogen in this complex microbial food chain. Novel laboratory biogas reactor prototypes were designed and constructed. The fates of pure hydrogen-producing cultures of Caldicellulosiruptor saccharolyticus and Enterobacter cloacae were followed in time in thermophilic and mesophilic natural biogas-producing communities, respectively. Molecular biological techniques were applied to study the altered ecosystems. A systematic study in 5-litre CSTR digesters revealed that a key fermentation parameter in the maintenance of an altered population balance is the loading rate of total organic solids. Intensification of the biogas production was observed and the results corroborate that the enhanced biogas productivity is associated with the increased abundance of the hydrogen producers. Fermentation parameters did not indicate signs of failure in the biogas production process. Rational construction of more efficient and sustainable biogas-producing microbial consortia is proposed. PMID:23484123

Demand-driven biogas production in anaerobic filters

International Nuclear Information System (INIS)

Lemmer, Andreas; Krümpel, Johannes

2017-01-01

Highlights: • Feasibility of demand-driven biogas production in anaerobic filters demonstrated. • Predictable ramping up of gas production by 300–400% within one hour. • Degradation degree remained stable >92% for all substrates and operation modes. • Measure of responsiveness to sudden changes in organic loading rate introduced. • Carbon balance for demand-driven operation. - Abstract: The growth in electricity generated from renewable energy sources is posing challenges for grid stability and the need to counter balance the intermittent power supply by these sources. Biogas technology can offer such grid services by adapting biogas production to balance the demand and subsequent electricity production of the combined heat and power unit. Innovative plant designs, such as two-staged anaerobic digestion, could possibly adapt to imbalances in the electricity grid within shorter time frames than traditional continuously stirred tank reactors (CSTR). The scope of this research paper was to demonstrate the feasibility of operating an anaerobic filter for highly flexible gas production. The repeatability of this type of operation was examined to demonstrate its predictability. Based on gas production profiles, a measure of responsiveness was introduced to determine whether and how rapidly adaptations to the production process are possible. Furthermore, the influence of substrate composition was tested and finally a carbon balance was derived to evaluate operation performance. The results indicated that anaerobic filters are well suited for flexible gas production and the results were well reproduced under the conditions presented. Substrate composition was found to have no effect on increasing the rate of methane production. The pH value in the reactor did have an effect on the solubility of CO_2 and HCO_3"− and therefore marked an important parameter that determines biogas composition, especially under varying organic loading rates. The carbon balance had

Conversion of hemicellulose and D-xylose into ethanol by the use of thermophilic anaerobic bacteria

Energy Technology Data Exchange (ETDEWEB)

Sommer, Peter

1998-02-01

Ethanol is a CO{sub 2} neutral liquid fuel that can substitute the use of fossil fuels in the transportation sector, thereby reducing the CO{sub 2} emission to the atmoshpere. CO{sub 2} emission is suspected to contribute significantly to the so-called greenhouse effect, the global heating. Substrates for production of ethanol must be cheap and plentiful. This can be met by the use of lignocellulosic biomass such as willow, wheat straw, hardwood and softwood. However, the complexity of these polymeric substrates and the presence of several types of carbohydrates (glucose, xylose, mannose, galactose, arabinose) require additional treatment to release the useful carbohydrates and ferment the major carbohydrates fractions. The costs related to the ethanol-production must be kept at a minimum to be price competitive compared to gasoline. Therefore all of the carbohydrates present in lignocellulose need to be converted into ethanol. Glucose can be fermented to ethanol by yeast strains such as Saccharomyces cerevisiae, which, however, is unable to ferment the other major carbohydrate fraction, D-xylose. The need for a microorganism able to ferment D-xylose is therefore apparent. Thermophilic anaerobic ethanol producing bacteria can therefore be considered for fermentation of D-xylose. Screening of 130 thermophilic anaerobic bacterial strains, from hot-springs, mesophilic and thermophilic biogas plants, paper pulp industries and brewery waste, were examined for production of ethanol from D-xylose and wet-oxidized hemicellulose hydrolysate. Several strains were isolated and one particular strain was selected for best performance during the screening test. This strain was characterized as a new species, Thermoanaerobacter mathranii. However, the ethanol yield on wet-oxidized hemicellulose hydrolysate was not satisfactory. The bacterium was adapted by isolation of mutant strains, now resistant to the inhibitory compounds present in the hydrolysate. Growth and ethanol yield

Anaerobic treatment of apple waste with swine manure for biogas production: Batch and continuous operation

International Nuclear Information System (INIS)

Kafle, Gopi Krishna; Kim, Sang Hun

2013-01-01

Highlights: ► Apple waste (AW) was co-digested with swine manure (SM). ► Mixture of AW and SM produced a higher biogas yield than SM only. ► Mixture of AW and SM produced a higher biogas yield at 55 °C than at 36.5 °C. ► Modified Gompertz model best fitted to the substrates used. ► Positive synergetic effect up to 33% AW during continuous digestion. -- Abstract: This study evaluated the performance of anaerobic digesters using a mixture of apple waste (AW) and swine manure (SM). Tests were performed using both batch and continuous digesters. The batch test evaluated the gas potential, gas production rate of the AW and SM (Experiment I), and the effect of AW co-digestion with SM (33:67,% volatile solids (VSs) basis) (Experiment II) at mesophilic and thermophilic temperatures. The first-order kinetic model and modified Gompertz model were also evaluated for methane yield. The continuous test evaluated the performance of a single stage completely stirred tank reactor (CSTR) with different mixture ratios of AW and SM at mesophilic temperature. The ultimate biogas and methane productivity of AW in terms of total chemical oxygen demand (TCOD) was determined to be 510 and 252 mL/g TCOD added, respectively. The mixture of AW and SM improved the biogas yield by approximately 16% and 48% at mesophilic and thermophilic temperatures, respectively, compared to the use of SM only, but no significant difference was found in the methane yield. The difference between the predicted and measured methane yield was higher with a first order kinetic model (4.6–18.1%) than with a modified Gompertz model (1.2–3.4%). When testing continuous digestion, the methane yield increased from 146 to 190 mL/g TCOD added when the AW content in the feed was increased from 25% to 33% (VS basis) at a constant organic loading rate (OLR) of 1.6 g VS/L/d and a hydraulic retention time (HRT) of 30 days. However, the total volatile fatty acids (TVFA) accumulation increased rapidly and the p

Arsenic volatilization in model anaerobic biogas digesters

International Nuclear Information System (INIS)

Mestrot, Adrien; Xie, Wan-Ying; Xue, Ximei; Zhu, Yong-Guan

2013-01-01

Highlights: • Arsenic is volatilized form all model anaerobic digesters, including the non-treated ones. • Volatile As species can be identified and quantified in all digesters. • Non-arsenic treated digesters volatilization rates are higher than Roxarsone treated ones. - Abstract: Arsenic is a class 1 non-threshold carcinogen which is highly ubiquitous. Arsenic undergoes many different transformations (biotic or abiotic) between and within environmental compartments, leading to a number of different chemical species possessing different properties and toxicities. One specific transformation is As biotic volatilization which is coupled with As biomethylation and has been scarcely studied due to inherent sampling issues. Arsenic methylation/volatilization is also linked with methanogenesis and occurs in anaerobic environments. In China, rice straw and animal manure are very often used to produce biogas and both can contain high amounts of As, especially if the rice is grown in areas with heavy mining or smelting industries and if Roxarsone is fed to the animals. Roxarsone is an As-containing drug which is widely used in China to control coccidian intestinal parasites, to improve feed efficiency and to promote rapid growth. Previous work has shown that this compound degrades to inorganic As under anaerobic conditions. In this study the focus is on biotic transformations of As in small microcosms designed as biogas digester models (BDMs) using recently validated As traps, thus, enabling direct quantification and identification of volatile As species. It is shown that although there was a loss of soluble As in the BDMs, their conditions favored biomethylation. All reactors produced volatile As, especially the monomethylarsonic acid spiked ones with 413 ± 148 ng As (mean ± SD, n = 3) which suggest that the first methylation step, from inorganic As, is a limiting factor. The most abundant species was trimethylarsine, but the toxic arsine was present in the

An evaluation of biogas production from anaerobic digester of a ...

African Journals Online (AJOL)

Ezekiel Adeniran

2015-09-15

Sep 15, 2015 ... average rate of production of biogas was found to be 641.83±88.26 m3/day. ... Key words: Anaerobic digester, biogas, constructed wetland, domestic sewage, ... of diseases and odour, when discharged in water bodies.

An experimental evaluation of energy economics of biogas production at mesophilic and thermophilic temperatures

International Nuclear Information System (INIS)

Ezeonu, F. C.

1997-01-01

Process economy, with regard to and energy content predicts the potentialities of biogas production options. Experimental study reveal from the kinetic data of daily biogas production that biomethanation reaction is faster in thermophilic digestion, with a higher yield of gas per reactor volume per day. Energy calculations show that it will take 3.55*10 5 kWh to produce 1 m 3 of methane from our feedstock with biogas energy equivalent of 1.25 kWh. The cost implication of this is enormous amounting to US $2,641.95 for the production of 1 m 3 of methane using brewers spent grins

Covering Materials for Anaerobic Digesters Producing Biogas

International Nuclear Information System (INIS)

Itodo, I. N.; Philips, T. K.

2002-01-01

The suitability of foam, concrete and clay soil as covering material on anaerobic digesters producing biogas was investigated using four batch-type digesters of 20 litres volume. The methane yield from the digesters was of the order: foam >control> concrete > clay soil. The digester covered with foam had the highest methane yield, best temperature control and most favourable pH conditions. It is most suitable as cover material on anaerobic digesters

Metagenomic binning reveals the functional roles of core abundant microorganisms in twelve full-scale biogas plants

DEFF Research Database (Denmark)

Campanaro, Stefano; Treu, Laura; Kougias, Panagiotis

2018-01-01

and environmental factors on MAGs abundance and to investigate the methanogenic performance of the biogas plants. Prediction of the functional properties of MAGs was obtained analyzing their KEGG pathways and their carbohydrate active domains. Network analysis allowed investigation of species-species associations......The aim of this work was to elucidate the microbial ecology in twelve mesophilic and thermophilic full-scale biogas plants using a genome-centric metagenomic approach. In this study both biogas plants treating manure and those treating sludge from waste water treatment plants were considered...... and shed light on syntrophic interactions between members belonging to the anaerobic digestion dark matter (phylum Fermentibacteria). By stratifying and comparing different levels of information, it was predicted that some MAGs have a crucial role in the manure-supplemented thermophilic biogas plants...

State of the art and future perspectives of thermophilic anaerobic digestion

DEFF Research Database (Denmark)

Ahring, Birgitte Kiær; Mladenovska, Zuzana; Iranpour, R.

2002-01-01

The slate of the art of thermophilic digestion is discussed. Thermophilic digestion is a well established technology in Europe for treatment of mixtures of waste in common large scale biogas plants or for treatment of the organic fraction of municipal solid waste. Due to a large number of failures...... over time with thermophilic digestion of sewage sludge this process has lost its appeal in the USA. New demands on sanitation of biosolids before land use will, however, bring the attention back to the use of elevated temperatures during sludge stabilization. In the paper we show how the use of a start......-up strategy based on the actual activity of key microbes can be used to ensure proper and fast transfer of mesophilic digesters into thermophilic operation. Extreme thermophilic temperatures of 65degreesC or more may be necessary in the future to meet the demands for full sanitation of the waste material...

A case study for biogas generation from covered anaerobic ponds treating abattoir wastewater: Investigation of pond performance and potential biogas production

International Nuclear Information System (INIS)

McCabe, Bernadette K.; Hamawand, Ihsan; Harris, Peter; Baillie, Craig; Yusaf, Talal

2014-01-01

Highlights: • We report on the performance of a novel covered anaerobic pond system. • Potential biogas production was estimated using BioWin modelling software. • Ponds maintained stable operation; however, accumulation of crust was an issue. • Modelling indicated that biogas yield can be influenced by decomposition efficiency. • Configuration and operation of ponds can also impact potential biogas production. - Abstract: Covered anaerobic ponds offer significant advantages to the red meat processing industry by capturing methane rich gas as a fuel source for bioenergy while reducing greenhouse gas emissions (GHG). This paper presents the results of a novel-designed anaerobic pond system at an Australian abattoir in relation to pond performance and potential biogas production. Key findings in assessing the effectiveness of the system revealed that the covered ponds are capable of efficient wastewater decomposition and biogas production. The primary issue with the covered ponds at the abattoir was the build-up of fat/crust that prevented the accurate measurement of biogas and effective use of the cover. In the absence of field biogas data the novel application of the computer modelling software BioWin® was carried out to simulate chemical oxygen demand (COD) removal rates and subsequent biogas yield. The unique parameter used to fit field data was the fraction of the inlet COD due to a superficial crust which did not follow anaerobic digestion. Field data effluent COD removal rates were matched to simulated rates predicted by BioWin when measured influent COD was reduced to 30%. Biogas modelling results suggest significant variation in the economic benefit of biogas energy, with the quantity of biogas potentially varying tenfold (from 328 m 3 /d to 3284 m 3 /d) depending on site factors such as pond efficiency, pond configuration and operational practices

Anaerobic digestibility of Scenedesmus obliquus and Phaeodactylum tricornutum under mesophilic and thermophilic conditions

International Nuclear Information System (INIS)

Zamalloa, Carlos; Boon, Nico; Verstraete, Willy

2012-01-01

Highlights: ► We investigate the digestion of two algae biomasses in hybrid flow-through reactors. ► We determine the bio-methane potential of these biomasses through batch assays. ► Conversion efficiencies of 20–50% with an HRT of 2.2 days are possible. ► We valorise microalgae biomass by anaerobic digestion in a high rate reactor. -- Abstract: Two types of non-axenic algal cultures, one dominated by the freshwater microalgae Scenedesmus obliquus and the other by the marine microalgae Phaeodactylum tricornutum, were cultivated in two types of simple photobioreactor systems. The production rates, expressed on dry matter (DM) basis, were in the order of 0.12 and 0.18 g DM L −1 d −1 for S. obliquus and P. tricornutum respectively. The biogas potential of algal biomass was assessed by performing standardized batch digestion as well as digestion in a hybrid flow-through reactor (combining a sludge blanket and a carrier bed), the latter under mesophilic and thermophilic conditions. Biomethane potential assays revealed the ultimate methane yield (B 0 ) of P. tricornutum biomass to be about a factor of 1.5 higher than that of S. obliquus biomass, i.e. 0.36 and 0.24 L CH 4 g −1 volatile solids (VS) added respectively. For S. obliquus biomass, the hybrid flow-through reactor tests operated at volumetric organic loading rate (Bv) of 2.8 gVS L −1 d −1 indicated low conversion efficiencies ranging between 26–31% at a hydraulic retention time (HRT) of 2.2 days for mesophilic and thermophilic conditions respectively. When digesting P. tricornutum at a Bv of 1.9 gVS L −1 d −1 at either mesophilic or thermophilic conditions and at an HRT of 2.2 days, an overall conversion efficiency of about 50% was obtained. This work indicated that the hydrolysis of the algae cells is limiting the anaerobic processing of intensively grown S. obliquus and P. tricornutum biomass.

Progress in biogas II - Biogas production from agricultural biomass and organic residues. Pt. 1. Proceedings; Progress in Biogas II - Biogasproduktion aus landwirtschaftlicher Biomasse und organischen Reststoffen. T. 1. Tagungsband

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-08-12

production - Methabe yield and energy balance (R. Bolduan); (19) Evaluation of a pre-treatment process for improved methane production from grass silage (A. Orozco); (20) Anaerobic fungi and biogas production (J. Prochazka); (21) Preservation of sugar beets for biogas production (A. Wagner); (22) Fibre, biogas and compost from banana agro-residues (leaves, pseudostem and rachis) by anaerobic digestion in plug flow type digester (H. Chanakya); (23) Extraction of biogas from waste products of he sugarcane industry (J. Rietzler); (24) Practical experiences with the digestion of straw in 2-stage AD plants - Extension of the value chain (W. Danner); (25) Improving biogas production on wastewater treatment plants by co-digestion of grass (D. Klein); (26) Generation of algal biomass for biogas production: energetic and environmental from a Life Cycle Assessment (LCA) perspective (F. Romagnoli); (27) Risk reduction in spreading plant pathogens by anaerobic digestion? First results from laboratory experiments (M. Heiermann); (28) Demand-oriented biogas production for the generation of peak load (R. Wallmann); (29) Investigation of mesophilic and thermophilic bioleaching method in a two-phase anaerobic digestion process (M. Schoenberg): (30) Efficient hydrogen fermentation for 2-stage anaerobic digestion processes: Conversion of sucrose containing substrates (S. Noebauer); (31) Process development of two-phase pressure formation - Influence of gas solubilities (A.-M. Wonneberger); (32) Benefits and limitations when treating liquid pig manure in an anaerobic membrane bioreactor (P. Messerl); (33) Experiences with continuous high-rate thermophilic dry anaerobic digestion of energy crops (L. De Baere); (34) The Sauter-biogas-system: spraying instead of stirring (S. Sauter); (35) Biogas production from raw palm oil mill effluent using a pilot-scale anaerobic hybrid reactor (C. Wangnai); (36) Eta max - the biogas power plant with high biological efficiency (M. Niederbacher); (37) Long time

Progress in biogas II - Biogas production from agricultural biomass and organic residues. Pt. 1. Proceedings; Progress in Biogas II - Biogasproduktion aus landwirtschaftlicher Biomasse und organischen Reststoffen. T. 1. Tagungsband

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-08-12

biogas production - Methabe yield and energy balance (R. Bolduan); (19) Evaluation of a pre-treatment process for improved methane production from grass silage (A. Orozco); (20) Anaerobic fungi and biogas production (J. Prochazka); (21) Preservation of sugar beets for biogas production (A. Wagner); (22) Fibre, biogas and compost from banana agro-residues (leaves, pseudostem and rachis) by anaerobic digestion in plug flow type digester (H. Chanakya); (23) Extraction of biogas from waste products of he sugarcane industry (J. Rietzler); (24) Practical experiences with the digestion of straw in 2-stage AD plants - Extension of the value chain (W. Danner); (25) Improving biogas production on wastewater treatment plants by co-digestion of grass (D. Klein); (26) Generation of algal biomass for biogas production: energetic and environmental from a Life Cycle Assessment (LCA) perspective (F. Romagnoli); (27) Risk reduction in spreading plant pathogens by anaerobic digestion? First results from laboratory experiments (M. Heiermann); (28) Demand-oriented biogas production for the generation of peak load (R. Wallmann); (29) Investigation of mesophilic and thermophilic bioleaching method in a two-phase anaerobic digestion process (M. Schoenberg): (30) Efficient hydrogen fermentation for 2-stage anaerobic digestion processes: Conversion of sucrose containing substrates (S. Noebauer); (31) Process development of two-phase pressure formation - Influence of gas solubilities (A.-M. Wonneberger); (32) Benefits and limitations when treating liquid pig manure in an anaerobic membrane bioreactor (P. Messerl); (33) Experiences with continuous high-rate thermophilic dry anaerobic digestion of energy crops (L. De Baere); (34) The Sauter-biogas-system: spraying instead of stirring (S. Sauter); (35) Biogas production from raw palm oil mill effluent using a pilot-scale anaerobic hybrid reactor (C. Wangnai); (36) Eta max - the biogas power plant with high biological efficiency (M. Niederbacher); (37

Biogas production from anaerobic digestion of food waste and relevant air quality implications.

Science.gov (United States)

Kuo, Jeff; Dow, Jason

2017-09-01

Biopower can diversify energy supply and improve energy resiliency. Increases in biopower production from sustainable biomass can provide many economic and environmental benefits. For example, increasing biogas production through anaerobic digestion of food waste would increase the use of renewable fuels throughout California and add to its renewables portfolio. Although a biopower project will produce renewable energy, the process of producing bioenergy should harmonize with the goal of protecting public health. Meeting air emission requirements is paramount to the successful implementation of any biopower project. A case study was conducted by collecting field data from a wastewater treatment plant that employs anaerobic codigestion of fats, oils, and grease (FOG), food waste, and wastewater sludge, and also uses an internal combustion (IC) engine to generate biopower using the biogas. This research project generated scientific information on (a) quality and quantity of biogas from anaerobic codigestion of food waste and municipal wastewater sludge, (b) levels of contaminants in raw biogas that may affect beneficial uses of the biogas, (c) removal of the contaminants by the biogas conditioning systems, (d) emissions of NO x , SO 2 , CO, CO 2 , and methane, and (e) types and levels of air toxics present in the exhausts of the IC engine fueled by the biogas. The information is valuable to those who consider similar operations (i.e., co-digestion of food waste with municipal wastewater sludge and power generation using the produced biogas) and to support rulemaking decisions with regards to air quality issues for such applications. Full-scale operation of anaerobic codigestion of food waste with municipal sludge is viable, but it is still new. There is a lack of readily available scientific information on the quality of raw biogas, as well as on potential emissions from power generation using this biogas. This research developed scientific information with regard to

Performance of thermophilic anaerobic digesters using inoculum mixes with enhanced methanogenic diversity

KAUST Repository

Ghanimeh, Sophia; El-Fadel, Mutasem; Saikaly, Pascal

2017-01-01

Reportedly, various mixes of seeds were quasi-randomly selected to startup anaerobic digesters. In contrast, this study examines the impact of inoculating thermophilic anaerobic digesters with a designed mix of non-acclimated seeds based

Biotechnological application of sustainable biogas production through dry anaerobic digestion of Napier grass.

Science.gov (United States)

Dussadee, Natthawud; Ramaraj, Rameshprabu; Cheunbarn, Tapana

2017-05-01

Napier grass (Pennisetum purpureum), represents an interesting substrate for biogas production. The research project evaluated biogas potential production from dry anaerobic digestion of Napier grass using batch experiment. To enhance the biogas production from ensiled Napier grass, thermal and alkaline pre-treatments were performed in batch mode. Alkali hydrolysis of Napier grass was performed prior to batch dry anaerobic digestion at three different mild concentrations of sodium hydroxide (NaOH). The study results confirmed that NaOH pretreated sample produced high yield of biogas than untreated (raw) and hot water pretreated samples. Napier grass was used as the mono-substrate. The biogas composition of carbon dioxide (30.10%), methane (63.50%) and 5 ppm of H 2 S was estimated from the biogas. Therefore, fast-growing, high-yielding and organic matter-enriched of Napier grass was promising energy crop for biogas production.

Development of an efficient anaerobic co-digestion process for garbage, excreta, and septic tank sludge to create a resource recycling-oriented society.

Science.gov (United States)

Sun, Zhao-Yong; Liu, Kai; Tan, Li; Tang, Yue-Qin; Kida, Kenji

2017-03-01

In order to develop a resource recycling-oriented society, an efficient anaerobic co-digestion process for garbage, excreta and septic tank sludge was studied based on the quantity of each biomass waste type discharged in Ooki machi, Japan. The anaerobic digestion characteristics of garbage, excreta and 5-fold condensed septic tank sludge (hereafter called condensed sludge) were determined separately. In single-stage mesophilic digestion, the excreta with lower C/N ratios yielded lower biogas volumes and accumulated higher volumes of volatile fatty acid (VFA). On the other hand, garbage allowed for a significantly larger volatile total solid (VTS) digestion efficiency as well as biogas yield by thermophilic digestion. Thus, a two-stage anaerobic co-digestion process consisting of thermophilic liquefaction and mesophilic digestion phases was proposed. In the thermophilic liquefaction of mixed condensed sludge and household garbage (wet mass ratio of 2.2:1), a maximum VTS loading rate of 24g/L/d was achieved. In the mesophilic digestion of mixed liquefied material and excreta (wet mass ratio of 1:1), biogas yield reached approximately 570ml/g-VTS fed with a methane content of 55% at a VTS loading rate of 1.0g/L/d. The performance of the two-stage process was evaluated by comparing it with a single-stage process in which biomass wastes were treated separately. Biogas production by the two-stage process was found to increase by approximately 22.9%. These results demonstrate the effectiveness of a two-stage anaerobic co-digestion process in enhancement of biogas production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Upflow anaerobic sludge blanket-hollow centered packed bed (UASB-HCPB) reactor for thermophilic palm oil mill effluent (POME) treatment

International Nuclear Information System (INIS)

Poh, P.E.; Chong, M.F.

2014-01-01

Upflow anaerobic sludge blanket-hollow centered packed bed (UASB-HCPB) reactor was developed with the aim to minimize operational problems in the anaerobic treatment of Palm Oil Mill Effluent (POME) under thermophilic conditions. The performance of UASB-HCPB reactor on POME treatment was investigated at 55 °C. Subsequent to start-up, the performance of the UASB-HCPB reactor was evaluated in terms of i) effect of hydraulic retention time (HRT); ii) effect of organic loading rate (OLR); and iii) effect of mixed liquor volatile suspended solid (MLVSS) concentration on thermophilic POME treatment. Start-up up of the UASB-HCPB reactor was completed in 36 days, removing 88% COD and 90% BOD respectively at an OLR of 28.12 g L −1  d −1 , producing biogas with 52% of methane. Results from the performance study of the UASB-HCPB reactor on thermophilic POME treatment indicated that HRT of 2 days, OLR of 27.65 g L −1  d −1 and MLVSS concentration of 14.7 g L −1 was required to remove 90% of COD and BOD, 80% of suspended solid and at the same time produce 60% of methane. - Highlights: • UASB-HCPB was proposed for POME treatment under thermophilic conditions. • Start-up up of the UASB-HCPB reactor was completed in 36 days. • 88% COD and 90% BOD were removed at an OLR of 28.12 g COD/L.day during start-up. • HRT of 2 days and OLR of 27.65 g COD/L.day was required to produce 60% methane. • Methanosarcina sp. forms the majority of microbial population in the UASB section

Temperature-phased anaerobic digestion of food waste: A comparison with single-stage digestions based on performance and energy balance.

Science.gov (United States)

Xiao, Benyi; Qin, Yu; Zhang, Wenzhe; Wu, Jing; Qiang, Hong; Liu, Junxin; Li, Yu-You

2018-02-01

The temperature-phased anaerobic digestion (TPAD) of food waste was studied for the purpose of comparing with single-stage mesophilic and thermophilic anaerobic digestion. The biogas and methane yields in the TPAD during the steady period were 0.759 ± 0.115 L/g added VS and 0.454 ± 0.201 L/g added VS, which were lower than those in the two single-stage anaerobic digestion. The improper sludge retention time may be the reason for the lower biogas and methane production in TPAD. The removal of volatile solids in the TPAD was 78.55 ± 4.59% and the lowest among the three anaerobic digestion processes. The reaction ratios of the four anaerobic digestion steps in the TPAD were all lower than those in the two single-stage anaerobic digestion. The energy conversion efficiency of the degraded substrate in the TPAD was similar with those in single-stage mesophilic and thermophilic anaerobic digestion systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Strategies for the anaerobic digestion of the organic fraction of municipal solid waste: an overview

DEFF Research Database (Denmark)

Hartmann, H.; Ahring, Birgitte Kiær

2006-01-01

Different process strategies for anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) are reviewed weighing high-solids versus low-solids, mesophilic versus thermophilic and single-stage versus multi-stage processes. The influence of different waste characteristics...... such as composition of biodegradable fractions, C:N ratio and particle size is described. Generally, source sorting of OFMSW and a high content of food waste leads to higher biogas yields than the use of mechanically sorted OFMSW. Thermophilic processes are more efficient than mesophilic processes in terms of higher...... biogas yields at different organic loading rates (OLR). Highest biogas yields are achieved by means of wet thermophilic processes at OLRs lower than 6 kg-VS(.)m(-3) d(-1). High-solids processes appear to be relatively more efficient when OLRs higher than 6 kg-VS(.)m(-3) d(-1) are applied. Multi...

Saponification of fatty slaughterhouse wastes for enhancing anaerobic biodegradability.

Science.gov (United States)

Battimelli, Audrey; Carrère, Hélène; Delgenès, Jean-Philippe

2009-08-01

The thermochemical pretreatment by saponification of two kinds of fatty slaughterhouse waste--aeroflotation fats and flesh fats from animal carcasses--was studied in order to improve the waste's anaerobic degradation. The effect of an easily biodegradable compound, ethanol, on raw waste biodegradation was also examined. The aims of the study were to enhance the methanisation of fatty waste and also to show a link between biodegradability and bio-availability. The anaerobic digestion of raw waste, saponified waste and waste with a co-substrate was carried out in batch mode under mesophilic and thermophilic conditions. The results showed little increase in the total volume of biogas, indicating a good biodegradability of the raw wastes. Mean biogas volume reached 1200 mL/g VS which represented more than 90% of the maximal theoretical biogas potential. Raw fatty wastes were slowly biodegraded whereas pretreated wastes showed improved initial reaction kinetics, indicating a better initial bio-availability, particularly for mesophilic runs. The effects observed for raw wastes with ethanol as co-substrate depended on the process temperature: in mesophilic conditions, an initial improvement was observed whereas in thermophilic conditions a significant decrease in biodegradability was observed.

Challenges in biogas production

DEFF Research Database (Denmark)

Rennuit, Charlotte

2017-01-01

Anaerobic digestion (AnD) is a sustainable process combining waste treatment, nutrient recycling and energy production which can contribute to limit climate change and environmental problems. However, in order for this technique to be more widely used, production of biogas from available wastes...... from a mixture of pig manure and other waste materials by separating the solid fraction of digestate and recycling it back to the digester. It is shown that separation and recycling of the dry matter rich solid fraction could successfully increase biogas production and a preliminary economic evaluation...... showed a potential increase of 1.9 to 6.8€ per ton of biomass treated. In the second part of this study, a biological treatment to improve energy production from wastewater sludge was investigated. Wastewater sludge was subjected to thermophilic aerobic digestion (TAD) from 2h to 5d. Increase in biogas...

Hydrogen and methane production from desugared molasses using a two‐stage thermophilic anaerobic process

DEFF Research Database (Denmark)

Kongjan, Prawit; O-Thong, Sompong; Angelidaki, Irini

2013-01-01

Hydrogen and methane production from desugared molasses by a two‐stage thermophilic anaerobic process was investigated in a series of two up‐flow anaerobic sludge blanket (UASB) reactors. The first reactor that was dominated with hydrogen‐producing bacteria of Thermoanaerobacterium thermosaccharo......Hydrogen and methane production from desugared molasses by a two‐stage thermophilic anaerobic process was investigated in a series of two up‐flow anaerobic sludge blanket (UASB) reactors. The first reactor that was dominated with hydrogen‐producing bacteria of Thermoanaerobacterium...... molasses. Furthermore, the mixed gas with a volumetric content of 16.5% H2, 38.7% CO2, and 44.8% CH4, containing approximately 15% energy by hydrogen is viable to be bio‐hythane....

A combination anaerobic digestion scheme for biogas production from dairy effluent-CSTR and ABR, and biogas upgrading

DEFF Research Database (Denmark)

Jürgensen, Lars; Ehimen, Ehiaze Augustine; Born, Jens

2018-01-01

Anaerobic digestion of low-strength dairy waste water was used for the production of biogas which is aimed at serving as a concentrated carbon dioxide (CO2) source for further methanation. Using hydrogen (which can be produced via electrolysis using renewably sourced electricity), the CO2 fraction...... of the produced biogas can be used as a mechanism to store surplus electricity by the Sabatier process, which converts the CO2 fractions to methane (CH4), i. e. synthetic natural gas. This study investigates the use a combined reactor scheme for the anaerobic digestion of dairy waste water, and the further...

Production of Bioethanol From Lignocellulosic Biomass Using Thermophilic Anaerobic Bacteria

DEFF Research Database (Denmark)

Georgieva, Tania I.

2006-01-01

and xylose and to tolerate the inhibitory compounds present in lignocellulosic hydrolysates is therefore apparent. Several thermophilic anaerobic xylan degrading bacteria from our culture collection (EMB group at BioCentrum-DTU) have been screened for a potential ethanol producer from hemicellulose...... hydrolysates, and out of the screening test, one particular strain (A10) was selected for the best performance. The strain was morphologically and physiologically characterized as Thermoanaerobacter mathranii strain A10. Unlike other thermophilic anaerobic bacteria, the wild-type strain Thermoanaerobacter...... Thermoanaerobacter BG1L1 was further studied. The experiments were carried out in a continuous immobilized reactor system (a fluidized bed reactor), which is likely to be the process design configuration for xylose fermentation in a Danish biorefinery concept for production of fuel ethanol. The immobilization...

Enhanced biogas yield from energy crops with rumen anaerobic fungi

Czech Academy of Sciences Publication Activity Database

Procházka, J.; Mrázek, Jakub; Štrosová, Lenka; Fliegerová, Kateřina; Zábranská, J.; Dohányos, M.

2012-01-01

Roč. 12, č. 3 (2012), s. 343-351 ISSN 1618-0240 R&D Projects: GA ČR GPP503/10/P394; GA MZe QI92A286 Institutional support: RVO:67985904 Keywords : Anaerobic digestion * Anaerobic fungi * Biogas yield Subject RIV: EI - Biotechnology ; Bionics Impact factor: 1.633, year: 2012

Fast Startup of Semi-Pilot-Scale Anaerobic Digestion of Food Waste Acid Hydrolysate for Biogas Production.

Science.gov (United States)

Huang, Chao; Zhao, Cheng; Guo, Hai-Jun; Wang, Can; Luo, Mu-Tan; Xiong, Lian; Li, Hai-Long; Chen, Xue-Fang; Chen, Xin-De

2017-12-27

In this study, a fast startup of semi-pilot-scale anaerobic digestion of food waste acid hydrolysate for biogas production was carried out for the first time. During the period of fast startup, more than 85% of chemical oxygen demand (COD) can be degraded, and even more than 90% of COD can be degraded during the later stage of anaerobic digestion. During this anaerobic digestion process, the biogas yield, the methane yield, and the CH 4 content in biogas were 0.542 ± 0.056 m 3 /kg COD consumption , 0.442 ± 0.053 m 3 /kg COD consumption , and 81.52 ± 3.05%, respectively, and these values were high and stable. Besides, the fermentation pH was very stable, in which no acidification was observed during the anaerobic digestion process (outlet pH was 7.26 ± 0.05 for the whole anaerobic digestion). Overall, the startup of this anaerobic digestion can be completed in a short period (the system can be stable 2 days after the substrate was pumped into the bioreactor), and anaerobic digestion of food waste acid hydrolysate is feasible and attractive for industrial treatment of food waste and biogas production.

Anaerobic co-digestion of dairy manure and potato waste

Science.gov (United States)

Yadanaparthi, Sai Krishna Reddy

Dairy and potato are two important agricultural commodities in Idaho. Both the dairy and potato processing industries produce a huge amount of waste which could cause environmental pollution. To minimize the impact of potential pollution associated with dairy manure (DM) and potato waste (PW), anaerobic co-digestion has been considered as one of the best treatment process. The purpose of this research is to evaluate the anaerobic co-digestion of dairy manure and potato waste in terms of process stability, biogas generation, construction and operating costs, and potential revenue. For this purpose, I conducted 1) a literature review, 2) a lab study on anaerobic co-digestion of dairy manure and potato waste at three different temperature ranges (ambient (20-25°C), mesophilic (35-37°C) and thermophilic (55-57°C) with five mixing ratios (DM:PW-100:0, 90:10, 80:20, 60:40, 40:60), and 3) a financial analysis for anaerobic digesters based on assumed different capital costs and the results from the lab co-digestion study. The literature review indicates that several types of organic waste were co-digested with DM. Dairy manure is a suitable base matter for the co-digestion process in terms of digestion process stability and methane (CH4) production (Chapter 2). The lab tests showed that co-digestion of DM with PW was better than digestion of DM alone in terms of biogas and CH4 productions (Chapter 3). The financial analysis reveals DM and PW can be used as substrate for full size anaerobic digesters to generate positive cash flow within a ten year time period. Based on this research, the following conclusions and recommendations were made: ▸ The ratio of DM:PW-80:20 is recommended at thermophilic temperatures and the ratio of DM:PW-90:10 was recommended at mesophilic temperatures for optimum biogas and CH4 productions. ▸ In cases of anaerobic digesters operated with electricity generation equipment (generators), low cost plug flow digesters (capital cost of 600/cow

Mesophilic and thermophilic anaerobic digestion of primary and secondary sludge. Effect of pre-treatment at elevated temperature

DEFF Research Database (Denmark)

Gavala, Hariklia N.; Yenal, U.; Skiadas, Ioannis V.

2003-01-01

Anaerobic digestion is an appropriate technique for the treatment of sludge before final disposal and it is employed worldwide as the oldest and most important process for sludge stabilization. In general, mesophilic anaerobic digestion of sewage sludge is more widely used compared to thermophilic...... digestion. Furthermore, thermal pre-treatment is suitable for the improvement of stabilization, enhancement of dewatering of the sludge, reduction of the numbers of pathogens and could be realized at relatively low cost especially at low temperatures. The present study investigates (a) the differences...... between mesophilic and thermophilic anaerobic digestion of sludge and (b) the effect of the pretreatment at 70 degreesC on mesophilic and thermophilic anaerobic digestion of primary and secondary sludge. The pretreatment step showed very positive effect on the methane potential and production rate upon...

Performance of a sisal fibre fixed-bed anaerobic digester for biogas ...

African Journals Online (AJOL)

A single stage anaerobic digester employing a sisal fibre waste fixed bed was studied for biogas production from sisal pulp waste. The fibre was colonized by microorganisms involved in biogas production. The sisal pulp waste to be digested was fed from the top and was sprinkled intermittently with recirculating leachate ...

Azo dye reduction by mesophilic and thermophilic anaerobic consortia

NARCIS (Netherlands)

Santos, dos A.B.; Madrid, de M.P.; Stams, A.J.M.; Lier, van J.B.; Cervantes, F.J.

2005-01-01

The reduction of the azo dye model compounds Reactive Red 2 (RR2) and Reactive Orange 14 (RO14) by mesophilic (30 C) and thermophilic (55 C) anaerobic consortia was studied in batch assays. The contribution of fermentative and methanogenic microorganisms in both temperatures was evaluated in the

Potential biodiesel and biogas production from corncob by anaerobic fermentation and black soldier fly.

Science.gov (United States)

Li, Wu; Li, Qing; Zheng, Longyu; Wang, Yuanyuan; Zhang, Jibin; Yu, Ziniu; Zhang, Yanlin

2015-10-01

Bioenergy has become attractive as alternatives of gradually exhausted fossil fuel. Obtaining high grade bioenergy from lignocellulose is attractive that can gradually meet the demand. This study reported biogas and biodiesel were produced from corncob by a two-step bioprocess, biogas was produced from corncob by anaerobic fermentation, then biogas residue was converted by black soldier fly larvae, and then biodiesel was produced from larvae grease. 86.70 L biogas was obtained from 400 g corncob with the accumulation of biogas yield of 220.71 mL/g VS(added) by anaerobic digestion. Besides, 3.17 g of biodiesel was produced from grease after inoculating black soldier fly larvae into 400 g biogas residue. Meanwhile, the results showed that the addition of black soldier fly larvae could be effective for the degradation of lignocellulose and the accumulation of grease. Copyright © 2015 Elsevier Ltd. All rights reserved.

Improvement of anaerobic digestion of sludge

Energy Technology Data Exchange (ETDEWEB)

Dohanyos, Michael; Zabranska, Jana; Kutil, Josef; Jenicek, Pavel

2003-07-01

Anaerobic digestion improvement can be accomplished by different methods. Besides optimization of process conditions is frequently used pretreatment of input sludge and increase of process temperature. Thermophilic process brings a higher solids reduction and biogas production, the high resistance to foaming, no problems with odour, the higher effect of destroying pathogens and the improvement of the energy balance of the whole treatment plant. Disintegration of excess activated sludge in lysate centrifuge was proved in full-scale conditions causing increase of biogas production. The rapid thermal conditioning of digested sludge is acceptable method of particulate matter disintegration and solubilization. (author)

Mesophilic and thermophilic anaerobic digestion of sulphate-containing wastewaters.

Science.gov (United States)

Colleran, E; Pender, S

2002-01-01

The effect of sulphate at an influent chemical oxygen demand (COD):sulphate ratio of 4 on the operational performance of anaerobic hybrid reactors treating molasses wastewater was investigated under mesophilic and thermophilic conditions in a long-term laboratory-scale study over a 1,081 day period. The presence of sulphate reduced the COD removal efficiency under both mesophilic and thermophilic conditions. At 55 degrees C, effluent acetate levels were consistently greater than 4000 mg l(-1) indicating that thermophilic acetate-utilising methane-producing bacteria (MPB) or sulphate-reducing bacteria (SRB) had not developed in the reactor under the conditions applied. At 37 degrees C, acetate was exclusively utilised by acetoclastic methanogens, whereas H2-utilising SRB predominated over H2-utilising MPB in the competition for hydrogen. By contrast, hydrogenotrophic MPB were shown to outcompete H2-utilising SRB during long-term thermophilic operation. 16SrDNA analysis of the seed sludge and reactor biomass on conclusion of the 37 degrees C and 55 degrees C trials illustrated that the dominant methanogen present on conclusion of the thermophilic trial in the absence of influent sulphate was related to Methanocorpusculum parvuum, and was capable of growth on both acetate and hydrogen. By contrast, an organism closely related to Methanobacterium thermoautotrophicum was the dominant methanogen present in the sulphate-fed reactor on completion of the thermophilic trial.

Evaluation of marine algae as a source of biogas in a two-stage anaerobic reactor system

International Nuclear Information System (INIS)

Vergara-Fernandez, Alberto; Vargas, Gisela; Alarcon, Nelson; Velasco, Antonio

2008-01-01

The marine algae are considered an important biomass source; however, their utilization as energy source is still low around the world. The technical feasibility of marine algae utilization as a source of renewable energy was studied to laboratory scale. The anaerobic digestion of Macrocystis pyrifera, Durvillea antarctica and their blend 1:1 (w/w) was evaluated in a two-phase anaerobic digestion system, which consisted of an anaerobic sequencing batch reactor (ASBR) and an upflow anaerobic filter (UAF). The results show that 70% of the total biogas produced in the system was generated in the UAF, and both algae species have similar biogas productions of 180.4(±1.5) mL g -1 dry algae d -1 , with a methane concentration around 65%. The same methane content was observed in biogas yield of algae blend; however, a lower biogas yield was obtained. In conclusion, either algae species or their blend can be utilized to produce methane gas in a two-phase digestion system

Evaluation of marine algae as a source of biogas in a two-stage anaerobic reactor system

Energy Technology Data Exchange (ETDEWEB)

Vergara-Fernandez, Alberto; Vargas, Gisela [Escuela de Ingenieria Ambiental, Facultad de Ingenieria, Universidad Catolica de Temuco, Manuel Montt 56, Casilla 15-D, Temuco (Chile); Alarcon, Nelson [Departamento de Ingenieria Quimica, Facultad de Ingenieria y Ciencias Geologicas, Universidad Catolica del Norte (Chile); Velasco, Antonio [Centro Nacional de Investigacion y Capacitacion Ambiental del Instituto Nacional de Ecologia (CENICA-INE), Av. San Rafael Atlixco 186, Col. Vicentina, Del. Iztapalapa, 09340, Mexico, DF (Mexico)

2008-04-15

The marine algae are considered an important biomass source; however, their utilization as energy source is still low around the world. The technical feasibility of marine algae utilization as a source of renewable energy was studied to laboratory scale. The anaerobic digestion of Macrocystis pyrifera, Durvillea antarctica and their blend 1:1 (w/w) was evaluated in a two-phase anaerobic digestion system, which consisted of an anaerobic sequencing batch reactor (ASBR) and an upflow anaerobic filter (UAF). The results show that 70% of the total biogas produced in the system was generated in the UAF, and both algae species have similar biogas productions of 180.4({+-}1.5) mL g{sup -1} dry algae d{sup -1}, with a methane concentration around 65%. The same methane content was observed in biogas yield of algae blend; however, a lower biogas yield was obtained. In conclusion, either algae species or their blend can be utilized to produce methane gas in a two-phase digestion system. (author)

Anaerobic digestion in combination with 2nd generation ethanol production for maximizing biofuels yield from lignocellulosic biomass – testing in an integrated pilot-scale biorefinery plant

DEFF Research Database (Denmark)

Uellendahl, Hinrich; Ahring, Birgitte Kiær

An integrated biorefinery concept for 2nd generation bioethanol production together with biogas production from the fermentation effluent was tested in pilot-scale. The pilot plant comprised pretreatment, enzymatic hydrolysis, hexose and pentose fermentation into ethanol and anaerobic digestion......-VS/(m3•d) a methane yield of 340 L/kg-VS was achieved for thermophilic operation while 270 L/kg-VS was obtained under mesophilic conditions. Thermophilic operation was, however, less robust towards further increase of the loading rate and for loading rates higher than 5 kg-VS/(m3•d) the yield was higher...... for mesophilic than for thermophilic operation. The effluent from the ethanol fermentation showed no signs of toxicity to the anaerobic microorganisms. Implementation of the biogas production from the fermentation effluent accounted for about 30% higher biofuels yield in the biorefinery compared to a system...

Mass and Energy Balances of Dry Thermophilic Anaerobic Digestion Treating Swine Manure Mixed with Rice Straw.

Science.gov (United States)

Zhou, Sheng; Zhang, Jining; Zou, Guoyan; Riya, Shohei; Hosomi, Masaaki

2015-01-01

To evaluate the feasibility of swine manure treatment by a proposed Dry Thermophilic Anaerobic Digestion (DT-AD) system, we evaluated the methane yield of swine manure treated using a DT-AD method with rice straw under different C/N ratios and solid retention time (SRT) and calculated the mass and energy balances when the DT-AD system is used for swine manure treatment from a model farm with 1000 pigs and the digested residue is used for forage rice production. A traditional swine manure treatment Oxidation Ditch system was used as the study control. The results suggest that methane yield using the proposed DT-AD system increased with a higher C/N ratio and shorter SRT. Correspondently, for the DT-AD system running with SRT of 80 days, the net energy yields for all treatments were negative, due to low biogas production and high heat loss of digestion tank. However, the biogas yield increased when the SRT was shortened to 40 days, and the generated energy was greater than consumed energy when C/N ratio was 20 : 1 and 30 : 1. The results suggest that with the correct optimization of C/N ratio and SRT, the proposed DT-AD system, followed by using digestate for forage rice production, can attain energy self-sufficiency.

Ability of industrial anaerobic ecosystems to produce methane from ethanol in psychrophilic, mesophilic and thermophilic conditions

International Nuclear Information System (INIS)

Mabala, Jojo Charlie

2012-01-01

The process of anaerobic degradation of organic matter is a natural phenomenon widespread in many ecosystems (eg, marshes, lakes, rice fields, digestive systems of animals and humans). A high microbial diversity is maintained during this process, reflecting a diversity of metabolic pathways involved. When complete, the anaerobic digestion results in the formation of biogas (mixture of methane and carbon dioxide). In terms of biotechnology, anaerobic treatment of organic pollution reduces the volume of waste and generates energy as methane recoverable in several forms (electricity, heat, natural gas, biofuels). Industrial digesters are mostly operated at 35 deg. C or 55 deg. C which requires exogenous energy. The objective of the thesis is to study the adaptability of ecosystems sourced from anaerobic industrial scale reactors treating different range of wastes from different processes to convert ethanol into biogas at various temperatures. The first phase of the study was to adapt, in laboratory reactors ecosystems to their original temperature with a readily biodegradable substrate (ethanol). Then, the performances of microbial communities (the maximum methanogenic potential and degradation kinetics) were estimated on a temperature gradient from 5 deg. C to 55 deg. C in batch reactors. The adaptation phase of the ecosystems in lab-scale reactors showed that the biogas averaged theoretical production and this production was followed by a decrease in reaction time with successive addition of the substrate. In addition, the kinetics of the biogas obtained varied greatly from one ecosystem to another. Molecular fingerprinting profiles (CE-SSCP) of bacterial and archaeal communities were performed at the beginning and at the end of conditioning. These community profiles were compared with each other by principal component analysis (PCA). Bacterial populations that ensured efficient performance were different from those that ensured a good adaptability. In addition, the

In situ identification of the synthrophic protein fermentative Coprothermobacter spp. involved in the thermophilic anaerobic digestion process.

Science.gov (United States)

Gagliano, Maria Cristina; Braguglia, Camilla Maria; Rossetti, Simona

2014-09-01

Thermophilic bacteria have recently attracted great attention because of their potential application in improving different biochemical processes such as anaerobic digestion of various substrates, wastewater treatment or hydrogen production. In this study we report on the design of a specific 16S rRNA-targeted oligonucleotide probe for detecting members of Coprothermobacter genus characterized by a strong protease activity to degrade proteins and peptides. The newly designed CTH485 probe and helper probes hCTH429 and hCTH439 were optimized for use in fluorescence in situ hybridization (FISH) on thermophilic anaerobic sludge samples. In situ probing revealed that thermo-adaptive mechanisms shaping the 16S rRNA gene may affect the identification of thermophilic microorganisms. The novel developed FISH probe extends the possibility to study the widespread thermophilic syntrophic interaction of Coprothermobacter spp. with hydrogenotrophic methanogenic archaea, whose establishment is a great benefit for the whole anaerobic system. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Probing the redox metabolism in the strictly anaerobic, extremely thermophilic, hydrogen-producing Caldicellulosiruptor saccharolyticus using amperometry

DEFF Research Database (Denmark)

Kostesha, Natalie; Willquist, Karin; Emnéus, Jenny

2011-01-01

Changes in the redox metabolism in the anaerobic, extremely thermophilic, hydrogen-forming bacterium Caldicellulosiruptor saccharolyticus were probed for the first time in vivo using mediated amperometry with ferricyanide as a thermotolerant external mediator. Clear differences in the intracellul...... in the intracellular electron flow and to probe redox enzyme properties of a strictly anaerobic thermophile in vivo.......Changes in the redox metabolism in the anaerobic, extremely thermophilic, hydrogen-forming bacterium Caldicellulosiruptor saccharolyticus were probed for the first time in vivo using mediated amperometry with ferricyanide as a thermotolerant external mediator. Clear differences in the intracellular...... the NADH-dependent lactate dehydrogenase, upon which more NADH was directed to membrane-associated enzymes for ferricyanide reduction, leading to a higher electrochemical signal. The method is noninvasive and the results presented here demonstrate that this method can be used to accurately detect changes...

Biogas production from brewery spent grain enhanced by bioaugmentation with hydrolytic anaerobic bacteria.

Science.gov (United States)

Čater, Maša; Fanedl, Lijana; Malovrh, Špela; Marinšek Logar, Romana

2015-06-01

Lignocellulosic substrates are widely available but not easily applied in biogas production due to their poor anaerobic degradation. The effect of bioaugmentation by anaerobic hydrolytic bacteria on biogas production was determined by the biochemical methane potential assay. Microbial biomass from full scale upflow anaerobic sludge blanket reactor treating brewery wastewater was a source of active microorganisms and brewery spent grain a model lignocellulosic substrate. Ruminococcus flavefaciens 007C, Pseudobutyrivibrio xylanivorans Mz5(T), Fibrobacter succinogenes S85 and Clostridium cellulovorans as pure and mixed cultures were used to enhance the lignocellulose degradation and elevate the biogas production. P. xylanivorans Mz5(T) was the most successful in elevating methane production (+17.8%), followed by the coculture of P. xylanivorans Mz5(T) and F. succinogenes S85 (+6.9%) and the coculture of C. cellulovorans and F. succinogenes S85 (+4.9%). Changes in microbial community structure were detected by fingerprinting techniques. Copyright © 2015 Elsevier Ltd. All rights reserved.

Design of A solar Thermophilic Anaerobic Reactor for Small Farms

NARCIS (Netherlands)

Mashad, El H.; Loon, van W.K.P.; Zeeman, G.; Bot, G.P.A.; Lettinga, G.

2004-01-01

A 10 m(3) completely stirred tank reactor has been designed for anaerobic treatment of liquid cow manure under thermophilic conditions (50degreesC), using a solar heating system mounted on the reactor roof. Simulation models for two systems have been developed. The first system consists of loose

Autogenerative high pressure digestion: anaerobic digestion and biogas upgrading in a single step reactor system

NARCIS (Netherlands)

Lindeboom, R.E.F.; Fermoso, F.G.; Weijma, J.; Zagt, K.; Lier, van J.B.

2011-01-01

Conventional anaerobic digestion is a widely applied technology to produce biogas from organic wastes and residues. The biogas calorific value depends on the CH4 content which generally ranges between 55 and 65%. Biogas upgrading to so-called ‘green gas’, with natural gas quality, generally proceeds

The production of anaerobic bacteria and biogas from dairy cattle waste in various growth mediums

Science.gov (United States)

Hidayati, Y. A.; Kurnani, T. B. A.; Marlina, E. T.; Rahmah, K. N.; Harlia, E.; Joni, I. M.

2018-02-01

The growth of anaerobic bacteria except the ruminal fluid quailty is strongly influenced by the media formulations. Previous researchers have set a standard media formulation for anaerobic bacteria from rumen, however the use of standard media formulations require chemicals with high cost. Moreover, other constraint of using standard media formulations is requires large quantities of media for anaerobic bacteria to grow. Therefore, it is necessary to find media with a new culture media formulation. Media used in this research were minimalist media consist of Nutrient Agar (NA), Lactose broth and rumen fluid; enriched media Rumen Fluid-Glucose-Agar (RGCA); and enriched media 98-5. The dairy cattle waste is utilized as source of anaerobic bacteria. The obtained data was analyzed by descriptive approach. The results showed that minimalist media produced anaerobic bacteria 2148 × 104 cfu/ml and biogas production: 1.06% CH4, 9.893% CO2; enriched media Rumen Fluid-Glucose-Agar (RGCA) produced anaerobic bacteria 1848 × 104 cfu/ml and biogas production 4.644% CH4, 9.5356% CO2; enriched media 98-5 produced anaerobic bacteria growth 15400 × 104 cfu/ml and biogas production 0.83% of CH4, 42.2% of CO2. It is conclude that the minimalist media was showed the best performance for the dairy cattle waste as source of anaerobic bacteria.

