WorldWideScience

Sample records for biogas reactor performance

  1. Reactor performances and microbial communities of biogas reactors: effects of inoculum sources.

    Science.gov (United States)

    Han, Sheng; Liu, Yafeng; Zhang, Shicheng; Luo, Gang

    2016-01-01

    Anaerobic digestion is a very complex process that is mediated by various microorganisms, and the understanding of the microbial community assembly and its corresponding function is critical in order to better control the anaerobic process. The present study investigated the effect of different inocula on the microbial community assembly in biogas reactors treating cellulose with various inocula, and three parallel biogas reactors with the same inoculum were also operated in order to reveal the reproducibility of both microbial communities and functions of the biogas reactors. The results showed that the biogas production, volatile fatty acid (VFA) concentrations, and pH were different for the biogas reactors with different inocula, and different steady-state microbial community patterns were also obtained in different biogas reactors as reflected by Bray-Curtis similarity matrices and taxonomic classification. It indicated that inoculum played an important role in shaping the microbial communities of biogas reactor in the present study, and the microbial community assembly in biogas reactor did not follow the niche-based ecology theory. Furthermore, it was found that the microbial communities and reactor performances of parallel biogas reactors with the same inoculum were different, which could be explained by the neutral-based ecology theory and stochastic factors should played important roles in the microbial community assembly in the biogas reactors. The Bray-Curtis similarity matrices analysis suggested that inoculum affected more on the microbial community assembly compared to stochastic factors, since the samples with different inocula had lower similarity (10-20 %) compared to the samples from the parallel biogas reactors (30 %).

  2. New steady-state microbial community compositions and process performances in biogas reactors induced by temperature disturbances

    DEFF Research Database (Denmark)

    Luo, Gang; De Francisci, Davide; Kougias, Panagiotis

    2015-01-01

    that stochastic factors had a minor role in shaping the profile of the microbial community composition and activity in biogas reactors. On the contrary, temperature disturbance was found to play an important role in the microbial community composition as well as process performance for biogas reactors. Although...... three different temperature disturbances were applied to each biogas reactor, the increased methane yields (around 10% higher) and decreased volatile fatty acids (VFAs) concentrations at steady state were found in all three reactors after the temperature disturbances. After the temperature disturbance...... in shaping the profile of the microbial community composition and activity in biogas reactors. New steady-state microbial community profiles and reactor performances were observed in all the biogas reactors after the temperature disturbance....

  3. Methanogenesis in Thermophilic Biogas Reactors

    DEFF Research Database (Denmark)

    Ahring, Birgitte Kiær

    1995-01-01

    Methanogenesis in thermophilic biogas reactors fed with different wastes is examined. The specific methanogenic activity with acetate or hydrogen as substrate reflected the organic loading of the specific reactor examined. Increasing the loading of thermophilic reactors stabilized the process as ....... Experiments using biogas reactors fed with cow manure showed that the same biogas yield found at 550 C could be obtained at 610 C after a long adaptation period. However, propionate degradation was inhibited by increasing the temperature.......Methanogenesis in thermophilic biogas reactors fed with different wastes is examined. The specific methanogenic activity with acetate or hydrogen as substrate reflected the organic loading of the specific reactor examined. Increasing the loading of thermophilic reactors stabilized the process...... as indicated by a lower concentration of volatile fatty acids in the effluent from the reactors. The specific methanogenic activity in a thermophilic pilot-plant biogas reactor fed with a mixture of cow and pig manure reflected the stability of the reactor. The numbers of methanogens counted by the most...

  4. Effect of post-digestion temperature on serial CSTR biogas reactor performance

    DEFF Research Database (Denmark)

    Boe, Kanokwan; Karakashev, Dimitar Borisov; Trably, Eric

    2009-01-01

    The effect of post-digestion temperature on a lab-scale serial continuous-flow stirred tank reactor (CSTR) system performance was investigated. The system consisted of a main reactor operated at 55 degrees C with hydraulic retention time (HRT) of 15 days followed by post-digestion reactors with HRT...

  5. 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...

  6. Effect of biogas sparging on the performance of bio-hydrogen reactor over a long-term operation

    Science.gov (United States)

    Nualsri, Chatchawin; Kongjan, Prawit; Imai, Tsuyoshi

    2017-01-01

    This study aimed to enhance hydrogen production from sugarcane syrup by biogas sparging. Two-stage continuous stirred tank reactor (CSTR) and upflow anaerobic sludge blanket (UASB) reactor were used to produce hydrogen and methane, respectively. Biogas produced from the UASB was used to sparge into the CSTR. Results indicated that sparging with biogas increased the hydrogen production rate (HPR) by 35% (from 17.1 to 23.1 L/L.d) resulted from a reduction in the hydrogen partial pressure. A fluctuation of HPR was observed during a long term monitoring because CO2 in the sparging gas and carbon source in the feedstock were consumed by Enterobacter sp. to produce succinic acid without hydrogen production. Mixed gas released from the CSTR after the sparging can be considered as bio-hythane (H2+CH4). In addition, a continuous sparging biogas into CSTR release a partial pressure in the headspace of the methane reactor. In consequent, the methane production rate is increased. PMID:28207755

  7. Performance and membrane fouling of a step-fed submerged membrane sequencing batch reactor treating swine biogas digestion slurry.

    Science.gov (United States)

    Han, Zhiying; Chen, Shixia; Lin, Xiaochang; Yu, Hongjun; Duan, Li'an; Ye, Zhangying; Jia, Yanbo; Zhu, Songming; Liu, Dezhao

    2018-01-02

    To identify the performance of step-fed submerged membrane sequencing batch reactor (SMSBR) treating swine biogas digestion slurry and to explore the correlation between microbial metabolites and membrane fouling within this novel reactor, a lab-scale step-fed SMSBR was operated under nitrogen loading rate of 0.026, 0.052 and 0.062 g NH 4 + -N (gVSS·d) -1 . Results show that the total removal efficiencies for NH 4 + -N, total nitrogen and chemical oxygen demand in the reactor (>94%, >89% and >97%, respectively) were high during the whole experiment. However, the cycle removal efficiency of NH 4 + -N decreased significantly when the nitrogen loading rate was increased to 0.062 g NH 4 + -N (gVSS·d) -1 . The total removal efficiency of total phosphorus in the step-fed SMSBR was generally higher than 75%, though large fluctuations were observed during the experiments. In addition, the concentrations of microbial metabolites, i.e., soluble microbial products (SMP) and extracellular polymeric substances (EPS) from activated sludge increased as nitrogen loading rate increased, both showing quadratic equation correlations with viscosity of the mixed liquid in the step-fed SMSBR (both R 2 > 0.90). EPS content was higher than SMP content, while protein (PN) was detected as the main component in both SMP and EPS. EPS PN was found to be well correlated with transmembrane pressure, membrane flux and the total membrane fouling resistance. Furthermore, the three-dimensional excitation-emission matrix fluorescence spectroscopy results suggested the tryptophan-like protein as one of the main contributors to the membrane fouling. Overall, this study showed that the step-fed SMSBR could be used to treat swine digestion slurry at nitrogen loading rate of 0.052 g NH 4 + -N (gVSS·d) -1 , and the control strategy of membrane fouling should be developed based on reducing the tryptophan-like PN in EPS.

  8. Realtime control of biogas reactors. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    Poulsen, Allan K.

    2010-12-15

    In this project several online methods were connected to a biogas pilot plant designed and built by Xergi A/S (Foulum, Denmark). The pilot plant was composed of two stainless steel tanks used as substrate storage and as digester, respectively. The total volume of the reactor tank was 300 L, the working volume 200 L and the headspace volume 100 L. The process temperature in the biogas reactor was maintained at 52 {+-} 0.5 deg. C during normal operating conditions. The biogas production was measured with a flow meter and a controller was used for automatic control of temperature, effluent removal, feeding and for data logging. A NIRS (near infrared spectrometer) was connected to a recurrent loop measuring on the slurry while a {mu}-GC (micro gas chromatograph) and a MIMS (membrane inlet mass spectrometer) enabled online measurements of the gas phase composition. During the project period three monitoring campaigns were accomplished. The loading rate of the biogas reactor was increased stepwise during the periods while the process was monitored. In the first two campaigns the load was increased by increasing the mass of organic material added to the reactor each day. However, this increasing amount changed the retention time in the reactor and in order to keep the retention time constant an increasing amount of inhibitor of the microbial process was instead added in the third campaign and as such maintaining a constant organic load mass added to the reactor. The effect is similar to an increase in process load, while keeping the load of organic material and hence retention time constant. Methods have been developed for the following online technologies and each technology has been evaluated with regard to future use as a tool for biogas process monitoring: 1) {mu}-GC was able to quantitative monitor important gas phase parameters in a reliable, fast and low-maintenance way. 2) MIMS was able to quantitative monitor gas phase composition in a reliable and fast manner

  9. Biogas production from UASB and polyurethane carrier reactors treating sisal processing wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Rubindamayugi, M S.T.; Salakana, L K.P. [Univ. of Dar es Salaam, Faculty of Science, Applied Microbiology Unit (Tanzania, United Republic of)