Biogas generation in anaerobic wastewater treatment under tetracycline antibiotic pressure

Science.gov (United States)

Lu, Meiqing; Niu, Xiaojun; Liu, Wei; Zhang, Jun; Wang, Jie; Yang, Jia; Wang, Wenqi; Yang, Zhiquan

2016-01-01

The effect of tetracycline (TC) antibiotic on biogas generation in anaerobic wastewater treatment was studied. A lab-scale Anaerobic Baffled Reactor (ABR) with three compartments was used. The reactor was operated with synthetic wastewater in the absence of TC and in the presence of 250 μg/L TC for 90 days, respectively. The removal rate of TC, volatile fatty acids (VFAs), biogas compositions (hydrogen (H2), methane (CH4), carbon dioxide (CO2)), and total biogas production in each compartment were monitored in the two operational conditions. Results showed that the removal rate of TC was 14.97–67.97% in the reactor. The presence of TC had a large negative effect on CH4 and CO2 generation, but appeared to have a positive effect on H2 production and VFAs accumulation. This response indicated that the methanogenesis process was sensitive to TC presence, but the acidogenesis process was insensitive. This suggested that the presence of TC had less influence on the degradation of organic matter but had a strong influence on biogas generation. Additionally, the decrease of CH4 and CO2 generation and the increase of H2 and VFAs accumulation suggest a promising strategy to help alleviate global warming and improve resource recovery in an environmentally friendly approach. PMID:27341657

Effect of temperature on methanogenesis stage of two-stage anaerobic digestion of palm oil mill effluent (POME) into biogas

Science.gov (United States)

Trisakti, B.; Irvan, Mahdalena; Taslim; Turmuzi, M.

2017-06-01

This study aimed to determine the effect of temperature on methanogenesis stage of conversion of palm oil mill effluent into biogas. Methanogenesis is the second stage of methanogenic anaerobic digestion. Improved performance of the methanogenesis process was determined by measuring the growth of microorganisms, degradation of organic materials, biogas production and composition. Initially, the suitable loading up was determined by varying the HRT 100, 40, 6, and 4.0 days in the continuous stirred tank reactor (CSTR) with mixing rate 100 rpm, pH 6.7-7.5 at room temperature. Next, effect of temperature on the process was determined by varying temperature at mesophilic range (30-42°C) and thermophilic range (43-55°C). Analysis of total solids (TS), volatile solids (VS), total suspended solids (TSS), volatile suspended solids (VSS), and chemical oxygen demand (COD) were conducted in order to study the growth of microorganisms and their abilities in converting organic compound to produce biogas. Degradation of organic content i.e. VS decomposition and COD removal increased with the increasing of temperature. At mesophilic range, VS decomposition and COD removal were 51.56 ± 8.30 and 79.82 ± 6.03, respectively. Meanwhile at thermopilic range, VS decomposition and COD removal were 67.44 ± 3.59 and 79.16 ± 1.75, respectively. Biogas production and its methane content also increased with the increasing of temperature, but CO2 content also increased. Biogas production at mesophilic range was 31.77 ± 3.46 L/kg-ΔVS and methane content was 75 . Meanwhile, biogas production at thermopilic range was 37.03 ± 5.16 L/kg-ΔVS and methane content was 62.25 ± 5.50 .

Cellulosic ethanol production via consolidated bioprocessing by a novel thermophilic anaerobic bacterium isolated from a Himalayan hot spring.

Science.gov (United States)

Singh, Nisha; Mathur, Anshu S; Tuli, Deepak K; Gupta, Ravi P; Barrow, Colin J; Puri, Munish

2017-01-01

Cellulose-degrading thermophilic anaerobic bacterium as a suitable host for consolidated bioprocessing (CBP) has been proposed as an economically suited platform for the production of second-generation biofuels. To recognize the overall objective of CBP, fermentation using co-culture of different cellulolytic and sugar-fermenting thermophilic anaerobic bacteria has been widely studied as an approach to achieving improved ethanol production. We assessed monoculture and co-culture fermentation of novel thermophilic anaerobic bacterium for ethanol production from real substrates under controlled conditions. In this study, Clostridium sp. DBT-IOC-C19, a cellulose-degrading thermophilic anaerobic bacterium, was isolated from the cellulolytic enrichment cultures obtained from a Himalayan hot spring. Strain DBT-IOC-C19 exhibited a broad substrate spectrum and presented single-step conversion of various cellulosic and hemicellulosic substrates to ethanol, acetate, and lactate with ethanol being the major fermentation product. Additionally, the effect of varying cellulose concentrations on the fermentation performance of the strain was studied, indicating a maximum cellulose utilization ability of 10 g L -1 cellulose. Avicel degradation kinetics of the strain DBT-IOC-C19 displayed 94.6% degradation at 5 g L -1 and 82.74% degradation at 10 g L -1 avicel concentration within 96 h of fermentation. In a comparative study with Clostridium thermocellum DSM 1313, the ethanol and total product concentrations were higher by the newly isolated strain on pretreated rice straw at an equivalent substrate loading. Three different co-culture combinations were used on various substrates that presented two-fold yield improvement than the monoculture during batch fermentation. This study demonstrated the direct fermentation ability of the novel thermophilic anaerobic bacteria on various cellulosic and hemicellulosic substrates into ethanol without the aid of any exogenous enzymes

Previously unclassified bacteria dominate during thermophilic and mesophilic anaerobic pre-treatment of primary sludge.

Science.gov (United States)

Pervin, Hasina M; Batstone, Damien J; Bond, Philip L

2013-06-01

Thermophilic biological pre-treatment enables enhanced anaerobic digestion for treatment of wastewater sludges but, at present, there is limited understanding of the hydrolytic-acidogenic microbial composition and its contribution to this process. In this study, the process was assessed by comparing the microbiology of thermophilic (50-65 °C) and mesophilic (35 °C) pre-treatment reactors treating primary sludge. A full-cycle approach for the 16S rRNA genes was applied in order to monitor the diversity of bacteria and their abundance in a thermophilic pre-treatment reactor treating primary sludge. For the thermophilic pre-treatment (TP), over 90% of the sequences were previously undetected and these had less than 97% sequence similarity to cultured organisms. During the first 83 days, members of the Betaproteobacteria dominated the community sequences and a newly designed probe was used to monitor a previously unknown bacterium affiliated with the genus Brachymonas. Between days 85 and 183, three phylotypes that affiliated with the genera Comamonas, Clostridium and Lysobacter were persistently dominant in the TP community, as revealed by terminal-restriction fragment length polymorphism (T-RFLP). Hydrolytic and fermentative functions have been speculated for these bacteria. Mesophilic pre-treatment (MP) and TP communities were different but they were both relatively dynamic. Statistical correlation analysis and the function of closely allied reference organisms indicated that previously unclassified bacteria dominated the TP community and may have been functionally involved in the enhanced hydrolytic performance of thermophilic anaerobic pre-treatment. This study is the first to reveal the diversity and dynamics of bacteria during anaerobic digestion of primary sludge. Copyright © 2013 Elsevier GmbH. All rights reserved.

Thermophilic anaerobic co-digestion of poultry litter and thin stillage.

Science.gov (United States)

Sharma, Deepak; Espinosa-Solares, Teodoro; Huber, David H

2013-05-01

The purpose of this study was to test whether the performance of a thermophilic CSTR digester that has been stabilized on poultry litter will be enhanced or diminished by the addition of thin stillage as co-substrate. Replicate laboratory digesters, derived from a stable pilot-scale digester, were operated with increasing ratios (w/w) of thin stillage/poultry litter feedstock. After a period of adaptation to 20% and 40% thin stillage, digester performance showed increases in biogas, percent methane and COD removal, as well as a decrease in volatile acids. Peak performance occurred with 60% thin stillage. However, 80% thin stillage caused significant reduction of performance, including declines of methanogenic activity and COD removal. In conclusion, supplementing the thermophilic digestion of poultry litter with thin stillage improved the bioenergy (methane) output, but thin stillage became inhibitory at high concentrations. Copyright © 2013 Elsevier Ltd. All rights reserved.

Methanomethylovorans thermophila sp. nov., a thermophilic, methylotrophic methanogen form an anaerobic reactor fed with methanol

NARCIS (Netherlands)

Jiang, B.; Parshina, S.N.; Doesburg, van W.C.J.; Lomans, B.P.; Stams, A.J.M.

2005-01-01

A novel thermophilic, obligately methylotrophic, methanogenic archaeon, strain L2FAWT, was isolated from a thermophilic laboratory-scale upflow anaerobic sludge blanket reactor fed with methanol as the carbon and energy source. Cells of strain L2FAWT were non-motile, irregular cocci, 0·7¿1·5 µm in

Biogas Production from Rice Husk Waste by using Solid State Anaerobic Digestion (SSAD) Method

Science.gov (United States)

Matin, Hashfi Hawali Abdul; Hadiyanto

2018-02-01

An effort to obtain alternative energy is still interesting subject to be studied, especially production of biogas from agriculture waste. This paper was an overview of the latest development of biogas researches from rice husk waste by Solid State Anaerobic Digestion (SSAD). The main obstacle of biogas production from rice husk waste was the lignin content which is very difficult degraded by microbes. Various pretreatments have been conducted, either physically, chemically as well as biologically. The SSAD method was an attractive option because of the low water content of rice husk waste. The biogas yield by SSAD method gave more attractive result compared to Liquid Anaerobic Digestion (LAD) method. Various studies were still conducted in batch mode laboratory scale and also has not found optimum operating conditions. Research on a larger scale such as bench and pilot scale with continuous systems will be an increase trend in the future research.

Utilization of biogas produced by anaerobic digestion of agro-industrial waste: Energy, economic and environmental effects.

Science.gov (United States)

Hublin, Andrea; Schneider, Daniel Rolph; Džodan, Janko

2014-07-01

Anaerobic digestion of agro-industrial waste is of significant interest in order to facilitate a sustainable development of energy supply. Using of material and energy potentials of agro-industrial waste, in the framework of technical, economic, and ecological possibilities, contributes in increasing the share of energy generated from renewable energy sources. The paper deals with the benefits arising from the utilization of biogas produced by co-digestion of whey and cow manure. The advantages of this process are the profitability of the plant and the convenience in realizing an anaerobic digestion plant to produce biogas that is enabled by the benefits from the sale of electric energy at favorable prices. Economic aspects are related to the capital cost (€ 2,250,000) of anaerobic digestion treatment in a biogas plant with a 300 kW power and 510 kW heating unit in a medium size farm (450 livestock units). Considering the optimum biogas yield of 20.7 dm(3) kg(-1) of wet substrate and methane content in the biogas obtained of 79%, the anaerobic process results in a daily methane production of 2,500 kg, with the maximum power generation of 2,160,000 kWh y(-1) and heat generation of 2,400,000 kWh y(-1) The net present value (NPV), internal rate of return (IRR) and payback period for implementation of profitable anaerobic digestion process is evaluated. Ecological aspects related to carbon dioxide (CO2) and methane (CH4) emission reduction are assessed. © The Author(s) 2014.

Programmed iron oxide nanoparticles disintegration in anaerobic digesters boosts biogas production.

Science.gov (United States)

Casals, Eudald; Barrena, Raquel; García, Ana; González, Edgar; Delgado, Lucía; Busquets-Fité, Martí; Font, Xavier; Arbiol, Jordi; Glatzel, Pieter; Kvashnina, Kristina; Sánchez, Antoni; Puntes, Víctor

2014-07-23

A novel concept of dosing iron ions using Fe3O4 engineered nanoparticles is used to improve biogas production in anaerobic digestion processes. Since small nanoparticles are unstable, they can be designed to provide ions in a controlled manner, and the highest ever reported improvement of biogas production is obtained. The nanoparticles evolution during operation is followed by an array of spectroscopic techniques. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of biogas production by dry anaerobic digestion of switchgrass-animal manure mixtures

Science.gov (United States)

Anaerobic digestion is a biological method used to convert organic wastes into a stable product for land application without adverse environmental effects. The biogas produced can be used as an alternative renewable energy source. Dry anaerobic digestion (> 15% TS; total solid) has an advantage ov...

Experimental biogas research by anaerobic digestion of waste of ...

African Journals Online (AJOL)

Currently, one of the most efficient and prospective methods of biodegradable waste management is anaerobic digestion in a bio-reactor. The use of this method for managing biodegradable waste generating in agriculture and elsewhere would result in the recovery of biogas that could be used as an alternative to natural ...

Moorella stamsii sp. nov., a new anaerobic thermophilic hydrogenogenic carboxydotroph isolated from digester sludge

NARCIS (Netherlands)

Alves, J.I.; Gelder, van A.H.; Alves, M.M.; Sousa, D.Z.; Plugge, C.M.

2013-01-01

A novel anaerobic, thermophilic, carbon monoxide-utilizing bacterium, strain E3-O, was isolated from anaerobic sludge of a municipal solid waste digester. Cells were straight rods, 0.6 to 1µm in diameter and 2 to 3 µm in length, growing as single cells or in pairs. Cells formed round terminal

Effects of shearing on biogas production and microbial community structure during anaerobic digestion with recuperative thickening.

Science.gov (United States)

Yang, Shufan; Phan, Hop V; Bustamante, Heriberto; Guo, Wenshan; Ngo, Hao H; Nghiem, Long D

2017-06-01

Recuperative thickening can intensify anaerobic digestion to produce more biogas and potentially reduce biosolids odour. This study elucidates the effects of sludge shearing during the thickening process on the microbial community structure and its effect on biogas production. Medium shearing resulted in approximately 15% increase in biogas production. By contrast, excessive or high shearing led to a marked decrease in biogas production, possibly due to sludge disintegration and cell lysis. Microbial analysis using 16S rRNA gene amplicon sequencing showed that medium shearing increased the evenness and diversity of the microbial community in the anaerobic digester, which is consistent with the observed improved biogas production. By contrast, microbial diversity decreased under either excessive shearing or high shearing condition. In good agreement with the observed decrease in biogas production, the abundance of Bacteroidales and Syntrophobaterales (which are responsible for hydrolysis and acetogenesis) decreased due to high shearing during recuperative thickening. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Start-up strategies for thermophilic anaerobic digestion of pig manure

International Nuclear Information System (INIS)

Moset, V.; Bertolini, E.; Cerisuelo, A.; Cambra, M.; Olmos, A.; Cambra-López, M.

2014-01-01

Sludge physicochemical composition, methane (CH 4 ) yield, and methanogenic community structure and dynamics using quantitative real-time polymerase chain reaction were determined after start-up of anaerobic digestion of pig manure. Eight thermophilic continuous stirred anaerobic digesters were used during 126 days. Four management strategies were investigated: a feedless and a non-feedless period followed by a gradual or an abrupt addition of pig manure (two digesters per strategy). During the first 43 days, VFA (volatile fatty acids) accumulations and low CH 4 yield were observed in all digesters. After this period, digesters recovered their initial status being propionic acid the last parameter to be re-established. Non-feedless digesters with an abrupt addition of pig manure showed the best performances (lower VFA accumulation and higher CH 4 yield). Differences in microbial orders and dynamics, however, were less evident among treatments. Hydrogenotrophic methanogenesis, Methanomicrobiales first and Methanobacteriales second, was the dominant metabolic pathway in all digesters. Further research is needed to clarify the role and activity of hydrogenotrophic methanogens during the recovery start-up period and to identify the best molecular tools and methodologies to monitor microbial populations and dynamics reliably and accurately in anaerobic digesters. - Highlights: • Four start-up strategies for thermophilic anaerobic digestion of pig manure were tested. • Physicochemical composition, methane yield and methanogenic community were determined. • During the first 43 days, a decline in reactor's performance occurred. • The best start-up strategy was non-feedless with an abrupt addition of pig slurry. • Hydrogenotrophic methanogenesis was the dominant metabolic pathway

A new multiple-stage electrocoagulation process on anaerobic digestion effluent to simultaneously reclaim water and clean up biogas.

Science.gov (United States)

Liu, Zhiguo; Stromberg, David; Liu, Xuming; Liao, Wei; Liu, Yan

2015-03-21

A new multiple-stage treatment process was developed via integrating electrocoagulation with biogas pumping to simultaneously reclaim anaerobic digestion effluent and clean up biogas. The 1st stage of electrocoagulation treatment under the preferred reaction condition led to removal efficiencies of 30%, 81%, 37% and >99.9% for total solids, chemical oxygen demand, total nitrogen and total phosphorus, respectively. Raw biogas was then used as a reactant and pumped into the effluent to simultaneously neutralize pH of the effluent and remove H2S in the biogas. The 2nd stage of electrocoagulation treatment on the neutralized effluent showed that under the selected reaction condition, additional 60% and 10% of turbidity and chemical oxygen demand were further removed. The study concluded a dual-purpose approach for the first time to synergistically combine biogas purification and water reclamation for anaerobic digestion system, which well addresses the downstream challenges of anaerobic digestion technology. Copyright © 2014 Elsevier B.V. All rights reserved.

Demand-driven biogas production from sugar beet silage in a novel fixed bed disc reactor under mesophilic and thermophilic conditions.

Science.gov (United States)

Terboven, Christiane; Ramm, Patrice; Herrmann, Christiane

2017-10-01

A newly developed fixed bed disc reactor (FBDR) which combines biofilm formation on biofilm carriers and reactor agitation in one single system was assessed for its applicability to demand-driven biogas production by variable feeding of sugar beet silage. Five different feeding patterns were studied at an organic loading of 4g VS L -1 d -1 under mesophilic and thermophilic conditions. High methane yields of 449-462L N kg VS were reached. Feeding variable punctual loadings caused immediate response with 1.2- to 3.5-fold increase in biogas production rates within 15min. Although variable feeding did not induce process instability, a temporary decrease in pH-value and methane concentration below 40% occurred. Thermophilic temperature was advantageous as it resulted in a more rapid, higher methane production and less pronounced decrease in methane content after feeding. The FBDR was demonstrated to be well-suited for flexible biogas production, but further research and comparison with traditional reactor systems are required. Copyright © 2017 Elsevier Ltd. All rights reserved.

Gelria glutamica gen. nov., sp. a thermophilic oligately syntrophic glutamate-degrading anaerobe

NARCIS (Netherlands)

Plugge, C.M.; Balk, M.; Zoetendal, E.G.; Stams, A.J.M.

2002-01-01

A novel anaerobic, Gram-positive, thermophilic, spore-forming, obligately syntrophic, glutamate-degrading bacterium, strain TGO(T), was isolated from a propionate-oxidizing methanogenic enrichment culture. The axenic culture was obtained by growing the bacterium on pyruvate. Cells were rod-shaped

Biogas final digestive byproduct applied to croplands as fertilizer contains high levels of steroid hormones

International Nuclear Information System (INIS)

Rodriguez-Navas, Carlos; Björklund, Erland; Halling-Sørensen, Bent; Hansen, Martin

2013-01-01

In this study we evaluate and demonstrate the occurrence of nine natural and one synthetic steroid hormone, including estrogens, androgens and progestagens in biogas final digestate byproduct (digestion liquid) commonly used as an agricultural fertilizer. We investigated two biogas sites that utilize different anaerobic digestion technologies (mesophilic and thermophilic) from swine manure and other organic wastes. Individual hormone concentration levels were observed up to 1478 ng g −1 dry weight or 22.5 mg kg −1 N with estrone and progesterone reaching highest concentration levels. Evaluation of the potential environmental burden through the application in agriculture was also assessed on the basis of predicted environmental concentrations. This study indicates that the biogas digestion process does not completely remove steroid hormones from livestock manure and use of final digestate byproduct on croplands contributes to the environmental emission of hormones. -- Eight steroid hormones were found in biogas digestate byproduct in the ng g −1 dm levels. Anaerobic digestion processes do not completely remove steroid hormones from organic waste residues

Biogas Production from Rice Husk Waste by using Solid State Anaerobic Digestion (SSAD Method

Directory of Open Access Journals (Sweden)

Hawali Abdul Matin Hashfi

2018-01-01

Full Text Available An effort to obtain alternative energy is still interesting subject to be studied, especially production of biogas from agriculture waste. This paper was an overview of the latest development of biogas researches from rice husk waste by Solid State Anaerobic Digestion (SSAD. The main obstacle of biogas production from rice husk waste was the lignin content which is very difficult degraded by microbes. Various pretreatments have been conducted, either physically, chemically as well as biologically. The SSAD method was an attractive option because of the low water content of rice husk waste. The biogas yield by SSAD method gave more attractive result compared to Liquid Anaerobic Digestion (LAD method. Various studies were still conducted in batch mode laboratory scale and also has not found optimum operating conditions. Research on a larger scale such as bench and pilot scale with continuous systems will be an increase trend in the future research.

Biological conversion of biogas to methanol using methanotrophs isolated from solid-state anaerobic digestate.

Science.gov (United States)

Sheets, Johnathon P; Ge, Xumeng; Li, Yueh-Fen; Yu, Zhongtang; Li, Yebo

2016-02-01

The aim of this work was to isolate methanotrophs (methane oxidizing bacteria) that can directly convert biogas produced at a commercial anaerobic digestion (AD) facility to methanol. A methanotrophic bacterium was isolated from solid-state anaerobic digestate. The isolate had characteristics comparable to obligate methanotrophs from the genus Methylocaldum. This newly isolated methanotroph grew on biogas or purified CH4 and successfully converted biogas from AD to methanol. Methanol production was achieved using several methanol dehydrogenase (MDH) inhibitors and formate as an electron donor. The isolate also produced methanol using phosphate with no electron donor or using formate with no MDH inhibitor. The maximum methanol concentration (0.43±0.00gL(-1)) and 48-h CH4 to methanol conversion (25.5±1.1%) were achieved using biogas as substrate and a growth medium containing 50mM phosphate and 80mM formate. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biogas Production from Brewer’s Yeast Using an Anaerobic Sequencing Batch Reactor

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Gregor Drago Zupančič

2017-01-01

Full Text Available Renewable energy sources are becoming increasingly important in the beverage and food industries. In the brewing industry, a significant percentage of the used raw materials finishes the process as secondary resource or waste. The research on the anaerobic digestion of brewer’s yeast has been scarce until recent years. One of the reasons for this is its use as a secondary resource in the food industry and as cattle feed. Additionally, market value of brewer’s yeast is higher than its energy value. Due to the increase of energy prices, brewer’s yeast has become of interest as energy substrate despite its difficult degradability in anaerobic conditions. The anaerobic co-digestion of brewer’s yeast and anaerobically treated brewery wastewater was studied using a pilot-scale anaerobic sequencing batch reactor (ASBR seeded with granular biomass. The experiments showed very good and stable operation with an organic loading rate of up to 8.0 kg/(m3·day, and with a maximum achieved organic loading rate of 13.6 kg/(m3·day in a single cycle. A specific biogas productivity of over 0.430 m3/kg of the total chemical oxygen demand (COD inserted, and total COD removal efficiencies of over 90 % were achieved. This study suggests that the brewer’s yeast can be successfully digested in an ASBR without adverse effects on the biogas production from brewer’s yeast/wastewater mixtures of up to 8 % (by volume. By using the brewer’s yeast in the ASBR process, the biogas production from brewery wastewater could be increased by 50 %.

Startup and stability of thermophilic anaerobic digestion of OFMSW

KAUST Repository

El-Fadel, Mutasem E.; Saikaly, Pascal; Ghanimeh, Sophia A.

2013-01-01

Anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW) is promoted as an energy source and more recently as a greenhouse gas (GHG) mitigation measure. In this context, AD systems operating at thermophilic temperatures (55-60°C)-compared to mesophilic temperatures (35-40°C)-have the unique feature of producing hygienic soil conditioners with greater process efficiency, higher energy yield, and more GHG savings. Startup of AD systems is often constrained by the lack of acclimated seeds, leading to process instability and failure. The authors focus on strategies to startup thermophilic digesters treating OFMSW in the absence of acclimated seeds and examines constraints associated with process stability and ways to overcome them. Relevant gaps in the literature and future research needs are delineated. © 2013 Taylor & Francis Group, LLC.

Bioactivity test and GRW biogas yield test. Methods for optimizing biogas plants for anaerobic digestion of biowaste; Rostocker Aktivitaets- und GRW-Biogasertragstest. Einsatz zur Optimierung von Abfallvergaerungsanlagen

Energy Technology Data Exchange (ETDEWEB)

Engler, Nils [Rostock Univ. (Germany). Lehrstuhl Abfall- und Soffstromwirtschaft; Schiffner, Maik [Rostock Univ. (Germany). Forschungsvorhaben ' ' Bilanzierung von Stoff- und Energiestroemen' ' ; Nelles, Michael [Rostock Univ. (Germany). Lehrstuhl Abfall- und Soffstromwirtschaft; Rostock Univ. (Germany). Inst. fuer Umweltingenieurwesen; Fritz, Thomas

2010-03-15

Anaerobic digestion to obtain biogas is one option for energetic use of biodegradable waste. Data as e. g. the expected biogas yield, the biogas composition or inhibition effects are essentially to estimate the potentials and risks of the use of biowaste in commercial bio gas plants. To deliver such data, several test methods were developed. The GRW biogas yield test was first applied at the university of applied science in Goettingen and enhanced in cooperation with the University of Rostock. The test is particularly suitable for inhomogeneous samples as e. g. biowaste. The Bioactivity Test is still under development. First results have shown that the test can be applied for the detection of potentially inhibition effects. Combination of both Tests can deliver data for optimizing biogas plants for anaerobic digestion of biowaste (orig.)

Biogas energy production from tropical biomass wastes by anaerobic digestion

Science.gov (United States)

Anaerobic digestion (AD) is an attractive technology in tropical regions for converting locally abundant biomass wastes into biogas which can be used to produce heat, electricity, and transportation fuels. However, investigations on AD of tropical forestry wastes, such as albizia biomass, and food w...

COMPARISON OF TWO CHEMICAL PRETREATMENTS OF RICE STRAW FOR BIOGAS PRODUCTION BY ANAEROBIC DIGESTION

Directory of Open Access Journals (Sweden)

Zilin Song,

2012-06-01

Full Text Available Lignocellulosic biomass is considered the most abundant renewable resource that has the potential to contribute remarkably in the supply of biofuel. Previous studies have shown that chemical pretreatment prior to anaerobic digestion (AD can increase the digestibility of lignocellulosic biomass and methane yield. In the present study, the effect of rice straw pretreatment using ammonium hydroxide (NH3•H2O and hydrogen peroxide (H2O2 on the biogasification performance through AD was investigated. A self-designed, laboratory-scale, and continuous anaerobic biogas digester was used for the evaluation. Results showed that the contents of the rice straw, i.e. the lignin, cellulose, and hemicellulose were degraded significantly after the NH3•H2O and H2O2 treatments, and that biogas production from all pretreated rice straw increased. In addition, the optimal treatments for biogas production were the 4% and 3% H2O2 treatments (w/w, which yielded 327.5 and 319.7 mL/gVS, biogas, respectively, higher than the untreated sample. Biogas production from H2O2 pretreated rice straw was more favorable than rice straw pretreated with same concentration of ammonia, ranking in the order of 4% ≈ 3% > 2% > 1%. The optimal amount of H2O2 treatment for rice straw biogas digestion is 3% when economics and biogas yields are considered.

Biogas production from food-processing industrial wastes by anaerobic digestion

DEFF Research Database (Denmark)

Fang, Cheng

Konfronteret med energikrise og klimaforandringer, har verden brug for grønne, effektive og kulstofneutrale energikilder, som kan erstatte fossile brændstoffer. Biogas, som dannes ved anaerob nedbrydning af organisk materiale, er en bæredygtig, pålidelig og vedvarende energikilde. Der er stor...

Presence and transcriptional activity of anaerobic fungi in agricultural biogas plants.

Science.gov (United States)

Dollhofer, Veronika; Callaghan, Tony M; Griffith, Gareth W; Lebuhn, Michael; Bauer, Johann

2017-07-01

Bioaugmentation with anaerobic fungi (AF) is promising for improved biogas generation from lignocelluloses-rich substrates. However, before implementing AF into biogas processes it is necessary to investigate their natural occurrence, community structure and transcriptional activity in agricultural biogas plants. Thus, AF were detected with three specific PCR based methods: (i) Copies of their 18S genes were found in 7 of 10 biogas plants. (ii) Transcripts of a GH5 endoglucanase gene were present at low level in two digesters, indicating transcriptional cellulolytic activity of AF. (iii) Phylogeny of the AF-community was inferred with the 28S gene. A new Piromyces species was isolated from a PCR-positive digester. Evidence for AF was only found in biogas plants operated with high proportions of animal feces. Thus, AF were most likely transferred into digesters with animal derived substrates. Additionally, high process temperatures in combination with long retention times seemed to impede AF survival and activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hydrolytic activities of extracellular enzymes in thermophilic and mesophilic anaerobic sequencing-batch reactors treating organic fractions of municipal solid wastes.

Science.gov (United States)

Kim, Hyun-Woo; Nam, Joo-Youn; Kang, Seok-Tae; Kim, Dong-Hoon; Jung, Kyung-Won; Shin, Hang-Sik

2012-04-01

Extracellular enzymes offer active catalysis for hydrolysis of organic solid wastes in anaerobic digestion. To evidence the quantitative significance of hydrolytic enzyme activities for major waste components, track studies of thermophilic and mesophilic anaerobic sequencing-batch reactors (TASBR and MASBR) were conducted using a co-substrate of real organic wastes. During 1day batch cycle, TASBR showed higher amylase activity for carbohydrate (46%), protease activity for proteins (270%), and lipase activity for lipids (19%) than MASBR. In particular, the track study of protease identified that thermophilic anaerobes degraded protein polymers much more rapidly. Results revealed that differences in enzyme activities eventually affected acidogenic and methanogenic performances. It was demonstrated that the superior nature of enzymatic capability at thermophilic condition led to successive high-rate acidogenesis and 32% higher CH(4) recovery. Consequently, these results evidence that the coupling thermophilic digestion with sequencing-batch operation is a viable option to promote enzymatic hydrolysis of organic particulates. Copyright © 2012 Elsevier Ltd. All rights reserved.

Environmental and economic analysis of power generation in a thermophilic biogas plant.

Science.gov (United States)

Ruiz, D; San Miguel, G; Corona, B; Gaitero, A; Domínguez, A

2018-08-15

This paper investigates the environmental and economic performance of the power production from biogas using Life Cycle Assessment, Life Cycle Costing and Cost Benefit Analysis methodologies. The analysis is based on a commercial thermophilic biogas plant located in Spain where is installed a Combined Heat and Power system that produces electricity that is sold to the grid. Power generation has been assumed as the only function of the biogas system, expanding the system boundaries to include the additional function related to the end-of-life management of the biowastes. Thus environmental burdens from the conventional management of residues were calculated separately and subtracted. The base scenario involves using agri-food waste, sewage sludge and pig/cow manure as substrates. This situation is compared against an alternative scenario where the production of synthetic fertilizer is surrogated by the digestate. The results have shown that the most impacting activities in all impacts categories of power production are primarily attributable to the operation and maintenance of the biogas plant except for water resource depletion and climate change. The avoided emissions associated with the conventional management of pig/cow manure more than offset GHG emissions of the biogas system resulting in a negative impact value of -73.9gCO 2 eq/kWh in the base case scenario. The normalized results show that local impact categories such as primarily human toxicity, fresh water ecotoxicity and particulate matter are the most significantly affected by the biogas system while global impact categories as climate change and ozone depletion are less severely affected. The operation and maintenance phase is also shown to be the largest contributor after the life cycle cost analysis, followed by the construction and dismantling of the biogas plant and the profitability of the project is primarily related to the income obtained from the management of the biowastes used as substrates

Anaerobic co-digestion of Tunisian green macroalgae Ulva rigida with sugar industry wastewater for biogas and methane production enhancement.

Science.gov (United States)

Karray, Raida; Karray, Fatma; Loukil, Slim; Mhiri, Najla; Sayadi, Sami

2017-03-01

Ulva rigida is a green macroalgae, abundantly available in the Mediterranean which offers a promising source for the production of valuable biomaterials, including methane. In this study, anaerobic digestion assays in a batch mode was performed to investigate the effects of various inocula as a mixture of fresh algae, bacteria, fungi and sediment collected from the coast of Sfax, on biogas production from Ulva rigida. The results revealed that the best inoculum to produce biogas and feed an anaerobic reactor is obtained through mixing decomposed macroalgae with anaerobic sludge and water, yielding into 408mL of biogas. The process was then investigated in a sequencing batch reactor (SBR) which led to an overall biogas production of 375mL with 40% of methane. Further co-digestion studies were performed in an anaerobic up-flow bioreactor using sugar wastewater as a co-substrate. A high biogas production yield of 114mL g -1 VS added was obtained with 75% of methane. The co-digestion proposed in this work allowed the recovery of natural methane, providing a promising alternative to conventional anaerobic microbial fermentation using Tunisian green macroalgae. Finally, in order to identify the microbial diversity present in the reactor during anaerobic digestion of Ulva rigida, the prokaryotic diversity was investigated in this bioreactor by the denaturing gradient gel electrophoresis (DGGE) method targeting the 16S rRNA gene. Copyright © 2016 Elsevier Ltd. All rights reserved.

Anaerobic Digestion of Saline Creeping Wild Ryegrass for Biogas Production and Pretreatment of Particleboard Material

Science.gov (United States)

The objective of this research was to develop an integrated process to produce biogas and high-quality particleboard using saline creeping wild ryegrass (CWR), Leymus triticoides through anaerobic digestion (AD). Besides producing biogas, AD also serves as a pretreatment method to remove the wax la...

Enrichment of anaerobic syngas-converting bacteria from thermophilic bioreactor sludge.

Science.gov (United States)

Alves, Joana I; Stams, Alfons J M; Plugge, Caroline M; Alves, M Madalena; Sousa, Diana Z

2013-12-01

Thermophilic (55 °C) anaerobic microbial communities were enriched with a synthetic syngas mixture (composed of CO, H2 , and CO2 ) or with CO alone. Cultures T-Syn and T-CO were incubated and successively transferred with syngas (16 transfers) or CO (9 transfers), respectively, with increasing CO partial pressures from 0.09 to 0.88 bar. Culture T-Syn, after 4 successive transfers with syngas, was also incubated with CO and subsequently transferred (9 transfers) with solely this substrate - cultures T-Syn-CO. Incubation with syngas and CO caused a rapid decrease in the microbial diversity of the anaerobic consortium. T-Syn and T-Syn-CO showed identical microbial composition and were dominated by Desulfotomaculum and Caloribacterium species. Incubation initiated with CO resulted in the enrichment of bacteria from the genera Thermincola and Thermoanaerobacter. Methane was detected in the first two to three transfers of T-Syn, but production ceased afterward. Acetate was the main product formed by T-Syn and T-Syn-CO. Enriched T-CO cultures showed a two-phase conversion, in which H2 was formed first and then converted to acetate. This research provides insight into how thermophilic anaerobic communities develop using syngas/CO as sole energy and carbon source can be steered for specific end products and subsequent microbial synthesis of chemicals. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Comprehensive microbial analysis of combined mesophilic anaerobic-thermophilic aerobic process treating high-strength food wastewater.

Science.gov (United States)

Jang, Hyun Min; Ha, Jeong Hyub; Park, Jong Moon; Kim, Mi-Sun; Sommer, Sven G

2015-04-15

A combined mesophilic anaerobic-thermophilic aerobic process was used to treat high-strength food wastewater in this study. During the experimental period, most of solid residue from the mesophilic anaerobic reactor (R1) was separated by centrifugation and introduced into the thermophilic aerobic reactor (R2) for further digestion. Then, thermophilic aerobically-digested sludge was reintroduced into R1 to enhance reactor performance. The combined process was operated with two different Runs: Run I with hydraulic retention time (HRT) = 40 d (corresponding OLR = 3.5 kg COD/m(3) d) and Run II with HRT = 20 d (corresponding OLR = 7 kg COD/m(3)). For a comparison, a single-stage mesophilic anaerobic reactor (R3) was operated concurrently with same OLRs and HRTs as the combined process. During the overall digestion, all reactors showed high stability without pH control. The combined process demonstrated significantly higher organic matter removal efficiencies (over 90%) of TS, VS and COD and methane production than did R3. Quantitative real-time PCR (qPCR) results indicated that higher populations of both bacteria and archaea were maintained in R1 than in R3. Pyrosequencing analysis revealed relatively high abundance of phylum Actinobacteria in both R1 and R2, and a predominance of phyla Synergistetes and Firmicutes in R3 during Run II. Furthermore, R1 and R2 shared genera (Prevotella, Aminobacterium, Geobacillus and Unclassified Actinobacteria), which suggests synergy between mesophilic anaerobic digestion and thermophilic aerobic digestion. For archaea, in R1 methanogenic archaea shifted from genus Methanosaeta to Methanosarcina, whereas genera Methanosaeta, Methanobacterium and Methanoculleus were predominant in R3. The results demonstrated dynamics of key microbial populations that were highly consistent with an enhanced reactor performance of the combined process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Antibiotic Resistance Genes and Correlations with Microbial Community and Metal Resistance Genes in Full-Scale Biogas Reactors As Revealed by Metagenomic Analysis

DEFF Research Database (Denmark)

Luo, Gang; Li, Bing; Li, Li-Guan

2017-01-01

resistance genes (MRGs). The total abundance of ARGs in all the samples varied from 7 × 10-3 to 1.08 × 10-1 copy of ARG/copy of 16S-rRNA gene, and the samples obtained from thermophilic biogas reactors had a lower total abundance of ARGs, indicating the superiority of thermophilic anaerobic digestion......Digested residues from biogas plants are often used as biofertilizers for agricultural crops cultivation. The antibiotic resistance genes (ARGs) in digested residues pose a high risk to public health due to their potential spread to the disease-causing microorganisms and thus reduce...... the susceptibility of disease-causing microorganisms to antibiotics in medical treatment. A high-throughput sequencing (HTS)-based metagenomic approach was used in the present study to investigate the variations of ARGs in full-scale biogas reactors and the correlations of ARGs with microbial communities and metal...

Biogas production as affected by heavy metals in the anaerobic digestion of sludge

Directory of Open Access Journals (Sweden)

Hussein I. Abdel-Shafy

2014-12-01

The sewage sludge samples were separated from the sewage water of the pilot plant at the National Research Centre, TDC site. The effect of heavy metals on the biogas production of the anaerobic digester was studied. The inhibitory effect on the biogas production and toxic level of metals was determined in this study. The general ranking of heavy metal toxicity appears to be Hg > Cd > Cr (III. The present investigation reveals that heavy metals in addition to the anaerobic digester decreased the biogas production as an indication of efficiency of the process. A significant decrease in gas production and volatile organic matter removal was obtained. It was also noted that an accumulation of organic acid intermediates was obtained as a result of methanogenic bacterial inhibition. This accumulation was limited during the pulse feed of metals. This is due to the rapid poisoning of the active bacterial forms in the digester.

Modeling the fate of antibiotic resistance genes and class 1 integrons during thermophilic anaerobic digestion of municipal wastewater solids.

Science.gov (United States)

Burch, Tucker R; Sadowsky, Michael J; LaPara, Timothy M

2015-10-19

This study investigated the use of thermophilic anaerobic digestion for removing antibiotic resistance genes (ARGs) from residual municipal wastewater solids. Four laboratory-scale anaerobic digesters were operated in 8-day batch cycles at temperatures of 40, 56, 60, and 63 °C. Two tetracycline resistance genes (tet(W) and tet(X)), a fluoroquinolone resistance gene (qnrA), the integrase gene of class 1 integrons (intI1), 16S rRNA genes of all Bacteria, and 16S rRNA genes of methanogens were quantified using real-time quantitative PCR. ARG and intI1 quantities decreased at all temperatures and were described well by a modified form of the Collins-Selleck disinfection kinetic model. The magnitudes of Collins-Selleck kinetic parameters were significantly greater at thermophilic temperatures compared to 40 °C, but few statistically significant differences were observed among these parameters for the thermophilic anaerobic digesters. This model allows for the direct comparison of different operating conditions (e.g., temperature) on anaerobic digestion performance in mitigating the quantity of ARGs in wastewater solids and could be used to design full-scale anaerobic digesters to specifically treat for ARGs as a "pollutant" of concern.

Anaerobic digestion of the microalga Spirulina at extreme alkaline conditions: biogas production, metagenome, and metatranscriptome

Science.gov (United States)

Nolla-Ardèvol, Vímac; Strous, Marc; Tegetmeyer, Halina E.

2015-01-01

A haloalkaline anaerobic microbial community obtained from soda lake sediments was used to inoculate anaerobic reactors for the production of methane rich biogas. The microalga Spirulina was successfully digested by the haloalkaline microbial consortium at alkaline conditions (pH 10, 2.0 M Na+). Continuous biogas production was observed and the obtained biogas was rich in methane, up to 96%. Alkaline medium acted as a CO2 scrubber which resulted in low amounts of CO2 and no traces of H2S in the produced biogas. A hydraulic retention time (HRT) of 15 days and 0.25 g Spirulina L−1 day−1 organic loading rate (OLR) were identified as the optimal operational parameters. Metagenomic and metatranscriptomic analysis showed that the hydrolysis of the supplied substrate was mainly carried out by Bacteroidetes of the “ML635J-40 aquatic group” while the hydrogenotrophic pathway was the main producer of methane in a methanogenic community dominated by Methanocalculus. PMID:26157422

Rapid startup of thermophilic anaerobic digester to remove tetracycline and sulfonamides resistance genes from sewage sludge.

Science.gov (United States)

Xu, Rui; Yang, Zhao-Hui; Wang, Qing-Peng; Bai, Yang; Liu, Jian-Bo; Zheng, Yue; Zhang, Yan-Ru; Xiong, Wei-Ping; Ahmad, Kito; Fan, Chang-Zheng

2018-01-15

Spread of antibiotic resistance genes (ARGs) originating from sewage sludge is highlighted as an eminent health threat. This study established a thermophilic anaerobic digester using one-step startup strategy to quickly remove tetracycline and sulfonamides resistance genes from sewage sludge. At least 20days were saved in the startup period from mesophilic to thermophilic condition. Based on the results of 16S rDNA amplicons sequencing and predicted metagenomic method, the successful startup largely relied on the fast colonization of core thermophilic microbial population (e.g. Firmicutes, Proteobacteria, Actinobacteria). Microbial metabolic gene pathways for substrate degradation and methane production was also increased by one-step mode. In addition, real-time quantitative PCR approach revealed that most targeted tetracycline and sulfonamides resistance genes ARGs (sulI, tetA, tetO, tetX) were substantially removed during thermophilic digestion (removal efficiency>80%). Network analysis showed that the elimination of ARGs was attributed to the decline of their horizontal (intI1 item) and vertical (potential hosts) transfer-related elements under high-temperature. This research demonstrated that rapid startup thermophilic anaerobic digestion of wastewater solids would be a suitable technology for reducing quantities of various ARGs. Copyright © 2017 Elsevier B.V. All rights reserved.

New thermophilic anaerobes that decompose crystalline cellulose

Energy Technology Data Exchange (ETDEWEB)

Taya, M; Hinoki, H; Suzuki, Y; Yagi, T; Yap, M G.S.; Kobayashi, T

1985-01-01

Two strains (designated as 25A and 3B) of cellulolytic, thermophilic, anaerobic, spore-forming bacteria were newly isolated from an alkaline hot spring through enrichment cultures at 60/sup 0/C. Though strain 25A was nearly identical to Clostridium thermocellum ATCC 27405 as a reference strain, strain 3B had some characteristics different from the reference; no flagellation, alkalophilic growth property (optimum pH of 7.5-8) and orange-colored pigmentation of the cell mass. Strain 3B effectively decomposed micro-crystalline cellulose (Avicel) and raw cellulosics (rice straw, newspaper, and bagasse) without physical or chemical pretreatments. 20 references, 2 figures, 2 tables.

Occurrence and molecular characterization of cultivable mesophilic and thermophilic obligate anaerobic bacteria isolated from paper mills.

Science.gov (United States)

Suihko, Maija-Liisa; Partanen, Laila; Mattila-Sandholm, Tiina; Raaska, Laura

2005-08-01

The aim of this work was to characterize the cultivable obligate anaerobic bacterial population in paper mill environments. A total of 177 anaerobically grown bacterial isolates were screened for aerotolerance, from which 67 obligate anaerobes were characterized by automated ribotyping and 41 were further identified by partial 16S rDNA sequencing. The mesophilic isolates indicated 11 different taxa (species) within the genus Clostridium and the thermophilic isolates four taxa within the genus Thermoanaerobacterium and one within Thermoanaerobacter (both formerly Clostridium). The most widespread mesophilic bacterium was closely related to C. magnum and occurred in three of four mills. One mill was contaminated with a novel mesophilic bacterium most closely related to C. thiosulfatireducens. The most common thermophile was T. thermosaccharolyticum, occurring in all four mills. The genetic relationships of the mill isolates to described species indicated that most of them are potential members of new species. On the basis of identical ribotypes clay could be identified to be the contamination source of thermophilic bacteria. Automated ribotyping can be a useful tool for the identification of clostridia as soon as comprehensive identification libraries are available.

Hydrolytic bacteria in mesophilic and thermophilic degradation of plant biomass

Energy Technology Data Exchange (ETDEWEB)

Zverlov, Vladimir V.; Hiegl, Wolfgang; Koeck, Daniela E.; Koellmeier, Tanja; Schwarz, Wolfgang H. [Department of Microbiology, Technische Universitaet Muenchen, Freising-Weihenstephan (Germany); Kellermann, Josef [Max Planck Institute for Biochemistry, Am Klopferspitz, Martinsried (Germany)

2010-12-15

Adding plant biomass to a biogas reactor, hydrolysis is the first reaction step in the chain of biological events towards methane production. Maize silage was used to enrich efficient hydrolytic bacterial consortia from natural environments under conditions imitating those in a biogas plant. At 55-60 C a more efficient hydrolyzing culture could be isolated than at 37 C. The composition of the optimal thermophilic bacterial consortium was revealed by sequencing clones from a 16S rRNA gene library. A modified PCR-RFLP pre-screening method was used to group the clones. Pure anaerobic cultures were isolated. 70% of the isolates were related to Clostridium thermocellum. A new culture-independent method for identification of cellulolytic enzymes was developed using the isolation of cellulose-binding proteins. MALDI-TOF/TOF analysis and end-sequencing of peptides from prominent protein bands revealed cellulases from the cellulosome of C. thermocellum and from a major cellulase of Clostridium stercorarium. A combined culture of C. thermocellum and C. stercorarium was shown to excellently degrade maize silage. A spore preparation method suitable for inoculation of maize silage and optimal hydrolysis was developed for the thermophilic bacterial consortium. This method allows for concentration and long-term storage of the mixed culture for instance for inoculation of biogas fermenters. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Hybrid alkali-hydrodynamic disintegration of waste-activated sludge before two-stage anaerobic digestion process.

Science.gov (United States)

Grübel, Klaudiusz; Suschka, Jan

2015-05-01

The first step of anaerobic digestion, the hydrolysis, is regarded as the rate-limiting step in the degradation of complex organic compounds, such as waste-activated sludge (WAS). The aim of lab-scale experiments was to pre-hydrolyze the sludge by means of low intensive alkaline sludge conditioning before applying hydrodynamic disintegration, as the pre-treatment procedure. Application of both processes as a hybrid disintegration sludge technology resulted in a higher organic matter release (soluble chemical oxygen demand (SCOD)) to the liquid sludge phase compared with the effects of processes conducted separately. The total SCOD after alkalization at 9 pH (pH in the range of 8.96-9.10, SCOD = 600 mg O2/L) and after hydrodynamic (SCOD = 1450 mg O2/L) disintegration equaled to 2050 mg/L. However, due to the synergistic effect, the obtained SCOD value amounted to 2800 mg/L, which constitutes an additional chemical oxygen demand (COD) dissolution of about 35 %. Similarly, the synergistic effect after alkalization at 10 pH was also obtained. The applied hybrid pre-hydrolysis technology resulted in a disintegration degree of 28-35%. The experiments aimed at selection of the most appropriate procedures in terms of optimal sludge digestion results, including high organic matter degradation (removal) and high biogas production. The analyzed soft hybrid technology influenced the effectiveness of mesophilic/thermophilic anaerobic digestion in a positive way and ensured the sludge minimization. The adopted pre-treatment technology (alkalization + hydrodynamic cavitation) resulted in 22-27% higher biogas production and 13-28% higher biogas yield. After two stages of anaerobic digestion (mesophilic conditions (MAD) + thermophilic anaerobic digestion (TAD)), the highest total solids (TS) reduction amounted to 45.6% and was received for the following sample at 7 days MAD + 17 days TAD. About 7% higher TS reduction was noticed compared with the sample after 9

Multiple approaches to characterize the microbial community in a thermophilic anaerobic digester running on swine manure: a case study.

Science.gov (United States)

Tuan, Nguyen Ngoc; Chang, Yi-Chia; Yu, Chang-Ping; Huang, Shir-Ly

2014-01-01

In this study, the first survey of microbial community in thermophilic anaerobic digester using swine manure as sole feedstock was performed by multiple approaches including denaturing gradient gel electrophoresis (DGGE), clone library and pyrosequencing techniques. The integrated analysis of 21 DGGE bands, 126 clones and 8506 pyrosequencing read sequences revealed that Clostridia from the phylum Firmicutes account for the most dominant Bacteria. In addition, our analysis also identified additional taxa that were missed by the previous researches, including members of the bacterial phyla Synergistetes, Planctomycetes, Armatimonadetes, Chloroflexi and Nitrospira which might also play a role in thermophilic anaerobic digester. Most archaeal 16S rRNA sequences could be assigned to the order Methanobacteriales instead of Methanomicrobiales comparing to previous studies. In addition, this study reported that the member of Methanothermobacter genus was firstly found in thermophilic anaerobic digester. Copyright © 2014 Elsevier GmbH. All rights reserved.

Cellulolytic properties of an extremely thermophilic anaerobe

Energy Technology Data Exchange (ETDEWEB)

Hudson, J A; Morgan, H W; Daniel, R M [Waikato Univ., Hamilton (New Zealand). Microbial Biochemistry and Biotechnology Unit

1990-09-01

An extremely thermophilic anaerobe was isolated from a New Zealand hot spring by incubating bacterial mat strands in a medium containing xylan. The Gramreaction-negative organism that was subsequently purified had a temperature optimum of 70deg C and a pH optimum of 7.0. The isolate, designated strain H173, grew on a restricted range of carbon sources. In batch culture H173 could degrade Avicel completely when supplied at 5 or 10 g l{sup -1}. There was an initial growth phase, during which a cellulase complex was produced and carbohydrates fermented to form acetic and lactic acids, followed by a phase where cells were not metabolising but the cellulase complex actively converted cellulose to glucose. When co-cultered with strain Rt8.B1, an ethanologenic extreme thermophile, glucose was fermented to ethanol and acetate, and no reducing sugars accumulated in the medium. In pH controlled batch culture H173 produced an increased amount of lactate and acetate but there was again a phase when reducing sugars accumulated in the medium, and these were converted to ethanol by co-culture with Rt8.B1. (orig.).

Feasibility of biogas production from anaerobic co-digestion of herbal-extraction residues with swine manure.

Science.gov (United States)

Li, Yan; Yan, Xi-Luan; Fan, Jie-Ping; Zhu, Jian-Hang; Zhou, Wen-Bin

2011-06-01

The objective of this work was to examine the feasibility of biogas production from the anaerobic co-digestion of herbal-extraction residues with swine manure. Batch and semi-continuous experiments were carried out under mesophilic anaerobic conditions. Batch experiments revealed that the highest specific biogas yield was 294 mL CH(4) g(-1) volatile solids added, obtained at 50% of herbal-extraction residues and 3.50 g volatile solids g(-1) mixed liquor suspended solids. Specific methane yield from swine manure alone was 207 mL CH(4) g(-1) volatile solid added d(-1) at 3.50 g volatile solids g(-1) mixed liquor suspended solids. Furthermore, specific methane yields were 162, 180 and 220 mL CH(4) g (-1) volatile solids added d(-1) for the reactors co-digesting mixtures with 10%, 25% and 50% herbal-extraction residues, respectively. These results suggested that biogas production could be enhanced efficiently by the anaerobic co-digestion of herbal-extraction residues with swine manure. Copyright © 2011 Elsevier Ltd. All rights reserved.

Inactivation of Clostridium difficile in sewage sludge by anaerobic thermophilic digestion.

Science.gov (United States)

Xu, Changyun; Salsali, Hamidreza; Weese, Scott; Warriner, Keith

2016-01-01

There has been an increase in community-associated Clostridium difficile infections with biosolids derived from wastewater treatment being identified as one potential source. The current study evaluated the efficacy of thermophilic digestion in decreasing levels of C. difficile ribotype 078 associated with sewage sludge. Five isolates of C. difficile 078 were introduced (final density of 5 log CFU/g) into digested sludge and subjected to anaerobic digestion at mesophilic (36 or 42 °C) or thermophilic (55 °C) temperatures for up to 60 days. It was found that mesophilic digestion at 36 °C did not result in a significant reduction in C. difficile spore levels. In contrast, thermophilic sludge digestion reduced endospore levels at a rate of 0.19-2.68 log CFU/day, depending on the strain tested. The mechanism of lethality was indirect - by stimulating germination then inactivating the resultant vegetative cells. Acidification of sludge by adding acetic acid (6 g/L) inhibited the germination of spores regardless of the sludge digestion temperature. In conclusion, thermophilic digestion can be applied to reduce C. difficile in biosolids, thereby reducing the environmental burden of the enteric pathogen.