    1998-12-31

    The fundamental benefits which makes anaerobic digestion technology (ADT) attractive to the poor developing include the low cost and energy production potential of the technology. In this study the potential of using UASB reactor and Polyurethane Carrier Reactor (PCR) as pollution control and energy recovery systems from sisal wastewater were investigated in lab-scale reactors. The PCR demonstrated the shortest startup period, whereas the UASB reactor showed the highest COD removal efficiency 79%, biogas production rate (4.5 l biogas/l/day) and process stability than the PCR under similar HRT of 15 hours and OLR of 8.2 g COD/l/day. Both reactor systems became overloaded at HRT of 6 hours and OLR of 15.7 g COD/l/day, biogas production ceased and reactors acidified to pH levels which are inhibiting to methanogenesis. Based on the combined results on reactor performances, the UASB reactor is recommended as the best reactor for high biogas production and treatment efficiency. It was estimated that a large-scale UASB reactor can be designed under the same loading conditions to produce 2.8 m{sup 3} biogas form 1 m{sup 3} of wastewater of 5.16 kg COD/m{sup 3}. Wastewater from one decortication shift can produce 9,446 m{sup 3} og biogas. The energy equivalent of such fuel energy is indicated. (au)

  10. Biogas production from UASB and polyurethane carrier reactors treating sisal processing wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Rubindamayugi, M.S.T.; Salakana, L.K.P. [Univ. of Dar es Salaam, Faculty of Science, Applied Microbiology Unit (Tanzania, United Republic of)

    1997-12-31

    The fundamental benefits which makes anaerobic digestion technology (ADT) attractive to the poor developing include the low cost and energy production potential of the technology. In this study the potential of using UASB reactor and Polyurethane Carrier Reactor (PCR) as pollution control and energy recovery systems from sisal wastewater were investigated in lab-scale reactors. The PCR demonstrated the shortest startup period, whereas the UASB reactor showed the highest COD removal efficiency 79%, biogas production rate (4.5 l biogas/l/day) and process stability than the PCR under similar HRT of 15 hours and OLR of 8.2 g COD/l/day. Both reactor systems became overloaded at HRT of 6 hours and OLR of 15.7 g COD/l/day, biogas production ceased and reactors acidified to pH levels which are inhibiting to methanogenesis. Based on the combined results on reactor performances, the UASB reactor is recommended as the best reactor for high biogas production and treatment efficiency. It was estimated that a large-scale UASB reactor can be designed under the same loading conditions to produce 2.8 m{sup 3} biogas form 1 m{sup 3} of wastewater of 5.16 kg COD/m{sup 3}. Wastewater from one decortication shift can produce 9,446 m{sup 3} og biogas. The energy equivalent of such fuel energy is indicated. (au)

  11. 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...

  12. Thermal pretreatment of the solid fraction of manure: Impact on the biogas reactor performance and microbial community

    DEFF Research Database (Denmark)

    Mladenovska, Z; Hartmann, H.; Kvist, T.

    2006-01-01

    Application of thermal treatment at 100-140 degrees C as a pretreatment method prior to anaerobic digestion of a mixture of cattle and swine manure was investigated. In a batch test, biogasification of manure with thermally pretreated solid fraction proceeded faster and resulted in the increase...... of methane yield. The performances of two thermophilic continuously stirred tank reactors (CSTR) treating manure with solid fraction pretreated for 40 minutes at 140 degrees C and non-treated manure were compared. The digester fed with the thermally pretreated manure had a higher methane productivity...... and butyrate - was low. The kinetic parameters of the VFA conversion revealed a reduced affinity of the microbial community from the CSTR fed with thermally pre-treated manure for acetate, propionate and butyrate. The bacterial and archaeal populations identified by t-RLFP analysis of 16S rRNA genes were found...

  13. Anaerobic digestion of manure and mixture of manure with lipids: biogas reactor performance and microbial community analysis

    DEFF Research Database (Denmark)

    Mladenovska, Zuzana; Dabrowski, Slawomir; Ahring, Birgitte Kiær

    2003-01-01

    Anaerobic digestion of cattle manure and a mixture of cattle manure with glycerol trioleate (GTO) was studied in lab-scale, continuously stirred tank reactors (CSTR) operated at 37degreesC. The reactor. codigesting manure and lipids exhibited a significantly higher specific methane yield and a hi......Anaerobic digestion of cattle manure and a mixture of cattle manure with glycerol trioleate (GTO) was studied in lab-scale, continuously stirred tank reactors (CSTR) operated at 37degreesC. The reactor. codigesting manure and lipids exhibited a significantly higher specific methane yield...