A Novel Process Configuration for Anaerobic Digestion of Source-Sorted Household Waste Using Hyper-Thermophilic Post-Treatment

DEFF Research Database (Denmark)

Hartmann, H.; Ahring, Birgitte Kiær

2005-01-01

A novel reactor configuration was investigated for anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW). An anaerobic hyper-thermophilic (68°C) reactor R68 was implemented as a post–treatment step for the effluent of a thermophilic reactor R1 (55°C) in order to enhance...... hydrolysis of recalcitrant organic matter, improve sanitation and ease the stripping of ammonia from the reactor. The efficiency of the combined system was studied in terms of methane yield, volatile solids (VS) reduction and volatile fatty acid (VFA) production at different hydraulic retention times (HRT...

A strict anaerobic extreme thermophilic hydrogen-producing culture enriched from digested household waste

DEFF Research Database (Denmark)

Karakashev, Dimitar Borisov; Kotay, Shireen Meher; Trably, Eric

2009-01-01

The aim of this study was to enrich, characterize and identify strict anaerobic extreme thermophilic hydrogen (H-2) producers from digested household solid wastes. A strict anaerobic extreme thermophilic H-2 producing bacterial culture was enriched from a lab-scale digester treating household...... wastes at 70 degrees C. The enriched mixed culture consisted of two rod-shaped bacterial members growing at an optimal temperature of 80 degrees C and an optimal pH 8.1. The culture was able to utilize glucose, galactose, mannose, xylose, arabinose, maltose, sucrose, pyruvate and glycerol as carbon...... sources. Growth on glucose produced acetate, H-2 and carbon dioxide. Maximal H-2 production rate on glucose was 1.1 mmol l(-1) h(-1) with a maximum H-2 yield of 1.9 mole H-2 per mole glucose. 16S ribosomal DNA clone library analyses showed that the culture members were phylogenetically affiliated...

Mesophilic and thermophilic anaerobic biodegradability of water hyacinth pre-treated at 80 degrees C.

Science.gov (United States)

Ferrer, Ivet; Palatsi, Jordi; Campos, Elena; Flotats, Xavier

2010-10-01

Water hyacinth (Eichornia crassipes) is a fast growing aquatic plant which causes environmental problems in continental water bodies. Harvesting and handling this plant becomes an issue, and focus has been put on the research of treatment alternatives. Amongst others, energy production through biomethanation has been proposed. The aim of this study was to assess the anaerobic biodegradability of water hyacinth under mesophilic and thermophilic conditions. The effect of a thermal sludge pre-treatment at 80 degrees C was also evaluated. To this end, anaerobic biodegradability tests were carried out at 35 degrees C and 55 degrees C, with raw and pre-treated water hyacinth. According to the results, the thermal pre-treatment enhanced the solubilisation of water hyacinth (i.e. increase in the soluble to total chemical oxygen demand (COD)) from 4% to 12% after 30 min. However, no significant effect was observed on the methane yields (150-190 L CH(4)/kg volatile solids). Initial methane production rates for thermophilic treatments were two fold those of mesophilic ones (6-6.5L vs. 3-3.5 L CH(4)/kg COD x day). Thus, higher methane production rates might be expected from thermophilic reactors working at short retention times. The study of longer low temperature pre-treatments or pre-treatments at elevated temperatures coupled to thermophilic reactors should be considered in the future. (c) 2009 Elsevier Ltd. All rights reserved.

Mesophilic and thermophilic anaerobic biodegradability of water hyacinth pre-treated at 80 oC

International Nuclear Information System (INIS)

Ferrer, Ivet; Palatsi, Jordi; Campos, Elena; Flotats, Xavier

2010-01-01

Water hyacinth (Eichornia crassipes) is a fast growing aquatic plant which causes environmental problems in continental water bodies. Harvesting and handling this plant becomes an issue, and focus has been put on the research of treatment alternatives. Amongst others, energy production through biomethanation has been proposed. The aim of this study was to assess the anaerobic biodegradability of water hyacinth under mesophilic and thermophilic conditions. The effect of a thermal sludge pre-treatment at 80 o C was also evaluated. To this end, anaerobic biodegradability tests were carried out at 35 o C and 55 o C, with raw and pre-treated water hyacinth. According to the results, the thermal pre-treatment enhanced the solubilisation of water hyacinth (i.e. increase in the soluble to total chemical oxygen demand (COD)) from 4% to 12% after 30 min. However, no significant effect was observed on the methane yields (150-190 L CH 4 /kg volatile solids). Initial methane production rates for thermophilic treatments were two fold those of mesophilic ones (6-6.5 L vs. 3-3.5 L CH 4 /kg COD.day). Thus, higher methane production rates might be expected from thermophilic reactors working at short retention times. The study of longer low temperature pre-treatments or pre-treatments at elevated temperatures coupled to thermophilic reactors should be considered in the future.

Study on submerged anaerobic membrane bioreactor (SAMBR) treating high suspended solids raw tannery wastewater for biogas production.

Science.gov (United States)

Umaiyakunjaram, R; Shanmugam, P

2016-09-01

This study deals with the treatment of high suspended solids raw tannery wastewater using flat sheet Submerged Anaerobic Membrane (0.4μm) Bioreactor (SAMBR) acclimatized with hypersaline anaerobic seed sludge for recovering biogas. The treatability of SAMBR achieved higher CODremoval efficiency (90%) and biogas yield (0.160L.g(-1) CODremoved) coincided with high r(2) values between permeate flux and TSS (0.95), biogas and COD removed (0.96). The acidification of hypersaline influent wastewater by biogas mixing with high CO2, achieved quadruplet benefit of gas liquid and solid separation, in-situ pH and NH3 control, in-situ CH4 enrichment, and prevention of membrane fouling. The initial high VFA became stable as time elapsed reveals the hydrolysing ability of particulate COD into soluble COD and into biogas, confirms the suitability of SAMBR for high suspended solids tannery wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

Anaerobic digestion foaming in full-scale biogas plants: A survey on causes and solutions

DEFF Research Database (Denmark)

Kougias, Panagiotis; Boe, Kanokwan; O-Thong, Sompong

2014-01-01

Anaerobic digestion foaming is a common operation problem in biogas plants with negative impacts on the biogas plants economy and environment. A survey of 16 Danish full-scale biogas plants on foaming problems revealed that most of them had experienced foaming in their processes up to three times...... of foaming in this case. Moreover, no difference in bacterial communities between the foaming and non-foaming reactors was observed, showing that filamentous bacteria were not the main reason for foaming in this case. © IWA Publishing 2014....

Kinetic study of thermophilic anaerobic digestion of solid wastes from potato processing

International Nuclear Information System (INIS)

Linke, Bernd

2006-01-01

Anaerobic treatment of solid wastes from potato processing was studied in completely stirred tank reactors (CSTR) at 55 o C. Special attention was paid to the effect of increased organic loading rate (OLR) on the biogas yield in long-term experiments. Both biogas yield and CH 4 in the biogas decreased with the increase in OLR. For OLR in the range of 0.8 gl -1 d -1 -3.4 gl -1 d -1 , biogas yield and CH 4 obtained were 0.85 l g -1 -0.65 l g -1 and 58%-50%, respectively. Biogas yield y as a function of maximum biogas yield y m , reaction rate constant k and HRT are described on the basis of a mass balance in a CSTR and a first order kinetic. The value of y m can be obtained from curve fitting or a simple batch test and k results from plotting y/(y m -y) against 1/OLR from long-term experiments. In the present study values for y m and k were obtained as 0.88 l g -1 and 0.089 d -1 , respectively. The simple model equations can apply for dimensioning completely stirred tank reactors (CSTR) digesting organic wastes from food processing industries, animal waste slurries or biogas crops

Life cycle environmental impacts of electricity from biogas produced by anaerobic digestion

Directory of Open Access Journals (Sweden)

Alessandra eFusi

2016-03-01

Full Text Available The aim of this study was to evaluate life cycle environmental impacts associated with the generation of electricity from biogas produced by the anaerobic digestion of agricultural products and waste. Five real plants in Italy were considered, using maize silage, slurry and tomato waste as feedstocks and co-generating electricity and heat; the latter is not utilized. The results suggest that maize silage and the operation of anaerobic digesters, including open storage of digestate, are the main contributors to the impacts of biogas electricity. The system which uses animal slurry is the best option, except for the marine and terrestrial eco-toxicity. The results also suggest that it is environmentally better to have smaller plants using slurry and waste rather than bigger installations which require maize silage to operate efficiently. Electricity from biogas is environmentally more sustainable than grid electricity for seven out of 11 impacts considered. However, in comparison with natural gas, biogas electricity is worse for seven out of 11 impacts. It also has mostly higher impacts than other renewables, with a few exceptions, notably solar photovoltaics. Thus, for the AD systems and mesophilic operating conditions considered in this study, biogas electricity can help reduce greenhouse gas (GHG emissions relative to a fossil-intensive electricity mix; however, some other impacts increase. If mitigation of climate change is the main aim, other renewables have a greater potential to reduce GHG emissions. If, in addition to this, other impacts are considered, then hydro, wind and geothermal power are better alternatives to biogas electricity. However, utilization of heat would improve significantly its environmental sustainability, particularly global warming potential, summer smog and the depletion of abiotic resources and the ozone layer. Further improvements can be achieved by banning open digestate storage to prevent methane emissions and

Life Cycle Environmental Impacts of Electricity from Biogas Produced by Anaerobic Digestion.

Science.gov (United States)

Fusi, Alessandra; Bacenetti, Jacopo; Fiala, Marco; Azapagic, Adisa

2016-01-01

The aim of this study was to evaluate life cycle environmental impacts associated with the generation of electricity from biogas produced by the anaerobic digestion (AD) of agricultural products and waste. Five real plants in Italy were considered, using maize silage, slurry, and tomato waste as feedstocks and cogenerating electricity and heat; the latter is not utilized. The results suggest that maize silage and the operation of anaerobic digesters, including open storage of digestate, are the main contributors to the impacts of biogas electricity. The system that uses animal slurry is the best option, except for the marine and terrestrial ecotoxicity. The results also suggest that it is environmentally better to have smaller plants using slurry and waste rather than bigger installations, which require maize silage to operate efficiently. Electricity from biogas is environmentally more sustainable than grid electricity for seven out of 11 impacts considered. However, in comparison with natural gas, biogas electricity is worse for seven out of 11 impacts. It also has mostly higher impacts than other renewables, with a few exceptions, notably solar photovoltaics. Thus, for the AD systems and mesophilic operating conditions considered in this study, biogas electricity can help reduce greenhouse gas (GHG) emissions relative to a fossil-intensive electricity mix; however, some other impacts increase. If mitigation of climate change is the main aim, other renewables have a greater potential to reduce GHG emissions. If, in addition to this, other impacts are considered, then hydro, wind, and geothermal power are better alternatives to biogas electricity. However, utilization of heat would improve significantly its environmental sustainability, particularly global warming potential, summer smog, and the depletion of abiotic resources and the ozone layer. Further improvements can be achieved by banning open digestate storage to prevent methane emissions and regulating

Life Cycle Environmental Impacts of Electricity from Biogas Produced by Anaerobic Digestion

Science.gov (United States)

Fusi, Alessandra; Bacenetti, Jacopo; Fiala, Marco; Azapagic, Adisa

2016-01-01

The aim of this study was to evaluate life cycle environmental impacts associated with the generation of electricity from biogas produced by the anaerobic digestion (AD) of agricultural products and waste. Five real plants in Italy were considered, using maize silage, slurry, and tomato waste as feedstocks and cogenerating electricity and heat; the latter is not utilized. The results suggest that maize silage and the operation of anaerobic digesters, including open storage of digestate, are the main contributors to the impacts of biogas electricity. The system that uses animal slurry is the best option, except for the marine and terrestrial ecotoxicity. The results also suggest that it is environmentally better to have smaller plants using slurry and waste rather than bigger installations, which require maize silage to operate efficiently. Electricity from biogas is environmentally more sustainable than grid electricity for seven out of 11 impacts considered. However, in comparison with natural gas, biogas electricity is worse for seven out of 11 impacts. It also has mostly higher impacts than other renewables, with a few exceptions, notably solar photovoltaics. Thus, for the AD systems and mesophilic operating conditions considered in this study, biogas electricity can help reduce greenhouse gas (GHG) emissions relative to a fossil-intensive electricity mix; however, some other impacts increase. If mitigation of climate change is the main aim, other renewables have a greater potential to reduce GHG emissions. If, in addition to this, other impacts are considered, then hydro, wind, and geothermal power are better alternatives to biogas electricity. However, utilization of heat would improve significantly its environmental sustainability, particularly global warming potential, summer smog, and the depletion of abiotic resources and the ozone layer. Further improvements can be achieved by banning open digestate storage to prevent methane emissions and regulating

Organic Waste Anaerobic degradation with bio-activator-5 Effective Microorganism (EM-5 to Produce Biogas

Directory of Open Access Journals (Sweden)

Metri Dian Insani

2014-06-01

Full Text Available Degradasi Anaerob Sampah Organik dengan Bioaktivator Effective Microorganism-5 (EM-5 untuk Menghasilkan Biogas Abstract: The purpose of this study was to: (1 analyze the differences in the use of corn cobs, kelaras bananas and banana peel with the addition of cow manure to biogas pressure, (2 analyze the differences in the use of corn cobs, kelaras bananas and banana peel with the addition of cow dung for a long time flame biogas produced, and (3 analyze the different uses corn cobs, kelaras bananas and banana peel with the addition of cow manure to the C / N ratio end. Experimental study was designed using a completely randomized design (CRD, with three treatments each in 3 repetitions. The research proves that: (1 there is a difference corncobs, kelaras bananas and banana peel with the addition of cow manure to biogas pressure, (2 there is a difference corncobs, kelaras bananas and banana peel with the addition of cow manure to the length of time the flame and (3 there is a difference corncobs, kelaras bananas and banana peel with the addition of cow manure to the C / N ratio end. Key Words: anaerobic degradation, organic waste, EM-5, biogas Abstrak: Tujuan penelitian ini adalah untuk: (1 menganalisis perbedaan penggunaan tongkol jagung, kelaras pisang, dan kulit pisang dengan penambahan kotoran sapi terhadap tekanan biogas, (2 menganalisis perbedaan penggunaan tongkol jagung, kelaras pisang, dan kulit pisang dengan penam-bahan kotoran sapi terhadap lama waktu nyala api biogas yang dihasilkan, dan (3 menganalisis per-bedaan penggunaan tongkol jagung, kelaras pisang, dan kulit pisang dengan penambahan kotoran sapi terhadap rasio C/N akhir. Penelitian eksperimen didesain menggunakan rancangan acak lengkap (RAL, dengan tiga perlakuan masing-masing dalam 3 kali ulangan. Hasil penelitian membuktikan bahwa: (1 terdapat perbedaan tongkol jagung, kelaras pisang, dan kulit pisang dengan penambahan kotoran sapi terhadap tekanan biogas, (2 terdapat

Whole farm impact of anaerobic digestion and biogas use on a New York dairy farm

Science.gov (United States)

Anaerobic digestion of manure for biogas production is one of many options for reducing the carbon footprint of milk production. This process reduces greenhouse gas emissions but increases the potential nitrogen and phosphorus losses from the farm. An anaerobic digester component was added to the In...

Enhancement of biogas production in anaerobic co-digestion by ultrasonic pretreatment

International Nuclear Information System (INIS)

Zou, Shuzhen; Wang, Xiaojiao; Chen, Yuanlin; Wan, Haiwen; Feng, Yongzhong

2016-01-01

Highlights: • Ultrasonic pretreatment changed physical structure of samples. • Ultrasonic pretreatment improved biogas production via changing environment before and during anaerobic digestion process. • The main factors affecting biogas production differ in different pretreated samples. - Abstract: This paper optimized the anaerobic digestion (AD) pretreatment process and identified the influence of pretreatment on the co-digestion of maize straw (MS) and dairy manure (DM). In the study, ultrasonic was used to pretreat MS and DM prior to digestion, with power intensities of 0, 189.39, 284.09, and 378.79 kJ at 0, 20, 30, and 40 min, respectively. Changes in the surface structures of MS and DM were observed by scanning electron microscopy (SEM), and factor analysis was used to analyze the main factors affecting biogas production in the AD process. The result showed that the structure of DM was distributed and that the structure of MS became more roughness following the ultrasonic pretreatment (UP). The highest total biogas production of co-digestion (240.32 mL/g VS_f_e_d) was obtained when MS was pretreated for 30 min without DM pretreatment (MS_3_0DM_0). This was significantly higher than that of the untreated sample (CK) (141.65 mL/g VS_f_e_d). The cellulose activity (CA), reducing sugar (RS) content, volatile fatty acid (VFA) content and pH in the digester feed, and their maximum and minimum values in the AD process was affected by UP. Factor 1 of MS_3_0DM_0 was determined by RS content, pH and VFA content that they had the most influence on biogas production on days 6, 18, 24 and 30. Factor 2 of it was determined by CA, and it had most influence on days 0, 12, 36 and 42 in the AD process, The result of the factor analysis indicated that the main factors affecting biogas production were affected by UP and they differ according to the different digestion stages. This research concluded that UP improved total biogas production via changing the initial

Effect of alkaline microwaving pretreatment on anaerobic digestion and biogas production of swine manure.

Science.gov (United States)

Yu, Tao; Deng, Yihuan; Liu, Hongyu; Yang, Chunping; Wu, Bingwen; Zeng, Guangming; Lu, Li; Nishimura, Fumitake

2017-05-10

Microwave assisted with alkaline (MW-A) condition was applied in the pretreatment of swine manure, and the effect of the pretreatment on anaerobic treatment and biogas production was evaluated in this study. The two main microwaving (MW) parameters, microwaving power and reaction time, were optimized for the pretreatment. Response surface methodology (RSM) was used to investigate the effect of alkaline microwaving process for manure pretreatment at various values of pH and energy input. Results showed that the manure disintegration degree was maximized of 63.91% at energy input of 54 J/g and pH of 12.0, and variance analysis indicated that pH value played a more important role in the pretreatment than in energy input. Anaerobic digestion results demonstrated that MW-A pretreatment not only significantly increased cumulative biogas production, but also shortened the duration for a stable biogas production rate. Therefore, the alkaline microwaving pretreatment could become an alternative process for effective treatment of swine manure.

Enrichment of Thermophilic Syntrophic Anaerobic Glutamate-Degrading Consortia using a Dialysis Membrane Reactor

NARCIS (Netherlands)

Plugge, C.M.; Stams, A.J.M.

2002-01-01

A dialysis cultivation system was used to enrich slow-growing moderately thermophilic anaerobic bacteria at high cell densities. Bicarbonate buffered mineral salts medium with 5 mM glutamate as the sole carbon and energy source was used and the incubation temperature was 55 degrees C. The reactor

The future of anaerobic digestion and biogas utilization

DEFF Research Database (Denmark)

Holm-Nielsen, J.B.; Al Seadi, T.; Oleskowicz-Popiel, Piotr

2009-01-01

One of the common tendencies of animal production activities in Europe and in developed countries in general is to intensify the animal production and to increase the size of the animal production units. High livestock density is always accompanied by production of a surplus of animal manure...... and to redistribute the excess of nutrients from manure and to optimize their recycling. Anaerobic digestion of animal manure and slurries offers several benefits by improving their fertilizer qualities, reducing odors and pathogens and producing a renewable fuel – the biogas. The EU policies concerning renewable...... energy systems (RES) have set forward a fixed goal of supplying 20% of the European energy demands from RES by year 2020. A major part of the renewable energy will originate from European farming and forestry. At least 25% of all bioenergy in the future can originate from biogas, produced from wet...

The future of anaerobic digestion and biogas utilisation

DEFF Research Database (Denmark)

Holm-Nielsen, Jens Bo; Al Seadi, Teodorita; Oleskowicz-Popiel, Piotr

2009-01-01

  One of the common tendencies of animal production activities in Europe and in developed countries in general is to intensify the animal production and to increase the size of the animal production units. High livestock density is always accompanied by production of a surplus of animal manure...... and to redistribute the excess of nutrients from manure and to optimize their recycling. Anaerobic digestion of animal manure and slurries offers several benefits by improving their fertilizer qualities, reducing odors and pathogens and producing a renewable fuel - the biogas. The EU policies concerning renewable...... energy systems (RES) have set forward a fixed goal of supplying 20% of the European energy demands from RES by year 2020. A major part of the renewable energy will originate from European farming and forestry. At least 25% of all bioenergy in the future can originate from biogas, produced from wet...

Organic Waste Anaerobic degradation with bio-activator-5 Effective Microorganism (EM-5) to Produce Biogas

OpenAIRE

Metri Dian Insani

2014-01-01

Degradasi Anaerob Sampah Organik dengan Bioaktivator Effective Microorganism-5 (EM-5) untuk Menghasilkan Biogas Abstract: The purpose of this study was to: (1) analyze the differences in the use of corn cobs, kelaras bananas and banana peel with the addition of cow manure to biogas pressure, (2) analyze the differences in the use of corn cobs, kelaras bananas and banana peel with the addition of cow dung for a long time flame biogas produced, and (3) analyze the different uses corn cobs,...

Anaerobic Digestion and Biogas Potential: Simulation of Lab and Industrial-Scale Processes

OpenAIRE

Ihsan Hamawand; Craig Baillie

2015-01-01

In this study, a simulation was carried out using BioWin 3.1 to test the capability of the software to predict the biogas potential for two different anaerobic systems. The two scenarios included: (1) a laboratory-scale batch reactor; and (2) an industrial-scale anaerobic continuous lagoon digester. The measured data related to the operating conditions, the reactor design parameters and the chemical properties of influent wastewater were entered into BioWin. A sensitivity analysis was carried...

Biogas final digestive byproduct applied to croplands as fertilizer contains high levels of steroid hormones

DEFF Research Database (Denmark)

Rodriguez-Navas, Carlos; Björklund, Erland; Halling-Sørensen, Bent

2013-01-01

that utilize different anaerobic digestion technologies (mesophilic and thermophilic) from swine manure and other organic wastes. Individual hormone concentration levels were observed up to 1478 ng g(-1) dry weight or 22.5 mg kg(-1) N with estrone and progesterone reaching highest concentration levels....... Evaluation of the potential environmental burden through the application in agriculture was also assessed on the basis of predicted environmental concentrations. This study indicates that the biogas digestion process does not completely remove steroid hormones from livestock manure and use of final digestate......In this study we evaluate and demonstrate the occurrence of nine natural and one synthetic steroid hormone, including estrogens, androgens and progestagens in biogas final digestate byproduct (digestion liquid) commonly used as an agricultural fertilizer. We investigated two biogas sites...

Two-phase anaerobic digestion for biogas production from dairy effluent—CSTR and ABR in series

DEFF Research Database (Denmark)

Jürgensen, L.; Ehimen, E. A.; Born, J.

2016-01-01

Anaerobic digestion of low-strength dairy waste water has been used for the production of biogas. A two-phase pilot scale process had been established within 90 d using a 1 m3continuous stirred tank reactor (CSTR) and a 200 l anaerobic baffled reactor (ABR) in series. The system was fed at constant...... retention time of 1.6 d and with changing feed strengths resulting in various organic loading rates between 1.25-4.50 g/(l d). The average COD removal was 82% with a biogas yield of 0.26 l/gCOD. The combination of CSTR and ABR overcame the disadvantages of both reactor types. By further optimization...

High ethanol tolerance of the thermophilic anaerobic ethanol producer Thermoanaerobacter BG1L1

DEFF Research Database (Denmark)

Georgieva, Tania I.; Mikkelsen, Marie Just; Ahring, Birgitte Kiær

2007-01-01

The low ethanol tolerance of thermophilic anaerobic bacteria, generally less than 2% (v/v) ethanol, is one of the main limiting factors for their potential use for second generation fuel ethanol production. In this work, the tolerance of thermophilic anaerobic bacterium Thermoanaerobacter BG 1L1...... to exogenously added ethanol was studied in a continuous immobilized reactor system at a growth temperature of 70 degrees C. Ethanol tolerance was evaluated based on inhibition of fermentative performance e.g.. inhibition of substrate conversion. At the highest ethanol concentration tested (8.3% v/v), the strain...... was able to convert 42% of the xylose initially present, indicating that this ethanol concentration is not the upper limit tolerated by the strain. Long-term strain adaptation to high ethanol concentrations (6 - 8.3%) resulted in an improvement of xylose conversion by 25% at an ethanol concentration of 5...

High performance biological methanation in a thermophilic anaerobic trickle bed reactor.

Science.gov (United States)

Strübing, Dietmar; Huber, Bettina; Lebuhn, Michael; Drewes, Jörg E; Koch, Konrad

2017-12-01

In order to enhance energy efficiency of biological methanation of CO 2 and H 2 , this study investigated the performance of a thermophilic (55°C) anaerobic trickle bed reactor (ATBR) (58.1L) at ambient pressure. With a methane production rate of up to 15.4m 3 CH4 /(m 3 trickle bed ·d) at methane concentrations above 98%, the ATBR can easily compete with the performance of other mixed culture methanation reactors. Control of pH and nutrient supply turned out to be crucial for stable operation and was affected significantly by dilution due to metabolic water production, especially during demand-orientated operation. Considering practical applications, inoculation with digested sludge, containing a diverse biocenosis, showed high adaptive capacity due to intrinsic biological diversity. However, no macroscopic biofilm formation was observed at thermophilic conditions even after 313days of operation. The applied approach illustrates the high potential of thermophilic ATBRs as a very efficient energy conversion and storage technology. Copyright © 2017 Elsevier Ltd. All rights reserved.

Experimentation on the anaerobic filter reactor for biogas production using rural domestic wastewater

Science.gov (United States)

Leju Celestino Ladu, John; Lü, Xi-wu; Zhong, Zhaoping

2017-08-01

The biogas production from anaerobic filter (AF) reactor was experimented in Taihu Lake Environmental Engineering Research Center of Southeast University, Wuxi, China. Two rounds of experimental operations were conducted in a laboratory scale at different Hydraulic retention time (HRT) and wastewater temperature. The biogas production rate during the experimentation was in the range of 4.63 to 11.78 L/d. In the first experimentation, the average gas production rate was 10.08 L/d, and in the second experimentation, the average gas production rate was 4.97 L/d. The experimentation observed the favorable Hydraulic Retention Time and wastewater temperature in AF was three days and 30.95°C which produced the gas concentration of 11.78 L/d. The HRT and wastewater temperature affected the efficiency of the AF process on the organic matter removal and nutrients removal as well. It can be deduced from the obtained results that HRT and wastewater temperature directly affects the efficiency of the AF reactor in biogas production. In conclusion, anaerobic filter treatment of organic matter substrates from the rural domestic wastewater increases the efficiency of the AF reactor on biogas production and gives a number of benefits for the management of organic wastes as well as reduction in water pollution. Hence, the operation of the AF reactor in rural domestic wastewater treatment can play an important element for corporate economy of the biogas plant, socio-economic aspects and in the development of effective and feasible concepts for wastewater management, especially for people in rural low-income areas.

Construction of Biodigesters to Optimize the Production of Biogas from Anaerobic Co-Digestion of Food Waste and Sewage

Directory of Open Access Journals (Sweden)

Claudinei de Souza Guimarães

2018-04-01

Full Text Available The objective of this study was to build and develop anaerobic biodigesters for optimization of biogas production using food waste (FW and sewage (S co-digestion from a wastewater treatment plant (WWTP. The biodigesters operated with different mixtures and in mesophilic phase (37 °C. During the 60 days of experiments, all control and monitoring parameters of the biodigesters necessary for biogas production were tested and evaluated. The biodigester containing FW, S and anaerobic sludge presented the biggest reduction of organic matter, expressed with removal of 88.3% TVS (total volatile solid and 84.7% COD (chemical oxygen demand the biggest biogas production (63 L and the highest methane percentage (95%. Specific methane production was 0.299 LCH4/gVS and removed. The use of biodigesters to produce biogas through anaerobic digestion may play an important role in local economies due to the opportunity to produce a renewable fuel from organic waste and also as an alternative to waste treatment. Finally, the embedded control and automation system was simple, effective, and robust, and the supervisory software was efficient in all aspects defined at its conception.

Multiscale hydrodynamic investigation to intensify the biogas production in upflow anaerobic reactors.

Science.gov (United States)

Jiang, Jiankai; Wu, Jing; Zhang, Jinbai; Poncin, Souhila; Li, Huai Z

2014-03-01

Hydrodynamics plays a main role for the performance of an anaerobic reactor involving three phases: wastewater, sludge granules and biogas bubbles. The present work was focused on an original approach to investigate the hydrodynamics at different scales and then to intensify the performance of such complex reactors. The experiments were carried out respectively in a 3D reactor at macroscale, a 2D reactor at mesoscale and a 1D anaerobic reactor at microscale. A Particle Image Velocimetry (PIV), a micro-PIV and a high-speed camera were employed to quantify the liquid flow fields and the relative motion between sludge granules and bubbles. Shear rates exerted on sludge granules were quantified from liquid flow fields. The optimal biogas production is obtained at mean shear rate varying from 28 to 48s(-1), which is controlled by two antagonistic mechanisms. The multiscale approach demonstrates pertinent mechanisms proper to each scale and allows a better understanding of such reactors. Copyright © 2014 Elsevier Ltd. All rights reserved.

In-situ biogas upgrading during anaerobic digestion of food waste amended with walnut shell biochar at bench scale.

Science.gov (United States)

Linville, Jessica L; Shen, Yanwen; Ignacio-de Leon, Patricia A; Schoene, Robin P; Urgun-Demirtas, Meltem

2017-06-01

A modified version of an in-situ CO 2 removal process was applied during anaerobic digestion of food waste with two types of walnut shell biochar at bench scale under batch operating mode. Compared with the coarse walnut shell biochar, the fine walnut shell biochar has a higher ash content (43 vs. 36 wt%) and higher concentrations of calcium (31 vs. 19 wt% of ash), magnesium (8.4 vs. 5.6 wt% of ash) and sodium (23.4 vs. 0.3 wt% of ash), but a lower potassium concentration (0.2 vs. 40% wt% of ash). The 0.96-3.83 g biochar (g VS added ) -1 fine walnut shell biochar amended digesters produced biogas with 77.5%-98.1% CH 4 content by removing 40%-96% of the CO 2 compared with the control digesters at mesophilic and thermophilic temperature conditions. In a direct comparison at 1.83 g biochar (g VS added ) -1 , the fine walnut shell biochar amended digesters (85.7% CH 4 content and 61% CO 2 removal) outperformed the coarse walnut shell biochar amended digesters (78.9% CH 4 content and 51% CO 2 removal). Biochar addition also increased alkalinity as CaCO 3 from 2800 mg L -1 in the control digesters to 4800-6800 mg L -1 , providing process stability for food waste anaerobic digestion.

Benefits of supplementing an industrial waste anaerobic digester with energy crops for increased biogas production.

Science.gov (United States)

Nges, Ivo Achu; Escobar, Federico; Fu, Xinmei; Björnsson, Lovisa

2012-01-01

Currently, there is increasing competition for waste as feedstock for the growing number of biogas plants. This has led to fluctuation in feedstock supply and biogas plants being operated below maximum capacity. The feasibility of supplementing a protein/lipid-rich industrial waste (pig manure, slaughterhouse waste, food processing and poultry waste) mesophilic anaerobic digester with carbohydrate-rich energy crops (hemp, maize and triticale) was therefore studied in laboratory scale batch and continuous stirred tank reactors (CSTR) with a view to scale-up to a commercial biogas process. Co-digesting industrial waste and crops led to significant improvement in methane yield per ton of feedstock and carbon-to-nitrogen ratio as compared to digestion of the industrial waste alone. Biogas production from crops in combination with industrial waste also avoids the need for micronutrients normally required in crop digestion. The batch co-digestion methane yields were used to predict co-digestion methane yield in full scale operation. This was done based on the ratio of methane yields observed for laboratory batch and CSTR experiments compared to full scale CSTR digestion of industrial waste. The economy of crop-based biogas production is limited under Swedish conditions; therefore, adding crops to existing industrial waste digestion could be a viable alternative to ensure a constant/reliable supply of feedstock to the anaerobic digester. Copyright © 2011 Elsevier Ltd. All rights reserved.

Preliminary experimental results of Sewage Sludge (SS) Co-digestion with Palm Oil Mill Effluent (POME) for Enhanced Biogas Production in Laboratory Scale Anaerobic Digester

International Nuclear Information System (INIS)

Sivasankari, R; Kumaran, P; Normanbhay, Saifuddin; Shamsuddin, Abd Halim

2013-01-01

An investigation on the feasibility of co-digesting Sewage Sludge with Palm Oil Mill Effluent for enhancing the biogas production and the corresponding effect of the co-digestion substrate ratio on the biogas production has been evaluated. Anaerobic co-digestion of POME with SS was performed at ratios of 100:0, 70:30, 60:40 and 0:100 to find the optimum blend required for enhanced waste digestion and biogas production. Single stage batch digestion was carried out for 12 days in a laboratory scale anaerobic digester. Co-digestion of sludge's at the 70:30 proportion resulted in optimal COD and C: N ratio which subsequently recorded the highest performance with regards to biogas production at 28.1 L's compared to the 1.98 L's of biogas produced from digestion of SS alone. From the results obtained, it is evident that co-digestion of POME and SS is an attractive option to be explored for enhancement of biogas production in anaerobic digesters.

The control of H2S in biogas using iron ores as in situ desulfurizers during anaerobic digestion process.

Science.gov (United States)

Zhou, Qiying; Jiang, Xia; Li, Xi; Jiang, Wenju

2016-09-01

In this study, five kinds of iron ores, limonite, hematite, manganese ore, magnetite and lava rock, were used as the in situ desulfurizers in the anaerobic digestion reactors to investigate their effects on controlling H2S in biogas. The results show that the addition of the five iron ores could significantly control the content of H2S in biogas, with the best performance for limonite. As limonite dosages increase (10-60 g/L), the contents of H2S in biogas were evidently decreased in the digesters with different initial sulfate concentrations (0-1000 mg/L). After the anaerobic digestion, the removed sulfur was mostly deposited on the surface of limonite. A possible mechanism of H2S control in biogas by limonite was proposed preliminarily, including adsorption, FeS precipitation, and Fe (III) oxidation. The results demonstrated that limonite was a promising in situ desulfurizer for controlling H2S in biogas with low cost and high efficiency.

Effects of Co and Ni nanoparticles on biogas and methane production from anaerobic digestion of slurry

International Nuclear Information System (INIS)

Abdelsalam, E.; Samer, M.; Attia, Y.A.; Abdel-Hadi, M.A.; Hassan, H.E.; Badr, Y.

2017-01-01

Highlights: • The addition of trace metals in form of nanoparticles reduced the lag phase. • Nanoparticles reduced time to achieve the highest biogas and methane production. • Biogas and methane production were proportional to nanoparticles concentration. • Nanoparticles biostimulate the methanogenic bacteria and increase their activity. - Abstract: Nanoparticles (NPs) were hypothesized to enhance the anaerobic process and to accelerate the slurry digestion, which increases the biogas and methane production. The effects of NPs on biogas and methane production were investigated using a specially designed batch anaerobic system. For this purpose, a series of 2 L biodigesters were manufactured and implemented to study the effects of Cobalt (Co) and Nickel (Ni) nanoparticles with different concentrations on biogas and methane production. The best results of NPs additives were determined based on the statistical analysis (Least Significant Difference using M-Stat) of biogas and methane production, which were 1 mg/L Co NPs and 2 mg/L Ni NPs (p < 0.05). These NPs additives delivered the highest biogas and methane yields in comparison with their other concentrations (0.5, 1, and 2 mg/L), their salts (CoCl_2, and NiCl_2) and the control. Furthermore, the addition of 1 mg/L Co NPs and 2 mg/L Ni NPs significantly increased the biogas volume (p < 0.05) by 1.64 and 1.74 times the biogas volume produced by the control, respectively. Moreover, the aforementioned additives significantly increased the methane volume (p < 0.05) by 1.86 and 2.01 times the methane volume produced by the control, respectively. The highest specific biogas and methane production were attained with 2 mg/L Ni NPs (p < 0.05), and were 614.5 ml Biogas g"−"1 VS and 361.6 ml CH_4 g"−"1 VS, respectively compared with the control which yielded only 352.6 ml Biogas g"−"1 VS and 179.6 ml CH_4 g"−"1 VS.

Thermophilic slurry-phase treatment of petroleum hydrocarbon waste sludges

International Nuclear Information System (INIS)

Castaldi, F.J.; Bombaugh, K.J.; McFarland, B.

1995-01-01

Chemoheterotrophic thermophilic bacteria were used to achieve enhanced hydrocarbon degradation during slurry-phase treatment of oily waste sludges from petroleum refinery operations. Aerobic and anaerobic bacterial cultures were examined under thermophilic conditions to assess the effects of mode of metabolism on the potential for petroleum hydrocarbon degradation. The study determined that both aerobic and anaerobic thermophilic bacteria are capable of growth on petroleum hydrocarbons. Thermophilic methanogenesis is feasible during the degradation of hydrocarbons when a strict anaerobic condition is achieved in a slurry bioreactor. Aerobic thermophilic bacteria achieved the largest apparent reduction in chemical oxygen demand, freon extractable oil, total and volatile solid,s and polycyclic aromatic hydrocarbons (PAHs) when treating oily waste sludges. The observed shift with time in the molecular weight distribution of hydrocarbon material was more pronounced under aerobic metabolic conditions than under strict anaerobic conditions. The changes in the hydrocarbon molecular weight distribution, infrared spectra, and PAH concentrations during slurry-phase treatment indicate that the aerobic thermophilic bioslurry achieved a higher degree of hydrocarbon degradation than the anaerobic thermophilic bioslurry during the same time period

Anaerobic digestion of macroalgal biomass and sediments sourced from the Orbetello lagoon, Italy

International Nuclear Information System (INIS)

Migliore, G.; Alisi, C.; Sprocati, A.R.; Massi, E.; Ciccoli, R.; Lenzi, M.; Wang, A.; Cremisini, C.

2012-01-01

The anaerobic digestion of marine macroalgae biomass could meet two currently important needs, the mitigation of the eutrophication effects and the production of renewable energy. Because of the abundance of seaweed biomass its conversion can be highly desirable and convenient, mostly for countries with long coastlines or eutrophic environments. The aim of the present work is to carry out an exploratory study of biogas production from macroalgal biomass collected from the Orbetello lagoon (Tuscany, Italy) by solely exploiting the intrinsic degradation potential of the ecosystem. A fresh algae mix and sediments has been used, as both feed and inoculum of an anaerobic digestion process under psychro-mesophilic, mesophilic and thermophilic conditions, in batch reactors, without any washing and drying treatment. The presence of sediment proved to be crucial in order to achieve a good methane yield (methane yield of 380 dm 3 kg −1 VS added ) comparable with literature data obtained through different approaches. The results gave evidence that such an approach will have to be considered when planning a selective anaerobic digestion of macroalgae that could be useful in local applications for coasts and eutrophic lagoons affected by seasonal or frequent algal blooms. -- Highlights: ► Biogas production from macroalgal biomass with minimal energy input is proposed. ► Psychro-mesophilic, mesophilic and thermophilic conditions were compared. ► Highly adapted bacterial pool was crucial to achieve a good methane yield. ► The applied process exploits the intrinsic degradation potential of the ecosystem.

Characterisation of community structure of bacteria in parallel mesophilic and thermophilic pilot scale anaerobe sludge digesters.

Science.gov (United States)

Tauber, T; Berta, Brigitta; Székely, Anna J; Gyarmati, I; Kékesi, Katalin; Márialigeti, K; Tóth, Erika M

2007-03-01

The aim of the present work was to compare the microbial communities of a mesophilic and a thermophilic pilot scale anaerobe sludge digester. For studying the communities cultivation independent chemotaxonomical methods (RQ and PLFA analyses) and T-RFLP were applied. Microbial communities of the mesophilic and thermophilic pilot digesters showed considerable differences, both concerning the species present, and their abundance. A Methanosarcina sp. dominated the thermophilic, while a Methanosaeta sp. the mesophilic digester among Archaea. Species diversity of Bacteria was reduced in the thermophilic digester. Based on the quinone patterns in both digesters the dominance of sulphate reducing respiratory bacteria could be detected. The PLFA profiles of the digester communities were similar though in minor components characteristic differences were shown. Level of branched chain fatty acids is slightly lower in the thermophilic digester that reports less Gram positive bacteria. The relative ratio of fatty acids characteristic to Enterobacteriaceae, Bacteroidetes and Clostridia shows differences between the two digesters: their importance generally decreased under thermophilic conditions. The sulphate reducer marker (15:1 and 17:1) fatty acids are present in low quantity in both digesters.

Production of biogas from organic waste in microreactors operated at two temperatures

International Nuclear Information System (INIS)

Murillo Roos, Mariana

2014-01-01

The process and the product of anaerobic digestion are evaluated for different proportions of organic substrates, in microreactors operated at thermophilic and mesophilic temperatures with interest to find alternatives that will generate energy from biomass. Small-scale tests are conducted to ensure the proper functioning of biodigesters and optimize operating conditions. The anaerobic digestion process is characterized in three manure mixing ratios: mix of leftovers (100:0,90:10 and 80:20) and two temperatures of work (35 degrees Celsius and 50 degrees Celsius), using a factorial arrangement with 2 replicates per treatment. The mixture is composed of manure, cow dung and scraps of fresh food (fruits and vegetables) and prepared food. The proportions were diluted to 5% total solids. Bottles are the experimental unit used consisting culture medium bottles of 1 liter with 500 mL of mixture. The test has run for 5 hydraulic retention times (HRT) of twenty days each. At this time the pH was evaluated, the daily production of biogas, biogas composition, total solids, volatile and fixed and the content of volatile fatty acids. The values obtained biogas productivity and CH 4 content have been similar to those reported in the literature and indicate that the systems have been successful [es

Sulfate addition as an effective method to improve methane fermentation performance and propionate degradation in thermophilic anaerobic co-digestion of coffee grounds, milk and waste activated sludge with AnMBR.

Science.gov (United States)

Li, Qian; Li, Yu-You; Qiao, Wei; Wang, Xiaochang; Takayanagi, Kazuyuki

2015-06-01

This study was conducted to investigate the effects of sulfate on propionate degradation and higher organic loading rate (OLR) achievement in a thermophilic AnMBR for 373days using coffee grounds, milk and waste activated sludge (WAS) as the co-substrate. Without the addition of sulfate, the anaerobic system failed at an OLR of 14.6g-COD/L/d, with propionate accumulating to above 2.23g-COD/L, and recovery by an alkalinity supplement was not successful. After sulfate was added into substrates at a COD/SO4(2-) ratio of 200:1 to 350:1, biogas production increased proportionally with OLR increasing from 4.06 to 15.2g-COD/L/d. Propionic acid was maintained at less than 100mg-COD/L due to the effective conversion of propionic acid to methane after the sulfate supplement was added. The long-term stable performance of the AnMBR indicated that adding sulfate was beneficial for the degradation of propionate and achieving a higher OLR under the thermophilic condition. Copyright © 2015 Elsevier Ltd. All rights reserved.

Low-temperature anaerobic treatment of hog manure and transformation of biogas into green energy

Energy Technology Data Exchange (ETDEWEB)

Van-Anh Truong, L.; Royer, R.

2004-08-01

A new environmental solution for hog manure management has been developed by Bio-Terre Systems Inc. in collaboration with Agriculture and Agri-Food Canada. The technical approach combines low-temperature anaerobic digestion, concentration of solids and production of biogas, a renewable energy source. Both small and large agricultural producers can benefit from this approach which helps transform organic matter into value-added by-products. They can fertilize their land with the liquid fraction, supply energy for their buildings with the biogas produced, and export surplus nutrients with the solid fraction. The technology also solves odour problems and destroys pathogenic microorganisms. No pretreatment is needed for this technology which makes use of robust anaerobic microorganisms that are low temperature tolerant. It is a stable process that provides continuous production of biogas with high energy potential. The automated system does not require much monitoring or maintenance. The environmental advantages include the production of biogas rich in methane, which can be used for electrical energy on the farm or sent to the electric power grids; production of high-value, odorless liquid fertilizer; a 50 per cent reduction of the amount of phosphorous in the liquid fraction; and, a 90 per cent reduction in greenhouse gas emissions from hog manure. The profitability of capital investment is assured by both the energy-savings and the agricultural benefits. 1 tab., 1 fig.

Anaerobic digestion of Chinese cabbage waste silage with swine manure for biogas production: batch and continuous study.

Science.gov (United States)

Kafle, Gopi Krishna; Bhattarai, Sujala; Kim, Sang Hun; Chen, Lide

2014-01-01

The aim of this study was to investigate the potential for anaerobic co-digestion of Chinese cabbage waste silage (CCWS) with swine manure (SM). Batch and continuous experiments were carried out under mesophilic anaerobic conditions (36-38°C). The batch test evaluated the effect of CCWS co-digestion with SM (SM: CCWS=100:0; 25:75; 33:67; 0:100, % volatile solids (VS) basis). The continuous test evaluated the performance of a single stage completely stirred tank reactor with SM alone and with a mixture of SM and CCWS. Batch test results showed no significant difference in biogas yield up to 25-33% of CCWS; however, biogas yield was significantly decreased when CCWS contents in feed increased to 67% and 100%. When testing continuous digestion, the biogas yield at organic loading rate (OLR) of 2.0 g VSL⁻¹ d⁻¹ increased by 17% with a mixture of SM and CCWS (SM:CCWS=75:25) (423 mL g⁻¹ VS) than with SM alone (361 mL g⁻¹ VS). The continuous anaerobic digestion process (biogas production, pH, total volatile fatty acids (TVFA) and TVFA/total alkalinity ratios) was stable when co-digesting SM and CCWS (75:25) at OLR of 2.0 g VSL⁻¹ d⁻¹ and hydraulic retention time of 20 days under mesophilic conditions.

Biogas Production from Batch Anaerobic Co-Digestion of Night Soil with Food Waste

Directory of Open Access Journals (Sweden)

Assadawut Khanto

2016-01-01

Full Text Available The objective of this study is to investigate the biogas production from Anaerobic Co-Digestion of Night Soil (NS with Food Waste (FW. The batch experiment was conducted through the NS and FW with a ratio of 70:30 by weight. The experiment is mainly evaluated by the characteristic of Co-Digestion and Biogas Production. In addition of food waste was inflating the COD loading from 17,863 to 42,063 mg/L which is 135 % increased. As the result, it shows that pH has dropped off in the beginning of 7-day during digestion and it was slightly increased into the range of optimum anaerobic condition. After digestion of the biogas production was 2,184 l and 56.5 % of methane fraction has obtained within 31 days of experimentation. The investigation of Biochemical Methane Potential (BMP and Specific Methanogenic Activities (SMA were highly observed. And the results were obtained by 34.55 mL CH4/gCODremoval and 0.38 g CH4-COD/gVSS-d. While the average COD removal from the 4 outlets got 92%, 94%, 94 % and 92 % respectively. However, the effluent in COD concentration was still high and it needs further treatment before discharge.

Isolation and characterization of Caldicellulosiruptor lactoaceticus sp. nov., an extremely thermophilic, cellulolytic, anaerobic bacterium

DEFF Research Database (Denmark)

Mladenovska, Zuzana; Mathrani, Indra M.; Ahring, Birgitte Kiær

1995-01-01

An anaerobic, extremely thermophilic, cellulolytic, non-spore-forming bacterium, strain 6A, was isolated from an alkaline hot spring in Hverageroi, Iceland. The bacterium was non-motile, rod-shaped (1.5-3.5 x 0.7 mu m) and occurred singly, in pairs or in chains and stained gram-negative. The growth...

Hollow fiber membrane based H-2 diffusion for efficient in situ biogas upgrading in an anaerobic reactor

DEFF Research Database (Denmark)

Luo, Gang; Angelidaki, Irini

2013-01-01

Bubbleless gas transfer through a hollow fiber membrane (HFM) module was used to supply H2 to an anaerobic reactor for in situ biogas upgrading, and it creates a novel system that could achieve a CH4 content higher than 90 % in the biogas. The increase of CH4 content and pH, and the decrease...

Biotechnological intensification of biogas production

Energy Technology Data Exchange (ETDEWEB)

Bagi, Z.; Acs, N.; Balint, B.; Horvath, L.; Dobo, K.; Perei, K.R.; Rakhely, G.; Kovacs, K.L. [Szeged Univ. (Hungary). Dept. of Biotechnology; Hungarian Academy of Sciences, Szeged (Hungary). Inst. of Biophysics

2007-08-15

The importance of syntrophic relationships among microorganisms participating in biogas formation has been emphasized, and the regulatory role of in situ hydrogen production has been recognized. It was assumed that the availability of hydrogen may be a limiting factor for hydrogenotrophic methanogens. This hypothesis was tested under laboratory and field conditions by adding a mesophilic (Enterobacter cloacae) or thermophilic hydrogen-producing (Caldicellulosyruptor saccharolyticus) strain to natural biogas-producing consortia. The substrates were waste water sludge, dried plant biomass from Jerusalem artichoke, and pig manure. In all cases, a significant intensification of biogas production was observed. The composition of the generated biogas did not noticeably change. In addition to being a good hydrogen producer, C. saccharolyticus has cellulolytic activity; hence, it is particularly suitable when cellulose-containing biomass is fermented. The process was tested in a 5-m{sup 3} thermophilic biogas digester using pig manure slurry as a substrate. Biogas formation increased at least 160-170% upon addition of the hydrogen-producing bacteria as compared to the biogas production of the spontaneously formed microbial consortium. Using the hydrogenase-minus control strain provided evidence that the observed enhancement was due to interspecies hydrogen transfer. The on-going presence of C. saccharolyticus was demonstrated after several months of semicontinuous operation. (orig.)

Pretreatment of wheat straw and conversion of xylose and xylan to ethanol by thermophilic anaerobic bacteria

DEFF Research Database (Denmark)

Ahring, Birgitte Kiær; Jensen, K.; Nielsen, P.

1996-01-01

solubilization was investigated. The two process parameters had little effect on the solubilization of hemicellulose. However alkaline conditions affected the furfural formation whereas oxygen had no effect. After pretreatment, the filtrate was used as a fermentation medium for thermophilic anaerobic bacterin...

Biological hydrogen production by moderately thermophilic anaerobic bacteria

International Nuclear Information System (INIS)

HP Goorissen; AJM Stams

2006-01-01

This study focuses on the biological production of hydrogen at moderate temperatures (65-75 C) by anaerobic bacteria. A survey was made to select the best (moderate) thermophiles for hydrogen production from cellulolytic biomass. From this survey we selected Caldicellulosiruptor saccharolyticus (a gram-positive bacterium) and Thermotoga elfii (a gram-negative bacterium) as potential candidates for biological hydrogen production on mixtures of C 5 -C 6 sugars. Xylose and glucose were used as model substrates to describe growth and hydrogen production from hydrolyzed biomass. Mixed substrate utilization in batch cultures revealed differences in the sequence of substrate consumption and in catabolites repression of the two microorganisms. The regulatory mechanisms of catabolites repression in these microorganisms are not known yet. (authors)

Comparison and analysis of organic components of biogas slurry from eichhornia crassipes solms and corn straw biogas slurry

Science.gov (United States)

Li, Q.; Li, Y. B.; Liu, Z. H.; Min, J.; Cui, Y.; Gao, X. H.

2017-11-01

Biogas slurry is one of anaerobic fermentations, and biomass fermentation biogas slurries with different compositions are different. This paper mainly presents through the anaerobic fermentation of Eichhornia crassipes solms biogas slurry and biogas slurry of corn straw, the organic components of two kinds of biogas slurry after extraction were compared by TLC, HPLC and spectrophotometric determination of nucleic acid and protein of two kinds of biogas slurry organic components, and analyzes the result of comparison.

A techno-economic evaluation of anaerobic biogas producing systems in developing countries.

Science.gov (United States)

Morgan, Hervan Marion; Xie, Wei; Liang, Jianghui; Mao, Hanping; Lei, Hanwu; Ruan, Roger; Bu, Quan

2018-02-01

Biogas production has been the focus of many individuals in the developing world; there have been several investigations that focus on improving the production process and product quality. In the developing world the lack of advanced technology and capital has hindered the development of energy production. Renewable energy has the potential to improve the standard of living for most of the 196 countries which are classified as developing economies. One of the easiest renewable energy compounds that can be produced is biogas (bio-methane). Biogas can be produced from almost any source of biomass through the anaerobic respiration of micro-organisms. Low budget energy systems are reviewed in this article along with various feedstock sources. Adapted gas purification and storage systems are also reviewed, along with the possible economic, social, health and environmental benefits of its implementation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Does the addition of proteases affect the biogas yield from organic material in anaerobic digestion?

Science.gov (United States)

Müller, Liane; Kretzschmar, Jörg; Pröter, Jürgen; Liebetrau, Jan; Nelles, Michael; Scholwin, Frank

2016-03-01

The aim of this study was to investigate the biochemical disintegration effect of hydrolytic enzymes in lab scale experiments. Influences of enzyme addition on the biogas yield as well as effects on the process stability were examined. The addition of proteases occurred with low and high dosages in batch and semi-continuous biogas tests. The feed mixture consisted of maize silage, chicken dung and cow manure. Only very high concentrated enzymes caused an increase in biogas production in batch experiments. In semi-continuous biogas tests no positive long-term effects (100 days) were observed. Higher enzyme-dosage led to a reduced biogas-yield (13% and 36% lower than the reference). Phenylacetate and -propionate increased (up to 372 mgl(-1)) before the other volatile fatty acids did. Volatile organic acids rose up to 6.8 gl(-1). The anaerobic digestion process was inhibited. Copyright © 2015 Elsevier Ltd. All rights reserved.