  14. 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.)

  15. Biogas engine performance estimation using ANN

    Directory of Open Access Journals (Sweden)

    Yusuf Kurtgoz

    2017-12-01

    Full Text Available Artificial neural network (ANN method was used to estimate the thermal efficiency (TE, brake specific fuel consumption (BSFC and volumetric efficiency (VE values of a biogas engine with spark ignition at different methane (CH4 ratios and engine load values. For this purpose, the biogas used in the biogas engine was produced by the anaerobic fermentation method from bovine manure and different CH4 contents (51%, 57%, 87% were obtained by purification of CO2 and H2S. The data used in the ANN models were obtained experimentally from a 4-stroke four-cylinder, spark ignition engine, at constant speed for different load and CH4 ratios. Using some of the obtained experimental data, ANN models were developed, and the rest was used to test the developed models. In the ANN models, the CH4 ratio of the fuel, engine load, inlet air temperature (Tin, air fuel ratio and the maximum cylinder pressure are chosen as the input parameters. TE, BSFC and VE are used as the output parameters. Root mean square error (RMSE, mean absolute percentage error (MAPE and correlation coefficient (R performance indicators are used to compare measured and predicted values. It has been shown that ANN models give good results in spark ignition biogas engines with high correlation and low error rates for TE, BSFC and VE values.

  16. Foam suppression in overloaded manure-based biogas reactors using antifoaming agents

    DEFF Research Database (Denmark)

    Kougias, Panagiotis; Boe, Kanokwan; Tsapekos, Panagiotis

    2014-01-01

    Foam control is an imperative need in biogas plants, as foaming is a major operational problem. In the present study, the effect of oils (rapeseed oil, oleic acid, and octanoic acid) and tributylphosphate on foam reduction and process performance in batch and continuous manure-based biogas reactors...... was investigated. The compounds were tested in dosages of 0.05%, 0.1% and 0.5% v/vfeed. The results showed that rapeseed oil was most efficient to suppress foam at the dosage of 0.05% and 0.1% v/vfeed, while octanoic acid was most efficient to suppress foam at dosage of 0.5% v/vfeed. Moreover, the addition...... of rapeseed oil also increased methane yield. In contrast, tributylphosphate, which was very efficient antifoam, was found to be inhibitory to the biogas process. © 2013 Elsevier Ltd....

  17. Antifoaming effect of chemical compounds in manure biogas reactors

    DEFF Research Database (Denmark)

    Kougias, Panagiotis; Tsapekos, Panagiotis; Boe, Kanokwan

    2013-01-01

    A precise and efficient antifoaming control strategy in bioprocesses is a challenging task as foaming is a very complex phenomenon. Nevertheless, foam control is necessary, as foam is a major operational problem in biogas reactors. In the present study, the effect of 14 chemical compounds on foam......), siloxanes (polydimethylsiloxane) and ester (tributylphosphate) were found to be the most efficient compounds to suppress foam. The efficiency of antifoamers was dependant on their physicochemical properties and greatly correlated to their chemical characteristics for dissolving foam. The antifoamers were...... more efficient in reducing foam when added directly into the liquid phase rather than added in the headspace of the reactor....

  18. Counteracting foaming caused by lipids or proteins in biogas reactors using rapeseed oil or oleic acid as antifoaming agents

    DEFF Research Database (Denmark)

    Kougias, Panagiotis; Boe, Kanokwan; Einarsdottir, E. S.

    2015-01-01

    in biogas reactors fed with protein or lipid rich substrates. The results showed that both antifoams efficiently suppressed foaming. Moreover rapeseed oil resulted in stimulation of the biogas production. Finally, it was reckoned that the chemical structure of lipids, and more specifically their carboxylic...... deterioration of the methanogenic process. Many commercial antifoams are derivatives of fatty acids or oils. However, it is well known that lipids can induce foaming in manure based biogas plants. This study aimed to elucidate the effect of rapeseed oil and oleic acid on foam reduction and process performance...

  19. Two-year microbial adaptation during hydrogen-mediated biogas upgrading process in a serial reactor configuration

    DEFF Research Database (Denmark)

    Treu, Laura; Kougias, Panagiotis; de Diego-Díaz, B.