THE EFFECT OF F/M RATIO TO THE ANAEROBIC DECOMPOSITION OF BIOGAS PRODUCTION FROM FISH OFFAL WASTE

Directory of Open Access Journals (Sweden)

Agus Hadiyarto

2016-01-01

Full Text Available Biogas is a gas produced from the anaerobic decomposition of organic compounds. In the production of biogas from anaerobic digestion, value of F/M ratio shows a ratio between the mass of food available in the waste substrate with a mass of microorganisms that act as decomposers. F/M ratio is too small causing microbes could not metabolize perfectly and vice versa on the value of the ratio F / M overload resulting metabolic imbalance. The purpose of this study was to assess the effect of F/M ratio to optimal production of biogas from fish offal waste. The process of anaerobic digestion is conducted in the biodigester with four-liter volume and batch system operated at ambient temperature for 38 days. As a raw material, fish offal and microbial sludge obtained from the curing of fish and river mud discharges in the region of Bandarharjo, Semarang, Central Java. F/M ratio is set at 0.2, 0.4, and 0.6 are derived from sewage sludge VSS weight ratio of fish offal with sludge containing microbes. The addition of micronutrients supplied with a concentration of 0.4 mg/liter. Yield maximum methane gas obtained was 164,7 l/kg CODMn when the ratio F/M was 0.2. Based on the results of the study, found that the ratio F/M affect the amount of biogas produced. Meanwhile, the retention time (HRT is only influenced by the ratio F/M.

Anaerobic composting of waste organic fraction. Compostaje anaerobico de la fraccion organica de los residuos

Energy Technology Data Exchange (ETDEWEB)

Baere, L. de; Verdonck, O.; Verstraete, W.

1994-01-01

The dry anaerobic composting can be carried out in mesophilic and thermophilic conditions. Gas production of 6,2 and 8.5 m''3 biogas m''3 daily in laboratory fermenters was obtained. The quality of waste is higher than obtained in aerobic process. The streptococcus sludge was destroyed. This experimental can be applied for big scale and it permits energy recovery and organic compost of municipal solid wastes. (Author)

Fungal pretreatment of albizia chips for enhanced biogas production by solid-state anaerobic digestion

Science.gov (United States)

Albizia biomass is a forestry waste, and holds a great potential in biogas production by solid-state anaerobic digestion (SS-AD). However, low methane yields from albizia chips were observed due to their recalcitrant structure. In this study, albizia chips were pretreated by Ceriporiopsis subvermisp...

Anaerobic treatment with biogas recovery of beverage industry waste water

International Nuclear Information System (INIS)

Cacciari, E.; Zanoni, G.

1992-01-01

This paper briefly describes the application, by a leading Italian non-alcoholic beverage firm, of an up-flow anaerobic sludge blanket process in the treatment of waste water deriving from the production and bottling of beverages. In addition to describing the key design, operation and performance characteristics of the treatment process, the paper focuses on the economic benefits being obtained through the use of the innovative expansive sludge bed anaerobic digestion system which has proven itself to be particularly suitable for the treatment of food and beverage industry liquid wastes. The system, which has already been operating, with good results, for six months, has shown itself to be capable of yielding overall COD removal efficiencies of up to 94.8% and of producing about 0.43 Ncubic meters of biogas per kg of removed COD

Anaerobic treatment with biogas recovery of beverage industry waste water

Energy Technology Data Exchange (ETDEWEB)

Cacciari, E; Zanoni, G [Passavant Impianti, Novate Milanese (Italy)

1992-03-01

This paper briefly describes the application, by a leading Italian non-alcoholic beverage firm, of an up-flow anaerobic sludge blanket process in the treatment of waste water deriving from the production and bottling of beverages. In addition to describing the key design, operation and performance characteristics of the treatment process, the paper focuses on the economic benefits being obtained through the use of the innovative expansive sludge bed anaerobic digestion system which has proven itself to be particularly suitable for the treatment of food and beverage industry liquid wastes. The system, which has already been operating, with good results, for six months, has shown itself to be capable of yielding overall COD removal efficiencies of up to 94.8% and of producing about 0.43 Ncubic meters of biogas per kg of removed COD.

Composition and uses of anaerobic digestion derived biogas from wastewater treatment facilities in North America.

Science.gov (United States)

Lackey, Jillian C; Peppley, B; Champagne, P; Maier, A

2015-08-01

A study was conducted to determine the current knowledge of biogas production and its use at municipal wastewater treatment plants (WWTPs) across North America. Information was provided by municipal WWTPs across Canada and the US. It was determined that hydrogen sulfide (H2S) and silicon (Si) compounds had sufficient variability to be of concern. The only biogas production trend that could be identified was a possible seasonal relationship with sludge input and biogas production. Secondary analysis was performed to observe trends in biogas usage in urban areas larger than 150,000 in the US and 50,000 in Canada; 66% of facilities had anaerobic digestion systems and, of those, only 35% had an energy recovery system. Climatic, population, and socio-political influences on the trends were considered. The primary conclusion was that more data is required to perform significant analyses on biogas production and composition variation. © The Author(s) 2015.

Synergistic effect of co-digestion to enhance anaerobic degradation of catering waste and orange peel for biogas production.

Science.gov (United States)

Anjum, Muzammil; Khalid, Azeem; Qadeer, Samia; Miandad, Rashid

2017-09-01

Catering waste and orange peel were co-digested using an anaerobic digestion process. Orange peel is difficult to degrade anaerobically due to the presence of antimicrobial agents such as limonene. The present study aimed to examine the feasibility of anaerobic co-digestion of catering waste with orange peel to provide the optimum nutrient balance with reduced inhibitory effects of orange peel. Batch experiments were conducted using catering waste as a potential substrate mixed in varying ratios (20-50%) with orange peel. Similar ratios were followed using green vegetable waste as co-substrate. The results showed that the highest organic matter degradation (49%) was achieved with co-digestion of catering waste and orange peel at a 50% mixing ratio (CF4). Similarly, the soluble chemical oxygen demand (sCOD) was increased by 51% and reached its maximum value (9040 mg l -1 ) due to conversion of organic matter from insoluble to soluble form. Biogas production was increased by 1.5 times in CF4 where accumulative biogas was 89.61 m 3 t -1 substrate compared with 57.35 m 3 t -1 substrate in the control after 80 days. The main reason behind the improved biogas production and degradation is the dilution of inhibitory factors (limonene), with subsequent provision of balanced nutrients in the co-digestion system. The tCOD of the final digestate was decreased by 79.9% in CF4, which was quite high as compared with 68.3% for the control. Overall, this study revealed that orange peel waste is a highly feasible co-substrate for anaerobic digestion with catering waste for enhanced biogas production.

Silver Sulfidation in Thermophilic Anaerobic Digesters and Effects on Antibiotic Resistance Genes

Energy Technology Data Exchange (ETDEWEB)

Kim, Bojeong; Miller, Jennifer H.; Monsegue, Niven; Levard, Clément; Hong, Yanjuan; Hull, Matthew S.; Murayama, Mitsuhiro; Brown, Gordon E.; Vikesland, Peter J.; Knocke, William R.; Pruden, Amy; Hochella, Michael F.

2015-12-15

Physical and chemical transformations and biological responses of silver nanoparticles (AgNPs) in wastewater treatment systems are of particular interest because of the extensive existing and continually growing uses of AgNPs in consumer products. In this study, we investigated the transformation of AgNPs and AgNO₃ during thermophilic anaerobic digestion and effects on selection or transfer of antibiotic resistance genes (ARGs). Ag₂S-NPs, sulfidation products of both AgNPs and AgNO₃, were recovered from raw and digested sludges and were analyzed by analytical transmission electron microscopy (TEM) and X-ray absorption spectroscopy (XAS). TEM and XAS revealed rapid (≤20 min) Ag sulfidation for both Ag treatments. Once transformed, Ag₂S-NPs (as individual NPs or an NP aggregate) persisted for the duration of the batch digestion. The digestion process produced Ag₂S-NPs that were strongly associated with sludge organics and/or other inorganic precipitates. Ag treatments (up to 1,000 mg Ag/kg) did not have an impact on the performance of thermophilic anaerobic digesters or ARG response, as indicated by quantitative polymerase chain reaction measurements of sul1, tet(W), and tet(O) and also intI1, an indicator of horizontal gene transfer of ARGs. Thus, rapid Ag sulfidation and stabilization with organics effectively sequester Ag and prevent biological interactions with the digester microbial community that could induce horizontal gene transfer or adversely impact digester performance through antimicrobial activity. This finding suggests that sulfide-rich anaerobic environments, such as digesters, likely have a high buffer capacity to mitigate the biological effects of AgNPs.

Harvesting biogas from wastewater sludge and food waste

International Nuclear Information System (INIS)

Chua, K H; Cheah, W L; Leong, Y P; Tan, C F

2013-01-01

Wastewater sludge and food waste are good source of biogas. Anaerobic treatment of slude and food waste able to produce biogas which is a potential renewable energy source. This study looks into the potential biogas generation and the effects of temperature on biogas generation. A lab scale reactor was used to simulate the biogas generation. The results show that wastewater sludge able to produced upto 44.82 ml biogas/kg of sludge. When mixed with food waste at a ratio of 30:70 (food waste), the biogas generated were 219.07 ml/kg of waste. Anaerobic of food waste alone produced biogas amount to 59.75 ml/kg of food waste. Anaerobic treatment also reduces the volume of waste. The effect of temperature shows that higher temperature produces more biogas than lower temperature.

Biogas-pH automation control strategy for optimizing organic loading rate of anaerobic membrane bioreactor treating high COD wastewater.

Science.gov (United States)

Yu, Dawei; Liu, Jibao; Sui, Qianwen; Wei, Yuansong

2016-03-01

Control of organic loading rate (OLR) is essential for anaerobic digestion treating high COD wastewater, which would cause operation failure by overload or less efficiency by underload. A novel biogas-pH automation control strategy using the combined gas-liquor phase monitoring was developed for an anaerobic membrane bioreactor (AnMBR) treating high COD (27.53 g·L(-1)) starch wastewater. The biogas-pH strategy was proceeded with threshold between biogas production rate >98 Nml·h(-1) preventing overload and pH>7.4 preventing underload, which were determined by methane production kinetics and pH titration of methanogenesis slurry, respectively. The OLR and the effluent COD were doubled as 11.81 kgCOD·kgVSS(-1)·d(-1) and halved as 253.4 mg·L(-1), respectively, comparing with a constant OLR control strategy. Meanwhile COD removal rate, biogas yield and methane concentration were synchronously improved to 99.1%, 312 Nml·gCODin(-1) and 74%, respectively. Using the biogas-pH strategy, AnMBR formed a "pH self-regulation ternary buffer system" which seizes carbon dioxide and hence provides sufficient buffering capacity. Copyright © 2015 Elsevier Ltd. All rights reserved.

The contribution of fermentative bacteria and methanogenic archaea to azo dye reduction by a thermophilic anaerobic consortium

NARCIS (Netherlands)

Santos, dos A.B.; Cervantes, F.J.; Madrid, de M.P.; Bok, de F.A.M.; Stams, A.J.M.; Lier, van J.B.

2006-01-01

The contribution of fermentative bacteria and methanogenic archaea to azo dye reduction by a thermophilic anaerobic consortium was studied. Additionally, the effects of different electron-donating substrates and the redox mediator riboflavin on dye reduction were assessed by using either a

Evaluation of anaerobic degradation, biogas and digestate production of cereal silages using nylon-bags.

Science.gov (United States)

Negri, Marco; Bacenetti, Jacopo; Fiala, Marco; Bocchi, Stefano

2016-06-01

In this study, the degradation efficiency and the biogas and digestate production during anaerobic digestion were evaluated for the cereal silages most used to feed biogas plants. To this purpose, silages of: maize from the whole plant, maize from the ear, triticale and wheat were digested, inside of nylon bags, in laboratory scale digesters, for 75days. Overall, the test involved 288 nylon bags. After 75days of digestion, the maize ear silage shows the highest degradation efficiency (about 98%) while wheat silage the lowest (about 83%). The biogas production ranges from 438 to 852Nm(3)/t of dry matter for wheat and ear maize silage, respectively. For all the cereal silages, the degradation as well as the biogas production are faster at the beginning of the digestion time. Digestate mass, expressed as percentage of the fresh matter, ranges from 38% to 84% for wheat and maize ear silage, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biomass and biogas : potentials, efficiencies and flexibility

NARCIS (Netherlands)

Hofstede, Gert; Wouterse, Brian; Faber, Folkert; Nap, Jan Peter

2012-01-01

In the field of ‘renewable energy resources’ formation of biogas Biomass and biogas: potentials, efficiencies and flexibility is an important option. Biogas can be produced from biomass in a multistep process called anaerobic digestion (AD) and is usually performed in large digesters. Anaerobic

Analysis of biogas transformation in experimental biogas plant

Directory of Open Access Journals (Sweden)

Eva Jelínková

2011-01-01

Full Text Available The topic of this paper is the analysis of anaerobic fermentation in an experimental biogas plant. Technological processes and operation parameters were monitored; these processes and parameters include, for example, the optimal structure of the input material and the consideration of the prolonging of the duration of the fermentation process. The goal of prolonging the fermentation process is to obtain higher biogas (and methane production and to decrease the fermentation residue effluvial emissions. Emphasis is also laid on the mutual co-fermentation of substrates with regard to further use of the results in solving technological problems in other biogas plants. This technological process was first monitored in 2009; that is, before the planned intensification and modernization of the experimental biogas plant. Thus, the evaluation of the process could become part of the planned intensification and modernization of the chosen biogas plant (extended by the addition of the second stage of methanogenesis. The results obtained from the experimental biogas plant, which is one of the pioneering biogas plants in the Czech Republic, may serve, to other biogas operators, as a base for the preparation of suitable input, and for improving the efficiency of anaerobic fermentation within their biogas plants. The goal of the improvement of the fermentation process is to fulfill the ecological aspects; that is, to cut down CO2 emissions and to reduce the negative impact of the fermentation process on the environment (reduction of effluvium and noise originating in biogas plants.

Conversion of hemicelluloses and D-xylose into ethanol by the use of thermophilic anaerobic bacteria

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-05-01

Ethanol is a CO{sub 2} neutral liquid fuel that can substitute the use of fossil fuels in the transportation sector, thereby reducing the CO{sub 2} emission to the atmosphere. CO{sub 2} emission is suspected to contribute significantly to the so-called greenhouse effect, the global heating. Substrates for production of ethanol must be cheap and plentiful. This can be met by the use of lignocellulosic biomass such as willow, wheat straw, hardwood and softwood. However, the complexity of these polymeric substrates and the presence of several types of carbohydrates (glucose, xylose, mannose, galactose, arabinose) require additional treatment to release the useful carbohydrates and ferment the major carbohydrates fractions. The costs related to the ethanol-production must be kept at a minimum to be price competitive compared to gasoline. Therefore all of the carbohydrates present in lignocellulose need to be converted into ethanol. Glucose can be fermented to ethanol by yeast strains such as Saccharomyces cerevisiae, which, however, is unable to ferment the other major carbohydrate fraction, D-xylose. Thermophilic anaerobic ethanol producing bacteria can be used for fermentation of the hemicelluloses fraction of lignocellulosic biomass. However, physiological studies of thermophilic anaerobic bacteria have shown that the ethanol yield decreases at increasing substrate concentration. The biochemical limitations causing this phenomenon are not known in detail. Physiological and biochemical studies of a newly characterized thermophilic anaerobic ethanol producing bacterium, Thermoanaerobacter mathranii, was performed. This study included extraction of intracellular metabolites and enzymes of the pentose phosphate pathway and glycolysis. These studies revealed several bottlenecks in the D-xylose metabolism. This knowledge makes way for physiological and genetic engineering of this strain to improve the ethanol yield and productivity at high concentration of D-xylose. (au)

Anaerobic co-digestion of winery waste and waste activated sludge: assessment of process feasibility.

Science.gov (United States)

Da Ros, C; Cavinato, C; Cecchi, F; Bolzonella, D

2014-01-01

In this study the anaerobic co-digestion of wine lees together with waste activated sludge in mesophilic and thermophilic conditions was tested at pilot scale. Three organic loading rates (OLRs 2.8, 3.3 and 4.5 kgCOD/m(3)d) and hydraulic retention times (HRTs 21, 19 and 16 days) were applied to the reactors, in order to evaluate the best operational conditions for the maximization of the biogas yields. The addition of lee to sludge determined a higher biogas production: the best yield obtained was 0.40 Nm(3)biogas/kgCODfed. Because of the high presence of soluble chemical oxygen demand (COD) and polyphenols in wine lees, the best results in terms of yields and process stability were obtained when applying the lowest of the three organic loading rates tested together with mesophilic conditions.

Decentralized biogas technology of anaerobic digestion and farm ecosystem: opportunities and challenges

Directory of Open Access Journals (Sweden)

Junye eWang

2014-03-01

Full Text Available Long-term economic and environmental concerns have resulted in a great amount of research on renewable sources of biomass and bioenergy to replace fossil fuels in the past decades. Decentralized biogas technology is one of the most potential technologies of biomass and bioenergy by using agricultural waste materials (e.g., animal manure, crop straw and by-products from food industries as feedstocks. By-products from biogas production, called digestate, are nutrient rich which could potentially be reused as green fertilizers in agriculture, thereby providing a sustainable substitute for synthetic fertilizers for ecosystem farm. Thus, the biogas production of anaerobic digestion (AD is win-win option for livestock and crop producers to address issues of waste management and energy supply, and to avoid contamination of surface and ground waters and emissions of odors and greenhouse gases. In this paper, we review biogas production technology and then evaluate environmental effects of digestate used as fertilizer. Finally, we discuss issues of deployment of decentralized biogas technology for ecosystem farms. Economic and technological barriers still exist for large scale deployment of biogas technology. Two national scale deployments in China and Nepal showed that the operational status of biogas digesters is not optimal and up to 50% of plants are non-functional after a short operation period regardless of the social and economic factors. Main barriers are a wide variation of feedstocks and environmental conditions (e.g., temperature over space and time. It becomes clear that the experimental conditions of the pilot plants need to be adjusted and calibrated to the local feedstocks and climate. Also, more research needs to be done in cold fermentation technology.

Evaluation of two-phase thermophilic anaerobic methane fermentation for the treatment of garbage

International Nuclear Information System (INIS)

Park, Y.J.; Hong, F.; Japan Science and Technology Agency, Tokyo; Tsuno, H.; Hidaka, T.; Cheon, J.H.; Japan Science and Technology Agency, Tokyo

2004-01-01

Municipal solid wastes (MSW) in Japan are generally incinerated. However, in recent years, garbage has been recognized as a renewable energy source. This has resulted in an increase in the use of biological processes, such as anaerobic digestion, to treat organic waste such as sewage sludge and garbage. The two phases of anaerobic digestion are the acidogenic phase and the methane producing phase. Both differ significantly in their nutritional and physiological requirements. This study evaluated the effectiveness of treating garbage with the two-phase thermophilic methane fermentation system (TPS). The performance of the acid fermentation phase in TPS was examined with particular reference to operational parameters such as pH, hydraulic retention time and organic loading rate on volatile fatty acid fermentation. It was shown that TPS was more efficient than the single-phase thermophilic methane fermentation system (SPS). Acidification control in the first stage resulted in better stability of methane fermentation in the second stage. VFA formation was optimized at a pH of 6. The recovery ratios of VFAs and methane were achieved in the range of 42 to 44 per cent and 88 to 91 per cent of garbage by high organic loading rate respectively. 12 refs., 6 tabs., 4 figs

Thermophilic anaerobic oxidation of methane by marine microbial consortia.

Science.gov (United States)

Holler, Thomas; Widdel, Friedrich; Knittel, Katrin; Amann, Rudolf; Kellermann, Matthias Y; Hinrichs, Kai-Uwe; Teske, Andreas; Boetius, Antje; Wegener, Gunter

2011-12-01

The anaerobic oxidation of methane (AOM) with sulfate controls the emission of the greenhouse gas methane from the ocean floor. AOM is performed by microbial consortia of archaea (ANME) associated with partners related to sulfate-reducing bacteria. In vitro enrichments of AOM were so far only successful at temperatures ≤25 °C; however, energy gain for growth by AOM with sulfate is in principle also possible at higher temperatures. Sequences of 16S rRNA genes and core lipids characteristic for ANME as well as hints of in situ AOM activity were indeed reported for geothermally heated marine environments, yet no direct evidence for thermophilic growth of marine ANME consortia was obtained to date. To study possible thermophilic AOM, we investigated hydrothermally influenced sediment from the Guaymas Basin. In vitro incubations showed activity of sulfate-dependent methane oxidation between 5 and 70 °C with an apparent optimum between 45 and 60 °C. AOM was absent at temperatures ≥75 °C. Long-term enrichment of AOM was fastest at 50 °C, yielding a 13-fold increase of methane-dependent sulfate reduction within 250 days, equivalent to an apparent doubling time of 68 days. The enrichments were dominated by novel ANME-1 consortia, mostly associated with bacterial partners of the deltaproteobacterial HotSeep-1 cluster, a deeply branching phylogenetic group previously found in a butane-amended 60 °C-enrichment culture of Guaymas sediments. The closest relatives (Desulfurella spp.; Hippea maritima) are moderately thermophilic sulfur reducers. Results indicate that AOM and ANME archaea could be of biogeochemical relevance not only in cold to moderate but also in hot marine habitats.

Horse manure as feedstock for anaerobic digestion.

Science.gov (United States)

Hadin, Sa; Eriksson, Ola

2016-10-01

Horse keeping is of great economic, social and environmental benefit for society, but causes environmental impacts throughout the whole chain from feed production to manure treatment. According to national statistics, the number of horses in Sweden is continually increasing and is currently approximately 360,000. This in turn leads to increasing amounts of horse manure that have to be managed and treated. Current practices could cause local and global environmental impacts due to poor performance or lack of proper management. Horse manure with its content of nutrients and organic material can however contribute to fertilisation of arable land and recovery of renewable energy following anaerobic digestion. At present anaerobic digestion of horse manure is not a common treatment. In this paper the potential for producing biogas and biofertiliser from horse manure is analysed based on a thorough literature review in combination with mathematical modelling and simulations. Anaerobic digestion was chosen as it has a high degree of resource conservation, both in terms of energy (biogas) and nutrients (digestate). Important factors regarding manure characteristics and operating factors in the biogas plant are identified. Two crucial factors are the type and amount of bedding material used, which has strong implications for feedstock characteristics, and the type of digestion method applied (dry or wet process). Straw and waste paper are identified as the best materials in an energy point of view. While the specific methane yield decreases with a high amount of bedding, the bedding material still makes a positive contribution to the energy balance. Thermophilic digestion increases the methane generation rate and yield, compared with mesophilic digestion, but the total effect is negligible. Copyright © 2016. Published by Elsevier Ltd.

A pH-based control of ammonia in biogas during anaerobic digestion of artificial pig manure and maize silage

NARCIS (Netherlands)

Strik, D.P.B.T.B.; Domnanovich, A.M.; Braun, R.; Holubar, P.

2006-01-01

The purposes of this study were to prove that ammonia can be present in biogas from anaerobic digestion and to control this ammonia by reducing the reactor pH. Ammonia containing biogas was produced for a period of more than 100 days, with a maximum of 332 ppm. Especially during periods of high free

Identification of anaerobic microorganisms for converting kitchen waste to biogas

International Nuclear Information System (INIS)

Amirhossein Malakahmad; Shahrom Mohd Zain; Noor Ezlin Ahmad Basri; Shamsul Rahman Mohamed Kutty; Mohd Hasnain Isa

2010-01-01

Anaerobic digestion process is one of the alternative methods to convert organic waste into methane gas which is a fuel and energy source. Activities of various kinds of microorganisms are the main factor for anaerobic digestion which produces methane gas. Therefore, in this study a modified Anaerobic Baffled Reactor (ABR) with working volume of 50 liters was designed to identify the microorganisms through biogas production. The mixture of 75% kitchen waste and 25% sewage sludge was used as substrate. Observations on microorganisms in the ABR showed that there exists a small amount of protozoa (5%) and fungi (2%) in the system, but almost 93% of the microorganism population consists of bacteria. It is definitely clear that bacteria are responsible for anaerobic biodegradation of kitchen waste. Results show that in the acidification zone of the ABR (front compartments of reactor) fast growing bacteria capable of growth at high substrate levels and reduced pH was dominant. A shift to slower growing scavenging bacteria that grow better at higher pH was occurring towards the end of the reactor. Due to the ability of activity in acetate environment the percentages of Methanococcus, Methanosarcina and Methanotrix were higher than other kinds of methane former in the system. (Author)

High-calorific biogas production from anaerobic digestion of food waste using a two-phase pressurized biofilm (TPPB) system.

Science.gov (United States)

Li, Yeqing; Liu, Hong; Yan, Fang; Su, Dongfang; Wang, Yafei; Zhou, Hongjun

2017-01-01

To obtain high calorific biogas via anaerobic digestion without additional upgrading equipment, a two-phase pressurized biofilm system was built up, including a conventional continuously stirred tank reactor and a pressurized biofilm anaerobic reactor (PBAR). Four different pressure levels (0.3, 0.6, 1.0 and 1.7MPa) were applied to the PBAR in sequence, with the organic loading rate maintained at 3.1g-COD/L/d. Biogas production, gas composition, process stability parameters were measured. Results showed that with the pressure increasing from 0.3MPa to 1.7MPa, the pH value decreased from 7.22±0.19 to 6.98±0.05, the COD removal decreased from 93.0±0.9% to 79.7±1.2% and the methane content increased from 80.5±1.5% to 90.8±0.8%. Biogas with higher calorific value of 36.2MJ/m 3 was obtained at a pressure of 1.7MPa. Pressure showed a significant effect on biogas production and gas quality in methanogenesis reactor. Copyright © 2016 Elsevier Ltd. All rights reserved.

Decentralized Biogas Technology of Anaerobic Digestion and Farm Ecosystem: Opportunities and Challenges

Energy Technology Data Exchange (ETDEWEB)

Wang, Junye, E-mail: junyew@athabascau.ca [Faculty of Science and Technology, Athabasca University, Athabasca, AB (Canada)

2014-03-26

Long-term economic and environmental concerns have resulted in a great amount of research on renewable sources of biomass and bioenergy to replace fossil fuels in the past decades. Decentralized biogas technology is one of the most potential technologies of biomass and bioenergy by using agricultural waste materials (e.g., animal manure, crop straw, and by-products from food industries) as feedstocks. By-products from biogas production, called digestate, are nutrient rich, which could potentially be reused as green fertilizers in agriculture, thereby providing a sustainable substitute for synthetic fertilizers for farm ecosystem. Thus, the biogas production of anaerobic digestion is win–win option for livestock and crop producers to address issues of waste management and energy supply, and to avoid contamination of surface and ground waters and emissions of odors and greenhouse gases. In this paper, we review biogas production technology and then evaluate environmental effects of digestate used as fertilizer. Finally, we discuss issues of deployment of decentralized biogas technology for farm ecosystem. Economic and technological barriers still exist for large scale deployment of biogas technology in rural region. Two national scale deployments in China and Nepal showed that the operational status of biogas digesters is not optimal and up to 50% of plants are non-functional after a short operation period regardless of the social and economic factors. Main barriers are a wide variation of feedstocks and environmental conditions (e.g., temperature) over space and time. It becomes clear that the experimental conditions of the pilot plants need to be adjusted and calibrated to the local feedstocks and climate. Also, more research needs to be done in cold fermentation technology. Thus, collaboration of all relevant designers, farmers, stakeholders, and regulators is proposed as the way forward, particularly as their complexity has been identified as the major hurdle

Decentralized Biogas Technology of Anaerobic Digestion and Farm Ecosystem: Opportunities and Challenges

International Nuclear Information System (INIS)

Wang, Junye

2014-01-01

Long-term economic and environmental concerns have resulted in a great amount of research on renewable sources of biomass and bioenergy to replace fossil fuels in the past decades. Decentralized biogas technology is one of the most potential technologies of biomass and bioenergy by using agricultural waste materials (e.g., animal manure, crop straw, and by-products from food industries) as feedstocks. By-products from biogas production, called digestate, are nutrient rich, which could potentially be reused as green fertilizers in agriculture, thereby providing a sustainable substitute for synthetic fertilizers for farm ecosystem. Thus, the biogas production of anaerobic digestion is win–win option for livestock and crop producers to address issues of waste management and energy supply, and to avoid contamination of surface and ground waters and emissions of odors and greenhouse gases. In this paper, we review biogas production technology and then evaluate environmental effects of digestate used as fertilizer. Finally, we discuss issues of deployment of decentralized biogas technology for farm ecosystem. Economic and technological barriers still exist for large scale deployment of biogas technology in rural region. Two national scale deployments in China and Nepal showed that the operational status of biogas digesters is not optimal and up to 50% of plants are non-functional after a short operation period regardless of the social and economic factors. Main barriers are a wide variation of feedstocks and environmental conditions (e.g., temperature) over space and time. It becomes clear that the experimental conditions of the pilot plants need to be adjusted and calibrated to the local feedstocks and climate. Also, more research needs to be done in cold fermentation technology. Thus, collaboration of all relevant designers, farmers, stakeholders, and regulators is proposed as the way forward, particularly as their complexity has been identified as the major hurdle

Life Cycle Assessment of different uses of biogas from anaerobic digestion of separately collected biodegradable waste in France. Final report

International Nuclear Information System (INIS)

2007-01-01

In the first part of the study, Gaz de France (GdF) and the French Environment Energy Management Agency (ADEME) wished to identify the best method to use the biogas from anaerobic digestion of separately collected biodegradable waste (bio-waste). Secondly, GdF and ADEME wished to evaluate the strength and weaknesses of the two main different organic recycling: anaerobic digestion (methanization) and composting. The study is based on the life cycle assessment method. The life cycle assessment used for this study consists in quantifying the environmental impacts of all of the activities which are related to the chosen use method. This methodology involves compiling a detailed account of all substances and energy flows removed or emitted from or into the environment at each stage of the life cycle. These flows are then translated into indicators of potential environment impacts. This methodology is based on the international standards ISO14040 and ISO 14044. The life cycle assessment was performed by RDC Environnement. In this study, two questions were treated: - Which is the best valorisation method for biogas produced from the anaerobic digestion of separately collected biodegradable waste: fuel, heat or electricity? ('Biogas' question); - Which is the best treatment for the separately collected biodegradable waste: anaerobic digestion (methanization) or industrial composting? ('Composting' question). The field of the study includes the arrival of the separately collected biodegradable waste at the anaerobic unit as well as the utilisation of the biogas energy and the agricultural use of the digestate from anaerobic digestion. For each biogas utilisation, the environmental impacts of each life cycle stage were considered as well as the impacts that were avoided due to the substitution of the use of non-renewable energy ('conventional' procedures). The modelling of the direct composting of the biodegradable waste was realised taking into account the followings

Comparative microbiological-hygienic studies in mesophilic and thermophilic fouling of sewage sludge

Energy Technology Data Exchange (ETDEWEB)

Pohlig-Schmitt, M.; Philipp, W.; Wekerle, J.; Strauch, D.

Investigations concerning the inactivation of microbial pathogens (bacteria, viruses and parasites) during anaerobic, alkaline dignestion of sludge are described. A thermophilic (54/sup 0/C) and a mesophilic (34/sup 0/C) operated biogas model plant were compared from the point of view of hygiene. Is was found that in the thermophilic process Salmonella senftenberg survived 13,5 h, Streptococcus faecium 55 h, Streptococcus faecalis 42 h and Klebsiella pneumoniae 0,5 h. Within 30 min eggs of Ascaris suum lost their infectivity Bovine Parvovirus was inactivated after 1 d to 2 d treatment. Survival times under mesophilic conditions of 13 d for Salmonella senftenberg and more than 8 mouth for Streptococcus faecium were found. Poliovirus Type 1 was inactivated in 8 d while Bovine Parvovirus survived no longer than 15 d. The results obtained in the thermophilic process were compared to those after heat treatment of the test microorganisms in ampules exposed in a wather-bath under defined conditions to 54/sup 0/C. It was found, that the bacteria survived only about half the time in this case. Poliovirus Type 1 was inactivated after 0,75 h and Bovine Parvovirus after 7 d exposure. (orig.RB)

Detection of putatively thermophilic anaerobic methanotrophs in diffuse hydrothermal vent fluids.

Science.gov (United States)

Merkel, Alexander Y; Huber, Julie A; Chernyh, Nikolay A; Bonch-Osmolovskaya, Elizaveta A; Lebedinsky, Alexander V

2013-02-01

The anaerobic oxidation of methane (AOM) is carried out by a globally distributed group of uncultivated Euryarchaeota, the anaerobic methanotrophic arachaea (ANME). In this work, we used G+C analysis of 16S rRNA genes to identify a putatively thermophilic ANME group and applied newly designed primers to study its distribution in low-temperature diffuse vent fluids from deep-sea hydrothermal vents. We found that the G+C content of the 16S rRNA genes (P(GC)) is significantly higher in the ANME-1GBa group than in other ANME groups. Based on the positive correlation between the P(GC) and optimal growth temperatures (T(opt)) of archaea, we hypothesize that the ANME-1GBa group is adapted to thrive at high temperatures. We designed specific 16S rRNA gene-targeted primers for the ANME-1 cluster to detect all phylogenetic groups within this cluster, including the deeply branching ANME-1GBa group. The primers were successfully tested both in silico and in experiments with sediment samples where ANME-1 phylotypes had previously been detected. The primers were further used to screen for the ANME-1 microorganisms in diffuse vent fluid samples from deep-sea hydrothermal vents in the Pacific Ocean, and sequences belonging to the ANME-1 cluster were detected in four individual vents. Phylotypes belonging to the ANME-1GBa group dominated in clone libraries from three of these vents. Our findings provide evidence of existence of a putatively extremely thermophilic group of methanotrophic archaea that occur in geographically and geologically distinct marine hydrothermal habitats.

Investigation of Poultry Waste for Anaerobic Digestion: A Case Study

Science.gov (United States)

Salam, Christopher R.

Anaerobic Digestion (AD) is a biological conversion technology which is being used to produce bioenergy all over the world. This energy is created from biological feedstocks, and can often use waste products from various food and agricultural processors. Biogas from AD can be used as a fuel for heating or for co-generation of electricity and heat and is a renewable substitute to using fossil fuels. Nutrient recycling and waste reduction are additional benefits, creating a final product that can be used as a fertilizer in addition to energy benefits. This project was conducted to investigate the viability of three turkey production wastes as AD feedstock: two turkey litters and a material separated from the turkey processing wastewater using dissolved air flotation (DAF) process. The DAF waste contained greases, oils and other non-commodity portions of the turkey. Using a variety of different process methods, types of bacteria, loading rates and food-to-microorganism ratios, optimal loading rates for the digestion of these three materials were obtained. In addition, the co-digestion of these materials revealed additional energy benefits. In this study, batch digestion tests were carried out to treat these three feedstocks, using mesophilic and thermophilic bacteria, using loading rates of 3 and 6 gVS/L They were tested separately and also as a mixture for co-digestion. The batch reactor used in this study had total and working volumes of 1130 mL and 500 mL, respectively. The initial organic loading was set to be 3 gVS/L, and the food to microorganism ratio was either 0.6 or 1.0 for different treatments based on the characteristics of each material. Only thermophilic (50 +/- 2ºC) temperatures were tested for the litter and DAF wastes in continuous digestion, but mesophilic and thermophilic batch digestion experiments were conducted. The optimum digestion time for all experiments was 14 days. The biogas yields of top litter, mixed litter, and DAF waste under

Application of ADM1 for modeling of biogas production from anaerobic digestion of Hydrilla verticillata.

Science.gov (United States)

Chen, Xiaojuan; Chen, Zhihua; Wang, Xun; Huo, Chan; Hu, Zhiquan; Xiao, Bo; Hu, Mian

2016-07-01

The present study focused on the application of anaerobic digestion model no. 1 (ADM1) to simulate biogas production from Hydrilla verticillata. Model simulation was carried out by implementing ADM1 in AQUASIM 2.0 software. Sensitivity analysis was used to select the most sensitive parameters for estimation using the absolute-relative sensitivity function. Among all the kinetic parameters, disintegration constant (kdis), hydrolysis constant of protein (khyd_pr), Monod maximum specific substrate uptake rate (km_aa, km_ac, km_h2) and half-saturation constants (Ks_aa, Ks_ac) affect biogas production significantly, which were optimized by fitting of the model equations to the data obtained from batch experiments. The ADM1 model after parameter estimation was able to well predict the experimental results of daily biogas production and biogas composition. The simulation results of evolution of organic acids, bacteria concentrations and inhibition effects also helped to get insight into the reaction mechanisms. Copyright © 2016. Published by Elsevier Ltd.

6th Conference 'Anaerobic treatment of biological wastes'. New tendencies in the biogas technology; 6. Fachtagung Anaerobe biologische Abfallbehandlung. Neue Tendenzen in der Biogastechnologie

Energy Technology Data Exchange (ETDEWEB)

Bilitewski, B.; Werner, P.; Dornack, Christina; Stegmann, R.; Rettenberger, G.; Faulstich, M.; Wittmaier, M. (eds.)

2008-07-01

Within this 6th conference at 23rd to 24th September, 2008, in Dresden (Federal Republic of Germany), the following lectures were held: (1) Development of biogas technology - influences and tendencies (H. Friedmann); (2) EEG 2009 - Effect on biogas branch (B. Dreher); (3) From composting to fermentation - material flows, technology, cost, practical experiences (M. Kern, T. Raussen, A. Lootsma, K. Funda); (4) Fermentation of vinasses from the production of bioethanol (H. Friedmann); (5) Substrate digestion and microbiological hydrolysis for biogas production from lignocellulosis containing substrates using beer draff as an example (D. Schieder, M. Faulstich, J. Voigt, J. Ellenriedere, B. Haeffner, K. Sommer); (6) Substitution of wheat and corn by grass and manure for improving the economic efficiency of biogas plants (M. Wittmaier); (7) High-efficiency anaerobic digestion with integrated micro filtration using clarification sludge as an example (W. Troesch, B. Kempter-Regel); (8) Modelling of anaerobic digestion; stationary and dynamic parameter of estimation (C. Cimatoribus); (9) Regulation of an anaerobic laboratory reactor by means of fuzzy logic (O. Bade); (10) Model based diagnosis of the state of process in biogas plants (W. Kloeden); (11) Suitability of ADM 1 in the modelling of biogas plants (K. Koch, M. Wichern, M. Luebken, H. Horn, M. Schlattmann, A. Gronauer); (12) Load dependent and automatical operation of biogas plants - an option for the future (M. Mueller, J. Proeter, F. Scholwin); (13) Chances for biogas generation and application in Vietnam (L. van Bot, M. Wittmaier, A. Karagiannidies, B. Bilitewski, P. Werner); (14) State of the art and developments in the fermentation of biological wastes in the Peoples Republic of China (M. Gehring, R. Li, B. Raininger); (15) Bio-methane potential from cattle and pig wastes in Greece (A. Karagiannidis, G. Perkoulidis, T. Kotsopoulos); (16) Contaminants in biogas plants - an assessment of the material flow using

Performance optimization and validation of ADM1 simulations under anaerobic thermophilic conditions

KAUST Repository

Atallah, Nabil M.

2014-12-01

In this study, two experimental sets of data each involving two thermophilic anaerobic digesters treating food waste, were simulated using the Anaerobic Digestion Model No. 1 (ADM1). A sensitivity analysis was conducted, using both data sets of one digester, for parameter optimization based on five measured performance indicators: methane generation, pH, acetate, total COD, ammonia, and an equally weighted combination of the five indicators. The simulation results revealed that while optimization with respect to methane alone, a commonly adopted approach, succeeded in simulating methane experimental results, it predicted other intermediary outputs less accurately. On the other hand, the multi-objective optimization has the advantage of providing better results than methane optimization despite not capturing the intermediary output. The results from the parameter optimization were validated upon their independent application on the data sets of the second digester.

Performance optimization and validation of ADM1 simulations under anaerobic thermophilic conditions

KAUST Repository

Atallah, Nabil M.; El-Fadel, Mutasem E.; Ghanimeh, Sophia A.; Saikaly, Pascal; Abou Najm, Majdi R.

2014-01-01

In this study, two experimental sets of data each involving two thermophilic anaerobic digesters treating food waste, were simulated using the Anaerobic Digestion Model No. 1 (ADM1). A sensitivity analysis was conducted, using both data sets of one digester, for parameter optimization based on five measured performance indicators: methane generation, pH, acetate, total COD, ammonia, and an equally weighted combination of the five indicators. The simulation results revealed that while optimization with respect to methane alone, a commonly adopted approach, succeeded in simulating methane experimental results, it predicted other intermediary outputs less accurately. On the other hand, the multi-objective optimization has the advantage of providing better results than methane optimization despite not capturing the intermediary output. The results from the parameter optimization were validated upon their independent application on the data sets of the second digester.

Copper stressed anaerobic fermentation: biogas properties, process stability, biodegradation and enzyme responses.

Science.gov (United States)

Hao, He; Tian, Yonglan; Zhang, Huayong; Chai, Yang

2017-12-01

The effect of copper (added as CuCl 2 ) on the anaerobic co-digestion of Phragmites straw and cow dung was studied in pilot experiments by investigating the biogas properties, process stability, substrate degradation and enzyme activities at different stages of mesophilic fermentation. The results showed that 30 and 100 mg/L Cu 2+ addition increased the cumulative biogas yields by up to 43.62 and 20.77% respectively, and brought forward the daily biogas yield peak, while 500 mg/L Cu 2+ addition inhibited biogas production. Meanwhile, the CH 4 content in the 30 and 100 mg/L Cu 2+ -added groups was higher than that in the control group. Higher pH values (close to pH 7) and lower oxidation-reduction potential (ORP) values in the Cu 2+ -added groups after the 8th day indicated better process stability compared to the control group. In the presence of Cu 2+ , the degradation of volatile fatty acids (VFAs) and other organic molecules (represented by chemical oxygen demand, COD) generated from hydrolysis was enhanced, and the ammonia nitrogen (NH 4 + -N) concentrations were more stable than in the control group. The contents of lignin and hemicellulose in the substrate declined in the Cu 2+ -added groups while the cellulose contents did not. Neither the cellulase nor the coenzyme F 420 activities could determine the biogas producing efficiency. Taking the whole fermentation process into account, the promoting effect of Cu 2+ addition on biogas yields was mainly attributable to better process stability, the enhanced degradation of lignin and hemicellulose, the transformation of intermediates into VFA, and the generation of CH 4 from VFA.

Performance and methanogenic community of rotating disk reactor packed with polyurethane during thermophilic anaerobic digestion

International Nuclear Information System (INIS)

Yang, Yingnan; Tsukahara, Kenichiro; Sawayama, Shigeki

2007-01-01

A newly developed anaerobic rotating disk reactor (ARDR) packed with polyurethane was used in continuous mode for organic waste removal under thermophilic (55 o C) anaerobic conditions. This paper reports the effects of the rotational speed on the methanogenic performance and community in an ARDR supplied with acetic acid synthetic wastewater as the organic substrate. The best performance was obtained from the ARDR with the rotational speed (ω) of 30 rpm. The average removal of dissolved organic carbon was 98.5%, and the methane production rate was 393 ml/l-reactor/day at an organic loading rate of 2.69 g/l-reactor/day. Under these operational conditions, the reactor had a greater biomass retention capacity and better reactor performance than those at other rotational speeds (0, 5 and 60 rpm). The results of 16S rRNA phylogenetic analysis indicated that the major methanogens in the reactor belonged to the genus Methanosarcina spp. The results of real-time polymerase chain reaction (PCR) analysis suggested that the cell density of methanogenic archaea immobilized on the polyurethane foam disk could be concentrated more than 2000 times relative to those in the original thermophilic sludge. Scanning electron microphotographs showed that there were more immobilized microbes at ω of 30 rpm than 60 rpm. A rotational speed on the outer layer of the disk of 6.6 m/min could be appropriate for anaerobic digestion using the polyurethane ARDR

Produksi biogas dari pencerna anaerob serasah dan eceng gondok (Eichhornia crassipes dengan sumber inokulum kotoran sapi dan kotoran ayam

Directory of Open Access Journals (Sweden)

REVOLUSI PRAJANINGRAT SAKTIYUDHA

2014-11-01

Full Text Available Saktiyudha RP. 2014. Biogas production from anaerobic digesters of leaf litter and water hyacinth (Eichhornia crassipes with a source of inoculum cattle and chicken manures. Bioteknologi 11: 23-27. Biogas is a renewable alternative energy source also has the added value, which is in the processing of waste biomass is environmentally friendly. This study aims to examine the production of biogas in anaerobic reform process based on a mixture of biomass litter substrate and water hyacinth (Eichhornia crassipes Mart. Solms using inoculum source of cattle manure and chicken manure. Litter biomass and water hyacinth biomass were as a substrate (80% in the anaerobic digester with inoculum source of cattle manure or chicken manure (20% through the fermentation process. Factorial experiment with four replications performed using a completely randomized design (CRD with two factors. The first factor in the form of variations in the substrate, the substrate control with 100 % litter, litter substrate variation and water hyacinth (75%:25%, and a mixture of litter and water hyacinth (50%:50% . The second factor were a variation of the source of inoculum, ie cattle manure and chicken manure. Parameter measurements performed at weeks 0th, 2nd, 4th, 6th. Parameters observed were volume of biogas, CH4 concentration, temperature, pH, COD, BOD, TS and VS. Data were analyzed by ANOVA followed by DMRT at 5 % level test. Highest production of biogas in the sixth week (862.5 ml was showed by the treatment of 75 % litter and 25 % water hyacinth with inoculum source of cattle manure. Removal efficiency of COD; BOD; TS and VS on that treatment were amounted to 76.12 %, 32.88 %, 66.53 % and 63.74 %.

A new degassing membrane coupled upflow anaerobic sludge blanket (UASB) reactor to achieve in-situ biogas upgrading and recovery of dissolved CH4 from the anaerobic effluent

International Nuclear Information System (INIS)

Luo, Gang; Wang, Wen; Angelidaki, Irini

2014-01-01

Highlights: • A new UASB configuration was developed by coupling with degassing membrane. • In-situ biogas upgrading was achieved with high methane content (>90%). • Decrease of dissolved methane in the anaerobic effluent was achieved. - Abstract: A new technology for in-situ biogas upgrading and recovery of CH 4 from the effluent of biogas reactors was proposed and demonstrated in this study. A vacuum degassing membrane module was used to desorb CO 2 from the liquid phase of a biogas reactor. The degassing membrane was submerged into a degassing unit (DU). The results from batch experiments showed that mixing intensity, transmembrane pressure, pH and inorganic carbon concentration affected the CO 2 desorption rate in the DU. Then, the DU was directly connected to an upflow anaerobic sludge blanket (UASB) reactor. The results showed the CH 4 content was only 51.7% without desorption of CO 2 , while it increased when the liquid of UASB was recycled through the DU. The CH 4 content increased to 71.6%, 90%, and 94% with liquid recirculation rate through the DU of 0.21, 0.42 and 0.63 L/h, respectively. The loss of methane due to dissolution in the effluent was reduced by directly pumping the reactor effluent through the DU. In this way, the dissolved CH 4 concentration in the effluent decreased from higher than 0.94 mM to around 0.13 mM, and thus efficient recovery of CH 4 from the anaerobic effluent was achieved. In the whole operational period, the COD removal efficiency and CH 4 yield were not obviously affected by the gas desorption

Performance optimization and validation of ADM1 simulations under anaerobic thermophilic conditions.

Science.gov (United States)

Atallah, Nabil M; El-Fadel, Mutasem; Ghanimeh, Sophia; Saikaly, Pascal; Abou-Najm, Majdi

2014-12-01

In this study, two experimental sets of data each involving two thermophilic anaerobic digesters treating food waste, were simulated using the Anaerobic Digestion Model No. 1 (ADM1). A sensitivity analysis was conducted, using both data sets of one digester, for parameter optimization based on five measured performance indicators: methane generation, pH, acetate, total COD, ammonia, and an equally weighted combination of the five indicators. The simulation results revealed that while optimization with respect to methane alone, a commonly adopted approach, succeeded in simulating methane experimental results, it predicted other intermediary outputs less accurately. On the other hand, the multi-objective optimization has the advantage of providing better results than methane optimization despite not capturing the intermediary output. The results from the parameter optimization were validated upon their independent application on the data sets of the second digester. Copyright © 2014 Elsevier Ltd. All rights reserved.

Continuous fermentative hydrogen production from cheese whey wastewater under thermophilic anaerobic conditions

Energy Technology Data Exchange (ETDEWEB)

Azbar, Nuri; Cetinkaya Dokgoez, F. Tuba; Keskin, Tugba; Korkmaz, Kemal S.; Syed, Hamid M. [Bioengineering Department, Faculty of Engineering, Ege University, EBILTEM, Bornova, 35100 Izmir (Turkey)

2009-09-15

Hydrogen (H{sub 2}) production from cheese processing wastewater via dark anaerobic fermentation was conducted using mixed microbial communities under thermophilic conditions. The effects of varying hydraulic retention time (HRT: 1, 2 and 3.5 days) and especially high organic load rates (OLR: 21, 35 and 47 g chemical oxygen demand (COD)/l/day) on biohydrogen production in a continuous stirred tank reactor were investigated. The biogas contained 5-82% (45% on average) hydrogen and the hydrogen production rate ranged from 0.3 to 7.9 l H{sub 2}/l/day (2.5 l/l/day on average). H{sub 2} yields of 22, 15 and 5 mmol/g COD (at a constant influent COD of 40 g/l) were achieved at HRT values of 3.5, 2, and 1 days, respectively. On the other hand, H{sub 2} yields were monitored to be 3, 9 and 6 mmol/g COD, for OLR values of 47, 35 and 21 g COD/l/day, when HRT was kept constant at 1 day. The total measurable volatile fatty acid concentration in the effluent (as a function of influent COD) ranged between 118 and 27,012 mg/l, which was mainly composed of acetic acid, iso-butyric acid, butyric acid, propionic acid, formate and lactate. Ethanol and acetone production was also monitored from time to time. To characterize the microbial community in the bioreactor at different HRTs, DNA in mixed liquor samples was extracted immediately for PCR amplification of 16S RNA gene using eubacterial primers corresponding to 8F and 518R. The PCR product was cloned and subjected to DNA sequencing. The sequencing results were analyzed by using MegaBlast available on NCBI website which showed 99% identity to uncultured Thermoanaerobacteriaceae bacterium. (author)

Anaerobic digestion of fruit and vegetable processing wastes for biogas production

Energy Technology Data Exchange (ETDEWEB)

Viswanath, P.; Sumithra Devi, S.; Nand, K. (Central Food Technological Research Inst., Mysore (IN))

1992-01-01

The effect of feeding different fruit and vegetable wastes, mango, pineapple, tomato, jackfruit, banana and orange, was studied in a 60-litre digester by cycling each waste every fifth day in order to operate the digester as and when there was supply of feed. The characteristics of the anaerobically digested fluid and digester performance in terms of biogas production were determined at different loading rates (LR) and at different hydraulic retention times (HRT) and the maximum biogas yield of 0.6 m{sup 3}/kg VS added was achieved at a 20-day HRT and 40 kg TS m{sup -3}day{sup -1} loading rate. The hourly gas production was observed in the digesters operated at 16 and 24 days HRT. The major yield (74.5%) of gas was produced within 12h of feeding at a 16-day HRT whereas at a 24-day HRT only 59.03% of the total gas could be obtained at this time. (author).

Anaerobic Digestion and Biogas Potential: Simulation of Lab and Industrial-Scale Processes

Directory of Open Access Journals (Sweden)

Ihsan Hamawand

2015-01-01

Full Text Available In this study, a simulation was carried out using BioWin 3.1 to test the capability of the software to predict the biogas potential for two different anaerobic systems. The two scenarios included: (1 a laboratory-scale batch reactor; and (2 an industrial-scale anaerobic continuous lagoon digester. The measured data related to the operating conditions, the reactor design parameters and the chemical properties of influent wastewater were entered into BioWin. A sensitivity analysis was carried out to identify the sensitivity of the most important default parameters in the software’s models. BioWin was then calibrated by matching the predicted data with measured data and used to simulate other parameters that were unmeasured or deemed uncertain. In addition, statistical analyses were carried out using evaluation indices, such as the coefficient of determination (R-squared, the correlation coefficient (r and its significance (p-value, the general standard deviation (SD and the Willmott index of agreement, to evaluate the agreement between the software prediction and the measured data. The results have shown that after calibration, BioWin can be used reliably to simulate both small-scale batch reactors and industrial-scale digesters with a mean absolute percentage error (MAPE of less than 10% and very good values of the indexes. Furthermore, by changing the default parameters in BioWin, which is a way of calibrating the models in the software, as well, this may provide information about the performance of the digester. Furthermore, the results of this study showed there may be an over estimation for biogas generated from industrial-scale digesters. More sophisticated analytical devices may be required for reliable measurements of biogas quality and quantity.

Research on Anaerobic Digestion: Optimization and Scalability of Mixed High-strength Food Processing Wastes for Renewable Biogas Energy

Energy Technology Data Exchange (ETDEWEB)

Yu, Zhongtang [The Ohio State Univ., Columbus, OH (United States); Hitzhusen, Fredrick [The Ohio State Univ., Columbus, OH (United States)

2012-12-27

This research project developed and improved anaerobic digestion technologies, created a comprehensive Inventory of Ohio Biomass and a database of microorganisms of anaerobic digesters, and advanced knowledge and understanding of the underpinning microbiology of the anaerobic digestion process. The results and finding of this research project may be useful for future development and implementation of anaerobic digesters, especially at livestock farms. Policy makers and investors may also find the information on the biomass availability in Ohio and valuation of energy projects useful in policy making and making of investment decisions. The public may benefit from the information on biogas as an energy source and the potential impact of anaerobic digester projects on their neighborhoods.

Biogas generation potential by anaerobic digestion for sustainable energy development in India

International Nuclear Information System (INIS)

Rao, P. Venkateswara; Baral, Saroj S.; Dey, Ranjan; Mutnuri, Srikanth

2010-01-01

The potential of biogas generation from anaerobic digestion of different waste biomass in India has been studied. Renewable energy from biomass is one of the most efficient and effective options among the various other alternative sources of energy currently available. The anaerobic digestion of biomass requires less capital investment and per unit production cost as compared to other renewable energy sources such as hydro, solar and wind. Further, renewable energy from biomass is available as a domestic resource in the rural areas, which is not subject to world price fluctuations or the supply uncertainties as of imported and conventional fuels. In India, energy demand from various sectors is increased substantially and the energy supply is not in pace with the demand which resulted in a deficit of 11,436 MW which is equivalent to 12.6% of peak demand in 2006. The total installed capacity of bioenergy generation till 2007 from solid biomass and waste to energy is about 1227 MW against a potential of 25,700 MW. The bioenergy potential from municipal solid waste, crop residue and agricultural waste, wastewater sludge, animal manure, industrial waste which includes distilleries, dairy plants, pulp and paper, poultry, slaughter houses, sugar industries is estimated. The total potential of biogas from all the above sources excluding wastewater has been estimated to be 40,734 Mm 3 /year. (author)

Boosting biogas yield of anaerobic digesters by utilizing concentrated molasses from 2nd generation bioethanol plant

Energy Technology Data Exchange (ETDEWEB)

Sarker, Shiplu [Department of Renewable Energy, Faculty of Engineering and Science, University of Agder, Grimstad-4879 (Norway); Moeller, Henrik Bjarne [Department of Biosystems Engineering, Faculty of Science and Technology, Aarhus University, Research center Foulum, Blichers Alle, Post Box 50, Tjele-8830 (Denmark)

2013-07-01

Concentrated molasses (C5 molasses) from 2nd generation bioethanol plant has been investigated for enhancing productivity of manure based digesters. A batch study at mesophilic condition (35+- 1 deg C) showed the maximum methane yield from molasses as 286 LCH4/kgVS which was approximately 63% of the calculated theoretical yield. In addition to the batch study, co-digestion of molasses with cattle manure in a semi-continuously stirred reactor at thermophilic temperature (50+- 1 deg C) was also performed with a stepwise increase in molasses concentration. The results from this experiment revealed the maximum average biogas yield of 1.89 L/L/day when 23% VSmolasses was co-digested with cattle manure. However, digesters fed with more than 32% VSmolasses and with short adaptation period resulted in VFA accumulation and reduced methane productivity indicating that when using molasses as biogas booster this level should not be exceeded.

Stable thermophilic anaerobic digestion of dissolved air flotation (DAF) sludge by co-digestion with swine manure.

Science.gov (United States)

Creamer, K S; Chen, Y; Williams, C M; Cheng, J J

2010-05-01

Environmentally sound treatment of by-products in a value-adding process is an ongoing challenge in animal agriculture. The sludge produced as a result of the dissolved air flotation (DAF) wastewater treatment process in swine processing facilities is one such low-value residue. The objective of this study was to determine the fundamental performance parameters for thermophilic anaerobic digestion of DAF sludge. Testing in a semi-continuous stirred tank reactor and in batch reactors was conducted to determine the kinetics of degradation and biogas yield. Stable operation could not be achieved using pure DAF sludge as a substrate, possibly due to inhibition by long-chain fatty acids or to nutrient deficiencies. However, in a 1:1 ratio (w/w, dry basis) with swine manure, operation was both stable and productive. In the semi-continuous stirred reactor at 54.5 degrees Celsius, a hydraulic residence time of 10 days, and an organic loading rate of 4.68 gVS/day/L, the methane production rate was 2.19 L/L/day and the specific methane production rate was 0.47 L/gVS (fed). Maximum specific methanogenic activity (SMA) in batch testing was 0.15 mmoles CH(4) h(-1) gVS(-1) at a substrate concentration of 6.9 gVS L(-1). Higher substrate concentrations cause an initial lag in methane production, possibly due to long-chain fatty acid or nitrogen inhibition. Copyright 2009 Elsevier Ltd. All rights reserved.

Reviewing the anaerobic digestion and co-digestion process of food waste from the perspectives on biogas production performance and environmental impacts.

Science.gov (United States)

Chiu, Sam L H; Lo, Irene M C

2016-12-01

In this paper, factors that affect biogas production in the anaerobic digestion (AD) and anaerobic co-digestion (coAD) processes of food waste are reviewed with the aim to improve biogas production performance. These factors include the composition of substrates in food waste coAD as well as pre-treatment methods and anaerobic reactor system designs in both food waste AD and coAD. Due to the characteristics of the substrates used, the biogas production performance varies as different effects are exhibited on nutrient balance, inhibitory substance dilution, and trace metal element supplement. Various types of pre-treatment methods such as mechanical, chemical, thermal, and biological methods are discussed to improve the rate-limiting hydrolytic step in the digestion processes. The operation parameters of a reactor system are also reviewed with consideration of the characteristics of the substrates. Since the environmental awareness and concerns for waste management systems have been increasing, this paper also addresses possible environmental impacts of AD and coAD in food waste treatment and recommends feasible methods to reduce the impacts. In addition, uncertainties in the life cycle assessment (LCA) studies are also discussed.

Metaproteome analysis to determine the metabolically active part of a thermophilic microbial community producing biogas from agricultural biomass.

Science.gov (United States)

Hanreich, Angelika; Heyer, Robert; Benndorf, Dirk; Rapp, Erdmann; Pioch, Markus; Reichl, Udo; Klocke, Michael

2012-07-01

Complex consortia of microorganisms are responsible for biogas production. A lot of information about the taxonomic structure and enzymatic potential of such communities has been collected by a variety of gene-based approaches, yet little is known about which of all the assumable metabolic pathways are active throughout the process of biogas formation. To tackle this problem, we established a protocol for the metaproteomic analysis of samples taken from biogas reactors fed with agricultural biomass. In contrast to previous studies where an anaerobic digester was fed with synthetic wastewater, the complex matrix in this study required the extraction of proteins with liquid phenol and the application of paper bridge loading for 2-dimensional gel electrophoresis. Proteins were subjected to nanoHPLC (high-performance liquid chromatography) coupled to tandem mass spectrometry for characterization. Several housekeeping proteins as well as methanogenesis-related enzymes were identified by a MASCOT search and de novo sequencing, which proved the feasibility of our approach. The establishment of such an approach is the basis for further metaproteomic studies of biogas-producing communities. In particular, the apparent status of metabolic activities within the communities can be monitored. The knowledge collected from such experiments could lead to further improvements of biogas production.

Ecology and biotechnological potential of the thermophilic fermentative Coprothermobacter spp.

Science.gov (United States)

Gagliano, M C; Braguglia, C M; Petruccioli, M; Rossetti, S

2015-05-01

Thermophilic bacteria have been isolated from several terrestrial, marine and industrial environments. Anaerobic digesters treating organic wastes are often an important source of these microorganisms, which catalyze a wide array of metabolic processes. Moreover, organic wastes are primarily composed of proteins, whose degradation is often incomplete. Coprothermobacter spp. are proteolytic anaerobic thermophilic microbes identified in several studies focused on the analysis of the microbial community structure in anaerobic thermophilic reactors. They are currently classified in the phylum Firmicutes; nevertheless, several authors showed that the Coprothermobacter group is most closely related to the phyla Dictyoglomi and Thermotoga. Since only a few proteolytic anaerobic thermophiles have been characterized so far, this microorganism has attracted the attention of researchers for its potential applications with high-temperature environments. In addition to proteolysis, Coprothermobacter spp. showed several metabolic abilities and may have a biotechnological application either as source of thermostable enzymes or as inoculum in anaerobic processes. Moreover, they can improve protein degradation by establishing a syntrophy with hydrogenotrophic archaea. To gain a better understanding of the phylogenesis, metabolic capabilities and adaptations of these microorganisms, it is of importance to better define the role in thermophilic environments and to disclose properties not yet investigated. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Methane Emission from Digestion of Palm Oil Mill Effluent (POME in a Thermophilic Anaerobic Reactor

Directory of Open Access Journals (Sweden)

I Irvan

2012-04-01

Full Text Available As the issue of global warming draws increasing concern, many studies to reduce CO2 and CH4 gases (greenhouse gases, GHG have been implemented in several countries, including in Indonesia. Considering that Indonesia has a huge numbers of palm oil mills, no doubt if their waste water treatment as one of the major sources in GHG.  This paper presents the results from a research project between Metawater Co., Ltd.-Japan and University of Sumatera Utara-Indonesia. The objective of the research is to study the methane emission of thermophilic fermentation in the treatment of palm oil mill effluent (POME on a laboratory scale. Anaerobic digestion was performed in two-litre water jacketed biodigester type continuous stirred tank reactor (CSTR and operated at a thermophilic temperature (55 oC. As raw material, a real liquid waste (POME from palm oil mill was used. Fresh POME was obtained from seeding pond of PTPN II waste water treatment facility which has concentration of 39.7 g of VS/L and COD value of 59,000 mg/L. To gain precise results, complete recording and reliable equipment of reactor was employed. As the experimental results, for hydraulic retention time (HRT 8 days, VS decomposition rate of 63.5% and gas generation of 6.05-9.82 L/day were obtained, while for HRT 6 and 4 days, VS decomposition rate of 61.2, 53.3% and gas generation of  6.93-8.94  and  13.95-16.14 L/day were obtained respectively. Keywords—methane (CH4, palm oil mill effluent (POME, anaerobic digestion, thermophilic, green house gases (GHG

Distributed power generation using biogas fuelled microturbines

Energy Technology Data Exchange (ETDEWEB)

Pointon, K.; Langan, M.

2002-07-01

This research sought to analyse the market for small scale biogas fuelled distributed power generation, to demonstrate the concept of a biogas fuelled microturbine using the Capstone microturbine in conjunction with an anaerobic digester, and undertake a technico-economic evaluation of the biogas fuelled microturbine concept. Details are given of the experimental trials using continuous and batch digesters, and feedstocks ranging from cow and pig slurries to vegetable wastes and municipal solid waste. The yields of methane are discussed along with the successful operation of the microturbine with biogas fuels, and anaerobic digestion projects.

Distributed power generation using biogas fuelled microturbines

International Nuclear Information System (INIS)

Pointon, K.; Langan, M.

2002-01-01

This research sought to analyse the market for small scale biogas fuelled distributed power generation, to demonstrate the concept of a biogas fuelled microturbine using the Capstone microturbine in conjunction with an anaerobic digester, and undertake a technico-economic evaluation of the biogas fuelled microturbine concept. Details are given of the experimental trials using continuous and batch digesters, and feedstocks ranging from cow and pig slurries to vegetable wastes and municipal solid waste. The yields of methane are discussed along with the successful operation of the microturbine with biogas fuels, and anaerobic digestion projects

Benefits of supplementing an industrial waste anaerobic digester with energy crops for increased biogas production

International Nuclear Information System (INIS)

Nges, Ivo Achu; Escobar, Federico; Fu Xinmei; Björnsson, Lovisa

2012-01-01

Highlights: ► This study demonstrates the feasibility of co-digestion food industrial waste with energy crops. ► Laboratory batch co-digestion led to improved methane yield and carbon to nitrogen ratio as compared to mono-digestion of industrial waste. ► Co-digestion was also seen as a means of degrading energy crops with nutrients addition as crops are poor in nutrients. ► Batch co-digestion methane yields were used to predict co-digestion methane yield in full scale operation. ► It was concluded that co-digestion led an over all economically viable process and ensured a constant supply of feedstock. - Abstract: Currently, there is increasing competition for waste as feedstock for the growing number of biogas plants. This has led to fluctuation in feedstock supply and biogas plants being operated below maximum capacity. The feasibility of supplementing a protein/lipid-rich industrial waste (pig manure, slaughterhouse waste, food processing and poultry waste) mesophilic anaerobic digester with carbohydrate-rich energy crops (hemp, maize and triticale) was therefore studied in laboratory scale batch and continuous stirred tank reactors (CSTR) with a view to scale-up to a commercial biogas process. Co-digesting industrial waste and crops led to significant improvement in methane yield per ton of feedstock and carbon-to-nitrogen ratio as compared to digestion of the industrial waste alone. Biogas production from crops in combination with industrial waste also avoids the need for micronutrients normally required in crop digestion. The batch co-digestion methane yields were used to predict co-digestion methane yield in full scale operation. This was done based on the ratio of methane yields observed for laboratory batch and CSTR experiments compared to full scale CSTR digestion of industrial waste. The economy of crop-based biogas production is limited under Swedish conditions; therefore, adding crops to existing industrial waste digestion could be a viable

Kinetics of thermophilic, anaerobic oxidation of straight and branched chain butyrate and valerate

DEFF Research Database (Denmark)

Batstone, Damien J.; Pind, Peter Frode; Angelidaki, Irini

2003-01-01

The degradation kinetics of normal and branched chain butyrate and valerate are important in protein-fed anaerobic systems, as a number of amino acids degrade to these organic acids. Including activated and primary wastewater sludge digesters, the majority of full-scale systems digest feeds...... is also addressed, extending previous pure-culture and batch studies. A previously published mathematical model was modified to allow competitive uptake of i-valerate, and used to model a thermophilic manure digester operated over 180 days. The digester was periodically pulsed with straight and branched...

Evaluation of Biogas Production Performance and Archaeal Microbial Dynamics of Corn Straw during Anaerobic Co-Digestion with Cattle Manure Liquid.

Science.gov (United States)

Zhang, Benyue; Zhao, Hongyan; Yu, Hairu; Chen, Di; Li, Xue; Wang, Weidong; Piao, Renzhe; Cui, Zongjun

2016-04-28

The rational utilization of crop straw as a raw material for natural gas production is of economic significance. In order to increase the efficiency of biogas production from agricultural straw, seasonal restrictions must be overcome. Therefore, the potential for biogas production via anaerobic straw digestion was assessed by exposing fresh, silage, and dry yellow corn straw to cow dung liquid extract as a nitrogen source. The characteristics of anaerobic corn straw digestion were comprehensively evaluated by measuring the pH, gas production, chemical oxygen demand, methane production, and volatile fatty acid content, as well as applying a modified Gompertz model and high-throughput sequencing technology to the resident microbial community. The efficiency of biogas production from fresh straw (433.8 ml/g) was higher than that of production from straw silage and dry yellow straw (46.55 ml/g and 68.75 ml/g, respectively). The cumulative biogas production from fresh straw, silage straw, and dry yellow straw was 365 l(-1) g(-1) VS, 322 l(-1) g-1 VS, and 304 l(-1) g(-1) VS, respectively, whereas cumulative methane production was 1,426.33%, 1,351.35%, and 1,286.14%, respectively, and potential biogas production was 470.06 ml(-1) g(-1) VS, 461.73 ml(-1) g(-1) VS, and 451.76 ml(-1) g(-1) VS, respectively. Microbial community analysis showed that the corn straw was mainly metabolized by acetate-utilizing methanogens, with Methanosaeta as the dominant archaeal community. These findings provide important guidance to the biogas industry and farmers with respect to rational and efficient utilization of crop straw resources as material for biogas production.

Anaerobic digestion as final step of a cellulosic ethanol biorefinery:

DEFF Research Database (Denmark)

Uellendahl, Hinrich; Ahring, Birgitte Kiær

2010-01-01

) and mesophilic (388C) operation of the UASB reactor was investigated. At an OLR of 3.5 kg- VS/(m3 day) a methane yield of 340 L/kg-VS was achieved for thermophilic operation (538C) while 270 L/kg-VS was obtained under mesophilic conditions (388C). For loading rates higher than 5 kg-VS/(m3 day) the methane yields...... of suspended matter reduced the degradation efficiency. The retention time of the anaerobic system could be reduced from 70 to 7 h by additional removal of suspended matter by clarification. Implementation of the biogas production from the fermentation effluent accounted for about 30% higher carbon utilization...

Characterization of acetate-utilizing methanogenic bacteria, depending on varying acetate concentrations, in a biogas plant. Phase 1

International Nuclear Information System (INIS)

Ahring, B.K.

1994-12-01

The present report contains the results of a project concerning behaviour of acetate-utilizing methanogenic bacteria in mesophilic and thermophilic biogas plants, collected in 1992 - 1994 period. Labelled acetates (2-C 14 -CH 3 COOH) have been used to characterize the types of methane bacteria populations in the Danish biogas plants, the optimum acetate concentration for these bacteria and acetate metabolism in mesophilic and thermophilic biogas reactors with low acetate concentrations. 2 publications are included. (EG)

Formation of metabolites during biodegradation of linear alkylbenzene sulfonate in an upflow anaerobic sludge bed reactor under thermophilic conditions

DEFF Research Database (Denmark)

Mogensen, Anders Skibsted; Ahring, Birgitte Kiær

2002-01-01

Biodegradation of linear alkylbenzene sulfonate (LAS) was shown in an upflow anaerobic sludge blanket reactor under thermophilic conditions. The reactor was inoculated with granular biomass and fed with a synthetic medium and 3 mumol/L of a mixture of LAS with alkylchain length of 10 to 13 carbon...

Performance of thermophilic anaerobic digesters using inoculum mixes with enhanced methanogenic diversity

KAUST Repository

Ghanimeh, Sophia

2017-05-30

BACKGROUND Reportedly, various mixes of seeds were quasi-randomly selected to startup anaerobic digesters. In contrast, this study examines the impact of inoculating thermophilic anaerobic digesters with a designed mix of non-acclimated seeds based on their methanogen composition, using Quantitative Polymerase Chain Reaction (QPCR) of 16S rRNA gene, to achieve high abundance and diversity of methanogens. RESULTS Based on QPCR results, two seed mixes were selected to inoculate two anaerobic digesters: digester (A) was inoculated with a control seed consisting of digestate, manure, and activated sludge; and digester (B) was inoculated with a further methanogen-enriched seed consisting of the control seed with added compost and leachate. Both seed combinations yielded a balanced microflora that is able to achieve a successful startup. However, upon reaching steady state, digester B exhibited lower propionate levels, resulting in lower VFA concentration and increased buffering capacity, indicating greater stability. Acetotrophs and hydrogenotrophs were dominated by Methanosarcinaceae and Methanobacteriales, respectively, in both digesters, exhibiting an average ratio of 66-to-34% in A and 76-to-24% in B during steady state. CONCLUSION The inoculation strategy in digester B resulted in improved stability, lower propionate concentration and 10% higher relative abundance of acetotrophs.

Energetic utilization of biogas arising of sanitary landfills

International Nuclear Information System (INIS)

Calderon U, R.

1995-01-01

The biogas is the gaseous product that is obtained from the fermentation of biodegradable organic matter; this process is known as anaerobic digestion. In this exposition, the formation process of biogas is described in its three continuos phases: 1. Hydrolysis phase, 2. Phase of acid generation and the acetic acid generation and 3. Phase of methane generation. Also, the biogas composition (methane, carbon dioxide, hydrogen, nitrogen, oxygen and traces) is present. Different types of anaerobic digestion as discontinuous digestion, continuo digestion, digestion with suspended biomass, digestion with adhered biomass, and digestion of two phases are shown. Finally, the process that occur in a landfill and its different phases of aerobic and anaerobic decomposition, are describe from its initial stage until the biogas generation

Anaerobic degradation of organic municipal solid waste together with liquid manure. Part 1; Anaerob nedbrydning af organisk husholdningsaffald sammen med gylle. Del 1

Energy Technology Data Exchange (ETDEWEB)

Hartmann, H.; Angelidaki, I.; Ahring, B.K.

2001-01-01

This project includes preliminary investigations about anaerobic degradation of organic municipal waste together with liquid manure. Investigations consist of characterization of organic municipal waste and preliminary test of anaerobic degradation of the waste. Characterization is related especially to the contents of environmentally hazardous substances, while the degradation process is characterized by means of determination of biogas potential in batch test and methane yield, organic VS (volatile solids) reduction and process stability in reactor test. In relation to environmentally hazardous substances the content of NPE and LAS in all tests of organic municipal waste was insignificant. The main problem was the content of DEHP, concentration of which is half of the cut-off value in the municipal waste. By TS (Total solid) reduction through the biogas process the DEHP concentration will thus exceed the cut-off value pr kg TS in the effluent if DEHP is not removed at the same time. The PAH concentration in the collected waste was only in one case at the level of the cut-off value which would exceed the cut-off value if no removal happens through the anaerobic degradation. The biogas potential of municipal waste was determined to be 187 m{sup 3}biogas/m{sup 3}waste, which makes organic municipal waste a very attractive waste type for biogas plants. No direct restraint by degradation of clean waste in batch test could be demonstrated. In the reactor test a stable degradation of organic municipal waste with an increasing supply of waste in mixture with manure could be established. By treatment of a mixture of municipal waste and manure in ratio to 50 : 50 a methane yield on 350 lCH{sub 4} kg VS and a VS-reduction between 50% and 60% could be obtained. Using clean municipal waste diluted with water the methane yield was higher than in the batch test and a VS reduction of up to 80% could be obtained. The analyses of DEHP and PAH in influent and effluent of the

CONVERSION OF ORGANIC MANURE INTO BIOGAS

Directory of Open Access Journals (Sweden)

Dario Brdarić

2009-12-01

Full Text Available Production of biogas with anaerobic degradation from organic waste is one of the pledge alternative energetic solutions, especially from organic manure made from animal farming and other residuals of agricultural production. According to 2005 livestock manufacture data daily quantity of animal excrements in Croatia, based on LSU number, is 784 015.26 m3. The aim of this paper is to determine the possibility of production of biogas from the most common types of domestic animals in Croatia. Anaerobic fermentation period of 40 days in mesophilic conditions produced from 1 kg of beef, 31 litres of biogas slurry and from pig slurry 14.83 litres of biogas. From our study it follows that the Republic of Croatia (based on the number of UG could produce 426,995,250.00 Nm3 biogas annually. Exploitation of biogas can decrease import of the referred energents, especially electric energy.

Effect of Physical and Chemical Operating Parameters on Anaerobic Digestion of Manure and Biogas Production: A Review

Directory of Open Access Journals (Sweden)

Saeed Samani Majd

2017-03-01

Conclusion: High COD removal decrease of VS were achieved in the range of 80-95 % and 65- 92 % respectively in bioreactors. The produced methane was also 48 mmol L-1 to 4681.3 m3 per month for reactors with a volume of 120 ml to 1330 m3 achieved respectively at 37 and 55˚C from the Mesophilic and thermophilic temperatures. Results summarized on the physical and chemical conditions in this paper, can be used to study the effective parameters and optimize conditions used in biogas production.

Replacing Natural Gas by Biogas — Determining the Bacterial Contamination of Biogas by PCR

Directory of Open Access Journals (Sweden)

Jiřina Čermáková

2012-01-01

Full Text Available A promising way of using biogas is to upgrade it to natural gas, which is referred to as Substitute Natural Gas (SNG or biomethane. Biomethane, or biogas, is produced by biological processes of harnessing the ability of microorganisms to degrade organic material to methane. Some of the microorganisms are aerosolized from the digester into the biogas; afterwards a bio-film is formed that attaches to the surfaces of the distribution pipes, and can find it was to the place where the end use of biogas takes place. This paper deals with the detection of microbial species in biogas, their influenceon corrosion and the potential risk that diseases can be spread via biogas using molecular techniques. Using molecular methods, we found that raw biogas contains about 8 million microorganisms per m3, which is most likely the result of microbial transmission from the anaerobic digestion process. Some bacterial species may contribute to the corrosion of pipelines and equipment; others are opportunistic pathogens that can cause toxic reactions. However, most bacterial species, more than 40 % in biogas, are still unknown, as is their influence on the digestion process and on human health. Further studies are needed to better understand the behavior of microorganisms in anaerobic digestion and to preventmicrobial-influenced corrosion and microbial dissemination.

Caldanaerobacter uzonensis sp. nov., an anaerobic, thermophilic, heterotrophic bacterium isolated from a hot spring.

Science.gov (United States)

Kozina, Irina V; Kublanov, Ilya V; Kolganova, Tatyana V; Chernyh, Nikolai A; Bonch-Osmolovskaya, Elizaveta A

2010-06-01

An anaerobic thermophilic bacterium, strain K67(T), was isolated from a terrestrial hot spring of Uzon Caldera, Kamchatka Peninsula. Analysis of the 16S rRNA gene sequence revealed that the novel isolate belongs to the genus Caldanaerobacter, with 95 % 16S rRNA gene sequence similarity to Caldanaerobacter subterraneus subsp. subterraneus SEBR 7858(T), suggesting that it represents a novel species of the genus Caldanaerobacter. Strain K67(T) was characterized as an obligate anaerobe, a thermophile (growth at 50-75 degrees capital ES, Cyrillic; optimum 68-70 degrees C), a neutrophile (growth at pH(25 degrees C) 4.8-8.0; optimum pH(25 degrees C) 6.8) and an obligate organotroph (growth by fermentation of various sugars, peptides and polysaccharides). Major fermentation products were acetate, H2 and CO2; ethanol, lactate and l-alanine were formed in smaller amounts. Thiosulfate stimulated growth and was reduced to hydrogen sulfide. Nitrate, sulfate, sulfite and elemental sulfur were not reduced and did not stimulate growth. Thus, according to the strain's phylogenetic position and phenotypic novelties (lower upper limit of temperature range for growth, the ability to grow on arabinose, the inability to reduce elemental sulfur and the formation of alanine as a minor fermentation product), the novel species Caldanaerobacter uzonensis sp. nov. is proposed, with the type strain K67(T) (=DSM 18923(T) =VKM capital VE, Cyrillic-2408(T)).

Improving anaerobic sewage sludge digestion by implementation of a hyper-thermophilic prehydrolysis step

DEFF Research Database (Denmark)

Lu, Jingquan; Gavala, Hariklia N.; Skiadas, Ioannis V.

2008-01-01

The present study focuses on a two-step process for treatment and stabilisation of primary sludge. The process consists of a hyperthermophilic hydrolysis step operated at 70 degrees C and a hydraulic retention time (HRT) of 2 clays followed by a thermophilic (55 degrees C) anaerobic digestion step......) with and Without pre-treatment respectively) and up to 115% increase of the methane production rate. Finally it was shown that the extra energy requirements for the operation of a pre-treatment step would be covered by the energy Produced from the extra methane production and in addition there would...

The role of zero valent iron on the fate of tetracycline resistance genes and class 1 integrons during thermophilic anaerobic co-digestion of waste sludge and kitchen waste.

Science.gov (United States)

Gao, Pin; Gu, Chaochao; Wei, Xin; Li, Xiang; Chen, Hong; Jia, Hanzhong; Liu, Zhenhong; Xue, Gang; Ma, Chunyan

2017-03-15

Activated sludge has been identified as a potential significant source of antibiotic resistance genes (ARGs) to the environment. Anaerobic digestion is extensively used for sludge stabilization and resource recovery, and represents a crucial process for controlling the dissemination of ARGs prior to land application of digested sludge. The objective of this study is to investigate the effect of zero valent iron (Fe 0 ) on the attenuation of seven representative tetracycline resistance genes (tet, tet(A), tet(C), tet(G), tet(M), tet(O), tet(W), and tet(X)), and the integrase gene intI1 during thermophilic anaerobic co-digestion of waste sludge and kitchen waste. Significant decrease (P  0.05) were found for all gene targets between digesters with Fe 0 dosages of 5 and 60 g/L. A first-order kinetic model favorably described the trends in concentrations of tet and intI1 gene targets during thermophilic anaerobic digestion with or without Fe 0 . Notably, tet genes encoding different resistance mechanisms behaved distinctly in anaerobic digesters, although addition of Fe 0 could enhance their reduction. The overall results of this research suggest that thermophilic anaerobic digestion with Fe 0 can be a potential alternative technology for the attenuation of tet and intI1 genes in waste sludge. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Single-Culture Bioprocess of Methanothermobacter thermautotrophicus to Upgrade Digester Biogas by CO2-to-CH4 Conversion with H2

Science.gov (United States)

Martin, Matthew R.; Fornero, Jeffrey J.; Angenent, Largus T.

2013-01-01

We optimized and tested a postbioprocessing step with a single-culture archaeon to upgrade biogas (i.e., increase methane content) from anaerobic digesters via conversion of CO2 into CH4 by feeding H2 gas. We optimized a culture of the thermophilic methanogen Methanothermobacter thermautotrophicus using: (1) a synthetic H2/CO2 mixture; (2) the same mixture with pressurization; (3) a synthetic biogas with different CH4 contents and H2; and (4) an industrial, untreated biogas and H2. A laboratory culture with a robust growth (dry weight of 6.4–7.4 g/L; OD600 of 13.6–15.4), a volumetric methane production rate of 21 L/L culture-day, and a H2 conversion efficiency of 89% was moved to an industrial anaerobic digester facility, where it was restarted and fed untreated biogas with a methane content of ~70% at a rate such that CO2 was in excess of the stoichiometric requirements in relation to H2. Over an 8-day operating period, the dry weight of the culture initially decreased slightly before stabilizing at an elevated level of ~8 g/L to achieve a volumetric methane production rate of 21 L/L culture-day and a H2 conversion efficiency of 62%. While some microbial contamination of the culture was observed via microscopy, it did not affect the methane production rate of the culture. PMID:24194675

A Single-Culture Bioprocess of Methanothermobacter thermautotrophicus to Upgrade Digester Biogas by CO2-to-CH4 Conversion with H2

Directory of Open Access Journals (Sweden)

Matthew R. Martin

2013-01-01

Full Text Available We optimized and tested a postbioprocessing step with a single-culture archaeon to upgrade biogas (i.e., increase methane content from anaerobic digesters via conversion of CO2 into CH4 by feeding H2 gas. We optimized a culture of the thermophilic methanogen Methanothermobacter thermautotrophicus using: (1 a synthetic H2/CO2 mixture; (2 the same mixture with pressurization; (3 a synthetic biogas with different CH4 contents and H2; and (4 an industrial, untreated biogas and H2. A laboratory culture with a robust growth (dry weight of 6.4–7.4 g/L; OD600 of 13.6–15.4, a volumetric methane production rate of 21 L/L culture-day, and a H2 conversion efficiency of 89% was moved to an industrial anaerobic digester facility, where it was restarted and fed untreated biogas with a methane content of ~70% at a rate such that CO2 was in excess of the stoichiometric requirements in relation to H2. Over an 8-day operating period, the dry weight of the culture initially decreased slightly before stabilizing at an elevated level of ~8 g/L to achieve a volumetric methane production rate of 21 L/L culture-day and a H2 conversion efficiency of 62%. While some microbial contamination of the culture was observed via microscopy, it did not affect the methane production rate of the culture.

Deep Conversion of Carbon Monoxide to Hydrogen and Formation of Acetate by the Anaerobic Thermophile Carboxydothermus hydrogenoformans

OpenAIRE

Henstra, Anne M.; Stams, Alfons J. M.

2011-01-01

Carboxydothermus hydrogenoformans is a thermophilic strictly anaerobic bacterium that catalyses the water gas shift reaction, the conversion of carbon monoxide with water to molecular hydrogen and carbon dioxide. The thermodynamically favorable growth temperature, compared to existing industrial catalytic processes, makes this organism an interesting alternative for production of cheap hydrogen gas suitable to fuel CO-sensitive fuel cells in a future hydrogen economy, provided sufficiently lo...

Conductive iron oxides accelerate thermophilic methanogenesis from acetate and propionate.

Science.gov (United States)

Yamada, Chihaya; Kato, Souichiro; Ueno, Yoshiyuki; Ishii, Masaharu; Igarashi, Yasuo

2015-06-01

Anaerobic digester is one of the attractive technologies for treatment of organic wastes and wastewater, while continuous development and improvements on their stable operation with efficient organic removal are required. Particles of conductive iron oxides (e.g., magnetite) are known to facilitate microbial interspecies electron transfer (termed as electric syntrophy). Electric syntrophy has been reported to enhance methanogenic degradation of organic acids by mesophilic communities in soil and anaerobic digester. Here we investigated the effects of supplementation of conductive iron oxides (magnetite) on thermophilic methanogenic microbial communities derived from a thermophilic anaerobic digester. Supplementation of magnetite accelerated methanogenesis from acetate and propionate under thermophilic conditions, while supplementation of ferrihydrite also accelerated methanogenesis from propionate. Microbial community analysis revealed that supplementation of magnetite drastically changed bacterial populations in the methanogenic acetate-degrading cultures, in which Tepidoanaerobacter sp. and Coprothermobacter sp. dominated. These results suggest that supplementation of magnetite induce electric syntrophy between organic acid-oxidizing bacteria and methanogenic archaea and accelerate methanogenesis even under thermophilic conditions. Findings from this study would provide a possibility for the achievement of stably operating thermophilic anaerobic digestion systems with high efficiency for removal of organics and generation of CH4. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Life cycle assessment of biogas from sewage treatment sludge; Livscykelanalys av biogas fraan avloppsreningsverksslam

Energy Technology Data Exchange (ETDEWEB)

Palm, David; Ek, Mats (IVL Swedish Environmental Research Inst., Stockholm (Sweden))

2010-08-15

This report analyses the environmental impact from 1MJ of biogas (as vehicle fuel) produced by anaerobic digestion of sewage sludge. Data are primarily taken from Kaeppala sewage treatment plant, but have been complemented with data from literature. As a base case, the biogas has only been given the environmental burden from upgrading and purification of raw gas. This is because the anaerobic digestion is an inherent part of the waste water treatment in Sweden, biogas being produced regardless of its chosen end utilization. Calculations have also been performed with system expansion where the anaerobic digestion, sludge treatment and replaced mineral fertilizer have been included in the analysis, as well as calculations based on economic and energy allocation. The results have been characterised in accordance to CML (2007) for the potential of global warming on a 100 year perspective, eutrophication, acidification, photochemical oxidation creation and particles. The study represents a Swedish state-of-the-art plant for biogas production but also includes a sensitivity analysis that cover a Swedish average plant and a worst case plant. The sensitivity analysis shows a major impact on the results from methane leakage during anaerobic digestion and upgrading. The electricity consumption and choice of Swedish average electricity versus Swedish marginal electricity is of less importance for the outcome of the study

Farm scale production of combined heat and power from biogas; Gaardsbaserad och gaardsnaera produktion av kraftvaerme fraan biogas

Energy Technology Data Exchange (ETDEWEB)

Lantz, Mikael

2010-08-15

The Swedish agricultural sector accounts for a significant and unutilized part of the Swedish biogas potential. There is also considerable interest among Swedish farmers to increase the production and utilization of biogas. The purpose of this study is to analyze the prerequisites for the production of combined heat and power (CHP) from biogas based on manure in different scale and with different technologies. The purpose is also to present economic calculations and the conditions required to reach profitability. Based on current economic conditions and with the assumptions made in the assessment, it is difficult to achieve profitability with conventional production of biogas. Levels of investment and operating costs are greatly dependent of scale and a larger biogas plant is normally more profitable than a smaller. There are, however, only marginal differences between a large farm based biogas plant and a much larger plant treating manure from several farms. The reason is that the positive effects of scale regarding investments, comparing the two plants, are reduced by increased costs for transportation and sanitation. However, the sanitation unit adapted at the large plant enables the plant to receive different external substrates such as food industry waste etc. resulting in a much higher biogas production per amount of treated substrate. The following conclusions are drawn in this study: - to achieve profitability in the production of CHP from biogas based on manure it is required, in most cases, that some of the heat produced could be used externally and that the digestate is given an economic value; - there are clear positive effects of scale between the smaller and the larger farm based biogas plant. However, differences are marginal between a large farm based biogas plant and a larger plant treating manure from several farms; - thermophilic operation could improve the profitability if used to increase the amount of substrate treated and especially if it is

Effect of alkaline microwaving pretreatment on anaerobic digestion and biogas production of swine manure

OpenAIRE

Tao Yu; Yihuan Deng; Hongyu Liu; Chunping Yang; Bingwen Wu; Guangming Zeng; Li Lu; Fumitake Nishimura

2017-01-01

Microwave assisted with alkaline (MW-A) condition was applied in the pretreatment of swine manure, and the effect of the pretreatment on anaerobic treatment and biogas production was evaluated in this study. The two main microwaving (MW) parameters, microwaving power and reaction time, were optimized for the pretreatment. Response surface methodology (RSM) was used to investigate the effect of alkaline microwaving process for manure pretreatment at various values of pH and energy input. Resul...

Co-digestion of cattle manure with food waste and sludge to increase biogas production

International Nuclear Information System (INIS)

Marañón, E.; Castrillón, L.; Quiroga, G.; Fernández-Nava, Y.; Gómez, L.; García, M.M.

2012-01-01

Highlights: ► Small increase in methane production was observed applying sonication pretreatment. ► Biogas productions between 720 and 1100 mL/Lreactor day were achieved. ► Volatile solids removal efficiencies ranged between 53% and 60%. ► Lower methane yields were obtained when operating under thermophilic conditions. ► Optimum OLR in lab-scale CSTR was 1.2–1.3 g VS/L day (HRT: 20 days). - Abstract: Anaerobic co-digestion strategies are needed to enhance biogas production, especially when treating certain residues such as cattle/pig manure. This paper presents a study of co-digestion of cattle manure with food waste and sewage sludge. With the aim of maximising biogas yields, a series of experiments were carried out under mesophilic and thermophilic conditions using continuously stirred-tank reactors, operating at different hydraulic residence times. Pretreatment with ultrasound was also applied to compare the results with those obtained with non-pretreated waste. Specific methane production decreases when increasing the OLR and decreasing HRT. The maximum value obtained was 603 LCH 4 /kg VS feed for the co-digestion of a mixture of 70% manure, 20% food waste and 10% sewage sludge (total solid concentration around 4%) at 36 °C, for an OLR of 1.2 g VS/L day. Increasing the OLR to 1.5 g VS/L day led to a decrease of around 20–28% in SMP. Lower methane yields were obtained when operating at 55 °C. The increase in methane production when applying ultrasound to the feed mixtures does not compensate for the energy spent in this pretreatment.

[Gradient elevation of temperature startup experiment of thermophilic ASBR treating thermal-hydrolyzed sewage sludge].

Science.gov (United States)

Ouyang, Er-Ming; Wang, Wei; Long, Neng; Li, Huai

2009-04-15

Startup experiment was conducted for thermophilic anaerobic sequencing batch reactor (ASBR) treating thermal-hydrolyzed sewage sludge using the strategy of the step-wise temperature increment: 35 degrees C-->40 degrees C-->47 degrees C-->53 degrees C. The results showed that the first step-increase (from 35 degrees C to 40 degrees C) and final step-increase (from 47 degrees C to 53 degrees C) had only a slight effect on the digestion process. The second step-increase (from 40 degrees C to 47 degrees C) resulted in a severe disturbance: the biogas production, methane content, CODeffluent and microorganism all have strong disturbance. At the steady stage of thermophilic ASBR treating thermal-hydrolyzed sewage sludge, the average daily gas production, methane content, specific methane production (CH4/CODinfluent), TCOD removal rate and SCOD removal rate were 2.038 L/d, 72.0%, 188.8 mL/g, 63.8%, 83.3% respectively. The results of SEM and DGGE indicated that the dominant species are obviously different at early stage and steady stage.

Study on anaerobic treatment of hazardous steel-mill waste rolling oil (SmWRO) for multi-benefit disposal route.

Science.gov (United States)

Ma, Huanhuan; Li, Zifu; Yin, Fubin; Kao, William; Yin, Yi; Bai, Xiaofeng

2014-01-01

Steel-mill waste rolling oil (SmWRO) is considered as hazardous substance with high treatment and disposal fees. Anaerobic process could not only transform the hazardous substance into activated sludge, but also generate valuable biogas. This study aimed at studying the biochemical methane potential of SmWRO under inoculum to substrate VS ratios (ISRs) of 0.25, 0.5, 1, 1.5, 2 and 3 using septic tank sludge as inoculum in mesophilic and thermophilic conditions, with blank tests for control. Specific biogas yield (mL/g VS(added)), net biogas yield (mL/g VS(removed)) and VS removal were analyzed. The ANOVA results indicated great influence of ISR and temperature on studied parameters. ISR of 1.5 at 55°C and ISR of 1.5 and 2 at 35°C were suggested with the highest specific biogas yield (262-265 and 303mL/g VS(added)). Kinetic analysis showed that Gompertz model fit the experimental data best with the least RMSE and largest R(2). Copyright © 2013 Elsevier Ltd. All rights reserved.

Influence of Hydraulic Retention Time on Biogas Production from Frozen Seafood Wastewater using Decanter Cake as Anaerobic Co-digestion Material

OpenAIRE

Thaniya Kaosol; Narumol Sohgrathok

2012-01-01

In this research, an anaerobic co-digestion using decanter cake from palm oil mill industry to improve the biogas production from frozen seafood wastewater is studied using Continuously Stirred Tank Reactor (CSTR) process. The experiments were conducted in laboratory-scale. The suitable Hydraulic Retention Time (HRT) was observed in CSTR experiments with 24 hours of mixing time using the mechanical mixer. The HRT of CSTR process impacts on the efficiency of biogas production. The best perform...

Developing a Family-Size Biogas-Fueled Electricity Generating System

OpenAIRE

Haryanto, Agus; Marotin, Fadli; Triyono, Sugeng; Hasanudin, Udin

2017-01-01

The purpose of this study is to develop a family-size biogas-fueled electricity generating system consisting of anaerobic digester, bio-filter scrubber, and power generating engine. Biogas was produced from a pilot scale wet anaerobic digester (5-m3 capacity). The biogas was filtered using bio-scrubber column filled with locally made compost to reduce hydrogen sulfide (H2S) content. Biogas composition was analysed using a gas chromatograph and its H2S level was measured using a H2S detector. ...

Biohydrogen production from desugared molasses (DM) using thermophilic mixed cultures immobilized on heat treated anaerobic sludge granules

DEFF Research Database (Denmark)

Kongjan, Prawit; O-Thong, Sompong; Angelidaki, Irini

2011-01-01

Hydrogen production from desugared molasses (DM) was investigated in both batch and continuous reactors using thermophilic mixed cultures enriched from digested manure by load shock (loading with DM concentration of 50.1 g-sugar/L) to suppress methanogens. H2 gas, free of methane, was produced......) and Thermoanaerobacterium thermosaccharolyticum with a relative abundance of 36%, 27%, and 10% of total microorganisms, respectively. This study shows that hydrogen production could be efficiently facilitated by using anaerobic granules as a carrier, where microbes from mixed culture enriched in the DM batch cultivation....... The enriched hydrogen producing mixed culture achieved from the 16.7 g-sugars/L DM batch cultivation was immobilized on heat treated anaerobic sludge granules in an up-flow anaerobic sludge blanket (UASB) reactor. The UASB reactor, operated at a hydraulic retention time (HRT) of 24 h fed with 16.7 g...

Action of amylolytic and pullulytic enzymes from various anaerobic thermophiles on linear and branched glucose polymers

Energy Technology Data Exchange (ETDEWEB)

Koch, R [Goettingen Univ. (Germany, F.R.). Inst. fuer Mikrobiologie; Antranikian, G [Technische Univ. Hamburg-Harburg, Hamburg (Germany, F.R.). Arbeitsbereich Biotechnologie 1

1990-10-01

A detailed study has been conducted on the action of starch hydrolyzing enzymes from thermophilic anaerobic bacteria belonging to the genera Clostridium, Thermoanaerobacter and Thermobacteroides. The appearance of multiple bands on polyacrylamide gels with amylolytic as well as pullulytic activities was shown to be a general feature of bacteria investigated. Analysis of the hydrolysis products of each protein band clearly demonstrated the capability of these organisms to hydrolyze {alpha}-1,4-glycosidic bonds in linear oligosaccharides and {alpha}-1,6-glycosidic linkages in pullulan. Furthermore, the enzyme system of thermophilic bacteria investigated was also capable of attacking in the {alpha}-1,6-linkages in branched oligosaccharides. Due to the action of these thermoactive enzymes with multiple specificity an almost complete hydrolysis of raw starch and maltodextrin could be achieved under the same conditions and in one step. (orig.).

District heating for increased biogas production. Technical and economical evaluation of district heating as heating source in biogas processes; Fjaerrvaerme foer utoekad biogasproduktion. Teknisk och ekonomisk utvaerdering av fjaerrvaerme foer uppvaermning av biogasprocesser

Energy Technology Data Exchange (ETDEWEB)

Lundqvist, Per (AaF-Consult AB, Stockholm (Sweden))

2009-11-15

This report presents a technical evaluation, the potential and an economical evaluation of the increased net biogas production by using district heating as energy supply for different types of biogas production units. The study presents generalized results for different plant sizes. The district heating is considered as replacement of the heat produced by burning biogas in a hot-water boiler. Hence more biogas could be available for upgrading to fuel-gas quality to be used in vehicles as a renewable fuel. The study is aimed at biogas producers, district heating and combined heat and power (CHP) companies. Biogas has a composition of mostly methane (about 65 %) and carbon dioxide (about 35 %) and small amounts of other gases e.g. sulphur dioxide (H{sub 2}S). Biogas up-grading is a process where the methane content is increased to about 97 % by removing most of the other gases in e.g. an absorption unit. The Swedish biogas is mainly produced in several sewage treatment plants and some co-digestion units but is also collected from dumps. Biogas is produced by anaerobic microorganisms at temperatures of about 36 and 55 deg C which correspond to the thermal optimum for mesophile and thermophile bacteria respectively. Co-digestion of animal material which e.g. is contained in collected organic household waste has to be pasteurized at 70 deg C for 1h according to EU-regulations. Such regulations may also be introduced to the sludge from municipal sewage treatment plants. Due to the fact that the process temperature is higher than the temperature of the substrate (sludge or organic waste material) as well as the outdoor temperature, both heating of the incoming substrate and compensation of heat losses are required. Traditionally most of the biogas has been burnt to generate the necessary heat for the process and premises at the plant. The excess gas has been burnt in a torch. In recent years the biogas produced in Sweden has found increased use as a renewable vehicle fuel

Experimental and feasibility assessment of biogas production by anaerobic digestion of fruit and vegetable waste from Joburg Market.

Science.gov (United States)

Masebinu, S O; Akinlabi, E T; Muzenda, E; Aboyade, A O; Mbohwa, C

2018-05-01

Substrate-induced instability of anaerobic digestion from fruit and vegetable waste (FVW) results in low biogas yield. In this study, substrate management through fruit to vegetable mix ratio in a two-stage semi-continuous digester was investigated as a pathway for optimality of yield. The experiment conducted over 105 days with 62.52 kg of FVWs sourced from Joburg Market, South Africa showed that a stable process was achieved at a fruit to vegetable waste mix ratio of 2.2:2.8. At this ratio, optimal organic loading rate ranged between 2.68 and 2.97 kg VS/m 3 -d which resulted in a specific biogas yield of 0.87 Nm 3 /kg VS with 57.58% methane on average. The results of the experimental study were used as a feasibility assessment for a full-scale 45 tonnes/d plant for Joburg Market considering three energy pathways. The plant will produce 1,605,455 Nm 3 /y of biogas with the potential for offsetting 15.2% of the Joburg Market energy demand. Conversion of all biogas to biomethane was the most economically attractive energy pathway with a net present value of $2,428,021, an internal rate of return of 16.90% and a simple payback period of 6.17 years. This route avoided the greenhouse gas emission of 12,393 tonnes CO 2 , eq. The study shows that the anaerobic digestion of FVWs as sole substrate is possible with financial and environmental attractiveness. Copyright © 2018 Elsevier Ltd. All rights reserved.

Optimisation of biogas production through a two-stage automated anaerobic digester system developed by the CSIR in South Africa

CSIR Research Space (South Africa)

Mema, V

2015-08-01

Full Text Available with the aim of producing biogas as a renewable energy source plays a critical role in addressing the energy demand at a wastewater treatment works depending on the type of technology applied. Efficacy of anaerobic digestion process is highly dependent...

Isolation and characterization of two novel ethanol-tolerant facultative-anaerobic thermophilic bacteria strains from waste compost.

Science.gov (United States)

Fong, Jiunn C N; Svenson, Charles J; Nakasugi, Kenlee; Leong, Caine T C; Bowman, John P; Chen, Betty; Glenn, Dianne R; Neilan, Brett A; Rogers, Peter L

2006-10-01

In a search for potential ethanologens, waste compost was screened for ethanol-tolerant thermophilic microorganisms. Two thermophilic bacterial strains, M5EXG and M10EXG, with tolerance of 5 and 10% (v/v) ethanol, respectively, were isolated. Both isolates are facultative anaerobic, non-spore forming, non-motile, catalase-positive, oxidase-negative, Gram-negative rods that are capable of utilizing a range of carbon sources including arabinose, galactose, mannose, glucose and xylose and produce low amounts of ethanol, acetate and lactate. Growth of both isolates was observed in fully defined minimal media within the temperature range 50-80 degrees C and pH 6.0-8.0. Phylogenetic analysis of the 16S rDNA sequences revealed that both isolates clustered with members of subgroup 5 of the genus Bacillus. G+C contents and DNA-DNA relatedness of M5EXG and M10EXG revealed that they are strains belonging to Geobacillus thermoglucosidasius. However, physiological and biochemical differences were evident when isolates M5EXG and M10EXG were compared with G. thermoglucosidasius type strain (DSM 2542(T)). The new thermophilic, ethanol-tolerant strains of G. thermoglucosidasius may be candidates for ethanol production at elevated temperatures.

Progress in biogas. Biogas production from agricultural biomass and organic residues. Pt. 1 and 2. Proceedings (oral presentations and poster presentations); Fortschritt beim Biogas. Biogas aus landwirtschaftlicher Biomasse and organischen Reststoffen. T. 1 und 2. Tagungsband. Vortraege and Poster

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

Within the International Conference ''Progress in Biogas - Biogas production from agricultural biomass and organic residues'' at the University Hohenheim (Stuttgart, Federal Republic of Germany) from 18th to 21st September, 2007, the following lectures were held: (1) Global relevance and potential of bioenergy for regional development; (2) Biogas electricity for France feed-in tariff and some other things to know before entering French market; (3) Policy drivers and future prospects for on-farm anaerobic digestion in Northern Ireland; (4) Biogas in Belgium, a swot analysis; (5) Status and prospects of biogas energy use in Ukraine; (6) Recent developments in Chinese agricultural biogas production; (7) Opportunities for agricultural based biogas systems in the province of Ontario, Canada; (8) Pre-treatment and digestion of separated collected household waste in Sweden; (9) To the problem of monitoring measures and prophylaxis measures with the utilization of organic residual substances in biological gas facilities from hygienic view; (10) Fermenting residues from biological gas facilities - nutrients and pollutants, possibilities of application in the agriculture; (11) Treatment and utilization of fermentation residues; (12) Potential of residual gas of NaWaRo feeded biogas plants in Baden-Wuerttemberg; (13) Operating analytics of biogas plants to improve efficiency and to ensure process stability; (14) The potential of biogas and electric power production from subproducts in the sugar and alcohol industries by the application of anaerobic digestion; (15) Co-digestion plant in dairy cattle farm in Emilia Romagna region (Italy); (16) Facing operational problems in a biodigeser in Yuvientsa - Amazonian Region of Ecuador; (17) Biogas plant instead of milk cow - payment and occupation with the use of grassilage; (18) Biogas in ecologic agriculture - experiences from 3 years of fermentation of grass-clover ley; (19) Combined solar-biogas basis for the

Progress in biogas. Biogas production from agricultural biomass and organic residues. Pt. 1 and 2. Proceedings (oral presentations and poster presentations); Fortschritt beim Biogas. Biogas aus landwirtschaftlicher Biomasse and organischen Reststoffen. T. 1 und 2. Tagungsband. Vortraege and Poster

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

Within the International Conference ''Progress in Biogas - Biogas production from agricultural biomass and organic residues'' at the University Hohenheim (Stuttgart, Federal Republic of Germany) from 18th to 21st September, 2007, the following lectures were held: (1) Global relevance and potential of bioenergy for regional development; (2) Biogas electricity for France feed-in tariff and some other things to know before entering French market; (3) Policy drivers and future prospects for on-farm anaerobic digestion in Northern Ireland; (4) Biogas in Belgium, a swot analysis; (5) Status and prospects of biogas energy use in Ukraine; (6) Recent developments in Chinese agricultural biogas production; (7) Opportunities for agricultural based biogas systems in the province of Ontario, Canada; (8) Pre-treatment and digestion of separated collected household waste in Sweden; (9) To the problem of monitoring measures and prophylaxis measures with the utilization of organic residual substances in biological gas facilities from hygienic view; (10) Fermenting residues from biological gas facilities - nutrients and pollutants, possibilities of application in the agriculture; (11) Treatment and utilization of fermentation residues; (12) Potential of residual gas of NaWaRo feeded biogas plants in Baden-Wuerttemberg; (13) Operating analytics of biogas plants to improve efficiency and to ensure process stability; (14) The potential of biogas and electric power production from subproducts in the sugar and alcohol industries by the application of anaerobic digestion; (15) Co-digestion plant in dairy cattle farm in Emilia Romagna region (Italy); (16) Facing operational problems in a biodigeser in Yuvientsa - Amazonian Region of Ecuador; (17) Biogas plant instead of milk cow - payment and occupation with the use of grassilage; (18) Biogas in ecologic agriculture - experiences from 3 years of fermentation of grass-clover ley; (19) Combined solar-biogas basis for the population social

Realization of microcontroller-based process control systems examplified on process state monitor for anaerobic biogas fermentation; Realisierung mikrocontrollerbasierter Prozessfuehrungssysteme am Beispiel eines Prozesszustandsmonitors fuer die anaerobe Biogasfermentation

Energy Technology Data Exchange (ETDEWEB)

Patzwahl, S.; Kramer, K.D. [Hochschule Harz, Wernigerode (Germany). Fachbereich Automatisierung und Informatik; Nacke, T. [Institut fuer Bioprozess- und Analysenmesstechnik e.V., Heilbad Heiligenstadt (Germany)

2004-07-01

This paper describes possibilities to realize microcontroller-based process control systems with use strategies of computational intelligence. All design steps are comprised in a design process with direct interface to the process. A further issue is a development system for firmware, which was programmed especially for main steps of the design process. The process of anaerobic fermentation in biogas plants serves as an sample for a control application. By using the design process and the programmed software a process state monitor was developed for this fermentation process. The system is able to classify the process state online in biogas fermentation plants. (orig.)