    2018-01-01

    Microbial dynamics in an upgrading biogas reactor system undergoing a more than two years-period at stable operating conditions were explored. The carbon dioxide generated during biomass degradation in the first reactor of the system was converted to methane into the secondary reactor by addition...... of external hydrogen. Considering the overall efficiency, the long-term operation period resulted in an improved biogas upgrading performance (99% methane content). However, a remarkable accumulation of acetate was revealed, indicating the enhancement of homoacetogenic activity. For this reason, a shift...

  20. Diversity of archaea and bacteria in a biogas reactor fed with ...

    African Journals Online (AJOL)

    Diversity of archaea and bacteria in a biogas reactor fed with Pennisetum sinese ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING ... rumen microbial community in a biogas reactor by 16S rRNA gene analysis, ...

  1. A novel bioinformatic strategy to characterise microbial communities in biogas reactors

    DEFF Research Database (Denmark)

    Treu, Laura; Campanaro, Stefano; De Francisci, Davide

    2014-01-01

    16S hypervariable regions, especially when working with the not high quality very short reads characteristics of next generation sequencers (Mande S.S. et al., 2012). Previous works analysed the microbial community composition in biogas reactors via 16S rDNA sequencing (Luo, G. et al., 2013; Werner......, J.J. et al., 2011). For this reason we developed a bioinformatics strategy in order to create a tool to review the generated dataset and to obtain a more strict control on the bacterial composition at the species level, with estimation of its reliability. The program perform local similarity search...... in the same genus, while others give multiple matches with the same probability. The software was used to analyse samples taken during the digestion process in three independent biogas reactors continuously fed with raw cattle manure. Among the most represented (>1%) considering the relative abundance...

  2. Bioaugmentation of Syntrophic Acetate-Oxidizing Culture in Biogas Reactors Exposed to Increasing Levels of Ammonia

    Science.gov (United States)

    Westerholm, Maria; Levén, Lotta

    2012-01-01

    The importance of syntrophic acetate oxidation for process stability in methanogenic systems operating at high ammonia concentrations has previously been emphasized. In this study we investigated bioaugmentation of syntrophic acetate-oxidizing (SAO) cultures as a possible method for decreasing the adaptation period of biogas reactors operating at gradually increased ammonia concentrations (1.5 to 11 g NH4+-N/liter). Whole stillage and cattle manure were codigested semicontinuously for about 460 days in four mesophilic anaerobic laboratory-scale reactors, and a fixed volume of SAO culture was added daily to two of the reactors. Reactor performance was evaluated in terms of biogas productivity, methane content, pH, alkalinity, and volatile fatty acid (VFA) content. The decomposition pathway of acetate was analyzed by isotopic tracer experiments, and population dynamics were monitored by quantitative PCR analyses. A shift in dominance from aceticlastic methanogenesis to SAO occurred simultaneously in all reactors, indicating no influence by bioaugmentation on the prevailing pathway. Higher abundances of Clostridium ultunense and Tepidanaerobacter acetatoxydans were associated with bioaugmentation, but no influence on Syntrophaceticus schinkii or the methanogenic population was distinguished. Overloading or accumulation of VFA did not cause notable dynamic effects on the population. Instead, the ammonia concentration had a substantial impact on the abundance level of the microorganisms surveyed. The addition of SAO culture did not affect process performance or stability against ammonia inhibition, and all four reactors deteriorated at high ammonia concentrations. Consequently, these findings further demonstrate the strong influence of ammonia on the methane-producing consortia and on the representative methanization pathway in mesophilic biogas reactors. PMID:22923397

  3. Solutions for Foaming Problems in Biogas Reactors Using Natural Oils or Fatty Acids as Defoamers

    DEFF Research Database (Denmark)

    Kougias, Panagiotis; Boe, Kanokwan; Angelidaki, Irini

    2015-01-01

    Foaming is one of the most common and important problems in biogas plants, leading to severe operational, economical, and environmental drawbacks. Because addition of easily degradable co-substrates for boosting the biogas production can suddenly raise the foaming problem, the full-scale biogas...... results from our previous extensive research along with some unpublished data on defoaming by rapeseed oil and oleic acid in manure-based biogas reactors. It was found that both compounds exhibited remarkable defoaming efficiency ranging from 30 to 57% in biogas reactors suffering from foaming problems...... promoted by the addition of protein, lipid, or carbohydrate co-substrates. However, in most cases, the defoaming efficiency of rapeseed oil was greater than that of oleic acid, and therefore, rapeseed oil is recommended to be used in biogas reactors to solve foaming problems....

  4. 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.

  5. Biogas and methane production in an aerobic reactor; Produccion de biogas y metano en un reactor anaerobio UASB

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez Borges, E.; Mendez Novelo, R.; Magana Pietra, A.