Investigation of mircroorganisms colonising activated zeolites during anaerobic biogas production from grass silage.

Science.gov (United States)

Weiss, S; Zankel, A; Lebuhn, M; Petrak, S; Somitsch, W; Guebitz, G M

2011-03-01

The colonisation of activated zeolites (i.e. clinoptilolites) as carriers for microorganisms involved in the biogas process was investigated. Zeolite particle sizes of 1.0-2.5mm were introduced to anaerobic laboratory batch-cultures and to continuously operated bioreactors during biogas production from grass silage. Incubation over 5-84 days led to the colonisation of zeolite surfaces in small batch-cultures (500 ml) and even in larger scaled and flow-through disturbed bioreactors (28 l). Morphological insights were obtained by using scanning electron microscopy (SEM). Single strand conformation polymorphism (SSCP) analysis based on amplification of bacterial and archaeal 16S rRNA fragments demonstrated structurally distinct populations preferring zeolite as operational environment. via sequence analysis conspicuous bands from SSCP patterns were identified. Populations immobilised on zeolite (e.g. Ruminofilibacter xylanolyticum) showed pronounced hydrolytic enzyme activity (xylanase) shortly after re-incubation in sterilised sludge on model substrate. In addition, the presence of methanogenic archaea on zeolite particles was demonstrated. Copyright © 2010 Elsevier Ltd. All rights reserved.

Boosting dark fermentation with co-cultures of extreme thermophiles for biohythane production from garden waste.

Science.gov (United States)

Abreu, Angela A; Tavares, Fábio; Alves, Maria Madalena; Pereira, Maria Alcina

2016-11-01

Proof of principle of biohythane and potential energy production from garden waste (GW) is demonstrated in this study in a two-step process coupling dark fermentation and anaerobic digestion. The synergistic effect of using co-cultures of extreme thermophiles to intensify biohydrogen dark fermentation is demonstrated using xylose, cellobiose and GW. Co-culture of Caldicellulosiruptor saccharolyticus and Thermotoga maritima showed higher hydrogen production yields from xylose (2.7±0.1molmol(-1) total sugar) and cellobiose (4.8±0.3molmol(-1) total sugar) compared to individual cultures. Co-culture of extreme thermophiles C. saccharolyticus and Caldicellulosiruptor bescii increased synergistically the hydrogen production yield from GW (98.3±6.9Lkg(-1) (VS)) compared to individual cultures and co-culture of T. maritima and C. saccharolyticus. The biochemical methane potential of the fermentation end-products was 322±10Lkg(-1) (CODt). Biohythane, a biogas enriched with 15% hydrogen could be obtained from GW, yielding a potential energy generation of 22.2MJkg(-1) (VS). Copyright © 2016 Elsevier Ltd. All rights reserved.

Combined thermophilic aerobic process and conventional anaerobic digestion: effect on sludge biodegradation and methane production.

Science.gov (United States)

Dumas, C; Perez, S; Paul, E; Lefebvre, X

2010-04-01

The efficiency of hyper-thermophilic (65 degrees Celsius) aerobic process coupled with a mesophilic (35 degrees Celsius) digester was evaluated for the activated sludge degradation and was compared to a conventional mesophilic digester. For two Sludge Retention Time (SRT), 21 and 42 days, the Chemical Oxygen Demand (COD) solubilisation and biodegradation processes, the methanisation yield and the aerobic oxidation were investigated during 180 days. The best results were obtained at SRT of 44 days; the COD removal yield was 30% higher with the Mesophilic Anaerobic Digestion/Thermophilic Aerobic Reactor (MAD-TAR) co-treatment. An increase of the sludge intrinsic biodegradability is also observed (20-40%), showing that the unbiodegradable COD in mesophilic conditions becomes bioavailable. However, the methanisation yield was quite similar for both processes at a same SRT. Finally, such a process enables to divide by two the volume of digester with an equivalent efficiency. Copyright 2009 Elsevier Ltd. All rights reserved.

Biogas production from potato-juice, a by-product from potato-starch processing, in upflow anaerobic sludge blanket (UASB) and expanded granular sludge bed (EGSB) reactors

DEFF Research Database (Denmark)

Fang, Cheng; Boe, Kanokwan; Angelidaki, Irini

2011-01-01

In this study, the utilization of potato-juice, the organic by-product from potato-starch processing, for biogas production was investigated in batch assay and in high rate anaerobic reactors. The maximum methane potential of the potato-juice determined by batch assay was 470mL-CH4/gVS-added. Ana......In this study, the utilization of potato-juice, the organic by-product from potato-starch processing, for biogas production was investigated in batch assay and in high rate anaerobic reactors. The maximum methane potential of the potato-juice determined by batch assay was 470mL-CH4/g...

Process control in biogas plants

DEFF Research Database (Denmark)

Holm-Nielsen, Jens Bo; Oleskowicz-Popiel, Piotr

2013-01-01

Efficient monitoring and control of anaerobic digestion (AD) processes are necessary in order to enhance biogas plant performance. The aim of monitoring and controlling the biological processes is to stabilise and optimise the production of biogas. The principles of process analytical technology...

Biogas utilization

Energy Technology Data Exchange (ETDEWEB)

Moser, M.A. [Resource Conservation Management, Inc., Berkeley, CA (United States)

1996-01-01

Options for successfully using biogas depend on project scale. Almost all biogas from anaerobic digesters must first go through a gas handling system that pressurizes, meters, and filters the biogas. Additional treatment, including hydrogen sulfide-mercaptan scrubbing, gas drying, and carbon dioxide removal may be necessary for specialized uses, but these are complex and expensive processes. Thus, they can be justified only for large-scale projects that require high-quality biogas. Small-scale projects (less than 65 cfm) generally use biogas (as produced) as a boiler fuel or for fueling internal combustion engine-generators to produce electricity. If engines or boilers are selected properly, there should be no need to remove hydrogen sulfide. Small-scale combustion turbines, steam turbines, and fuel cells are not used because of their technical complexity and high capital cost. Biogas cleanup to pipeline or transportation fuel specifications is very costly, and energy economics preclude this level of treatment.

Methodology for Analysing Energy Demand in Biogas Production Plants—A Comparative Study of Two Biogas Plants

Directory of Open Access Journals (Sweden)

Emma Lindkvist

2017-11-01

Full Text Available Biogas production through anaerobic digestion may play an important role in a circular economy because of the opportunity to produce a renewable fuel from organic waste. However, the production of biogas may require energy in the form of heat and electricity. Therefore, resource-effective biogas production must consider both biological and energy performance. For the individual biogas plant to improve its energy performance, a robust methodology to analyse and evaluate the energy demand on a detailed level is needed. Moreover, to compare the energy performance of different biogas plants, a methodology with a consistent terminology, system boundary and procedure is vital. The aim of this study was to develop a methodology for analysing the energy demand in biogas plants on a detailed level. In the methodology, the energy carriers are allocated to: (1 sub-processes (e.g., pretreatment, anaerobic digestion, gas cleaning, (2 unit processes (e.g., heating, mixing, pumping, lighting and (3 a combination of these. For a thorough energy analysis, a combination of allocations is recommended. The methodology was validated by applying it to two different biogas plants. The results show that the methodology is applicable to biogas plants with different configurations of their production system.

Biogas

Energy Technology Data Exchange (ETDEWEB)

Cohen, A [CSM Suiker BV, Amsterdam (Netherlands); Van Velsen, A F.M.

1985-03-01

Process and processing of anaerobic digestion are described. Methane bacteria are only the last link in a long step by step degradation of organic wastes by a large number of microorganisms. In this article the following processes get special attention: septic tank process, used for isolated residential buildings; manure digestion systems; anaerobic sludge processes. A Dutch development is the upflow anaerobic sludge blanket reactor (UASB). Newest process is the fluid bed process, which enables a very fast sedimentation and short residence time. The sensibility for toxic compounds in waste water remains a problem in all biogas processes. (A.V.)

Improving the mixing performances of rice straw anaerobic digestion for higher biogas production by computational fluid dynamics (CFD) simulation.

Science.gov (United States)

Shen, Fei; Tian, Libin; Yuan, Hairong; Pang, Yunzhi; Chen, Shulin; Zou, Dexun; Zhu, Baoning; Liu, Yanping; Li, Xiujin

2013-10-01

As a lignocellulose-based substrate for anaerobic digestion, rice straw is characterized by low density, high water absorbability, and poor fluidity. Its mixing performances in digestion are completely different from traditional substrates such as animal manures. Computational fluid dynamics (CFD) simulation was employed to investigate mixing performances and determine suitable stirring parameters for efficient biogas production from rice straw. The results from CFD simulation were applied in the anaerobic digestion tests to further investigate their reliability. The results indicated that the mixing performances could be improved by triple impellers with pitched blade, and complete mixing was easily achieved at the stirring rate of 80 rpm, as compared to 20-60 rpm. However, mixing could not be significantly improved when the stirring rate was further increased from 80 to 160 rpm. The simulation results agreed well with the experimental results. The determined mixing parameters could achieve the highest biogas yield of 370 mL (g TS)(-1) (729 mL (g TS(digested))(-1)) and 431 mL (g TS)(-1) (632 mL (g TS(digested))(-1)) with the shortest technical digestion time (T 80) of 46 days. The results obtained in this work could provide useful guides for the design and operation of biogas plants using rice straw as substrates.

Optimising the anaerobic co-digestion of urban organic waste using dynamic bioconversion mathematical modelling

DEFF Research Database (Denmark)

Fitamo, Temesgen Mathewos; Boldrin, Alessio; Dorini, G.

2016-01-01

Mathematical anaerobic bioconversion models are often used as a convenient way to simulate the conversion of organic materials to biogas. The aim of the study was to apply a mathematical model for simulating the anaerobic co-digestion of various types of urban organic waste, in order to develop...... in a continuously stirred tank reactor. The model's outputs were validated with experimental results obtained in thermophilic conditions, with mixed sludge as a single substrate and urban organic waste as a co-substrate at hydraulic retention times of 30, 20, 15 and 10 days. The predicted performance parameter...... (methane productivity and yield) and operational parameter (concentration of ammonia and volatile fatty acid) values were reasonable and displayed good correlation and accuracy. The model was later applied to identify optimal scenarios for an urban organic waste co-digestion process. The simulation...

Biogas Improvement by Adding Australian Zeolite During the Anaerobic Digestion of C:N Ratio Adjusted Swine Manure

DEFF Research Database (Denmark)

Wijesinghe, D. Thushari N.; Dassanayake, Kithsiri B.; Sommer, Sven G.

2018-01-01

Abstract: Maintenance of the ideal carbon: nitrogen (C:N) ratio with a minimum level of TAN is a key challenge for achieving maximum potential CH4 production through the anaerobic digestion process of agricultural waste such as swine manure. Biogas production can be enhanced by adding zeolite...... into the anaerobic digestion medium. However, the effects of zeolite addition to C:N ratio adjusted feedstock, on the digester performance is unknown. The objectives of this study were to investigate the effect of Australian zeolite on anaerobic digestion of swine manure with a C:N ratio adjusted to 30...... and to determine the optimal zeolite application rate to achieve the best performance. The Australian zeolite significantly enhanced CH4 production and reduced the lag phase of anaerobic digestion in batch production. The optimal addition rate of zeolite was appeared to be around 40 g/L. The better digester...

Effects of operational shocks on key microbial populations for biogas production in UASB (Upflow Anaerobic Sludge Blanket) reactors

International Nuclear Information System (INIS)

Couras, C.S.; Louros, V.L.; Grilo, A.M.; Leitão, J.H.; Capela, M.I.; Arroja, L.M.; Nadais, M.H.

2014-01-01

This work compares the overall performance and biogas production of continuous and intermittent UASB (Upflow Anaerobic Sludge Blanket) reactors treating dairy wastewater and subjected to fat, hydraulic and temperature shocks. The systems were monitored for methane production, effluent concentration, volatile fatty acids, and microbial populations of the Eubacteria, Archaea and Syntrophomonadaceae groups. This last microbial group has been reported in literature as being determinant for the degradation of fatty substrates present in the wastewater and subsequent biogas production. Results show that both continuous and intermittent systems supported the applied shocks. However, the intermittent systems exhibited better performance than the continuous systems in biogas production and physical-chemical parameters. Syntrophomonadaceae microbial group was present in the intermittent systems, but was not detected in the biomass from the continuous systems. Hydraulic and temperature shocks, but not the fat shock, caused severe losses in the relative abundance of the Syntrophomonadaceae group in intermittent systems, leading to undetectable levels during the temperature shock. The severity of the effects of the applied shocks on the key microbial group Syntrophomonadaceae, were classified as: fats < hydraulic < temperature. Results from a full-scale anaerobic reactor confirm the effect of intermittent operation on the presence of Syntrophomonadaceae and the effect on reactor performance. - Highlights: • We compared intermittent and continuous UASB reactors upon operational shocks. • Syntrophomonadaceae key microbial group for maximizing biogas was quantified by FISH. • Syntrophomonadaceae is present in intermittent but not in continuous UASB reactors. • Syntrophomonadaceae abundance increases with fat shock in intermittent UASB reactor. • Syntrophomonadaceae abundance decreases with hydraulic or temperature shock

Environmental perspectives on using cast seaweed for biogas production

DEFF Research Database (Denmark)

Fredenslund, Anders Michael; Møller, Henrik Bjarne; Christensen, Thomas Budde

Solrød Municipality, Denmark is working towards building a biogas plant utilizing locally available organic wastes including cast seaweed, which is collected each year, since the local inhabitants see this material as a nuisance. A preliminary study suggested favorable conditions for contstructing...... a mixed substrate biogas plant. Continuously fed reactor experiments showed that the intended mix of substrate including cast seaweed could be used as raw material for a biogas plant in thermophilic operation. The environmental analysis suggests existence of several positive benefits of utilizing cast...

Improving the stability of thermophilic anaerobic digesters treating SS-OFMSW through enrichment with compost and leachate seeds

KAUST Repository

Ghanimeh, Sophia A.

2013-03-01

This paper examines the potential of improving the stability of thermophilic anaerobic digestion of source-sorted organic fraction of municipal solid waste (SS-OFMSW) by adding leachate and compost during inoculation. For this purpose, two stable thermophilic digesters, A (control) and B (with added leachate and compost), were subjected to a sustained substrate shock by doubling the organic loading rate for one week. Feeding was suspended then gradually resumed to reach the pre-shock loading rate (2. gVS/l/d). Digester A failed, exhibiting excessive increase in acetate and a corresponding decrease in pH and methane generation, and lower COD and solids removal efficiencies. In contrast, digester B was able to restore its functionality with 90% recovery of pre-shock methane generation rate at stable pH, lower hydrogen levels, and reduced VFAs and ammonia accumulation. © 2012 Elsevier Ltd.

Improving the stability of thermophilic anaerobic digesters treating SS-OFMSW through enrichment with compost and leachate seeds

KAUST Repository

Ghanimeh, Sophia A.; El-Fadel, Mutasem E.; Saikaly, Pascal

2013-01-01

This paper examines the potential of improving the stability of thermophilic anaerobic digestion of source-sorted organic fraction of municipal solid waste (SS-OFMSW) by adding leachate and compost during inoculation. For this purpose, two stable thermophilic digesters, A (control) and B (with added leachate and compost), were subjected to a sustained substrate shock by doubling the organic loading rate for one week. Feeding was suspended then gradually resumed to reach the pre-shock loading rate (2. gVS/l/d). Digester A failed, exhibiting excessive increase in acetate and a corresponding decrease in pH and methane generation, and lower COD and solids removal efficiencies. In contrast, digester B was able to restore its functionality with 90% recovery of pre-shock methane generation rate at stable pH, lower hydrogen levels, and reduced VFAs and ammonia accumulation. © 2012 Elsevier Ltd.

Co-digestion of cattle manure with food waste and sludge to increase biogas production

Energy Technology Data Exchange (ETDEWEB)

Maranon, E., E-mail: emara@uniovi.es [Department of Chemical Engineering and Environmental Technology, University Institute of Technology of Asturias, Campus of Gijon, University of Oviedo, 33203 Gijon (Spain); Castrillon, L.; Quiroga, G.; Fernandez-Nava, Y. [Department of Chemical Engineering and Environmental Technology, University Institute of Technology of Asturias, Campus of Gijon, University of Oviedo, 33203 Gijon (Spain); Gomez, L.; Garcia, M.M. [Zero Emissions Technology, 41018 Seville (Spain)

2012-10-15

Highlights: Black-Right-Pointing-Pointer Small increase in methane production was observed applying sonication pretreatment. Black-Right-Pointing-Pointer Biogas productions between 720 and 1100 mL/Lreactor day were achieved. Black-Right-Pointing-Pointer Volatile solids removal efficiencies ranged between 53% and 60%. Black-Right-Pointing-Pointer Lower methane yields were obtained when operating under thermophilic conditions. Black-Right-Pointing-Pointer Optimum OLR in lab-scale CSTR was 1.2-1.3 g VS/L day (HRT: 20 days). - Abstract: Anaerobic co-digestion strategies are needed to enhance biogas production, especially when treating certain residues such as cattle/pig manure. This paper presents a study of co-digestion of cattle manure with food waste and sewage sludge. With the aim of maximising biogas yields, a series of experiments were carried out under mesophilic and thermophilic conditions using continuously stirred-tank reactors, operating at different hydraulic residence times. Pretreatment with ultrasound was also applied to compare the results with those obtained with non-pretreated waste. Specific methane production decreases when increasing the OLR and decreasing HRT. The maximum value obtained was 603 LCH{sub 4}/kg VS{sub feed} for the co-digestion of a mixture of 70% manure, 20% food waste and 10% sewage sludge (total solid concentration around 4%) at 36 Degree-Sign C, for an OLR of 1.2 g VS/L day. Increasing the OLR to 1.5 g VS/L day led to a decrease of around 20-28% in SMP. Lower methane yields were obtained when operating at 55 Degree-Sign C. The increase in methane production when applying ultrasound to the feed mixtures does not compensate for the energy spent in this pretreatment.

Changes of resistome, mobilome and potential hosts of antibiotic resistance genes during the transformation of anaerobic digestion from mesophilic to thermophilic.

Science.gov (United States)

Tian, Zhe; Zhang, Yu; Yu, Bo; Yang, Min

2016-07-01

This study aimed to reveal how antibiotic resistance genes (ARGs) and their horizontal and vertical transfer-related items (mobilome and bacterial hosts) respond to the transformation of anaerobic digestion (AD) from mesophilic to thermophilic using one-step temperature increase. The resistomes and mobilomes of mesophilic and thermophilic sludge were investigated using metagenome sequencing, and the changes in 24 representative ARGs belonging to three categories, class 1 integron and bacterial genera during the transition period were further followed using quantitative PCR and 454-pyrosequencing. After the temperature increase, resistome abundance in the digested sludge decreased from 125.97 ppm (day 0, mesophilic) to 50.65 ppm (day 57, thermophilic) with the reduction of most ARG types except for the aminoglycoside resistance genes. Thermophilic sludge also had a smaller mobilome, including plasmids, insertion sequences and integrons, than that of mesophilic sludge, suggesting the lower horizontal transfer potential of ARGs under thermophilic conditions. On the other hand, the total abundance of 18 bacterial genera, which were suggested as the possible hosts for 13 ARGs through network analysis, decreased from 23.27% in mesophilic sludge to 11.92% in thermophilic sludge, indicating fewer hosts for the vertical expansion of ARGs after the increase in temperature. These results indicate that the better reduction of resistome abundance by thermophilic AD might be associated with the decrease of both the horizontal and vertical transferability of ARGs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thermophilic (55 - 65°C) and extreme thermophilic (70 - 80°C) sulfate reduction in methanol and formate-fed UASB reactors

NARCIS (Netherlands)

Vallero, M.V.G.; Camarero, E.; Lettinga, G.; Lens, P.N.L.

2004-01-01

The feasibility of thermophilic (55-65 degreesC) and extreme thermophilic (70-80 degreesC) sulfate-reducing processes was investigated in three lab-scale upflow anaerobic sludge bed (UASB) reactors fed with either methanol or formate as the sole substrates and inoculated with mesophilic granular

Modeling temperature variations in a pilot plant thermophilic anaerobic digester.

Science.gov (United States)

Valle-Guadarrama, Salvador; Espinosa-Solares, Teodoro; López-Cruz, Irineo L; Domaschko, Max

2011-05-01

A model that predicts temperature changes in a pilot plant thermophilic anaerobic digester was developed based on fundamental thermodynamic laws. The methodology utilized two simulation strategies. In the first, model equations were solved through a searching routine based on a minimal square optimization criterion, from which the overall heat transfer coefficient values, for both biodigester and heat exchanger, were determined. In the second, the simulation was performed with variable values of these overall coefficients. The prediction with both strategies allowed reproducing experimental data within 5% of the temperature span permitted in the equipment by the system control, which validated the model. The temperature variation was affected by the heterogeneity of the feeding and extraction processes, by the heterogeneity of the digestate recirculation through the heating system and by the lack of a perfect mixing inside the biodigester tank. The use of variable overall heat transfer coefficients improved the temperature change prediction and reduced the effect of a non-ideal performance of the pilot plant modeled.

Cloning, sequencing, and sequence analysis of two novel plasmids from the thermophilic anaerobic bacterium Anaerocellum thermophilum

DEFF Research Database (Denmark)

Clausen, Anders; Mikkelsen, Marie Just; Schrøder, I.

2004-01-01

The nucleotide sequence of two novel plasmids isolated from the extreme thermophilic anaerobic bacterium Anaerocellum thermophilum DSM6725 (A. thermophilum), growing optimally at 70degreesC, has been determined. pBAS2 was found to be a 3653 bp plasmid with a GC content of 43%, and the sequence re...... with highest similarity to DNA repair protein from Campylobacter jejuni (25% aa). Orf34 showed similarity to sigma factors with highest similarity (28% aa) to the sporulation specific Sigma factor, Sigma 28(K) from Bacillus thuringiensis....

Mass and Energy Balances of Dry Thermophilic Anaerobic Digestion Treating Swine Manure Mixed with Rice Straw

OpenAIRE

Zhou, Sheng; Zhang, Jining; Zou, Guoyan; Riya, Shohei; Hosomi, Masaaki

2015-01-01

To evaluate the feasibility of swine manure treatment by a proposed Dry Thermophilic Anaerobic Digestion (DT-AD) system, we evaluated the methane yield of swine manure treated using a DT-AD method with rice straw under different C/N ratios and solid retention time (SRT) and calculated the mass and energy balances when the DT-AD system is used for swine manure treatment from a model farm with 1000 pigs and the digested residue is used for forage rice production. A traditional swine manure trea...

Winery waste recycling through anaerobic co-digestion with waste activated sludge.

Science.gov (United States)

Da Ros, C; Cavinato, C; Pavan, P; Bolzonella, D

2014-11-01

In this study biogas and high quality digestate were recovered from winery waste (wine lees) through anaerobic co-digestion with waste activated sludge both in mesophilic and thermophilic conditions. The two conditions studied showed similar yields (0.40 m(3)/kgCODfed) but different biological process stability: in fact the mesophilic process was clearly more stable than the thermophilic one in terms of bioprocess parameters. The resulting digestates showed good characteristics for both the tested conditions: heavy metals, dioxins (PCDD/F), and dioxin like bi-phenyls (PCBs) were concentred in the effluent if compared with the influent because of the important reduction of the solid dry matter, but remained at levels acceptable for agricultural reuse. Pathogens in digestate decreased. Best reductions were observed in thermophilic condition, while at 37°C the concentration of Escherichia coli was at concentrations level as high as 1000 UFC/g. Dewatering properties of digestates were evaluated by means of the capillary suction time (CST) and specific resistance to filtration (SRF) tests and it was found that a good dewatering level was achievable only when high doses of polymer (more than 25 g per kg dry solids) were added to sludge. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of mixing on biogas production during mesophilic anaerobic digestion of screened dairy manure in a Pilot plant

Energy Technology Data Exchange (ETDEWEB)

Rico, Carlos; Tejero, Inaki [Department of Sciences and Techniques of Water and Environment, University of Cantabria, Santander (Spain); Rico, Jose Luis; Munoz, Noelia; Gomez, Beatriz [Department of Chemical Engineering and Inorganic Chemistry, University of Cantabria, Santander (Spain)

2011-10-15

The effect of mixing on biogas production of a 1.5-m{sup 3} pilot continuous stirred tank reactor (CSTR) processing screened dairy manure was evaluated. Mixing was carried out by recirculation of reactor content with a mono pump. The experiment was conducted at a controlled temperature of 37{+-}1 C and hydraulic retention times (HRTs) of 20 and 10 days. The effect of continuous and intermittent operation of the recirculation pump on biogas production was studied. At 10 days of HRT, the results showed a minimal influence of recirculation rate on biogas production and that continuous recirculation did not improve reactor performance. At 20 days of HRT, the recirculation rate did not affect reactor performance. Combination of low solid content in feed animal slurry and long HRTs results in minimal mixing requirements for anaerobic digestion. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Serial CSTR digester configuration for improving biogas production from manure

DEFF Research Database (Denmark)

Boe, Kanokwan; Angelidaki, Irini

2009-01-01

distribution ratio of 80/20 and 90/10, and total HRT of 15 days. The results showed that the serial CSTR could obtain 11% higher biogas yield compared to the single CSTR. The increased biogas yield in the serial CSTR was mainly from the second reactor, which accounted for 16% and 12% of total biogas yield......A new configuration of manure digesters for improving biogas production has been investigated in laboratory scale. A single thermophilic continuous-flow stirred tank reactor (CSTR) operated with a hydraulic retention time (HRT) of 15 days was compared to a serial CSTR configuration with volume...

Biohydrogen and methane production by co-digestion of cassava stillage and excess sludge under thermophilic condition.

Science.gov (United States)

Wang, Wen; Xie, Li; Chen, Jinrong; Luo, Gang; Zhou, Qi

2011-02-01

Thermophilic anaerobic hydrogen and methane production by co-digestion of cassava stillage (CS) and excess sludge (ES) was investigated in this study. The improved hydrogen and subsequent methane production were observed by co-digestion of CS with certain amount of ES in batch experiments. Compared with one phase anaerobic digestion, two phase anaerobic digestion offered an attractive alternative with more abundant biogas production and energy yield, e.g., the total energy yield in two phase obtained at VS(CS)/VS(ES) of 3:1 was 25% higher than the value of one phase. Results from continuous experiments further demonstrated that VS(CS)/VS(ES) of 3:1 was optimal for hydrogen production with the highest hydrogen yield of 74 mL/gtotal VS added, the balanced nutrient condition with C/N ratio of 1.5 g carbohydrate-COD/gprotein-COD or 11.9 g C/gN might be the main reason for such enhancement. VS(CS)/VS(ES) of 3:1 was also optimal for continuous methane production considering the higher methane yield of 350 mL/gtotal VS added and the lower propionate concentration in the effluent. Copyright © 2010 Elsevier Ltd. All rights reserved.

Nitrogen in the Process of Waste Activated Sludge Anaerobic Digestion

Directory of Open Access Journals (Sweden)

Suschka Jan

2014-07-01

Full Text Available Primary or secondary sewage sludge in medium and large WWTP are most often processed by anaerobic digestion, as a method of conditioning, sludge quantity minimization and biogas production. With the aim to achieve the best results of sludge processing several modifications of technologies were suggested, investigated and introduced in the full technical scale. Various sludge pretreatment technologies before anaerobic treatment have been widely investigated and partially introduced. Obviously, there are always some limitations and some negative side effects. Selected aspects have been presented and discussed. The problem of nitrogen has been highlighted on the basis of the carried out investigations. The single and two step - mesophilic and thermophilic - anaerobic waste activated sludge digestion processes, preceded by preliminary hydrolysis were investigated. The aim of lab-scale experiments was pre-treatment of the sludge by means of low intensive alkaline and hydrodynamic disintegration. Depending on the pretreatment technologies and the digestion temperature large ammonia concentrations, up to 1800 mg NH4/dm3 have been measured. Return of the sludge liquor to the main sewage treatment line means additional nitrogen removal costs. Possible solutions are discussed.

Biogas from mesophilic anaerobic digestion of cow dung using gelatin as additive

Science.gov (United States)

Salam, Bodius; Rahman, Md Mizanur; Sikder, Md Asif R.; Islam, Majedul

2017-06-01

A research work was conducted to investigate the enhanced production ability of biogas from mesophilic anaerobic digestions of cow dung (CD) using gelatin as additive. Five laboratory scale digesters were constructed to digest cow dung, where one set up was used for digestion of cow dung without additive and the other set up were used for digestion with additive. Gelatin additive was added in the slurry of amount 0.29, 0,57, 0.85 and 1.14% (wt.). The digesters were made of glass conical flask of 1-liter capacity each. Cow dung was used 335 gm and water was used 365 gm in each experiment. In the slurry, total solid content was maintained 8% (wt.) for all the observations. The digesters were fed on batch basis. The digesters were operated at ambient temperatures of 26 - 35°C. The total gas yield was obtained about 14.4 L/kg CD for digestion without additive and about 65% more biogas for digestion with 0.29% gelatin additive. The retention time for digestion without additive was 38 days and with additive retention time varied between 24 and 52 days.

The effects of the antibiotics ampicillin, florfenicol, sulfamethazine, and tylosin on biogas production and their degradation efficiency during anaerobic digestion.

Science.gov (United States)

Mitchell, Shannon M; Ullman, Jeffrey L; Teel, Amy L; Watts, Richard J; Frear, Craig

2013-12-01

The impacts of four common animal husbandry antibiotics (ampicillin, florfenicol, sulfamethazine, and tylosin) on anaerobic digestion (AD) treatment efficiency and the potential for antibiotic degradation during digestion were evaluated. Sulfamethazine and ampicillin exhibited no impact on total biogas production up to 280 and 350 mg/L, respectively, although ampicillin inhibited biogas production rates during early stages of AD. Tylosin reduced biogas production by 10-38% between 130 and 913 mg/L. Florfenicol reduced biogas by ≈ 5%, 40% and 75% at 6.4, 36 and 210 mg/L, respectively. These antibiotic concentrations are higher than commonly seen for mixed feedlot manure, so impacts on full scale AD should be minimal. Antibiotic degradation products were found, confirming AD effectively degraded ampicillin, florfenicol, and tylosin, although some products were persistent throughout the process. Contamination of AD solid and liquid effluents with sulfamethazine and antibiotic transformation products from florfenicol and tylosin could present an environmental concern. Published by Elsevier Ltd.

Anaerobic Co-digestion of Cow Dung and Rice Straw to Produce Biogas using Semi-Continuous Flow Digester: Effect of Urea Addition

Science.gov (United States)

Haryanto, A.; Sugara, B. P.; Telaumbanua, M.; Rosadi, R. A. B.

2018-05-01

The objective this research was to investigate the effect of urea addition on the biogas yield from co-digestion of rice straw and cow dung using semi-continuous anaerobic digester. The experiment was conducted by using self-made semi-continuous anaerobic digester having a working volume of 30 L. Cow dung was provided from Department of Animal Husbandry, University of Lampung; while rice straw was collected from farmer at Way Galih, Tanjung Bintang, South Lampung. Rice straw was sun-dried to about 12% of moisture content and then ground into fine particles. Cow dung and ground straw were mixed at a dung-to-straw ratio of 3:1 based on total solid (TS) and four different urea additions (0, 0.25, 0.65, and 1.30 g/L) were applied to have a C/N ratio between 20 and 30. The mixture was diluted with water to create TS content of 10%. As much as 30 L of the substrate mixture was introduced into the digester as a starting load. The same substrate was added daily at a loading rate of 0.5 L/d. The experiment was made in triplicate and observation was performed for two months. Total and volatile solids of influent and effluent and daily biogas production were observed. The biogas quality was measured by its methane content using gas chromatography. Results showed that urea addition influenced the biogas yield and its quality. Substrate mixture with urea addition of 0.25 g/L (C/N ratio of 27.3) was the best in terms of biogas yield (434.2 L/kgVSr), methane content (50.12%), and methane yield (217.6 L/kgVSr).

International scientific conference biogas science 2009. Vol. 1. Lectures; Internationale Wissenschaftstagung Biogas Science 2009. Bd. 1. Vortraege

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-12-15

Within the international conference of the Bavarian State Research Center for Agriculture (Munich, Federal Republic of Germany) at 2nd to 4th December, 2009, in Erding (Federal Republic of Germany), the following lectures were held: (1) Significance of the sector biogas within the scope of renewable energies (P. Schuesseler); (2) Anaerobic digestion, a superior renewable energy degradation method (G. Lettinga); (3) Trends of the biogas technology - Challenges for the practice (J. Pellmeyer); (4) Extensification of cultivation procedures for the production of biogas substrates (K. Deiglmayer et al.); (5) Approaches for the optimization of crop rotations for biogas plants at Bavarian conditions of cultivation (E. Sticksel et al.); (6) Development and comparison of site specific production systems for energy crops (Ch. Strauss et al.); (7) Which type of maize is useful for the production of biogas? (B. Eder et al.); (8) Fermentation of interim fruits, food stocks and residues of harvest: Review on the possibilities of power generation and avoidance of direct and indirect emissions of climatic gases (W. Stinner et al.); (9) Optimization of anaerobic fermentation by means of mineral additives (H. Heuwinkel et al.); (10) The accuracy of the measurement of gas yields of substrates using the batch method (H. Heuwinkel et al.); (11) Combined mechanical-enzymatic pre-treatment of an improved digestion of substrates during the fermentation of renewable raw materials (D. Schiedr et al.); (12) Anaerobic semi-continuous co-digestion of dairy cattle manure and agricultural residues: Effect of operational parameters (E. Alkaya et al.); (13) Do hydrolytic enzymes enhance methane formation of agricultural feedstock? (T. Suarez Quinones et al.); (14) DAUMEN-Energy ''Design fo Separation and Augmented Methanisation of Fibres Substrates - Contribution to sustainable biogas production'' (P. Stopp et al.); (15) Continuous two-phase solid-state anaerobic digestion

Bio-hydrolysis and bio-hydrogen production from food waste by thermophilic and hyperthermophilic anaerobic process.

Science.gov (United States)

Algapani, Dalal E; Qiao, Wei; Su, Min; di Pumpo, Francesca; Wandera, Simon M; Adani, Fabrizio; Dong, Renjie

2016-09-01

High-temperature pretreatment plays a key role in the anaerobic digestion of food waste (FW). However, the suitable temperature is not yet determined. In this work, a long-term experiment was conducted to compare hydrolysis, acidogenesis, acetogenesis, and hydrogen production at 55°C and 70°C, using real FW in CSTR reactors. The results obtained indicated that acidification was the rate-limiting step at both temperatures with similar process kinetics characterizations. However, the thermophilic pretreatment was more advantageous than the hyperthermophilic with suspended solids solubilization of 47.7% and 29.5% and total VFA vs. soluble COD ratio of 15.2% and 4.9%, for thermophilic and hyperthermophilic treatment, respectively, with a hydrolytic reaction time (HRT) of 10days and an OLR of 14kgCOD/m(3)d. Moreover, stable hydrogen yield (70.7ml-H2/gVSin) and content in off gas (58.6%) was achieved at HRT 5days, pH 5.5, and temperature of 55°C, as opposed to 70°C. Copyright © 2016 Elsevier Ltd. All rights reserved.

Performance and microbial community analysis of the anaerobic reactor with coke oven gas biomethanation and in situ biogas upgrading

DEFF Research Database (Denmark)

Wang, Wen; Xie, Li; Luo, Gang

2013-01-01

(HFM). With pH control at 8.0, the added H2 and CO were fully consumed and no negative effects on the anaerobic degradation of sewage sludge were observed. The maximum CH4 content in the biogas was 99%. The addition of SCOG resulted in enrichment and dominance of homoacetogenetic genus Treponema...

Establishment of thermophilic anaerobic terephthalic acid degradation system through one-step temperature increase startup strategy - Revealed by Illumina Miseq Sequencing.

Science.gov (United States)

Ma, Kai-Li; Li, Xiang-Kun; Wang, Ke; Meng, Ling-Wei; Liu, Gai-Ge; Zhang, Jie

2017-10-01

Over recent years, thermophilic digestion was constantly focused owing to its various advantage over mesophilic digestion. Notably, the startup approach of thermophilic digester needs to be seriously considered as unsuitable startup ways may result in system inefficiency. In this study, one-step temperature increase startup strategy from 37 °C to 55 °C was applied to establish a thermophilic anaerobic system treating terephthalic acid (TA) contained wastewater, meanwhile, the archaeal and bacterial community compositions at steady periods of 37 °C and 55 °C during the experimental process was also compared using Illumina Miseq Sequencing. The process operation demonstrated that the thermophilic TA degradation system was successfully established at 55 °C with over 95% COD reduction. For archaea community, the elevation of operational temperature from 37 °C to 55 °C accordingly increase the enrichment of hydrogenotrophic methanogens but decrease the abundance of the acetotrophic ones. While for bacterial community, the taxonomic analysis suggested that Syntrophorhabdus (27.40%) was the dominant genus promoting the efficient TA degradation under mesophilic condition, whereas OPB95 (24.99%) and TA06 (14.01%) related populations were largely observed and probably take some crucial role in TA degradation under thermophilic condition. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modeling the performance of the anaerobic phased solids digester system for biogas energy production

International Nuclear Information System (INIS)

Rapport, Joshua L.; Zhang, Ruihong; Jenkins, Bryan M.; Hartsough, Bruce R.; Tomich, Thomas P.

2011-01-01

A process model was developed to predict the mass and energy balance for a full-scale (115 t d -1 ) high-solids anaerobic digester using research data from lab and pilot scale (1-3000 kg d -1 wet waste) systems. Costs and revenues were estimated in consultation with industry partners and the 20-year project cash flow, net present worth (NPW), simple payback, internal rate of return, and revenue requirements were calculated. The NPW was used to compare scenarios in order to determine the financial viability of using a generator for heat and electricity or a pressure swing adsorption unit for converting biogas to compressed natural gas (CNG). The full-scale digester consisted of five 786 m 3 reactors (one biogasification reactor and four hydrolysis reactors) treating a 50:50 mix (volatile solids basis) of food and green waste, of which 17% became biogas, 32% residual solids, and 51% wastewater. The NPW of the projects were similar whether producing electricity or CNG, as long as the parasitic energy demand was satisfied with the biogas produced. When producing electricity only, the power output was 1.2 MW, 7% of which was consumed parasitically. When producing CNG, the system produced 2 hm 3 y -1 natural gas after converting 22% of the biogas to heat and electricity which supplied the parasitic energy demand. The digester system was financially viable whether producing electricity or CNG for discount rates of up to 13% y -1 without considering debt (all capital was considered equity), heat sales, feed-in tariffs or tax credits.

Macroscopic mass and energy balance of a pilot plant anaerobic bioreactor operated under thermophilic conditions.

Science.gov (United States)

Espinosa-Solares, Teodoro; Bombardiere, John; Chatfield, Mark; Domaschko, Max; Easter, Michael; Stafford, David A; Castillo-Angeles, Saul; Castellanos-Hernandez, Nehemias

2006-01-01

Intensive poultry production generates over 100,000 t of litter annually in West Virginia and 9 x 10(6) t nationwide. Current available technological alternatives based on thermophilic anaerobic digestion for residuals treatment are diverse. A modification of the typical continuous stirred tank reactor is a promising process being relatively stable and owing to its capability to manage considerable amounts of residuals at low operational cost. A 40-m3 pilot plant digester was used for performance evaluation considering energy input and methane production. Results suggest some changes to the pilot plant configuration are necessary to reduce power consumption although maximizing biodigester performance.

Ultrasound assisted biogas production from landfill leachate

International Nuclear Information System (INIS)

Oz, Nilgün Ayman; Yarimtepe, Canan Can

2014-01-01

Highlights: • Effect of low frequency ultrasound pretreatment on leachate was investigated. • Three different ultrasound energy inputs (200, 400 and 600 W/l) was applied. • Low-frequency ultrasound treatment increased soluble COD in landfill leachate. • Application of ultrasound to leachate increased biogas production about 40%. • Application of ultrasound to leachate increased total methane production rate about 20%. - Abstract: The aim of this study is to increase biogas production and methane yield from landfill leachate in anaerobic batch reactors by using low frequency ultrasound as a pretreatment step. In the first part of the study, optimum conditions for solubilization of organic matter in leachate samples were investigated using various sonication durations at an ultrasound frequency of 20 kHz. The level of organic matter solubilization during ultrasonic pretreatment experiments was determined by calculating the ratio of soluble chemical oxygen demand (sCOD) to total chemical oxygen demand (tCOD). The sCOD/tCOD ratio was increased from 47% in raw leachate to 63% after 45 min sonication at 600 W/l. Non-parametric Friedman’s test indicated that ultrasonic pretreatment has a significant effect on sCOD parameter for leachate (p < 0.05). In the second part of the study, anaerobic batch reactors were operated for both ultrasonically pretreated and untreated landfill leachate samples in order to assess the effect of sonication on biogas and methane production rate. In anaerobic batch reactor feed with ultrasonically pretreated leachate, 40% more biogas was obtained compared to the control reactor. For statistical analysis, Mann–Whitney U test was performed to compare biogas and methane production rates for raw and pretreated leachate samples and it has been found that ultrasonic pretreatment significantly enhanced biogas and methane production rates from leachate (p < 0.05) in anaerobic batch reactors. The overall results showed that low frequency

Ultrasound assisted biogas production from landfill leachate

Energy Technology Data Exchange (ETDEWEB)

Oz, Nilgün Ayman, E-mail: nilgunayman@comu.edu.tr; Yarimtepe, Canan Can

2014-07-15

Highlights: • Effect of low frequency ultrasound pretreatment on leachate was investigated. • Three different ultrasound energy inputs (200, 400 and 600 W/l) was applied. • Low-frequency ultrasound treatment increased soluble COD in landfill leachate. • Application of ultrasound to leachate increased biogas production about 40%. • Application of ultrasound to leachate increased total methane production rate about 20%. - Abstract: The aim of this study is to increase biogas production and methane yield from landfill leachate in anaerobic batch reactors by using low frequency ultrasound as a pretreatment step. In the first part of the study, optimum conditions for solubilization of organic matter in leachate samples were investigated using various sonication durations at an ultrasound frequency of 20 kHz. The level of organic matter solubilization during ultrasonic pretreatment experiments was determined by calculating the ratio of soluble chemical oxygen demand (sCOD) to total chemical oxygen demand (tCOD). The sCOD/tCOD ratio was increased from 47% in raw leachate to 63% after 45 min sonication at 600 W/l. Non-parametric Friedman’s test indicated that ultrasonic pretreatment has a significant effect on sCOD parameter for leachate (p < 0.05). In the second part of the study, anaerobic batch reactors were operated for both ultrasonically pretreated and untreated landfill leachate samples in order to assess the effect of sonication on biogas and methane production rate. In anaerobic batch reactor feed with ultrasonically pretreated leachate, 40% more biogas was obtained compared to the control reactor. For statistical analysis, Mann–Whitney U test was performed to compare biogas and methane production rates for raw and pretreated leachate samples and it has been found that ultrasonic pretreatment significantly enhanced biogas and methane production rates from leachate (p < 0.05) in anaerobic batch reactors. The overall results showed that low frequency

Biogas Production Using Anaerobic Biodigester from Cassava Starch Effluent

Directory of Open Access Journals (Sweden)

S. Sunarso

2010-12-01

Full Text Available IKMs’ factory activity in Margoyoso produces liquid and solid wastes. The possible alternative was to use the liquid effluent as biogas raw material. This study focuses on the used of urea, ruminant, yeast, microalgae, the treatment of gelled and ungelled feed for biogas production, pH control during biogas production using buffer Na2CO3, and feeding management in the semi-continuous process of biogas production that perform at ambient temperature for 30 days. Ruminant bacteria, yeast, urea, and microalgae was added 10% (v/v, 0.08% (w/v, 0.04% (w/v, 50% (v/v of mixing solution volume, respectively. The pH of slurry was adjusted with range 6.8-7.2 and was measured daily and corrected when necessary with Na2CO3. The total biogas production was measured daily by the water displacement technique. Biogas production from the ungelling and gelling mixture of cassava starch effluent, yeast, ruminant bacteria, and urea were 726.43 ml/g total solid and 198 ml/g total solid. Biogas production from ungelling mixture without yeast was 58.6 ml/g total solid. Biogas production from ungelling mixture added by microalgae without yeast was 58.72 ml/g total solid and that with yeast was 189 ml/g total solid. Biogas production from ungelling mixture of cassava starch effluent, yeast, ruminant bacteria, and urea in semi-continuous process was 581.15 ml/g total solid. Adding of microalgae as nitrogen source did not give significant effect to biogas production. But adding of yeast as substrate activator was very helpful to accelerate biogas production. The biogas production increased after cassava starch effluent and yeast was added. Requirement of sodium carbonate (Na2CO3 to increase alkalinity or buffering capacity of fermenting solution depends on pH-value

Effects of sludge recirculation rate and mixing time on performance of a prototype single-stage anaerobic digester for conversion of food wastes to biogas and energy recovery.

Science.gov (United States)

Ratanatamskul, Chavalit; Saleart, Tawinan

2016-04-01

Food wastes have been recognized as the largest waste stream and accounts for 39.25 % of total municipal solid waste in Thailand. Chulalongkorn University has participated in the program of in situ energy recovery from food wastes under the Ministry of Energy (MOE), Thailand. This research aims to develop a prototype single-stage anaerobic digestion system for biogas production and energy recovery from food wastes inside Chulalongkorn University. Here, the effects of sludge recirculation rate and mixing time were investigated as the main key parameters for the system design and operation. From the results obtained in this study, it was found that the sludge recirculation rate of 100 % and the mixing time of 60 min per day were the most suitable design parameters to achieve high efficiencies in terms of chemical oxygen demand (COD), total solids (TS), and total volatile solid (TVS) removal and also biogas production by this prototype anaerobic digester. The obtained biogas production was found to be 0.71 m(3)/kg COD and the composition of methane was 61.6 %. Moreover, the efficiencies of COD removal were as high as 82.9 % and TVS removal could reach 83.9 % at the optimal condition. Therefore, the developed prototype single-stage anaerobic digester can be highly promising for university canteen application to recover energy from food wastes via biogas production.

Biogas production from pineapple core - A preliminary study

Science.gov (United States)

Jehan, O. S.; Sanusi, S. N. A.; Sukor, M. Z.; Noraini, M.; Buddin, M. M. H. S.; Hamid, K. H. K.

2017-09-01

Anaerobic digestion of pineapple waste was investigated by using pineapple core as the sole substrate. Pineapple core was chosen due to its high total sugar content thus, indicating high amount of fermentable sugar. As digestion process requires the involvement of microorganisms, wastewater from the same industry was added in the current study at ratio of 1:1 by weight. Two different sources of wastewater (Point 1 and Point 2) were used in this study to distinguish the performance of microorganism consortia in both samples. The experiment was conducted by using a lab scale batch anaerobic digester made up from 5L container with separate gas collecting system. The biogas produced was collected by using water displacement method. The experiment was conducted for 30 days and the biogas produced was collected and its volume was recorded at 3 days interval. Based on the data available, wastewater from the first point recorded higher volume of biogas with the total accumulated biogas volume is 216.1 mL. Meanwhile, wastewater sample from Point 2 produced a total of 140.5 mL of biogas, by volume. The data shows that the origin and type of microorganism undeniably play significant role in biogas production. In fact, other factors; pH of wastewater and temperature were also known to affect biogas production. The anaerobic digestion is seen as the promising and sustainable alternatives to current disposal method.

Fate of antibiotic resistance genes in mesophilic and thermophilic anaerobic digestion of chemically enhanced primary treatment (CEPT) sludge.

Science.gov (United States)

Jang, Hyun Min; Shin, Jingyeong; Choi, Sangki; Shin, Seung Gu; Park, Ki Young; Cho, Jinwoo; Kim, Young Mo

2017-11-01

Anaerobic digestion (AD) of chemically enhanced primary treatment (CEPT) sludge and non-CEPT (conventional sedimentation) sludge were comparatively operated under mesophilic and thermophilic conditions. The highest methane yield (692.46±0.46mL CH 4 /g VS removed in CEPT sludge) was observed in mesophilic AD of CEPT sludge. Meanwhile, thermophilic conditions were more favorable for the removal of total antibiotic resistance genes (ARGs). In this study, no measurable difference in the fates and removal of ARGs and class 1 integrin-integrase gene (intI1) was observed between treated non-CEPT and CEPT sludge. However, redundancy analysis indicated that shifts in bacterial community were primarily accountable for the variations in ARGs and intI1. Network analysis further revealed potential host bacteria for ARGs and intI1. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biogas from algae, seaweed and seagrass?; Biogas aus Algen, Tang und Seegras?

Energy Technology Data Exchange (ETDEWEB)

Schneider, Holger [Fachhochschule Flensburg (Germany)

2011-07-01

Algae, seaweed and sea grass are discussed again and again as alternative sources for raw materials for agricultural biogas plants. The author of the contribution under consideration reports on the identification and optimization of the biogas potential of microalgae, macroalgae and flotsam (mixture of seaweed, seaweed, and so on). Algae, seaweed and sea grass can be fermented into biogas by means of an anaerobic process. The specific yield of biogas is small. The processing of these substrates requires a technical adjustment of the biogas plants. Thus, the effective use of these substrates will continue to fall. The achievable benefit highly depends on the location of the facilities and on the available substrates with the corresponding specific gas yields. The economic efficiency of these substrates in agricultural systems must be examined in each case.

A new degassing membrane coupled upflow anaerobic sludge blanket (UASB) reactor to achieve in-situ biogas upgrading and recovery of dissolved CH4 from the anaerobic effluent

DEFF Research Database (Denmark)

Luo, Gang; Wang, Wen; Angelidaki, Irini

2014-01-01

A new technology for in-situ biogas upgrading and recovery of CH4 from the effluent of biogas reactors was proposed and demonstrated in this study. A vacuum degassing membrane module was used to desorb CO2 from the liquid phase of a biogas reactor. The degassing membrane was submerged...... into a degassing unit (DU). The results from batch experiments showed that mixing intensity, transmembrane pressure, pH and inorganic carbon concentration affected the CO2 desorption rate in the DU. Then, the DU was directly connected to an upflow anaerobic sludge blanket (UASB) reactor. The results showed the CH4...... content was only 51.7% without desorption of CO2, while it increased when the liquid of UASB was recycled through the DU. The CH4 content increased to 71.6%, 90%, and 94% with liquid recirculation rate through the DU of 0.21, 0.42 and 0.63L/h, respectively. The loss of methane due to dissolution...

Sewage biogas conversion into electricity; Conversao do biogas de tratamento de esgoto em eletricidade

Energy Technology Data Exchange (ETDEWEB)

Coelho, Suani Teixeira; Velazquez, Silvia Maria Stortini Gonzalez; Martins, Osvaldo Stella; Abreu, Fernando Castro de [Universidade de Sao Paulo (CENBIO/IEE/USP), Sao Paulo, SP (Brazil). Inst. de Eletrotecnica e Energia. Centro Nacional de Referencia em Biomassa], e-mails: suani@iee.usp.br, sgvelaz@iee.usp.br, omartins@iee.usp.br, fcabreu@iee.usp.br

2006-07-01

This article intend to present some considerations directed to electricity generation with small systems (micro turbine and conventional engines ), using biogas generated by sewage treatment process in SABESP (Basic Sanitation Company of Sao Paulo State), located at Barueri, Brazil. This project, pioneer in Latin America, is being accomplished together with BUN - Biomass Users Network of Brazil (proponent), in association with CENBIO - Biomass Reference National Center (executer), with patronage of FINEP / CT-ENERG (financial backer), by means of Convention no: 23.01.0653.00, regarding to ENERG BIOG Project - 'Installation and Tests of an Electric Energy Generation Demonstration Unit from Biogas Sewage Treatment'. The study is being done at Barueri Sewage Treatment Plant. This plant operate with anaerobic digestion process, which has as mainly products biogas (composed mainly by methane) and sludge. Part of the methane produced at the anaerobic process is burnt in a boiler being used to increase digesters temperature. The rest of the methane is burnt in flare to reduce the impacts caused by gases emissions. This article presents some technical, financial and environmental project results, related to the exploitation of sewer biogas for power generation, as well as bigger details about generation systems (biogas micro turbine), used in the facility. (author)

Anaerobic co-digestion of animal manure and wheat straw for optimized biogas production by the addition of magnetite and zeolite

International Nuclear Information System (INIS)

Liu, Linlin; Zhang, Tong; Wan, Haiwen; Chen, Yuanlin; Wang, Xiaojiao; Yang, Gaihe; Ren, Guangxin

2015-01-01

Highlights: • The additives of magnetite and zeolite in anaerobic digestion were studied. • Mineral additives increased methane production significantly. • Mineral additives provided a good environment for methanogens. • The optimum conditions for anaerobic digestion process were optimized. - Abstract: To enhance biogas production and identify new additive materials for the co-digestion of wheat straw, sheep manure, and chicken manure, batch experiments were investigated in this study. Experiments were conducted on the influence of additive materials on a range of manure/straw ratios (3:7, 5:5, and 7:3) and biogas production under a mesophilic temperature (35 °C). Results showed that the maximum increments of methane production (L/kg · VS add ) with the addition of 3 g magnetite and 1 g natural zeolite were 52.01% and 51.01%, respectively. The addition of magnetite and zeolite in the anaerobic digestion process produced a good fermentation environment. By using the response optimizer when the manure proportion was 52%, the best methane yield was obtained with the addition of 2.7 g magnetite. For zeolite, the best addition dose was 1 g and the optimum manure proportion is 63%. Magnetite had a more extensive increase in methane yield than zeolite

Potential of biogas and methane production from anaerobic digestion of poultry slaughterhouse effluent

Directory of Open Access Journals (Sweden)

Natália da Silva Sunada

2012-11-01

Full Text Available The objective of this study was to evaluate the efficiency of anaerobic digestion on the treatment of effluent from poultry slaughterhouse. The experiment was conducted at the Laboratory of Waste Recycling from Animal Production/FCA/UFGD. During four weeks, eight experimental digesters, semi-continuous models, were loaded and set according to the hydraulic retention time (HRT of 7, 14, 21 and 28 days, and according to the solid fraction treatment, separated with 1 mm sieve or without separation. The average weekly production of biogas and methane as well as the methane concentrations, the potential production per amount of chemical oxygen demand (COD added and reduced, the concentrations of N, P and K at the beginning and end of process, and the most likely numbers of total and thermotolerant coliforms were evaluated. For data analysis, a completely randomized design was performed in a 4 × 2 factorial arrangement (4 HRT: 7, 14, 21 and 28 days and separation with 1 mm sieve or without separation, with repetition over time. The highest production of biogas and methane was statistically significant for the HRT of 7 and 14 days (5.29 and 2.38 L of biogas and 4.28 and 1.73 L of methane, respectively. There was an interaction between HRT and the separation of the solid with sieve and the highest production was obtained in the treatment without separation. Similar behavior was observed for the potential production with a maximum of 0.41 m³ methane.kg-1 COD added with an HRT of 7 days without separation of the solid fraction. The separation of the solid fraction is not recommended in the pretreatment of liquid effluent from poultry slaughterhouse, once the potential for production and production of methane and biogas were reduced with this treatment.