    1998-06-01

    On the basis of the results obtained during the evaluation of an anaerobic digester in treating pig farm sewage, mathematical models were constructed predicting the system`s efficiency in producing biogas from such waste, and the methane content of this gas, as a function of the influent`s hydraulic retention time(HRT) and chemical oxygen demand (COD). The experimental device consisted of a UASB reactor at the bottom and a high-rate sedimentator at the top with a total operational volume of 534 litres. The results obtained to establish the critical operating parameters are reported. The production of biogas was 259 1/m``3 and methane 217 1/m``3 with an HRT of 1.3 days when a load of 3.1 kg-COD/m``3 day was applied. The mathematical models presented analyses biogas production as a variable response and the influents` HRT and COD as independent variables to assess the efficiency of the system. (Author) 13 refs.

  6. Simultaneous hydrogen utilization and in situ biogas upgrading in an anaerobic reactor

    DEFF Research Database (Denmark)

    Luo, Gang; Johansson, Sara; Boe, Kanokwan

    2012-01-01

    . The methane production rate of the reactor with H2 addition was 22% higher, compared to the control reactor only fed with manure. The CO2 content in the produced biogas was only 15%, while it was 38% in the control reactor. However, the addition of hydrogen resulted in increase of pH (from 8.0 to 8.3) due......The possibility of converting hydrogen to methane and simultaneous upgrading of biogas was investigated in both batch tests and fully mixed biogas reactor, simultaneously fed with manure and hydrogen. Batch experiments showed that hydrogen could be converted to methane by hydrogenotrophic...

  7. EVALUATING HYDROGEN PRODUCTION IN BIOGAS REFORMING IN A MEMBRANE REACTOR

    Directory of Open Access Journals (Sweden)

    F. S. A. Silva

    2015-03-01

    Full Text Available Abstract Syngas and hydrogen production by methane reforming of a biogas (CH4/CO2 = 2.85 using carbon dioxide was evaluated in a fixed bed reactor with a Pd-Ag membrane in the presence of a nickel catalyst (Ni 3.31% weight/γ-Al2O3 at 773 K, 823 K, and 873 K and 1.01×105 Pa. Operation with hydrogen permeation at 873 K increased the methane conversion to approximately 83% and doubled the hydrogen yield relative to operation without hydrogen permeation. A mathematical model was formulated to predict the evolution of the effluent concentrations. Predictions based on the model showed similar evolutions for yields of hydrogen and carbon monoxide at temperatures below 823 K for operations with and without the hydrogen permeation. The hydrogen yield reached approximately 21% at 823 K and 47% at 873 K under hydrogen permeation conditions.

  8. Performance optimization of the Växtkraft biogas production plant

    International Nuclear Information System (INIS)

    Thorin, Eva; Lindmark, Johan; Nordlander, Eva; Odlare, Monica; Dahlquist, Erik; Kastensson, Jan; Leksell, Niklas; Pettersson, Carl-Magnus

    2012-01-01

    Highlights: ► Pre-treatment of ley crop can increase the biogas plant performance. ► Membrane filtration can increase the capacity of the biogas plant. ► Mechanical pre-treatment of the ley crop shows the highest energy efficiency. ► Using a distributor to spread the residues as fertilizer show promising results. -- Abstract: All over the world there is a strong interest and also potential for biogas production from organic residues as well as from different crops. However, to be commercially competitive with other types of fuels, efficiency improvements of the biogas production process are needed. In this paper, results of improvements studies done on a full scale co-digestion plant are presented. In the plant organic wastes from households and restaurants are mixed and digested with crops from pasture land. The areas for improvement of the plant addressed in this paper are treatment of the feed material to enhance the digestion rate, limitation of the ballast of organics in the water stream recirculated in the process, and use of the biogas plant residues at farms. Results from previous studies on pre-treatment and membrane filtration of recirculated process water are combined for an estimation of the total improvement potential. Further, the possibility of using neural networks to predict biogas production using historical data from the full-scale biogas plant was investigated. Results from an investigation using the process residues as fertilizer are also presented. The results indicate a potential to increase the biogas yield from the process with up to over 30% with pre-treatment of the feed and including membrane filtration in the process. Neural networks have the potential to be used for prediction of biogas production. Further, it is shown that the residues from biogas production can be used as fertilizers but that the emission of N 2 O from the fertilized soil is dependent on the soil type and spreading technology.

  9. biogas

    DEFF Research Database (Denmark)

    2015-01-01

    Functions for working with biogas data. Both low- and high-level functions are included for carrying out common tasks for analysis of biogas and related data. Molar mass and calculated oxygen demand (COD') can be determined from a chemical formula. Measured gas volume can be corrected for water...... vapor and to (possibly user-defined) standard temperature and pressure. Gas composition, cumulative production, or other variables can be interpolated to a specified time. Cumulative biogas and methane production (and rates) can be calculated using volumetric, manometric, or gravimetric methods for any...... be summarized in several different ways (e.g., omitting normalization) using the same function. Lastly, biogas and methane production can be predicted from substrate composition and additional, optional data....

  10. Modeling of Biogas Production Process from Cow Manure with Completely Stirred Tank Reactor under Semi Continuously Feeding

    Directory of Open Access Journals (Sweden)

    J Taghinazhad

    2018-03-01

    Full Text Available Introduction Anaerobic digestion (AD is a process of breaking down organic matter, such as manure, in the absence of oxygen by concerted action of various groups of anaerobic bacteria. The AD process generates biogas, an important renewable energy source that is composed mostly of methane (CH4, and carbon dioxide (CO2 which can be used as an energy source. Biogas originates from biogenic material and is therefore a type of biofuel. Enhancement of biogas production from cattle dung or animal wastes by co-digesting with crop residues like sugarcane stalk, maize stalks, rice straw, cotton stalks, wheat straw, water hyacinth, onion waste and oil palm fronds as well as with liquid waste effluent such as palm oil mill effluent. Nevertheless, the search for cost effective and environmentally friendly methods of enhancing biogas generation (i.e. biogas yield still needs to be further investigated. Many workers have studied the reaction kinetics of biogas production and developed kinetic models for the anaerobic digestion process. Objective of this study is to investigate the effect of biological additive using of organic loading rate (OLR in biogas production from cow dung. In addition, cumulative biogas production was simulated using logistic growth model, and modified Gompertz models, respectively. Materials and Methods The study was performed in 2015-2016 at the agricultural research center of Ardabil Province, Moghan (39.39 °N, 48.88° E. Fresh cow manure used for this research was collected from the research farm of the Institute for Animal Breeding and Animal Husbandry, Moghan. It was kept in 30 l containers at ambient temperature until fed to the reactors. In this study, experiments were conducted to investigate the biogas production from anaerobic digestion of cow manure (CM with effect of organic loading rate (OLR at mesophilic temperature (35°C±2 in a long time experiment with completely stirred tank reactor (CSTR under semi continuously

  11. 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

  12. Integrated biogas upgrading and hydrogen utilization in an anaerobic reactor containing enriched hydrogenotrophic methanogenic culture

    DEFF Research Database (Denmark)

    Luo, Gang; Angelidaki, Irini

    2012-01-01

    Biogas produced by anaerobic digestion, is mainly used in a gas motor for heat and electricity production. However, after removal of CO2, biogas can be upgraded to natural gas quality, giving more utilization possibilities, such as utilization as autogas, or distant utilization by using...... the existing natural gas grid. The current study presents a new biological method for biogas upgrading in a separate biogas reactor, containing enriched hydrogenotrophic methanogens and fed with biogas and hydrogen. Both mesophilic- and thermophilic anaerobic cultures were enriched to convert CO2 to CH4...... by addition of H2. Enrichment at thermophilic temperature (55°C) resulted in CO2 and H2 bioconversion rate of 320 mL CH4/(gVSS h), which was more than 60% higher than that under mesophilic temperature (37°C). Different dominant species were found at mesophilic- and thermophilic-enriched cultures, as revealed...

  13. Counteracting foaming caused by lipids or proteins in biogas reactors using rapeseed oil or oleic acid as antifoaming agents.

    Science.gov (United States)

    Kougias, P G; Boe, K; Einarsdottir, E S; Angelidaki, I

    2015-08-01

    Foaming is one of the major operational problems in biogas plants, and dealing with foaming incidents is still based on empirical practices. Various types of antifoams are used arbitrarily to combat foaming in biogas plants, but without any scientific support this action can lead to serious deterioration of the methanogenic process. Many commercial antifoams are derivatives of fatty acids or oils. However, it is well known that lipids can induce foaming in manure based biogas plants. This study aimed to elucidate the effect of rapeseed oil and oleic acid on foam reduction and process performance in biogas reactors fed with protein or lipid rich substrates. The results showed that both antifoams efficiently suppressed foaming. Moreover rapeseed oil resulted in stimulation of the biogas production. Finally, it was reckoned that the chemical structure of lipids, and more specifically their carboxylic ends, is responsible for their foam promoting or foam counteracting behaviour. Thus, it was concluded that the fatty acids and oils could suppress foaming, while salt of fatty acids could generate foam. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Comparative analysis of the microbial diversity in liquid and foaming layer in biogas reactors