An overview of physico-chemical mechanisms of biogas production by microbial communities: a step towards sustainable waste management.

Science.gov (United States)

Goswami, Ramansu; Chattopadhyay, Pritam; Shome, Arunima; Banerjee, Sambhu Nath; Chakraborty, Amit Kumar; Mathew, Anil K; Chaudhury, Shibani

2016-06-01

Biogas is a combination of methane, CO 2 , nitrogen, H 2 S and traces of few other gases. Almost any organic waste can be biologically transformed into biogas and other energy-rich organic compounds through the process of anaerobic digestion (AD) and thus helping in sustainable waste management. Although microbes are involved in each step of AD, knowledge about those microbial consortia is limited due to the lack of phylogenetic and metabolic data of predominantly unculturable microorganisms. However, culture-independent methods like PCR-based ribotyping has been successfully employed to get information about the microbial consortia involved in AD. Microbes identified have been found to belong mainly to the bacterial phyla of Proteobacteria, Chloroflexi, Firmicutes and Bacteroidetes. Among the archaeal population, the majority have been found to be methanogens (mainly unculturable), the remaining being thermophilic microbes. Thus, the AD process as a whole could be controlled by regulating the microbial consortia involved in it. Optimization in the feedstock, pH, temperature and other physical parameters would be beneficial for the microbial growth and viability and thus helpful for biogas production in AD. Besides, the biogas production is also dependent upon the activity of several key genes, ion-specific transporters and enzymes, like genes coding for methyl-CoM reductase, formylmethanofuran transferase, formate dehydrogenase present in the microbes. Fishing for these high-efficiency genes will ultimately increase the biogas production and sustain the production plant.

The effects of micro-aeration on the phylogenetic diversity of microorganisms in a thermophilic anaerobic municipal solid-waste digester.

Science.gov (United States)

Tang, Yueqin; Shigematsu, Toru; Ikbal; Morimura, Shigeru; Kida, Kenji

2004-05-01

We demonstrated previously that micro-aeration allows construction of an effective thermophilic methane-fermentation system for treatment of municipal solid waste (MSW) without production of H(2)S. In the present study, we compared the microbial communities in a thermophilic MSW digester without aeration and with micro-aeration by fluorescence in situ hybridization (FISH), denaturing gradient gel electrophoresis (DGGE), phylogenetic analysis of libraries of 16S rRNA gene clones and quantitative real-time PCR. Moreover, we studied the activity of sulfate-reducing bacteria (SRB) by analysis of the transcription of the gene for dissimilatory sulfite reductase (dsr). Experiments using FISH revealed that microorganisms belonging to the domain Bacteria dominated in the digester both without aeration and with micro-aeration. Phylogenetic analysis based on 16S rRNA gene and analysis of bacteria by DGGE did not reveal any obvious difference within the microbial communities under the two aeration conditions, and bacteria affiliated with the phylum Firmicutes were dominant. In Archaea, the population of Methanosarcina decreased while the population of Methanoculleus increased as a result of micro-aerations as revealed by the analysis of 16S rRNA gene clones and quantitative real-time PCR. Reverse transcription and PCR (RT-PCR) demonstrated the transcription of dsrA not only in the absence of aeration but also in the presence of micro-aeration, even under conditions where no H(2)S was detected in the biogas. In conclusion, micro-aeration has no obvious effects on the phylogenetic diversity of microorganisms. Furthermore, the activity of SRBs in the digester was not repressed even though the concentration of H(2)S in the biogas was very low under the micro-aeration conditions.

Biogas properties and enzymatic analysis during anaerobic fermentation of Phragmites australis straw and cow dung: influence of nickel chloride supplement.

Science.gov (United States)

Tian, Yonglan; Zhang, Huayong; Chai, Yang; Wang, Lijun; Mi, Xueyue; Zhang, Luyi; Ware, Maxwell Adam

2017-02-01

The importance of nickel (added as NiCl 2 ) on mesophilic anaerobic fermentation of Phragmites australis straw and cow dung was demonstrated by investigating the biogas properties, pH values, organic matter degradation [chemical oxygen demand (COD)] and enzyme activities (cellulase, protease and dehydrogenase) during the fermentation process. The results showed that Ni 2+ addition increased the cumulative biogas yields by >18 % by improving the efficiency of first peak stage and bringing forward the second peak stage. The pH values were not significantly influenced by Ni 2+ addition (p > 0.05). Biogas yields were associated with variations in COD concentrations rather than momentary concentrations. At the start-up stage of fermentation (4th day), the biogas yields increased gradually together with the increase of dehydrogenase activities at elevated Ni 2+ concentrations when cellulase and protease activities were similar in all test groups. It is suggested that Ni 2+ addition was mainly dependent on the methanogenic stage. After the start-up stage, the impact of Ni 2+ addition on biogas production was mainly dependent on its effect on cellulase activities, rather than protease or dehydrogenase activities.

10. Biogas conference Dresden. Anaerobic treatment of biological wastes. Proceedings

International Nuclear Information System (INIS)

Dornack, Christina; Liebetrau, Jan; Fassauer, Burkhardt; Nelles, Michael

2015-01-01

The biogas conference in Dresden will be held for the tenth time and is still the only conference in Germany, which focuses on the production of biogas solely from waste. This year, the implementation of paragraph 11 of the Recycling and Waste Management Act and the amendment of the Renewable Energies Act (EEG) in 2014, the chances of the waste management biogas technology will be spotlighted here. The efficiency and wise use of the end products of the biogas production - the biogas and fermentation residues are equally critical for the success of biogas technology as the emission reduction of biogas plants. In this context, the biogas technology will also be dependent in the future on legal requirements and funding instruments such as the EEG. For the technical implementation, the development of reliable system concepts with specific sinking biogas and electricity supply costs and with greater flexibility in terms of launching needs-based biogas and electricity production. The contributions in this paper discuss possible solutions and implementations from the perspective of politics, associations, research and practice. Innovative topics will be discussed, which will be decisive for the future of biogas production from organic wastes. [de

Using contaminated plants involved in phytoremediation for anaerobic digestion.

Science.gov (United States)

Cao, Zewei; Wang, Shengxiao; Wang, Ting; Chang, Zhizhou; Shen, Zhenguo; Chen, Yahua

2015-01-01

This study investigated the anaerobic digestion capability of five plants and the effects of copper (Cu) and S,S'-ethylenediaminedisuccinic acid (EDDS, a chelator widely used in chelant-assisted phytoremediation) on biogas production to determine a feasible disposal method for plants used in remediation. The results showed that in addition to Phytolacca americana L., plants such as Zea mays L., Brassica napus L., Elsholtzia splendens Nakai ex F. Maekawa, and Oenothera biennis L. performed well in biogas production. Among these, O. biennis required the shortest period to finish anaerobic digestion. Compared to normal plants with low Cu content, the plants used in remediation with increased Cu levels (100 mg kg(-1)) not only promoted anaerobic digestion and required a shorter anaerobic digestion time, but also increased the methane content in biogas. When the Cu content in plants increased to 500, 1000, and 5000 mg kg(-1), the cumulative biogas production decreased by 12.3%, 14.6%, and 41.2%, respectively. Studies also found that EDDS conspicuously restrained biogas production from anaerobic digestion. The results suggest that anaerobic digestion has great potential for the disposal of contaminated plants and may provide a solution for the resource utilization of plants used in remediation.

Effect of alkaline pretreatment on mesophilic and thermophilic anaerobic digestion of a submerged macrophyte: Inhibition and recovery against dissolved lignin during semi-continuous operation.

Science.gov (United States)

Koyama, Mitsuhiko; Watanabe, Keiko; Kurosawa, Norio; Ishikawa, Kanako; Ban, Syuhei; Toda, Tatsuki

2017-08-01

The long-term effect of alkaline pretreatment on semi-continuous anaerobic digestion (AD) of the lignin-rich submerged macrophyte Potamogeton maackianus was investigated using mesophilic and thermophilic conditions. In pretreated reactors, dissolved lignin accumulated to high levels. CH 4 production under the pretreated condition was higher than that of the untreated condition, but decreased from Days 22 (mesophilic) and 42 (thermophilic). However, CH 4 production subsequently recovered, although dissolved lignin accumulated. Further, the change in the microbial community was observed between conditions. These results suggest that dissolved lignin temporarily inhibited AD, although acclimatization to dissolved lignin occurred during long-term operation. During the steady state period, mesophilic conditions achieved a 42% increase in the CH 4 yield using pretreatment, while thermophilic conditions yielded an 8% increment. Because volatile fatty acids accumulated even after acclimatization during the thermophilic pretreated condition and was discharged with the effluent, improvement of the methanogenic step would enable enhanced CH 4 recovery. Copyright © 2017 Elsevier Ltd. All rights reserved.

Inhibition of Anaerobic Biological Treatment: A Review

Science.gov (United States)

Hou, Li; Ji, Dandan; Zang, Lihua

2018-01-01

Anaerobic digestion is a method for treating living and industrial wastewater by anaerobic degradation of organic compounds, which can produce biogas (carbon dioxide and methane mixture) and microbial biomass. And biogas as a renewable resource, can replace the use of ore fuel. In the process of anaerobic digestion, the problems of low methane yield and unstable reaction process are often encountered, which limits the widespread use of this technology. Various inhibitors are the main limiting factors for anaerobic digestion. In this paper, the main factors limiting anaerobic digestion are reviewed, and the latest research progress is introduced.

Anaerobic bio filter systems to have the best yield of biogas with the treatment of piggery wastewater

International Nuclear Information System (INIS)

Athula, Jayamanne M. D. A.

2006-01-01

Animal husbandry is a leading food supplying industry for the mankind. Wastewater generation from animal husbandry is a real environmental threat for many countries. Piggery wastewater with high Chemical Oxygen Demand (COD is between 8000 to 15000 mg/lt) is having a very high potential of biogas production, under anaerobic condition. This research was based upon the fixing of series of Up flow Anaerobic Floating Filters (UAFF) to catch a maximum yield of biogas from piggery wastewater with better cleaning facility. These experiments achieved more than 90% of COD removal of piggery wastewater with better cleaning facility. Other analyzed results of the experiments shows that the removal rate of biological Oxygen Demand (BOD) also is more than 90% with 90% of avarrage removal rates of Suspended Solids (SS) and Total Solids (TS). Average volumetric biogas yield was reched up to 450 lts/Cum.day in the different loading rates held between 2.24 to 5.92 kg. COD/Cum.day. Encouraged by this attractive results of the lab-scale unit, and another medium scale unit installed at a piggery site, a few companies funded for developing full-scale units with low cost construction methodolgy. A few companies funded for developing full-scale units with low cost construction methodology. A few farmers for animalhusbandry. Centrl Environmental Authority of Sri Lanka (CEA) has lready monitored the parameters of the treated wastewater with this treatment system and satisfactory levels were ensured. A few private farmers for animal husbandry in Sri Lanka are now precticing this system satisfactory as a good start for a long journey towards the prospects of biogas energy with a clean farm environment. This UAFF syste can easily practice with other type of wastewaters from the field of animal husbandry. Some of them are cattle farms. poultry farms, Lamb and sheep farms etc. Technical paper with full data analysis is available with a pictorial power point presentation.(Author)

Effect of high-voltage pulsed electric field (HPEF pretreatment on biogas production rates of hybrid Pennisetum by anaerobic fermentation

Directory of Open Access Journals (Sweden)

Baijuan Wang

2018-02-01

Full Text Available In this paper, the raw materials of hybrid Pennisetum were pretreated in different conditions of high voltage pulsed electric field (HPEF to improve its material utilization ratios and biogas production rates of anaerobic fermentation. Then, anaerobic digestion experiments were conducted within 32 days at moderate temperature (35 °C with TS mass fraction (6%, inoculation rate (20% and initial pH (7.0. It is indicated that compared with the control group, 9 groups of hybrid Pennisetum pretreated by HPEF are obviously superior in gas production efficiency of anaerobic fermentation, and higher in cumulative gas production, peak daily gas production and maximum methane concentration; that the most remarkable stimulation occurs in the HPEF condition of 15 kV/120 Hz/60 min, in that situation, the cumulative gas production in the fermentation period of 32 days is up to 9587 mL, 26.95% higher than that of the control group, the peak daily gas production increases and the range of peak period extends. It is demonstrated that the optimal HPEF pretreatment time is 60 min and three HPEF parameters have a better effect on gas production in the order of voltage > time > frequency; and that the effect degree of treatment parameters on peak daily gas production is voltage, frequency and time in turn. It is concluded that HPEF can improve material utilization ratio and gas production rate of hybrid Pennisetum by anaerobic fermentation and shorten the gas production cycle. By virtue of this physical pretreatment method, the resource of Pennisetum is utilized sufficiently and the classes of energy plants are enlarged effectively. Keywords: Hybrid Pennisetum, Anaerobic fermentation, High voltage pulsed electric field (HPEF, Biogas, Material utilization ratio, Gas generation rate, Model, Stimulation

Comparative evaluation of different types of biogas suitable for tropical country

International Nuclear Information System (INIS)

Sahu, S.N.; Gbagbo, J.K.N.; Aneke, F.U.

1997-04-01

The biogas technology - anaerobic digestion - is described together with different types of biogas plants suitable for tropical countries. Cost-benefit analysis of establishing biogas plants, financial support options, and the benefits of using biogas as an energy source in rural areas are presented. (LN)

Farm-scale thermophilic co-digestion of dairy manure with a biodiesel byproduct in cold regions

International Nuclear Information System (INIS)

Andriamanohiarisoamanana, Fetra J.; Yamashiro, Takaki; Ihara, Ikko; Iwasaki, Masahiro; Nishida, Takehiro; Umetsu, Kazutaka

2016-01-01

Highlights: • Co-digestion of dairy manure and crude glycerin was conducted using a 60 m"3 reactor. • The highest methane yield was 0.323 m"3/kgVS obtained at 4.2% (v/v) of crude glycerin. • The optimum organic loading rate for crude glycerol was 1.32 kgVS_C_G/m"3 d. • Reactor energy self-sufficiency was observed with net energy output of 25 kW h/d. - Abstract: Conversion of organic wastes into applicable energy sources is the best way to improve organic waste management. In this study, the performance of thermophilic co-digestion of dairy manure (DM) and crude glycerol (CG) in a 60-m"3 farm-scale biogas digester located in a cold region was investigated during the winter. Compared to the anaerobic digestion of DM alone, the methane production increased by approximately twofold during co-digestion of DM and CG. The highest methane yield was 0.323 m"3/kgVS obtained at 4.2% (v/v) of CG. Despite the increase in methane production with organic loading rate, the methane yield of CG reduced remarkably at 2.64 kgVS_C_G/m"3 d, while the highest was at 1.32 kgVS_C_G/m"3 d. During the co-digestion, a net energy at an average of 25 kWh/d was obtained for farm operation, whereas a supply of kerosene and electricity from national grid were required for the digester and farm operations during anaerobic digestion of DM. During winter, the improvement of biogas yield through the addition of CG enabled the sustainability of a farm-scale biogas production system and reduced its environmental impact.

Biogas. Present situation and future potential; Biogas. Nulaege och framtida potential

Energy Technology Data Exchange (ETDEWEB)

Nordberg, Ulf [Swedish Inst. of Agricultural and Environmental Engineering, Uppsala (Sweden)

2006-12-15

The report contains a general overview of present technology concerning production of biogas through anaerobic breakdown of easily recycled organic material as well as implementation areas for biogas. The work has been done in three parts: description of present situation, technical limitations and development efforts, synthesis. In Sweden there are more than 220 biogas plants for handling crops, sludge and organic residue material. Production of biogas occurs primarily at sewage treatment plants and landfills. Total capacity in 2004 was approx. 300,000 m{sup 3} anaerobic chamber volume, of which approx. 73% was utilised. Planned increase in capacity was approx. 125,000 m{sup 3} or approx. 42%.The substrate brought to the plants was comprised of approx. 45% manure, 30% offal, 10% biowaste from households and 15% other substrates. Calculations based on the energy content of input substrate indicate that approx. 10% of the gas was from manure, 65% from offal, 25% from household waste and 5% from other substrates. In 2005 a total of 1,5 TWh of biogas was produced in Sweden. Biogas is used primarily for heating purposes followed by use as vehicle fuel and in electricity production. More than 55 GWh is torched away. Sewage treatment plants are not included. Interest in using biogas as fuel has increased. The theoretical biogas potential in Sweden has been calculated to be 14-17 TWh per year, of which approx. 80% is found in agriculturally related biomass. Approximately 3 TWh originates from various types of household and industrial waste. Generally it can be said that there is a large potential for improvement and increased efficiency within the whole chain of substrate collection, preparatory treatment of substrates, operational control of biogas plants, upgrade/treatment and use of gas as well as spreading and use of biofertilizer. The greatest increase in substrate will come from the amount of crops from the agricultural sector. The contacts between farmers and plant

Effect of ultrasonic pre-treatment on biogas yield and specific energy in anaerobic digestion of fruit and vegetable wholesale market wastes

Directory of Open Access Journals (Sweden)

Reyhaneh Zeynali

2017-11-01

Full Text Available Ultrasonic pre-treatment has been considered as an environmentally friendly process for enhancing the biodegradability of organic matter in anaerobic digestion. However the consumed energy during the pre-treatment is a matter of challenge especially where energy generation is the main purpose of a biogas plant. The aim of the present work was to study the efficiency of ultrasonic pre-treatment in enhancement of biogas production from fruits and vegetable wholesale market waste. Three sonication times (9, 18, 27 min operating at 20 kHz and amplitude of 80 μm were used on the substrate. The highest methane yield was obtained at 18 min sonication (2380 kJ kg−1 total solids while longer exposure to sonication led to lower methane yield. This amount of biogas was obtained in 12 d of batch time. The energy content of the biogas obtained from this reactor was two times of the input energy for sonication.

Biogas utilization: Experimental investigation on biogas flameless combustion in lab-scale furnace

International Nuclear Information System (INIS)

Hosseini, Seyed Ehsan; Wahid, Mazlan Abdul

2013-01-01

Highlights: • High costs of biogas purification and low calorific value of biogas are the main obstacles of biogas utilization. • The energy of biogas can be extracted by flameless combustion without any modification in burner or combustion system. • The efficiency of biogas flameless combustion and conventional combustion were 53% and 32% respectively. • The temperature inside the biogas flameless chamber is uniform. • In biogas flameless combustion, NO x and CO 2 formation decrease drastically in comparison with traditional combustion. - Abstract: Biogas generated in the anaerobic digestion of biomass and organic wastes by micro-organisms can be applied for heating, transportation and power generation as a renewable energy source. However, low calorific value (LCV) of biogas is one the most important bottlenecks of biogas conversion into electrical or thermal energy. Indeed, the presence of corrosive gases such as H 2 S and water vapor in biogas components makes some dilemmas in biogas purification and utilization. In order to obtain the efficient biogas utilization method, different biogas resources, physical and chemical properties of biogas and biogas combustion characteristics should be considered. In this paper biogas was utilized in lab-scale flameless combustion furnace and the performance of flameless combustion chamber fueled by biogas has been presented. Results demonstrated that flameless combustion is one of the best feasible strategies for biogas utilization. Uniformity of temperature in the flameless furnace increases the durability of refractory and related equipment. Simplicity of the flameless burner, pollutant formation reduction and fuel consumption decreases are the main causes of biogas flameless combustion supremacy

Anaerobic digestion of cider apple residues

Energy Technology Data Exchange (ETDEWEB)

Contreras Lopez, A. (E.T.S.I.I., U.N.E.D., Madrid (Spain). Dept. Quimica Applicada a la Ingenieria); Lopez Bobo, R. (E.T.S. Ingeneiros Industriales, Asturias (Spain). Dept. de Energia)

1992-12-01

Apple residue from the cider industry is used here for anaerobic fermentation. The effect of retention time and volatile solids concentration on the production of biogas and methane was investigated by using continuously mixed anaerobic fermentors with a working volume of 1 1. The maximum proportions of biogas and methane obtained were 430 1 biogas/kg per day (12 days' retention time and 3% of volatile solids) and 281 1 of methane per day (a retention time of 30 days and 2% of volatile solids), respectively. (author)

Biogas production from Jatropha curcas press-cake.

Science.gov (United States)

Staubmann, R; Foidl, G; Foidl, N; Gübitz, G M; Lafferty, R M; Arbizu, V M; Steiner, W

1997-01-01

Seeds of the tropical plant Jatropha curcas (purge nut, physic nut) are used for the production of oil. Several methods for oil extraction have been developed. In all processes, about 50% of the weight of the seeds remain as a press cake containing mainly protein and carbohydrates. Investigations have shown that this residue contains toxic compounds and cannot be used as animal feed without further processing. Preliminary experiments have shown that the residue is a good substrate for biogas production. Biogas formation was studied using a semicontinous upflow anaerobic sludge blanket (UASB) reactor; a contact-process and an anaerobic filter each reactor having a total volume of 110 L. A maximum production rate of 3.5 m3 m"3 d"1 was obtained in the anaerobic filter with a loading rate of 13 kg COD m~3 d"1. However, the UASB reactor and the contact-process were not suitable for using this substrate. When using an anaerobic filter with Jatropha curcas seed cake as a substrate, 76% of the COD was degraded and 1 kg degraded COD yielded 355 L of biogas containing 70% methane.

Biogas production from Jatropha curcas press-cake

Energy Technology Data Exchange (ETDEWEB)

Staubmann, R.; Guebitz, G.M.; Lafferty, R.M. [Graz Technical Univ. (Austria)] [and others

1997-12-31

Seeds of the tropical plant Jatropha curcas (purge nut, physic nut) are used for the production of oil. Several methods for oil extraction have been developed. In all processes, about 50% of the weight of the seeds remain as a press cake containing mainly protein and carbohydrates. Investigations have shown that this residue contains toxic compounds and cannot be used as animal feed without further processing. Preliminary experiments have shown that the residue is a good substrate for biogas production. Biogas formation was studied using a semicontinous upflow anaerobic sludge blanket (UASB) reactor; a contact-process and an anaerobic filter each reactor having a total volume of 110 L. A maximum production rate of 3.5 m{sup 3} m{sup -3} d{sup -1} was obtained in the anaerobic filter with a loading rate of 13 kg COD m{sup -3} d{sup -1}. However, the UAS reactor and the contact-process were not suitable for using this substrate. When using an anaerobic filter with Jatropha curcas seed cake as a substrate, 76% of the COD was degraded and 1 kg degraded COD yielded 355 L of biogas containing 70% methane. 28 refs., 3 figs., 4 tabs.

Substrate Handbook for Biogas Production; Substrathandbok foer biogasproduktion

Energy Technology Data Exchange (ETDEWEB)

Carlsson, My; Uldal, Martina (AnoxKaldnes AB, Lund (Sweden))

2009-02-15

Today, co-digestion plants in Sweden treat a broad range of different substrates, of which some have not previously been used for anaerobic digestion. The major part of this organic waste derives from households, restaurants, food industries and farms. When evaluating a new substrate as feed for anaerobic digestion, several different aspects need to be taken into consideration, such as anaerobic degradability, TS/VS content, nutrient composition and risk for mechanical problems. Consequently, there is a need for practical guidelines on how to evaluate new substrates as raw materials for biogas production, including not only gas yield but also what practical and microbiological problems that may arise when the specific substrate is treated together with other substrates in the plant. The aim with this handbook is to provide a basis on how to evaluate new substrates as feed for anaerobic digestion. The intention is that this material will save time and effort for the personnel at the plant when they come in contact with new types of waste. Also, the aim is to facilitate the process of identifying new substrates within the ABP-regulation (1774/2002) and what requirements are then demanded on handling. The work with the handbook has been divided in three different parts; (1) an extensive literature study and a compilation of the achieved results, (2) interviews with personnel at most of the Swedish co-digestion plants to identify substrates and problems of interest, and (3) lab tests of selected substrates. The lab tests included Bio Methane Potential (BMP) tests as well as a simple characterization of each substrate based on fat/protein/carbohydrate content. All data origins from anaerobic digestion within the mesophilic temperature range, but the results and discussion are applicable also for thermophilic anaerobic digestion. The result of this work is a written report together with an Excel file which are to be directly used by the biogas plants as a basis in the

A bio-electrochemical system for removing inhibitors of anaerobic digestion processes from anaerobic reactors

DEFF Research Database (Denmark)

2014-01-01

Inhibition of anaerobic digestion process by high level of ammonia (NH4 +/I\\IH3) is the most serious problem existing in biogas plants. No viable/applicable method to overcome this problem has been found up to now. This invention proposes an innovative submersible bio-electrochemical membrane...... reactor to recover ammonia from anaerobic digestion reactor, and thereby alleviate or counteract ammonia inhibition and enhance the conversion of ammonia-rich wastes to biogas. The invention may further reduce overall cost, giving synergistic advantages for both ammonia recycling and biogas plants...... by recovering acid (e.g., H2SO4, HCI), that can be used to treat the recovered ammonia....

empirical model for predicting rate of biogas production

African Journals Online (AJOL)

users

Rate of biogas production using cow manure as substrate was monitored in two laboratory scale ... Biogas is a Gas obtained by anaerobic ... A. A. Adamu, Petroleum and Natural Gas Processing Department, Petroleum Training Institute, P.M.B..

An innovative intermittent-vacuum assisted thermophilic anaerobic digestion process for effective animal manure utilization and treatment.

Science.gov (United States)

Zhang, Renchuan; Anderson, Erik; Addy, Min; Deng, Xiangyuan; Kabir, Fayal; Lu, Qian; Ma, Yiwei; Cheng, Yanling; Liu, Yuhuan; Chen, Paul; Ruan, Roger

2017-11-01

Intermittent-vacuum stripping (IVS) was developed as a pretreatment for thermophilic anaerobic digestion (TAD) to improve methanogenesis and hydrolysis activity through preventing free ammonia and hydrogen sulfide (H 2 S) inhibition from liquid swine manure (LSM). Over 98% of ammonia and 38% organic nitrogen were removed in 60min from 55°C to 85°C with vacuum pressure (from 100.63±3.79mmHg to 360.91±7.39mmHg) at initial pH 10.0 by IVS. Thermophilic methanogenesis and hydrolysis activity of pretreated LSM increased 52.25% (from 11.56±1.75% to 17.60±0.49%) in 25days and 40% (from 10days to 6days) in bio-methane potential assay. Over 80% H 2 S and total nitrogen were removed by IVS assistance, while around 70% nitrogen was recycled as ammonium sulfate. Therefore, IVS-TAD combination could be an effective strategy to improve TAD efficiency, whose elution is more easily utilized in algae cultivation and/or hydroponic system. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Isolation and identification of seven thermophilic and anaerobic bacteria from hot springs in Tengchong Rehai].

Science.gov (United States)

Lu, Yueqing; Chen, Bo; Liu, Xiaoli; Ji, Xiuling; Wei, Yunlin; Lin, Lianbing

2009-09-01

In order to study the taxonomic characteristic and physiological, biochemical properties of anaerobic bacteria from hot springs in Tengchong Rehai, Yunnan Province, China. Using Hungate anaerobic technique We isolated seven strains from hot springs in Tengchong Rehai, Yunnan province, and analyzed their 16S rRNA gene sequences. The seven isolates were rod-shaped, Gram-negative, obligate anaerobe, and spores formation was not observed. All strains could grow well at 70 degrees C. Growth of strain RH0802 occurred between 60 and 80 degrees C, optimally around 70 degrees C. The pH range for its growth was between 5.5 and 8.5, with an optimum around 7.0. Strain RH0802 grew on a wide range of carbon sources, including glucose, starch, mannitol, mannose, ribose, maltose, cellobiose, xylose, fructose, galactose, xylan and glycerol, but it could not utilize sucrose or pyruvate. 16S rRNA gene phylogenetic analysis showed that the maximum similarity between the five strains and the strains of genus Caldanaerobacter was up to 98%, except RH0804 and RH0806, which reached to 96% and 93%, respectively. The two isolates were presumed to be potential novel species. The GenBank accession numbers of RH0802 to RH0808 were FJ748766, FJ748762, FJ748761, FJ748763, FJ748765, FJ748764 and FJ748767. The results showed that the seven thermophilic anaerobes belonged to the genus Caldanaerobacter.

Releasing the full potential of AIKAN - a dry anaerobic digestion biogas technology. Final report

Energy Technology Data Exchange (ETDEWEB)

Joernsgaerd, B.; Broegger Kristensen, M.; Wittrup Hansen, M. [Solum Gruppen, Hedehusene (Denmark); Uellendahl, H. [Aalborg Univ. (AAU), Aalborg (Denmark)

2013-07-15

This final project report contains a summary of the findings and documentation which have been carried out as a part of the EUDP-supported project ''Documentation and En-ergy Yield Optimisation of AIKAN{sup }- a dry anaerobic digestion biogas technology''. The aim was to improve documentation of the AIKAN{sup }technology, improve performance of the AIKAN{sup }technology and thus remove important barriers for market entry on principal export markets caused by the lack of performance documentation. The final report also contains a description of the subsequent process and technology improvements which have been carried out in order to improve and optimize the production process at the full scale AIKAN{sup }biogas plant, Biovaekst, in Audebo, Denmark. The relevant analyses carried out as part of the different work packages are attached as appendixes to the report. It is the intention that the final report and the attached appendices should function as a work of reference for the employees involved in the day to day running and optimization of the AIKAN{sup }technology. (Author)

Comparison of kinetic model for biogas production from corn cob

Science.gov (United States)

Shitophyta, L. M.; Maryudi

2018-04-01

Energy demand increases every day, while the energy source especially fossil energy depletes increasingly. One of the solutions to overcome the energy depletion is to provide renewable energies such as biogas. Biogas can be generated by corn cob and food waste. In this study, biogas production was carried out by solid-state anaerobic digestion. The steps of biogas production were the preparation of feedstock, the solid-state anaerobic digestion, and the measurement of biogas volume. This study was conducted on TS content of 20%, 22%, and 24%. The aim of this research was to compare kinetic models of biogas production from corn cob and food waste as a co-digestion using the linear, exponential equation, and first-kinetic models. The result showed that the exponential equation had a better correlation than the linear equation on the ascending graph of biogas production. On the contrary, the linear equation had a better correlation than the exponential equation on the descending graph of biogas production. The correlation values on the first-kinetic model had the smallest value compared to the linear and exponential models.

Feasibility of biogas utilization in fuel cells; Viabilidade do uso de biogas em celulas a combustivel

Energy Technology Data Exchange (ETDEWEB)

Sprenger, Humberto Elias [Programa de Pos-graduacao em Desenvolvimento de Tecnologia (PRODETEC/LACTEC/IEP), Cutitiba, PR (Brazil); Cantao, Mauricio Pereira [Instituto de Tecnologia para o Desenvolvimento (LACTEC), Curitiba, PR (Brazil)], E-mail: mauricio.cantao@utp.br

2010-10-15

Waste water treatment stations using upflow anaerobic sludge blanket (UASB) produce biogas, composed of carbon dioxide diluted methane plus minority compounds. This kind of reactor is worthwhile but demands methane burning in order to reduce atmospheric pollution and damage to ozone layer. Meanwhile, biogas can be used for energy generation due to its heating value. In this paper a technical and economic feasibility study about the use of biogas as a hydrogen source for fuel cells feeding is presented. Two methods for assessment of biogas production in UASB reactor were compared for ETE Atuba Sul case. (author)

Biogas : Animal Waste That Can be Alternative Energy Source

Directory of Open Access Journals (Sweden)

Tuti Haryati

2006-09-01

Full Text Available Biogas is a renewable energy which can be used as alternative fuel to replace fossil fuel such as oil and natural gas . Recently, diversification on the use of energy has increasingly become an important issue because the oil sources are depleting . Utilization of agricultural wastes for biogas production can minimize the consumption of commercial energy source such as kerosene as well as the use of firewood . Biogas is generated by the process of organic material digestion by certain anaerobe bacteria activity in aerobic digester . Anaerobic digestion process is basically carried out in three steps i.e. hydrolysis, acidogenic and metanogenic . Digestion process needs certain condition such as C : N ratio, temperature, acidity and also digester design . Most anaerobic digestions perform best at 32 - 35°C or at 50 - 55°C, and pH 6 .8 - 8 . At these temperatures, the digestion process essentially converts organic matter in the present of water into gaseous energy . Generally, biogas consists of methane about 60 - 70% and yield about 1,000 British Thermal Unit/ft 3 or 252 Kcal/0.028 m3 when burned . In several developing countries, as well as in Europe and the United States, biogas has been commonly used as a subtitute environmental friendly energy . Meanwhile, potentially Indonesia has abundant potential of biomass waste, however biogas has not been used maximally .

A study on economic feasibility of biogas plant for a small town

International Nuclear Information System (INIS)

Ansari, S.H.

2011-01-01

Energy crisis is one of the major problems of our country now a day. We should emphasis on new energy resources to fulfill our demand. In renewable energy resources, biogas is one of them. Biogas is produced by anaerobic digestion of organic matters. In anaerobic digestion, biodegradable materials are decomposed into biogas by bacteria in the absence of air. Kitchen waste contain large amount of these biodegradable materials. The report of economic feasibility for biogas plant using kitchen waste of housing colony consisting of 200 houses for power generation and cooking purposes is carried out. (author)

Biogas recovery in anaerobic digestion plants for pig wastewater

International Nuclear Information System (INIS)

Collivigarelli, C.; Sorlini, S.

2001-01-01

This work deals with a monitoring of thee anaerobic digestion plants in mesophilic conditions treating pig wastewater with the aim to study the treatment efficiency and energetic aspects. A good waste stabilization is reached in all plants, as shown by the high removal efficiency of total and volatile solids and COD, mainly due to the digestion process. On the contrary, Kjeldahl nitrogen and ammonia (low) removal takes place mainly in the final storage tank, thanks to ammonia stripping. The digestion process not only produces a well stabilized wastewater, that can be more surely reused for agricultural spreading, but it offers also an important energy recovery from the biogas combustion, whose specific production varies from 0,78 to 0,99 Nm 3 t - 1 (live weight) d - 1. It is used in cogeneration plants for the combined production of thermal energy (that is reused for waste heating in the digestion tank at mesophilic conditions and for other internal utilizations) and electric energy (that is used for internal requirements while the surplus is sent into the public grid) [it

Effects of sludge inoculum and organic feedstock on active microbial communities and methane yield during anaerobic digestion

Directory of Open Access Journals (Sweden)

David eWilkins

2015-10-01

Full Text Available Anaerobic digestion (AD is a widespread microbial technology used to treat organic waste and recover energy in the form of methane (biogas. While most AD systems have been designed to treat a single input, mixtures of digester sludge and solid organic waste are emerging as a means to improve efficiency and methane yield. We examined laboratory anaerobic cultures of AD sludge from two sources amended with food waste, xylose, and xylan at mesophilic temperatures, and with cellulose at meso- and thermophilic temperatures, to determine whether and how the inoculum and substrate affect biogas yield and community composition. All substrate and inoculum combinations yielded methane, with food waste most productive by mass. Pyrosequencing of transcribed bacterial and archaeal 16S rRNA showed that community composition varied across substrates and inocula, with differing ratios of hydrogenotrophic/acetoclastic methanogenic archaea associated with syntrophic partners. While communities did not cluster by either inoculum or substrate, additional sequencing of the bacterial 16S rRNA gene in the source sludge revealed that the bacterial communities were influenced by their inoculum. These results suggest that complete and efficient AD systems could potentially be assembled from different microbial inocula and consist of taxonomically diverse communities that nevertheless perform similar functions.

Towards a sustainable paradigm of waste-to-energy process: Enhanced anaerobic digestion of sludge with woody biochar

Energy Technology Data Exchange (ETDEWEB)

Shen, Yanwen; Linville, Jessica L.; Ignacio-de Leon, Patricia Anne A.; Schoene, Robin P.; Urgun-Demirtas, Meltem

2016-11-01

This study presents an integrated waste-to-energy process, using two waste streams, sludge generated from the municipal wastewater treatment plants (WWTPs) and biochar generated from the biomass gasification systems, to produce fungible biomethane and nutrient-rich digestate with fertilizer value. Two woody biochar, namely pinewood (PBC) and white oak biochar (WOBC) were used as additives during anaerobic digestion (AD) of WWTP sludge to enhance methane production at mesophilic and thermophilic temperatures. The PBC and WOBC have porous structure, large surface area and desirable chemical properties to be used as AD amendment material to sequester CO2 from biogas in the digester. The biochar-amended digesters achieved average methane content in biogas of up to 92.3% and 79.0%, corresponding to CO2 sequestration by up to 66.2% and 32.4% during mesophilic and thermophilic AD, respectively. Biochar addition enhanced process stability by increasing the alkalinity, but inhibitory effects were observed at high dosage. It also alleviated free ammonia inhibition by up to 10.5%. The biochar-amended digesters generated digestate rich in macro- and micronutrients including K (up to 300 m/L), Ca (up to 750 mg/L), Mg (up to 1800 mg/L) and Fe (up to 390 mg/L), making biochar-amended digestate a potential alternative used as agricultural lime fertilizer.

The conversion of renewable biogas source into energy; A conversao da fonte renovavel biogas em energia

Energy Technology Data Exchange (ETDEWEB)

Coelho, Suani Teixeira; Velazquez, Silvia Maria Stortini Gonzalez; Martins, Osvaldo Stella; Abreu, Fernando Castro de [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Eletrotecnica e Energia]|[Centro Nacional de Referencia em Biomassa (CENBIO), Sao Paulo, SP (Brazil)]. E-mails: suani@iee.usp.br; sgvelaz@iee.sup.br; omartins@iee.usp.br; fcabreu@iee.usp.br

2006-07-01

This article intend to present some considerations directed to electricity generation with small systems (micro turbine and conventional engines ), using biogas generated by sewage treatment process in SABESP (Basic Sanitation Company of Sao Paulo State), located at Barueri, Brazil. This project, pioneer in Latin America, is being accomplished together with BUN - Biomass Users Network of Brazil (proponent), in association with CENBIO - Biomass Reference National Center (executer), with patronage of FINEP / CT-ENERG (financial backer), by means of Convention No: 23.01.0653.00, regarding to ENERG-BIOG Project - Installation and Tests of an Electric Energy Generation Demonstration Unit from Biogas Sewage Treatment. The study is being done at Barueri Sewage Treatment Plant.This plant operate with anaerobic digestion process, which has as mainly products biogas (composed mainly by methane) and sludge. Part of the methane produced at the anaerobic process is burnt in a boiler being used to increase digesters temperature. The rest of the methane is burnt in flare to reduce the impacts caused by gases emissions. This article presents some technical, financial and environmental project results, related to the exploitation of sewer biogas for power generation, as well as bigger details about generation systems (biogas micro turbine), used in the facility. (author)

Anaerobic digestion of slaughterhouse by-products

International Nuclear Information System (INIS)

Hejnfelt, Anette; Angelidaki, Irini

2009-01-01

Anaerobic digestion of animal by-products was investigated in batch and semi-continuously fed, reactor experiments at 55 o C and for some experiments also at 37 o C. Separate or mixed by-products from pigs were tested. The methane potential measured by batch assays for meat- and bone flour, fat, blood, hair, meat, ribs, raw waste were: 225, 497, 487, 561, 582, 575, 359, 619 dm 3 kg -1 respectively, corresponding to 50-100% of the calculated theoretical methane potential. Dilution of the by-products had a positive effect on the specific methane yield with the highest dilutions giving the best results. High concentrations of long-chain fatty acids and ammonia in the by-products were found to inhibit the biogas process at concentrations higher than 5 g lipids dm -3 and 7 g N dm -3 respectively. Pretreatment (pasteurization: 70 o C, sterilization: 133 o C, and alkali hydrolysis (NaOH) had no effect on achieved methane yields. Mesophilic digestion was more stable than thermophilic digestion, and higher methane yield was noticed at high waste concentrations. The lower yield at thermophilic temperature and high waste concentration was due to ammonia inhibition. Co-digestion of 5% pork by-products mixed with pig manure at 37 o C showed 40% higher methane production compared to digestion of manure alone.

Anaerobic digestion of slaughterhouse by-products

Energy Technology Data Exchange (ETDEWEB)

Hejnfelt, Anette; Angelidaki, Irini [Department of Environmental Engineering, Technical University of Denmark, DTU, Building 113, DK-2800 Kgs. Lyngby (Denmark)

2009-08-15

Anaerobic digestion of animal by-products was investigated in batch and semi-continuously fed, reactor experiments at 55 C and for some experiments also at 37 C. Separate or mixed by-products from pigs were tested. The methane potential measured by batch assays for meat- and bone flour, fat, blood, hair, meat, ribs, raw waste were: 225, 497, 487, 561, 582, 575, 359, 619 dm{sup 3} kg{sup -1} respectively, corresponding to 50-100% of the calculated theoretical methane potential. Dilution of the by-products had a positive effect on the specific methane yield with the highest dilutions giving the best results. High concentrations of long-chain fatty acids and ammonia in the by-products were found to inhibit the biogas process at concentrations higher than 5 g lipids dm{sup -3} and 7 g N dm{sup -3} respectively. Pretreatment (pasteurization: 70 C, sterilization: 133 C), and alkali hydrolysis (NaOH) had no effect on achieved methane yields. Mesophilic digestion was more stable than thermophilic digestion, and higher methane yield was noticed at high waste concentrations. The lower yield at thermophilic temperature and high waste concentration was due to ammonia inhibition. Co-digestion of 5% pork by-products mixed with pig manure at 37 C showed 40% higher methane production compared to digestion of manure alone. (author)

Anaerobic digestion of solid biomass and biowaste

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-07-01

Within the International Trade Fair for Biogas Plant Technology from 23rd to 24th February, 2012 in Berlin, the following lectures were held: (1) Presentation and results of the EU project 24biomass'' (Claudia Lutsyuk); (2) The Polish biogas market (Tomasz Surowiec); (3) Presence and future of the biogas sector in Poland - EBE project (Eugeniusz Jedrysik); (4) Modern biogas generation in Poland - Case studies of the company Poldanor (Jens Bo Holm-Nielsen); (5) Low space requirement - The challenge in the integration of biogas plants in existing composting facilities - examples from real life (Michael Oertig); (6) Integration of biogas plants in composting facilities by partial-flow fermentation (Bruno Mattheeuws); (7) The significance of an efficient removal of foreign matter from biomass before fermentation in a waste incinerator for municipal wastes (Stephan Schulte); (8) Sustainable enhancement of the anaerobic degradation and increase of the biogas production by means of ultrasonic treatment - examples from real life (Silvana Velten); (9) Cultivation of energy plants on sandy soils in the northeastern part of Germany (Gunter Ebel); (10) Topinambur, a new sustainable energy crop for biogas generation (Vito Pignatelli); (11) Potential of biogas generation from reed (Vilis Dubrovskis); (12) Biogas generation from maize straw - a new procedure of harvesting and processing (Thomas Amon); (13) Generation of biogas by cofermentation of pig manure and grass silage: a pilot study (Ximmin Zhan); (14) Thermophilic dry fermentation of poultry litter and energy crops for the generation of biogas, organic fertilizer and protection of water resources from environmental damages in the Mid-Atlantic region of the USA (John Intersoll); (15) Energetic utilisation of horse manure (Saskia Oldenburg); (16) Realization of the greatest and most modern Hungarian biogas plant in Szarvas (Ludwig Dinkloh); (16) Biogas in Russia - The investment program of the cooperation &apos

Anaerobic digestion of solid biomass and biowaste

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-07-01

Within the International Trade Fair for Biogas Plant Technology from 23rd to 24th February, 2012 in Berlin, the following lectures were held: (1) Presentation and results of the EU project 24biomass'' (Claudia Lutsyuk); (2) The Polish biogas market (Tomasz Surowiec); (3) Presence and future of the biogas sector in Poland - EBE project (Eugeniusz Jedrysik); (4) Modern biogas generation in Poland - Case studies of the company Poldanor (Jens Bo Holm-Nielsen); (5) Low space requirement - The challenge in the integration of biogas plants in existing composting facilities - examples from real life (Michael Oertig); (6) Integration of biogas plants in composting facilities by partial-flow fermentation (Bruno Mattheeuws); (7) The significance of an efficient removal of foreign matter from biomass before fermentation in a waste incinerator for municipal wastes (Stephan Schulte); (8) Sustainable enhancement of the anaerobic degradation and increase of the biogas production by means of ultrasonic treatment - examples from real life (Silvana Velten); (9) Cultivation of energy plants on sandy soils in the northeastern part of Germany (Gunter Ebel); (10) Topinambur, a new sustainable energy crop for biogas generation (Vito Pignatelli); (11) Potential of biogas generation from reed (Vilis Dubrovskis); (12) Biogas generation from maize straw - a new procedure of harvesting and processing (Thomas Amon); (13) Generation of biogas by cofermentation of pig manure and grass silage: a pilot study (Ximmin Zhan); (14) Thermophilic dry fermentation of poultry litter and energy crops for the generation of biogas, organic fertilizer and protection of water resources from environmental damages in the Mid-Atlantic region of the USA (John Intersoll); (15) Energetic utilisation of horse manure (Saskia Oldenburg); (16) Realization of the greatest and most modern Hungarian biogas plant in Szarvas (Ludwig Dinkloh); (16) Biogas in Russia - The investment program of the cooperation ''Bio

Enhancement of anaerobic sludge digestion by high-pressure homogenization.

Science.gov (United States)

Zhang, Sheng; Zhang, Panyue; Zhang, Guangming; Fan, Jie; Zhang, Yuxuan

2012-08-01

To improve anaerobic sludge digestion efficiency, the effects of high-pressure homogenization (HPH) conditions on the anaerobic sludge digestion were investigated. The VS and TCOD were significantly removed with the anaerobic digestion, and the VS removal and TCOD removal increased with increasing the homogenization pressure and homogenization cycle number; correspondingly, the accumulative biogas production also increased with increasing the homogenization pressure and homogenization cycle number. The optimal homogenization pressure was 50 MPa for one homogenization cycle and 40 MPa for two homogenization cycles. The SCOD of the sludge supernatant significantly increased with increasing the homogenization pressure and homogenization cycle number due to the sludge disintegration. The relationship between the biogas production and the sludge disintegration showed that the accumulative biogas and methane production were mainly enhanced by the sludge disintegration, which accelerated the anaerobic digestion process and improved the methane content in the biogas. Copyright © 2012 Elsevier Ltd. All rights reserved.

COD removal and biogas production at the manipueira treatment in anaerobic one-stage reactor with different supporting media; Remocao de DQO e producao de biogas no tratamento de manipueira em reator anaerobico monofasico com diferentes meios de suporte

Energy Technology Data Exchange (ETDEWEB)

Torres, Douglas Guedes Batista; Kunzler, Kathia Regina; Gomes, Simone Damasceno; Tavares, Maria Herminia Ferreira; Assis, Tatiane Martins de [Universidade Estadual do Oeste do Parana (UNIOESTE), PR (Brazil)], Emails: simoned@unioeste.br, mhstavar@certto.com.br

2009-07-01

This study aims at evaluating the efficiency for organic load removal and biogas production for the manipueira treatment in two anaerobic reactors using as supporting media bamboo rings and polyurethane. The manipueira loads added to the systems were 0.548, 1.156, 1.471 and 3.049 g COD/ L{sub reactorday}, gradually increased. With bamboo as supporting media, the load increasing carried the greatest biogas production, with 3.049 g COD/ L{sub reactorday}. Using polyurethane, the greatest production occurred with the 1.471 g CODL{sub reactorday} {sup -1}load. Therefore, it was shown that the supporting media use allowed greater loads and biogas productions, comparatively to the literature data. (author)

Macro algae as substrate for biogas production

DEFF Research Database (Denmark)

Møller, Henrik; Sarker, Shiplu; Gautam, Dhan Prasad

Algae as a substrate for biogas is superior to other crops since it has a much higher yield of biomass per unit area and since algae grows in the seawater there will be no competition with food production on agricultural lands. So far, the progress in treating different groups of algae as a source...... of energy is promising. In this study 5 different algae types were tested for biogas potential and two algae were subsequent used for co-digestion with manure. Green seaweed, Ulva lactuca and brown seaweed Laminaria digitata was co-digested with cattle manure at mesophilic and thermophilic condition...

Anaerobic bioconversion of organic waste into biogas by hot water treatment at near-critical conditions: application in bioregenerative life support.

Science.gov (United States)

Lissens, Geert; Verstraete, Willy; Albrecht, Tobias; Brunner, Gerd; Lasseur, Christophe

2003-01-01

The feasibility of nearly-complete conversion of lignocellulosic waste (70% food crops, 20% faecal matter and 10% green algae) into biogas was investigated in the context of a Life Support Project. The treatment comprised a series of processes, i.e. a mesophilic laboratory scale CSTR (continuously stirred tank reactor), an upflow biofilm reactor and a hydrothermolysis system in near-critical water. By the one-stage CSTR, a biogas yield of 75% with a specific biogas production of 0.37 l biogas g(-1) VSS (volatile suspended solids) added at a HRT (hydraulic retention time) of 20 d was obtained. Biogas yields further increased with 10-15% at HRT > 20 d, indicating the hydrolysis of lignocellulose to be the rate-limiting conversion step. The solids present in the CSTR-effluent were subsequently treated by hot water treatment (T approximately 310-350 degrees C, p approximately 240 bar), resulting in effective carbon liquefaction (50-60% without and 83% with carbon dioxide saturation) and complete hygienisation of the residue. Subsequent anaerobic digestion of the hydrolysate allowed further conversion of 48-60% on COD (chemical oxygen demand) basis. Thus, the total process yielded biogas corresponding with a COD conversion up to 90% of the original organic matter. It appears that mesophilic digestion in conjunction with hydrothermolysis at near-critical conditions offers interesting features for (nearly) complete, non-toxic and hygienic carbon and energy recovery from human waste in a bioregenerative life support context.

Biogas in Alsace: potential, economic study

International Nuclear Information System (INIS)

Maurer, Michel

2004-01-01

The purpose of this work is to determine the potential of biogas production in Alsace. Every fields that could provide organic matter for anaerobic fermentation are first identified, and the energy corresponding to the theoretical production of biogas is then quantified. By knowing these rates, the effective development of biogas production is then discussed and oriented to the agricultural field. The technical and economical aspects of the production of biogas in a farm are then described. The biogas issue, approached thanks to some visits of existing sites and the creation of a simulation software, leads to a specific analysis among the whole Alsatian estates. The study presents finally the real opportunities of development for two pilot projects in Alsace, knowing the specific context for farm biogas production in France. (author) [fr

Pemanfaatan Biogas Sebagai Bahan Bakar Generator Set Motor Bensin

OpenAIRE

Kusairi S., Ach; Yangsen, Kelvin

2015-01-01

Biogas is a compound formed from the decomposition of organic substances in anaerobic condition, the main constituent of biogas is methane and carbon dioxide, biogas can be used as fuel or otto cycle engine with diesel. In this study, the use of biogas from the landfill Cahaya Kencana then to gasoline motor generator sets using this type with a capacity 1kVA four steps that have been previously modified in order to be able to use biogas, but no purification process before being used as fuel. ...

Odor from anaerobic digestion of swine slurry: influence of pH, temperature and organic loading

Directory of Open Access Journals (Sweden)

Gerardo Ortiz

2014-12-01

Full Text Available Farm slurry management from storage and/or treatment is the main source of odors from swine production, which are determined by factors such as operational variations (organic loading, cleaning of facilities and animal diet (pH or environmental conditions (temperature. The aim of this study was to evaluate the influence of pH, temperature and organic loading on odor generation during anaerobic digestion of swine slurry. The methodology employed batch experimental units under controlled pH (6.0, 6.5, 7.0 and 8.0 and temperature (20, 35 and 55 °C conditions. Additionally, an Upflow Anaerobic Sludge Blanket (UASB system was operated under two Organic Loading Rate (OLR conditions as Chemical Oxygen Demand (COD (Phase I: 0.4 g L-1 d-1 of COD, Phase II: 1.1 g L-1 d-1 of COD. Odor (batch and UASB reactor was evaluated by detection and recognition threshold as Dilution Threshold (D-T. Acidic conditions (pH 6.0 and thermophilic temperatures (55 °C increased odors (1,358 D-T and acidified the system (Intermediate/Total Alkalinity ratio (IT/TA: 0.85 in batch experiments. Increasing OLR on UASB reactor reduced odors from 6.3 to 9.6 D-T d-1 due to an increase in the production of biogas (0.4 to 0.6 g g-1 COD removed of biogas.

Mesophilic and thermophilic activated sludge post-treatment of paper mill process water

NARCIS (Netherlands)

Vogelaar, J.C.T.; Bouwhuis, E.; Klapwijk, A.; Spanjers, H.; Lier, van J.B.

2002-01-01

Increasing system closure in paper mills and higher process water temperatures make the applicability of thermophilic treatment systems increasingly important. The use of activated sludge as a suitable thermophilic post-treatment system for anaerobically pre-treated paper process water from a paper

Monitoring and controlling the biogas process

Energy Technology Data Exchange (ETDEWEB)

Ahring, B K; Angelidaki, I [The Technical Univ. of Denmark, Dept. of Environmental Science and Engineering, Lyngby (Denmark)

1997-08-01

Many modern large-scale biogas plants have been constructed recently, increasing the demand for proper monitoring and control of these large reactor systems. For monitoring the biogas process, an easy to measure and reliable indicator is required, which reflects the metabolic state and the activity of the bacterial populations in the reactor. In this paper, we discuss existing indicators as well as indicators under development which can potentially be used to monitor the state of the biogas process in a reactor. Furthermore, data are presented from two large scale thermophilic biogas plants, subjected to temperature changes and where the concentration of volatile fatty acids was monitored. The results clearly demonstrated that significant changes in the concentration of the individual VFA occurred although the biogas production was not significantly changed. Especially the concentrations of butyrate, isobutyrate and isovalerate showed significant changes. Future improvements of process control could therefore be based on monitoring of the concentration of specific VFA`s together with information about the bacterial populations in the reactor. The last information could be supplied by the use of modern molecular techniques. (au) 51 refs.

Effect of ferrous chloride on biogas production and enzymatic activities during anaerobic fermentation of cow dung and Phragmites straw.

Science.gov (United States)

Zhang, Huayong; Tian, Yonglan; Wang, Lijun; Mi, Xueyue; Chai, Yang

2016-06-01

The effect of ferrous (added as FeCl2) on the anaerobic co-digestion of Phragmites straw and cow dung was studied by investigating the biogas properties, pH values, organic matter degradation (COD) and enzyme activities (cellulase, protease and dehydrogenase) at different stages of mesophilic fermentation. The results showed that Fe(2+) addition increased the cumulative biogas yields by 18.1 % by extending the peak period with high daily biogas yields. Meanwhile, the methane (CH4) contents in the Fe(2+) added groups were generally higher than the control group before the 15th day. The pH values were not significantly impacted by Fe(2+) concentrations during the fermentation process. The COD concentrations, cellulase, protease and dehydrogenase activities varied with the added Fe(2+) concentrations and the stages of the fermentation process. At the beginning stage of fermentation (4th day), Fe(2+) addition increased the biogas production by improving the cellulase and dehydrogenase activities which caused a decline in COD. At the peak stage of fermentation (8th day), Fe(2+) addition enhanced the cellulase and protease activities, and resulted in lower COD contents than the control group. When the biogas yields decreased again (13th day), the COD contents varied similar with the protease and dehydrogenase activities, whilst cellulase activities were not sensitive to Fe(2+) concentrations. At the end of fermentation (26th day), Fe(2+) addition decreased the cellulase activities, led to lower COD contents and finally resulted the lower biogas yields than the control group. Taking the whole fermentation process into account, the promoting effect of Fe(2+) addition on biogas yields was mainly attributed to the extension of the gas production peak stage and the improvement of cellulase activities.

Microalgal cultivation with biogas slurry for biofuel production.

Science.gov (United States)

Zhu, Liandong; Yan, Cheng; Li, Zhaohua

2016-11-01

Microalgal growth requires a substantial amount of chemical fertilizers. An alternative to the utilization of fertilizer is to apply biogas slurry produced through anaerobic digestion to cultivate microalgae for the production of biofuels. Plenty of studies have suggested that anaerobic digestate containing high nutrient contents is a potentially feasible nutrient source to culture microalgae. However, current literature indicates a lack of review available regarding microalgal cultivation with biogas slurry for the production of biofuels. To help fill this gap, this review highlights the integration of digestate nutrient management with microalgal production. It first unveils the current status of microalgal production, providing basic background to the topic. Subsequently, microalgal cultivation technologies using biogas slurry are discussed in detail. A scale-up scheme for simultaneous biogas upgrade and digestate application through microalgal cultivation is then proposed. Afterwards, several uncertainties that might affect this practice are explored. Finally, concluding remarks are put forward. Copyright © 2016 Elsevier Ltd. All rights reserved.

AMMONOX-Ammonia for enhancing biogas yield & reducing NOx

DEFF Research Database (Denmark)

Gavala, Hariklia N.; Kristensen, P.G.; Paamand, K.

2013-01-01

The continuously increasing demand for renewable energy sources renders anaerobic digestion to one of the most promising technologies for renewable energy production. Due to the animal production intensification, manure is being used as the primary feedstock for most of the biogas plants. However...... of innovative ammonia recovery technology and c) the coupling of the excess ammonia obtained from manure with the catalytic elimination of NOx emissions when the biogas is used for subsequent electricity generation with gas engines.......The continuously increasing demand for renewable energy sources renders anaerobic digestion to one of the most promising technologies for renewable energy production. Due to the animal production intensification, manure is being used as the primary feedstock for most of the biogas plants. However......, biogas plants digesting liquid manure alone are not economically viable due to the relatively low organic content of the manure, usually 3-5%.Thus, their economical profitable operation relies partly on increasing the methane yield from manure, and especially of its solid fraction, usually called...

Kinetics of butyrate, acetate, and hydrogen metabolism in a thermophilic, anaerobic, butyrate-degrading triculture.

Science.gov (United States)

Ahring, B K; Westermann, P

1987-02-01

Kinetics of butyrate, acetate, and hydrogen metabolism were determined with butyrate-limited, chemostat-grown tricultures of a thermophilic butyrate-utilizing bacterium together with Methanobacterium thermoautotrophicum and the TAM organism, a thermophilic acetate-utilizing methanogenic rod. Kinetic parameters were determined from progress curves fitted to the integrated form of the Michaelis-Menten equation. The apparent half-saturation constants, K(m), for butyrate, acetate, and dissolved hydrogen were 76 muM, 0.4 mM, and 8.5 muM, respectively. Butyrate and hydrogen were metabolized to a concentration of less than 1 muM, whereas acetate uptake usually ceased at a concentration of 25 to 75 muM, indicating a threshold level for acetate uptake. No significant differences in K(m) values for butyrate degradation were found between chemostat- and batch-grown tricultures, although the maximum growth rate was somewhat higher in the batch cultures in which the medium was supplemented with yeast extract. Acetate utilization was found to be the rate-limiting reaction for complete degradation of butyrate to methane and carbon dioxide in continuous culture. Increasing the dilution rate resulted in a gradual accumulation of acetate. The results explain the low concentrations of butyrate and hydrogen normally found during anaerobic digestion and the observation that acetate is the first volatile fatty acid to accumulate upon a decrease in retention time or increase in organic loading of a digestor.

Sludge storage lagoon biogas recovery and use

Energy Technology Data Exchange (ETDEWEB)

Muller, D.; Norville, C. (Memphis and Shelby County Div. of Planning and Development, TN (United States))

1991-07-01

The City of Memphis has two wastewater treatment plants. The SWTP employs two large anaerobic digestion sludge lagoons as part of the overall sludge treatment system. Although these lagoons are effective in concentrating and digesting sludge, they can generate offensive odors. The SWTP uses aerobic digesters to partially stabilize the sludge and help reduce objectionable odors before it enters the lagoons. The anaerobic digestion of sludge in the lagoons results in the dispersion of a large quantity of biogas into the atmosphere. The City realized that if the lagoons could be covered, the odor problem could be resolved, and at the same, time, biogas could be recovered and utilized as a source of energy. In 1987, the City commissioned ADI International to conduct a feasibility study to evaluate alternative methods of covering the lagoons and recovering and utilizing the biogas. The study recommended that the project be developed in two phases: (1) recovery of the biogas and (2) utilization of the biogas. Phase 1 consists of covering the two lagoons with an insulated membrane to control odor and temperature and collect the biogas. Phase 1 was found to be economically feasible and offered a unique opportunity for the City to save substantial operating costs at the treatment facility. The Memphis biogas recovery project is the only application in the world where a membrane cover has been used on a municipal wastewater sludge lagoon. It is also the largest lagoon cover system in the world.

Anaerobic Digestion: Process

DEFF Research Database (Denmark)

Angelidaki, Irini; Batstone, Damien J.

2011-01-01

Organic waste may degrade anaerobically in nature as well as in engineered systems. The latter is called anaerobic digestion or biogasification. Anaerobic digestion produces two main outputs: An energy-rich gas called biogas and an effluent. The effluent, which may be a solid as well as liquid...... with very little dry matter may also be called a digest. The digest should not be termed compost unless it specifically has been composted in an aerated step. This chapter describes the basic processes of anaerobic digestion. Chapter 9.5 describes the anaerobic treatment technologies, and Chapter 9...

Characterization of the planktonic microbiome in upflow anaerobic sludge blanket reactors during adaptation of mesophilic methanogenic granules to thermophilic operational conditions

DEFF Research Database (Denmark)

Zhu, Xinyu; Treu, Laura; Kougias, Panagiotis

2017-01-01

Upflow anaerobic sludge blanket (UASB) technology refers to reactor technology where granules, i.e. self-immobilised microbial associations, are the biological catalysts involved in the anaerobic digestion process. During the start-up period, UASB reactors operate at relatively long HRT and there......Upflow anaerobic sludge blanket (UASB) technology refers to reactor technology where granules, i.e. self-immobilised microbial associations, are the biological catalysts involved in the anaerobic digestion process. During the start-up period, UASB reactors operate at relatively long HRT...... and therefore the liquid phase of the reactor becomes a favourable environment for microbial growth. The current study aimed to elucidate the dynamicity of the suspended microbial community in UASB reactors, during the transition from mesophilic to thermophilic conditions. High throughput 16S rRNA amplicon...... sequencing was used to characterize the taxonomic composition of the microbiome. The results showed that the microbial community was mainly composed by hydrolytic and fermentative bacteria. Results revealed relevant shifts in the microbial community composition, which is mainly determined by the operational...

Hydrogen assisted biological biogas upgrading

DEFF Research Database (Denmark)

Bassani, Ilaria

Wind and biomass are promoted worldwide as sustainable forms of energy. Anaerobic digestion of biomass produces biogas with ∼50−70% CH4 and 30−50% CO2. However, biogas with >90% CH4 content has higher heating value, can be injected into the natural gas grid or used as alternative to natural gas...... as vehicle fuel. Methods currently available for biogas upgrading mainly consists of physicochemical CO2 removal, requiring the use of chemical substances and energy input and, thus, increasing process costs. This PhD project proposes an alternative to existing biogas upgrading technologies, where H2......, produced by water electrolysis, using excess of electricity from wind mills, is coupled with the CO2 contained in the biogas to convert them to CH4. This process is defined as biological biogas upgrading and is carried out by hydrogenotrophic methanogenic archaea that couples CO2 with H2 to produce...

Promotion and marketing of the biogas way

International Nuclear Information System (INIS)

Mistry, P.B.; Lindboe, H.H.

1992-01-01

The biological process of anaerobic digestion is used primarily as a tool for waste treatment. It also produces energy in the form of biogas - a feature by which it is often called the biogas technology. This paper outlines special features of this process, together with other advantages and disadvantages of applying the AD or the biogas technology, to satisfy ever increasing regulatory requirements and public concerns over pollution at both global and local levels. The paper then gives suggestions which could be implemented at the Commission, national and regional levels to propagate the implementation of the biogas technology. (au)

Biodigester economic viability for electrical power production using biogas from swine waste

Energy Technology Data Exchange (ETDEWEB)

Cervi, Ricardo Ghantous; Esperancini, Maura Seiko Tsutsui; Bueno, Osmar de Carvalho [Universidade Estadual Paulista (FCA/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas], E-mail: ricardogc@fca.unesp.br; Souza, Samuel Nelson Melegari de [Universidade Estadual do Oeste do Parana (CCET/UNIOESTE), Cascavel, PR (Brazil). Centro de Ciencias Exatas e Tecnologicas

2008-07-01

The increase of energy use in agriculture and the raising prices of electricity demand studies on alternate sources of energy and improvement on biogas use efficiency so that agricultural activities become more competitive. Biogas production through anaerobic biodigestion represents an important breakthrough for the problem of swine waste and energy availability for rural areas. This work aimed to analyze the economy on biodigester investment for electrical power production using biogas from anaerobic biodigestion of swine waste. Two factors were used for this evaluation: the cost of electrical power production through biogas and time for equipment investment return. Results show that investment return time can be only 2.45 years for electrical power at peak time. (author)

Bioenergy and biofertilizer : improvement of biogas production from filter cake

Energy Technology Data Exchange (ETDEWEB)

Fonte, A.H. [Environmental Bioremediation Group, Research and Development Agency, GeoCuba, Camaguey (Cuba); Alvarez, R.C. [Provincial Direction of Soils, Camaguey (Cuba)

2000-07-01

The anaerobic digestion of sugar mill filter cake (SMFC) was studied using a natural zeolite to intensify the biogas production. The anaerobic digestion (AD) of agricultural waste mixtures in certain proportions is the underlying basis of biogas generation. Earlier studies have shown that certain inert materials can act as stimulators in biogas production when used in conjunction with AD. This study involved three experiments using filter cake from different sugar mills using three doses of zeolite to determine how they stimulate biogas production. Another objective of the study was to determine if the mud of the digester containing the added zeolite has an impact on plants and soil. The study was conducted under glass house conditions using a brown soil with carbonates with neutral pH and high contents of P{sub 2}O{sub 5}, K{sub 2}O and organic matter. It was concluded that it is possible to increase the biogas yield and to improve AD behaviour of the filter cake by using a zeolite adapted to unique operating conditions. The amount of yield depends on the origin of the filter cake, the stimulator dose and age. Results were in the order of 20-40 per cent biogas production. Fresh filter cake was found to produce more biogas. The mud of the anaerobic digestion of the filter cake containing zeolite positively impacted on the agronomic behaviour of the sorghum in relation to P{sub 2}O{sub 5}, K{sub 2}O and organic matter content. 19 refs., 4 tabs.

Improved anaerobic biodegradation of biosolids by the addition of food waste as a co-substrate

Energy Technology Data Exchange (ETDEWEB)

Kim, H.-W.; Han, S.-K.; Song, Y.-C.; Baek, B.-C.; Yoo, K.-S.; Lee, J.-J.; Shin, H.-S.

2003-07-01

The temperature phased anaerobic digestion (TPAD) process was applied to increase the performance of anaerobic treatment of biosolids. Previously obtained results indicate that this system showed the advantages of thermophilic and mesophilic anaerobic digestion process. By comparing the performance of each reactor of the system, it was illustrated that the main stage of methane production was the thermophilic reactor which has faster microbial metabolism. However, the result revealed that substrate characteristics of low VS/TS limited the system performance. Therefore, to evaluate the effect of food waste as a co-substrate for improving anaerobic biodegradability, biochemical methane potential (BMP) tests were conducted in thermophilic conditions with biomass of thermophilic reactor. It was confirmed that the co-digestion of sewage sludge mixed with food waste had a distinct improvement on biodegradability. The most significant advantages were the preferable environment provided by food waste for the growth and activity of anaerobes and the mutual assistance between biosolids and food waste. (author)

Anaerobic co-digestion of the organic fraction of municipal solid waste with FOG waste from a sewage treatment plant: Recovering a wasted methane potential and enhancing the biogas yield

International Nuclear Information System (INIS)

Martin-Gonzalez, L.; Colturato, L.F.; Font, X.; Vicent, T.

2010-01-01

Anaerobic digestion is applied widely to treat the source collected organic fraction of municipal solid wastes (SC-OFMSW). Lipid-rich wastes are a valuable substrate for anaerobic digestion due to their high theoretical methane potential. Nevertheless, although fat, oil and grease waste from sewage treatment plants (STP-FOGW) are commonly disposed of in landfill, European legislation is aimed at encouraging more effective forms of treatment. Co-digestion of the above wastes may enhance valorisation of STP-FOGW and lead to a higher biogas yield throughout the anaerobic digestion process. In the present study, STP-FOGW was evaluated as a co-substrate in wet anaerobic digestion of SC-OFMSW under mesophilic conditions (37 o C). Batch experiments carried out at different co-digestion ratios showed an improvement in methane production related to STP-FOGW addition. A 1:7 (VS/VS) STP-FOGW:SC-OFMSW feed ratio was selected for use in performing further lab-scale studies in a 5 L continuous reactor. Biogas yield increased from 0.38 ± 0.02 L g VS feed -1 to 0.55 ± 0.05 L g VS feed -1 as a result of adding STP-FOGW to reactor feed. Both VS reduction values and biogas methane content were maintained and inhibition produced by long chain fatty acid (LCFA) accumulation was not observed. Recovery of a currently wasted methane potential from STP-FOGW was achieved in a co-digestion process with SC-OFMSW.

A comparative study of leachate quality and biogas generation in simulated anaerobic and hybrid bioreactors

Energy Technology Data Exchange (ETDEWEB)

Xu, Qiyong; Tian, Ying; Wang, Shen; Ko, Jae Hac, E-mail: jaehacko@pkusz.edu.cn

2015-07-15

Highlights: • Temporary aeration shortened the initial acid inhibition phase for methanogens. • COD decreased faster in the hybrid bioreactor than that in the anaerobic control. • Methane generations from hybrid bioreactors were 133.4 L/kg{sub vs} and 113.2 L/kg{sub vs}. • MSW settlement increased with increasing the frequency of intermittent aeration. - Abstract: Research has been conducted to compare leachate characterization and biogas generation in simulated anaerobic and hybrid bioreactor landfills with typical Chinese municipal solid waste (MSW). Three laboratory-scale reactors, an anaerobic (A1) and two hybrid bioreactors (C1 and C2), were constructed and operated for about 10 months. The hybrid bioreactors were operated in an aerobic–anaerobic mode with different aeration frequencies by providing air into the upper layer of waste. Results showed that the temporary aeration into the upper layer aided methane generation by shortening the initial acidogenic phase because of volatile fatty acids (VFAs) reduction and pH increase. Chemical oxygen demand (COD) decreased faster in the hybrid bioreactors, but the concentrations of ammonia–nitrogen in the hybrid bioreactors were greater than those in the anaerobic control. Methanogenic conditions were established within 75 d and 60 d in C1 and C2, respectively. However, high aeration frequency led to the consumption of organic matters by aerobic degradation and resulted in reducing accumulative methane volume. The temporary aeration enhanced waste settlement and the settlement increased with increasing the frequency of aeration. Methane production was inhibited in the anaerobic control; however, the total methane generations from hybrid bioreactors were 133.4 L/kg{sub vs} and 113.2 L/kg{sub vs}. As for MSW with high content of food waste, leachate recirculation right after aeration stopped was not recommended due to VFA inhibition for methanogens.

Analysis of methanogenic activity in a thermophilic-dry anaerobic reactor: Use of fluorescent in situ hybridization

International Nuclear Information System (INIS)

Montero, B.; Garcia-Morales, J.L.; Sales, D.; Solera, R.

2009-01-01

Methanogenic activity in a thermophilic-dry anaerobic reactor was determined by comparing the amount of methane generated for each of the organic loading rates with the size of the total and specific methanogenic population, as determined by fluorescent in situ hybridization. A high correlation was evident between the total methanogenic activity and retention time [-0.6988Ln(x) + 2.667] (R 2 0.8866). The total methanogenic activity increased from 0.04 x 10 -8 mLCH 4 cell -1 day -1 to 0.38 x 10 -8 mLCH 4 cell -1 day -1 while the retention time decreased, augmenting the organic loading rates. The specific methanogenic activities of H 2 -utilizing methanogens and acetate-utilizing methanogens increased until they stabilised at 0.64 x 10 -8 mLCH 4 cell -1 day -1 and 0.33 x 10 -8 mLCH 4 cell -1 day -1 , respectively. The methanogenic activity of H 2 -utilizing methanogens was higher than acetate-utilizing methanogens, indicating that maintaining a low partial pressure of hydrogen does not inhibit the acetoclastic methanogenesis or the anaerobic process

Biogas from Agricultural Residues as Energy Source in Hybrid Concentrated Solar Power

NARCIS (Netherlands)

Corré, W.J.; Conijn, J.G.

2016-01-01

This paper explores the possibilities of sustainable biogas use for hybridisation of Concentrated Solar Power (HCSP) in Europe. The optimal system for the use of biogas from agricultural residues (manure and crop residues) in HCSP involves anaerobic digestion with upgrading of biogas to

Drivers of microbial community composition in mesophilic and thermophilic temperature-phased anaerobic digestion pre-treatment reactors.

Science.gov (United States)

Pervin, Hasina M; Dennis, Paul G; Lim, Hui J; Tyson, Gene W; Batstone, Damien J; Bond, Philip L

2013-12-01

Temperature-phased anaerobic digestion (TPAD) is an emerging technology that facilitates improved performance and pathogen destruction in anaerobic sewage sludge digestion by optimising conditions for 1) hydrolytic and acidogenic organisms in a first-stage/pre-treatment reactor and then 2) methogenic populations in a second stage reactor. Pre-treatment reactors are typically operated at 55-65 °C and as such select for thermophilic bacterial communities. However, details of key microbial populations in hydrolytic communities and links to functionality are very limited. In this study, experimental thermophilic pre-treatment (TP) and control mesophilic pre-treatment (MP) reactors were operated as first-stages of TPAD systems treating activated sludge for 340 days. The TP system was operated sequentially at 50, 60 and 65 °C, while the MP rector was held at 35 °C for the entire period. The composition of microbial communities associated with the MP and TP pre-treatment reactors was characterised weekly using terminal-restriction fragment length polymorphism (T-RFLP) supported by clone library sequencing of 16S rRNA gene amplicons. The outcomes of this approach were confirmed using 454 pyrosequencing of gene amplicons and fluorescence in-situ hybridisation (FISH). TP associated bacterial communities were dominated by populations affiliated to the Firmicutes, Thermotogae, Proteobacteria and Chloroflexi. In particular there was a progression from Thermotogae to Lutispora and Coprothermobacter and diversity decreased as temperature and hydrolysis performance increased. While change in the composition of TP associated bacterial communities was attributable to temperature, that of MP associated bacterial communities was related to the composition of the incoming feed. This study determined processes driving the dynamics of key microbial populations that are correlated with an enhanced hydrolytic functionality of the TPAD system. Copyright © 2013 Elsevier Ltd. All rights

The Effect of Acid Pre-Treatment using Acetic Acid and Nitric Acid in The Production of Biogas from Rice Husk during Solid State Anaerobic Digestion (SS-AD)

Science.gov (United States)

Nugraha, Winardi Dwi; Syafrudin; Keumala, Cut Fadhila; Matin, Hasfi Hawali Abdul; Budiyono

2018-02-01

Pretreatment during biogas production aims to assist in degradation of lignin contained in the rice husk. In this study, pretreatment which is used are acid and biological pretreatment. Acid pretreatment was performed using acetic acid and nitric acid with a variety levels of 3% and 5%. While biological pretreatment as a control variable. Acid pretreatment was conducted by soaking the rice straw for 24 hours with acid variation. The study was conducted using Solid State Anaerobic Digestion (SS-AD) with 21% TS. Biogas production was measured using water displacement method every two days for 60 days at room temperature conditions. The results showed that acid pretreatment gave an effect on the production of biogas yield. The yield of the biogas produced by pretreatment of acetic acid of 5% and 3% was 43.28 and 45.86 ml/gr.TS. While the results without pretreatment biogas yield was 29.51 ml/gr.TS. The results yield biogas produced by pretreatment using nitric acid of 5% and 3% was 12.14 ml/gr.TS and 21.85 ml/gr.TS. Results biogas yield with acetic acid pretreatment was better than the biogas yield results with nitric acid pretreatment.

Methods and apparatus for hydrogen based biogas upgrading

DEFF Research Database (Denmark)

2013-01-01

The present invention relates to an anaerobic process for biogas upgrading and hydrogen utilization comprising the use of acidic waste as co-substrate.In this process,H2 and CO2 will be converted to CH4, which will result in lower CO2 content in the biogas. The invention relates to both in situ...... and ex situ methods of biogas upgrading. The invention further relates to a bioreactor comprising hollow fibre membranes....

Thermophilic archaea activate butane via alkyl-coenzyme M formation.

Science.gov (United States)

Laso-Pérez, Rafael; Wegener, Gunter; Knittel, Katrin; Widdel, Friedrich; Harding, Katie J; Krukenberg, Viola; Meier, Dimitri V; Richter, Michael; Tegetmeyer, Halina E; Riedel, Dietmar; Richnow, Hans-Hermann; Adrian, Lorenz; Reemtsma, Thorsten; Lechtenfeld, Oliver J; Musat, Florin

2016-11-17

The anaerobic formation and oxidation of methane involve unique enzymatic mechanisms and cofactors, all of which are believed to be specific for C 1 -compounds. Here we show that an anaerobic thermophilic enrichment culture composed of dense consortia of archaea and bacteria apparently uses partly similar pathways to oxidize the C 4 hydrocarbon butane. The archaea, proposed genus 'Candidatus Syntrophoarchaeum', show the characteristic autofluorescence of methanogens, and contain highly expressed genes encoding enzymes similar to methyl-coenzyme M reductase. We detect butyl-coenzyme M, indicating archaeal butane activation analogous to the first step in anaerobic methane oxidation. In addition, Ca. Syntrophoarchaeum expresses the genes encoding β-oxidation enzymes, carbon monoxide dehydrogenase and reversible C 1 methanogenesis enzymes. This allows for the complete oxidation of butane. Reducing equivalents are seemingly channelled to HotSeep-1, a thermophilic sulfate-reducing partner bacterium known from the anaerobic oxidation of methane. Genes encoding 16S rRNA and methyl-coenzyme M reductase similar to those identifying Ca. Syntrophoarchaeum were repeatedly retrieved from marine subsurface sediments, suggesting that the presented activation mechanism is naturally widespread in the anaerobic oxidation of short-chain hydrocarbons.

Biogas from manure and waste residues; Biogas ur goedsel, avfall och restprodukter

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-09-15

The consumption of fossil fuels must be reduced if we are to meet environmental and climate related goals and reduce the greenhouse effect. In contrast to fossil fuels, biogas is renewable and carbon dioxide neutral. Biogas is also the cleanest fuel on the market and has the potential to replace much of the fossil fuel used in Sweden. The residue produced after anaerobic digestion is a valuable fertilizer and soil conditioner. Organic wastes are recycled through the biogas process to become a resource. This creates a sustainable recycling of nutrients and energy between urban and rural areas, and between consumption and production. This handbook is intended as a source of information on biogas, targeting politicians and decision- and policy makers in local authorities, farmers and farmers' organisations, and indeed anyone with an interest in biogas in Sweden and abroad. The handbook starts with an introduction of biogas in Sweden today. In part two general information is given about biogas technologies, a description of the biogas process, from the use of substrates to the final distribution of biogas and organic residues, followed by short information about economic support and incentives. In the last part twelve Swedish biogas plants are described, which have been particularly successful, and which can therefore serve as models for the future. The plants are grouped into four different categories: codigestion plants, farm-based biogas plants, sewage treatment plants and industrial plants. Each case study is described as of March 2012. Production figures are given for 2011, unless otherwise stated.

Growing Chlorella vulgaris on thermophilic anaerobic digestion swine manure for nutrient removal and biomass production.

Science.gov (United States)

Deng, Xiang-Yuan; Gao, Kun; Zhang, Ren-Chuan; Addy, Min; Lu, Qian; Ren, Hong-Yan; Chen, Paul; Liu, Yu-Huan; Ruan, Roger

2017-11-01

Liquid swine manure was subjected to thermophilic anaerobic digestion, ammonia stripping and centrifugation in order to increase the available carbon sources and decrease the ammonia concentration and turbidity. Chlorella vulgaris (UTEX 2714) was grown on minimally diluted (2×, 3× and 4×) autoclaved and non-autoclaved pretreated anaerobic digestion swine manure (PADSM) in a batch-culture system for 7days. Results showed that C. vulgaris (UTEX 2714) grew best on 3× PADSM media, and effectively removed NH 4 + -N, TN, TP and COD by 98.5-99.8%, 49.2-55.4%, 20.0-29.7%, 31.2-34.0% and 99.8-99.9%, 67.4-70.8%, 49.3-54.4%, 73.6-78.7% in differently diluted autoclaved and non-autoclaved PADSM, respectively. Results of chemical compositions indicated that contents of pigment, carbohydrate, protein and lipid in C. vulgaris (UTEX 2714) changed with the culture conditions. Moreover, its fatty acid profiles suggested that this alga could be used as animal feed if cultivated in autoclaved PADSM or as good-quality biodiesel feedstock if cultivated in non-autoclaved PADSM. Copyright © 2017 Elsevier Ltd. All rights reserved.

Improve biogas production from low-organic-content sludge through high-solids anaerobic co-digestion with food waste.

Science.gov (United States)

Liu, Chuanyang; Li, Huan; Zhang, Yuyao; Liu, Can

2016-11-01

Anaerobic co-digestion of sewage sludge and food waste was tested at two different total solid (TS) concentrations. In the low-solids group with TS 4.8%, the biogas production increased linearly as the ratio of food waste in substrate increased from 0 to 100%, but no synergetic effect was found between the two substrates. Moreover, the additive food waste resulted in the accumulation of volatile fatty acids and decelerated biogas production. Thus, the blend ratio of food waste should be lower than 50%. While in the high-solids group with TS 14%, the weak alkaline environment with pH 7.5-8.5 avoided excessive acidification but high concentration of free ammonia was a potential risk. However, good synergetic effect was found between the two substrates because the added food waste improved mass transfer in sludge cake. Thus, 50% was recommended as the optimum ratio of food waste in substrate because of the best synergetic effect. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of zinc on biogas production and antibiotic resistance gene profiles during anaerobic digestion of swine manure.

Science.gov (United States)

Zhang, Ranran; Wang, Xiaojuan; Gu, Jie; Zhang, Yajun

2017-11-01

This study determined the accumulated biogas, methane content, and absolute abundances (AAs) of 14 common antibiotic resistance genes (ARGs) and two integrons during the anaerobic digestion of swine manure for 52days with different amounts of added zinc. The accumulated biogas increased by 51.2% and 56.0% with 125mgL -1 (L) and 1250mgL -1 (H) zinc, respectively, compared with the control with no added zinc (CK), but there was no significant difference between L and H. Compared with CK, excluding tetW and tetC, all the other ARGs detected in this study increased in the L and H reactors. However, the low concentration of zinc (L reactor) caused greater increases in the AAs of ARGs in the AD products. Redundancy analysis showed that NO 3 -N and bio-zinc significantly explained the changes in genes, where they accounted for 60.9% and 20.3% of the total variation in the environmental factors, respectively. Copyright © 2017. Published by Elsevier Ltd.

Bacteria and archaea communities in full-scale thermophilic and mesophilic anaerobic digesters treating food wastewater: Key process parameters and microbial indicators of process instability.

Science.gov (United States)

Lee, Joonyeob; Shin, Seung Gu; Han, Gyuseong; Koo, Taewoan; Hwang, Seokhwan

2017-12-01

In this study, four different mesophilic and thermophilic full-scale anaerobic digesters treating food wastewater (FWW) were monitored for 1-2years in order to investigate: 1) microbial communities underpinning anaerobic digestion of FWW, 2) significant factors shaping microbial community structures, and 3) potential microbial indicators of process instability. Twenty-seven bacterial genera were identified as abundant bacteria underpinning the anaerobic digestion of FWW. Methanosaeta harundinacea, M. concilii, Methanoculleus bourgensis, M. thermophilus, and Methanobacterium beijingense were revealed as dominant methanogens. Bacterial community structures were clearly differentiated by digesters; archaeal community structures of each digester were dominated by one or two methanogen species. Temperature, ammonia, propionate, Na + , and acetate in the digester were significant factors shaping microbial community structures. The total microbial populations, microbial diversity, and specific bacteria genera showed potential as indicators of process instability in the anaerobic digestion of FWW. Copyright © 2017 Elsevier Ltd. All rights reserved.

Study of Biogas Production from Cassava Industrial Waste by Anaerobic Process

Directory of Open Access Journals (Sweden)

Budiyono

2018-01-01

Full Text Available Biogas production processes from tapioca wastewater have several problems that cause the biogas production is not optimal, such as pH drop at beginning of the process because the rate of acid formation is too fast and the rate of starch wastewater degradation is too slow. Therefore, to obtain optimal biogas production it is required two-stage reactor. The purposes of this research were to (i study the influence of one stage fermentation and two stage fermentation on biogas production, (ii study the effect of buffer Na2CO3 on biogas production, and (iii study the effect of methanogenic bacteria concentration on biogas production from cassava starch effluent. The first method of our research was hydrolysis process by “Saccharomyces cereviceae” as substrate activator. The second is the arrangement of pH and the last is process of methane production. The results showed that the highest biogas production is achieved at concentration of methanogenic bacteria 20% (v/v that is equal to 2458 ml. At concentration of 8% (v/v and 15% (v/v, biogas production was 2105 ml and 2117 ml. The addition of Na2CO3 can extend to 16 days with accumulation of 372 ml. While without the addition of buffer, biogas production period was only 9 days with accumulation of 620 ml. In semi continuous process, the analysis carried out every 3 days. Highest biogas production achieved in the variable addition of yeast with the accumulation 9329 ml. Without yeast, accumulation of biogas was 6831 ml. Yeast is use as substrate activator so it can accelerate the hydrolysis process and increased biogas production. The addition of Na2CO3 is increase the alkalinity so the pH drop did not occur early in the process.

Biogas. The oldest form of renewable energy

International Nuclear Information System (INIS)

Kotevski, Darko

2004-01-01

Biomass is the oldest form of renewable energy known and human kind have been making good use of it since fire was discovered. Using biomass as economically viable source of energy presents rather difficult challenge, but one that is increasingly seen as having real potential as an alternative to fossil fuels. Typical biomass sources are wood, agricultural residues, cultivated energy crops, industry and municipal organic waste and animal manure. Converting biomass to energy can be done in several ways: direct combustion, gasification, anaerobic digestion, steam reforming etc. Biogas is a product of anaerobic digestion and it consists mostly of methane (60%). For this process, the most commonly used source is animal manure, which is digested under special conditions in anaerobic digesters. Biogas can be used for electricity production, hot water needs, spatial heating, cooking, etc. (Original)

Dynamic real-time substrate feed optimization of anaerobic co-digestion plants

NARCIS (Netherlands)

Gaida, Daniel

2014-01-01

In anaerobic co-digestion plants a mix of organic materials is converted to biogas using the anaerobic digestion process. These organic materials, called substrates, can be crops, sludge, manure, organic wastes and many more. They are fed on a daily basis and significantly affect the biogas

Guide biogas. From production to utilization. 5. compl. rev. ed.; Leitfaden Biogas. Von der Gewinnung zur Nutzung

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

The book under consideration is a guide for biogas and consists of the following contributions: (a) Targets of the guide (M. Kaltschmitt); (b) Fundamentals of anaerobic fermentation (J. Friehe); (c) Systems engineering for supplying biogas (J. Postel); (d) Description of selected substrates (J. Friehe); (e) Operation of biogas plants (J. Liebetrau); (f) Gas processing and possibilities of utilization (M. Wetthaeuser); (g) Legal and administrative framework conditions (H. von Bredow); (g) Economy (S. Hartmann); (h) Company organisation (G. Reinhold); (i) Quality and utilization of fermentation residues (H. Doehler); (j) Implementation of a project (E. Fischer); (k) Position and significance of biogas as a renewable energy resource in Germany (M. Kaltschmitt); (l) Project examples (J. Friehe).

Review of desulfurization process for biogas purification

Science.gov (United States)

Xiao, Cong; Ma, Yunqian; Ji, Dandan; Zang, Lihua

2017-12-01

Hydrogen sulfide (H2S) is a toxic and odorous compound present in biogas produced by the anaerobic digestion of biosolids and other organic materials. Elimination of H2S is necessary as it is extremely hazardous to human health, poisonous to process catalysts and corrosive to equipment. The desulfurization technology is an important part for efficient utilization of biogas. In this paper, the traditional wet and dry desulfurization technology for biogas was reviewed, and the new research progress of biological desulfurization technologies are also introduced.

University of Wisconsin Oshkosh Anaerobic Dry Digestion Facility

Energy Technology Data Exchange (ETDEWEB)

Koker, John [Univ. of Wisconsin, Oshkosh, WI (United States); Lizotte, Michael [Univ. of Wisconsin, Oshkosh, WI (United States)

2017-02-08

The University of Wisconsin Oshkosh Anaerobic Dry Digestion Facility is a demonstration project that supported the first commercial-scale use in the United States of high solids, static pile technology for anaerobic digestion of organic waste to generate biogas for use in generating electricity and heat. The research adds to the understanding of startup, operation and supply chain issues for anaerobic digester technology. Issues and performance were documented for equipment installation and modifications, feedstock availability and quality, weekly loading and unloading of digestion chambers, chemical composition of biogas produced, and energy production. This facility also demonstrated an urban industrial ecology approach to siting such facilities near sewage treatment plants (to capture and use excess biogas generated by the plants) and organic yard waste collection sites (a source of feedstock).

Mechanism and Effect of Temperature on Variations in Antibiotic Resistance Genes during Anaerobic Digestion of Dairy Manure

Science.gov (United States)

Sun, Wei; Qian, Xun; Gu, Jie; Wang, Xiao-Juan; Duan, Man-Li

2016-07-01

Animal manure comprises an important reservoir for antibiotic resistance genes (ARGs), but the variation in ARGs during anaerobic digestion at various temperatures and its underlying mechanism remain unclear. Thus, we performed anaerobic digestion using dairy manure at three temperature levels (moderate: 20 °C, mesophilic: 35 °C, and thermophilic: 55 °C), to analyze the dynamics of ARGs and bacterial communities by quantitative PCR and 16S rRNA gene sequencing. We found that 8/10 detected ARGs declined and 5/10 decreased more than 1.0 log during thermophilic digestion, whereas only four and five ARGs decreased during moderate and mesophilic digestion, respectively. The changes in ARGs and bacterial communities were similar under the moderate and mesophilic treatments, but distinct from those in the thermophilic system. Potential pathogens such as Bacteroidetes, Proteobacteria, and Corynebacterium were removed by thermophilic digestion but not by moderate and mesophilic digestion. The bacterial community succession was the dominant mechanism that influenced the variation in ARGs and integrons during anaerobic digestion. Thermophilic digestion decreased the amount of mesophilic bacteria (Bacteroidetes and Proteobacteria) carrying ARGs. Anaerobic digestion generally decreased the abundance of integrons by eliminating the aerobic hosts of integrons (Actinomycetales and Bacilli). Thermophilic anaerobic digestion is recommended for the treatment and reuse of animal manure.

Mechanism and Effect of Temperature on Variations in Antibiotic Resistance Genes during Anaerobic Digestion of Dairy Manure.

Science.gov (United States)

Sun, Wei; Qian, Xun; Gu, Jie; Wang, Xiao-Juan; Duan, Man-Li

2016-07-22

Animal manure comprises an important reservoir for antibiotic resistance genes (ARGs), but the variation in ARGs during anaerobic digestion at various temperatures and its underlying mechanism remain unclear. Thus, we performed anaerobic digestion using dairy manure at three temperature levels (moderate: 20 °C, mesophilic: 35 °C, and thermophilic: 55 °C), to analyze the dynamics of ARGs and bacterial communities by quantitative PCR and 16S rRNA gene sequencing. We found that 8/10 detected ARGs declined and 5/10 decreased more than 1.0 log during thermophilic digestion, whereas only four and five ARGs decreased during moderate and mesophilic digestion, respectively. The changes in ARGs and bacterial communities were similar under the moderate and mesophilic treatments, but distinct from those in the thermophilic system. Potential pathogens such as Bacteroidetes, Proteobacteria, and Corynebacterium were removed by thermophilic digestion but not by moderate and mesophilic digestion. The bacterial community succession was the dominant mechanism that influenced the variation in ARGs and integrons during anaerobic digestion. Thermophilic digestion decreased the amount of mesophilic bacteria (Bacteroidetes and Proteobacteria) carrying ARGs. Anaerobic digestion generally decreased the abundance of integrons by eliminating the aerobic hosts of integrons (Actinomycetales and Bacilli). Thermophilic anaerobic digestion is recommended for the treatment and reuse of animal manure.

Simple biogas desulfurization by microaeration - Full scale experience.

Science.gov (United States)

Jeníček, P; Horejš, J; Pokorná-Krayzelová, L; Bindzar, J; Bartáček, J

2017-08-01

Hydrogen sulfide in biogas is common problem during anaerobic treatment of wastewater with high sulfate concentration (breweries, distilleries, etc.) and needs to be removed before biogas utilization. Physico-chemical desulfurization methods are energetically demanding and expensive compare to biochemical methods. Microaeration, i.e. dosing of small amount of air, is suitable and cost effective biochemical method of sulfide oxidation to elemental sulfur. It has been widely used in biogas plants, but its application in anaerobic reactors for wastewater treatment has been rarely studied or tested. The lack of full-scale experience with microaeration in wastewater treatment plants has been overcome by evaluating the results of seven microaerobic digesters in central Europe. The desulfurization efficiency has been more than 90% in most of the cases. Moreover, microaeration improved the degradability of COD and volatile suspended solids. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of hydrogen and formate on the degradation of propionate and butyrate in thermophilic granules from an upflow anaerobic sludge blanket reactor.

OpenAIRE

Schmidt, J E; Ahring, B K

1993-01-01

Degradation of propionate and butyrate in whole and disintegrated granules from a thermophilic (55 degrees C) upflow anaerobic sludge blanket reactor fed with acetate, propionate, and butyrate as substrates was examined. The propionate and butyrate degradation rates in whole granules were 1.16 and 4.0 mumol/min/g of volatile solids, respectively, and the rates decreased 35 and 25%, respectively, after disintegration of the granules. The effect of adding different hydrogen-oxidizing bacteria (...

10. Biogas conference Dresden. Anaerobic treatment of biological wastes. Proceedings; 10. Biogastagung Dresden. Anaerobe biologische Abfallbehandlung. Tagungsband

Energy Technology Data Exchange (ETDEWEB)

Dornack, Christina [Technische Univ. Dresden (Germany). Inst. fuer Abfallwirtschaft und Altlasten; Scholwin, Frank [Institut fuer Biogas, Kreislaufwirtschaft und Energie, Weimar (Germany); Liebetrau, Jan [Deutsches Biomasseforschungszentrum (DBFZ), Leipzig (Germany); Fassauer, Burkhardt [Fraunhofer-Institut fuer Keramische Technologien und Systeme (IKTS), Hermsdorf (Germany); Nelles, Michael (ed.) [Rostock Univ. (Germany). Lehrstuhl fuer Abfall- und Stoffstromwirtschaft

2015-07-01

The biogas conference in Dresden will be held for the tenth time and is still the only conference in Germany, which focuses on the production of biogas solely from waste. This year, the implementation of paragraph 11 of the Recycling and Waste Management Act and the amendment of the Renewable Energies Act (EEG) in 2014, the chances of the waste management biogas technology will be spotlighted here. The efficiency and wise use of the end products of the biogas production - the biogas and fermentation residues are equally critical for the success of biogas technology as the emission reduction of biogas plants. In this context, the biogas technology will also be dependent in the future on legal requirements and funding instruments such as the EEG. For the technical implementation, the development of reliable system concepts with specific sinking biogas and electricity supply costs and with greater flexibility in terms of launching needs-based biogas and electricity production. The contributions in this paper discuss possible solutions and implementations from the perspective of politics, associations, research and practice. Innovative topics will be discussed, which will be decisive for the future of biogas production from organic wastes. [German] Die Biogastagung in Dresden findet zum zehnten Mal statt und ist nach wie vor die einzige Tagung in Deutschland, welche die Biogaserzeugung ausschliesslich aus Reststoffen thematisiert. In diesem Jahr sollen vor dem Hintergrund der Umsetzung des paragraph 11 des Kreislaufwirtschaftswirtschaftsgesetzes und der Novellierung des EEG 2014 die Chancen der abfallwirtschaftlichen Biogastechnologie beleuchtet werden. Die effiziente und sinnvolle Nutzung der Endprodukte der Biogaserzeugung - des Biogases und des Gaerrests sind ebenso entscheidend fuer den Erfolg der Biogastechnologie wie die Emissionsminderung aus Biogasanlagen. In diesem Zusammenhang wird die Biogastechnologie auch zukuenftig auf gesetzliche Vorgaben und

Biochemistry and physiology of anaerobic bacteria

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-05-18

We welcome you to The Power of Anaerobes. This conference serves two purposes. One is to celebrate the life of Harry D. Peck, Jr.,who was born May 18, 1927 and would have celebrated his 73rd birthday at this conference. He died November 20, 1998. The second is to gather investigators to exchange views within the realm of anaerobic microbiology, an area in which tremendous progress has been seen during recent years. It is sufficient to mention discoveries of a new form of life (the archaea), hyper or extreme thermophiles, thermophilic alkaliphiles and anaerobic fungi. With these discoveries has come a new realization about physiological and metabolic properties of microorganisms, and this in turn has demonstrated their importance for the development, maintenance and sustenance of life on Earth.

Effect of chemo-mechanical disintegration on sludge anaerobic digestion for enhanced biogas production.

Science.gov (United States)

Kavitha, S; Pray, S Saji; Yogalakshmi, K N; Kumar, S Adish; Yeom, Ick-Tae; Banu, J Rajesh

2016-02-01

The effect of combined surfactant-dispersion pretreatment on dairy waste activated sludge (WAS) reduction in anaerobic digesters was investigated. The experiments were performed with surfactant, Sodium dodecyl sulfate (SDS) in the range of 0.01 to 0.1 g/g suspended solids (SS) and disperser with rpm of 5000-25,000. The COD (chemical oxygen demand) solubilization, suspended solids reduction, and biogas generation increased for an energy input of 7377 kJ/kg total solids (TS) (12,000 rpm, 0.04 g/g SS, and 30 min) and were found to be 38, 32, and 75 %, higher than that of control. The pretreated sludge improved the performance of semicontinuous anaerobic digesters of 4 L working volume operated at four different SRTs (sludge retention time). SRT of 15 days was found to be appropriate showing 49 and 51 % reduction in SS and volatile solids (VS), respectively. The methane yield of the pretreated sample was observed to be 50 mL/g VS removed which was observed to be comparatively higher than the control (12 mL/g VS removed) at optimal SRT of 15 days. To the best of the authors' knowledge, this study is the first to be reported and not yet been documented in literature.

Prospects of Anaerobic Digestion Technology in China

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

As the world's largest developing country, China must face the problem of managing municipal solid waste, and the challenge of organic waste disposal is even more serious. Considering the characteristics of traditional waste disposal technologies and the subsequent secondary pollution, anaerobic digestion has various advantages such as reduction in the land needed for disposal and preservation of environmental quality. In light of the energy crisis, this paper focuses on the potential production of biogas from biowaste through anaerobic digestion processes, the problems incurred by the waste collection system, and the efficiency of the anaerobic digestion process. Use of biogas in a combined heat and power cogeneration system is also discussed. Finally, the advantages of anaerobic digestion technology for the Chinese market are summarized. The anaerobic digestion is suggested to be a promising treating technology for the organic wastes in China.

The Use of Gas Chromatography for Biogas Analysis

Science.gov (United States)

Andersen, Amanda; Seeley, John; Aurandt, Jennifer

2010-04-01

Energy from natural gas accounts for 24 percent of energy consumed in the US. Natural gas is a robust form of energy which is rich in methane content and is low in impurities. This quality suggests that it is a very clean and safe gas; it can be used in providing heat, a source for cooking, and in powering vehicles. The downside is that it is a non-renewable resource. On the contrary, methane rich gas that is produced by the breakdown of organic material in an anaerobic environment, called biogas, is a renewable energy source. This research focuses on the gas analysis portion of the creation of the anaerobic digestion and verification laboratory where content and forensic analysis of biogas is performed. Gas Chromatography is implemented as the optimal analytical tool for quantifying the components of the biogas including methane, carbon dioxide, hydrogen sulfide and siloxanes. In addition, the problems associated with the undesirable components are discussed. Anaerobic digestion of primary sludge has consistently produced about 55 percent methane; future goals of this research include studying different substrates to increase the methane yield and decrease levels of impurities in the gas.

A fuzzy logic approach to control anaerobic digestion.

Science.gov (United States)

Domnanovich, A M; Strik, D P; Zani, L; Pfeiffer, B; Karlovits, M; Braun, R; Holubar, P

2003-01-01

One of the goals of the EU-Project AMONCO (Advanced Prediction, Monitoring and Controlling of Anaerobic Digestion Process Behaviour towards Biogas Usage in Fuel Cells) is to create a control tool for the anaerobic digestion process, which predicts the volumetric organic loading rate (Bv) for the next day, to obtain a high biogas quality and production. The biogas should contain a high methane concentration (over 50%) and a low concentration of components toxic for fuel cells, e.g. hydrogen sulphide, siloxanes, ammonia and mercaptanes. For producing data to test the control tool, four 20 l anaerobic Continuously Stirred Tank Reactors (CSTR) are operated. For controlling two systems were investigated: a pure fuzzy logic system and a hybrid-system which contains a fuzzy based reactor condition calculation and a hierachial neural net in a cascade of optimisation algorithms.

Enhanced biogas production from anaerobic co-digestion of pig slurry and horse manure with mechanical pre-treatment.

Science.gov (United States)

Lopes, Madalena; Baptista, Patrícia; Duarte, Elizabeth; Moreira, António L N

2018-01-02

Enhanced biogas production from anaerobic co-digestion of pig slurry and horse manure with mechanical pre-treatment. In this study, co-digestion of horse manure and pig slurry was investigated in a continuously stirred tank reactor, with a mechanical pre-treatment. Experiments were conducted at 37°C, with hydraulic retention times of 23 days and increasing shares of horse manure, corresponding to different horse manure to pig slurry ratios (HM:PS) equal to 0:100, 10:90, 13:87 and 20:80, in terms of percentage of inlet volatile solids (%VS inlet). The results show that the best synergetic effect between the microbial consortia of pig slurry and the high Carbon to Nitrogen ratio (C/N) of horse manure is obtained for the mixture of 20:80%VS inlet, yielding the highest specific methane production (SMP = 142.6 L kg TCOD -1 ) and the highest soluble chemical oxygen demand (SCOD) reduction (68.5%), due to the high volatile dissolved solids content and soluble chemical oxygen demand to total chemical oxygen demand ratio (SCOD/TCOD). Thus, co-digestion of horse manure and pig slurry is shown to be a promising approach for biogas production and as a waste treatment solution. Furthermore, the analysis provides a methodology for the pre-treatment of these substrates and to investigate into the best combination for improved biogas production.

Monitoring of biogas test plants

DEFF Research Database (Denmark)

Holm-Nielsen, Jens Bo; Esbensen, Kim H.

2011-01-01

realistic bioreactor scales, it is necessary to obtain a fairly constant level of volatile fatty acid (VFA) concentration, which furthers a stable biogas production. Uncontrolled VFA contents have a significant negative impact on biogas production; VFA concentrations should not exceed 5–6000 mg/L lest......Most studies reported in the literature have investigated near infrared spectroscopy (NIR) in laboratory-scale or minor pilot biogas plants only; practically no other studies have examined the potential for meso-scale/full-scale on-line process monitoring. The focus of this study is on a meso......-scale biogas test plant implementation of process analytical technologies (PAT) to develop multivariate calibration/prediction models for anaerobic digestion (AD) processes. A 150 L bioreactor was fitted with a recurrent loop at which NIR spectroscopy and attendant reference sampling were carried out. In all...

Continuous thermal hydrolysis and energy integration in sludge anaerobic digestion plants.

Science.gov (United States)

Fdz-Polanco, F; Velazquez, R; Perez-Elvira, S I; Casas, C; del Barrio, D; Cantero, F J; Fdz-Polanco, M; Rodriguez, P; Panizo, L; Serrat, J; Rouge, P

2008-01-01

A thermal hydrolysis pilot plant with direct steam injection heating was designed and constructed. In a first period the equipment was operated in batch to verify the effect of sludge type, pressure and temperature, residence time and solids concentration. Optimal operation conditions were reached for secondary sludge at 170 degrees C, 7 bar and 30 minutes residence time, obtaining a disintegration factor higher than 10, methane production increase by 50% and easy centrifugation In a second period the pilot plant was operated working with continuous feed, testing the efficiency by using two continuous anaerobic digester operating in the mesophilic and thermophilic range. Working at 12 days residence time, biogas production increases by 40-50%. Integrating the energy transfer it is possible to design a self-sufficient system that takes advantage of this methane increase to produce 40% more electric energy. (c) IWA Publishing 2008.

Mechanism and Effect of Temperature on Variations in Antibiotic Resistance Genes during Anaerobic Digestion of Dairy Manure