    DEFF Research Database (Denmark)

    Campanaro, Stefano; Treu, Laura; Kougias, Panagiotis

    2014-01-01

    Foaming incidents have been recorded in many biogas plants causing severe operational, economical and environmental problems (Kougias et al., 2014). However, the foaming phenomenon in biogas reactors fed with agro-industrial wastes has not been extensively investigated, especially with respect...... to the microbial composition of the digesters (Moeller et al., 2012). In the cited literature, it has been reported that specific microorganisms, which are mainly filamentous (e.g. Gordonia species, Microthrix parvicella), are attached to biogas bubbles and transferred to the air/liquid interface of sludge...... was to investigate the microbial diversity in the liquid versus the foaming layer in manure-based biogas reactors suffering by foaming incidents in order to elucidate potential role and contribution of the microorganisms in foam promotion. The experimental work was carried out in three thermophilic continuous...

  15. Kinetic study on the effect of temperature on biogas production using a lab scale batch reactor.

    Science.gov (United States)

    Deepanraj, B; Sivasubramanian, V; Jayaraj, S

    2015-11-01

    In the present study, biogas production from food waste through anaerobic digestion was carried out in a 2l laboratory-scale batch reactor operating at different temperatures with a hydraulic retention time of 30 days. The reactors were operated with a solid concentration of 7.5% of total solids and pH 7. The food wastes used in this experiment were subjected to characterization studies before and after digestion. Modified Gompertz model and Logistic model were used for kinetic study of biogas production. The kinetic parameters, biogas yield potential of the substrate (B), the maximum biogas production rate (Rb) and the duration of lag phase (λ), coefficient of determination (R(2)) and root mean square error (RMSE) were estimated in each case. The effect of temperature on biogas production was evaluated experimentally and compared with the results of kinetic study. The results demonstrated that the reactor with operating temperature of 50°C achieved maximum cumulative biogas production of 7556ml with better biodegradation efficiency. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Biogas upgrading by injection of hydrogen in a two-stage Continuous Stirred-Tank Reactor system

    DEFF Research Database (Denmark)

    Bassani, Ilaria; Kougias, Panagiotis; Treu, Laura

    An innovative method for biogas upgrading (i.e. CH4 content more than 90%) combines the coupling of H2, which could be produced by water electrolysis using surplus renewable electricity produced from wind mills, with the CO2 of the biogas. CO2 is biologically converted to CH4 by hydrogenotrophic....... It was shown that after the H2 addition, the CH4 rate increased by 45%, resulting in an average CH4 content of approximately 85%, with a maximum of 93.9%. The increase of the pH to 8.5, due to the CO2 conversion, was not an inhibitory factor, demonstrating the adaptation of microorganisms to these pH levels...... methanogens. In this study, a novel serial biogas reactor system is presented, in which the produced biogas from the first stage reactor was introduced in the second stage, where also H2 was injected. The effects of the H2 addition on the process performance and on the microbial community were investigated...

  17. Energy performance and consumption for biogas heat pump air conditioner

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhenjun [Architectural Engineering College, Qingdao Agricultural University, 266109 (China); Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Tianjin University, Tianjin, 300072 (China); Wu, Huaizhi; Wu, Meiling [Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Tianjin University, Tianjin, 300072 (China)

    2010-12-15

    Biogas engine-driven heat pump air conditioner is a new-style system which includes biogas engine-driven heat pump, primary heat exchanger, second heat exchanger, sprayed room and fans, pumps, etc. In summertime, the air can be reheated by the waste heat water from the biogas engine in the system, while the air can be reheated and humidified by the waste heat water in winter. Reducing or displacing electrical heating requirements can achieve the great opportunity for significant energy savings. This paper, therefore, aims to improve the energy performance of the AC system by using the waste heat from the biogas engine. The mathematic model was used to research the BHPAC. Explicitly, we investigated the influence of various factors including the outdoor air temperature and humidity in summer and winter. Results show that the biogas engine-driven heat pump air conditioner can save more energy than the electrical power heat pump. In summer, the minimum for percentage of primary energy saving for BHPAC is over 25%. With the outdoor air dry-bulb temperature and the relative humidity rises, the saving energy percentage rises. In winter, the minimum for percentage of primary energy saving for BHPAC is 37%. The more the outdoor air relative humidity of the outdoor air decreases, the more the BHPAC saves energy. It is proved that the system which is a highly actively fully utilizing energy technology has good partial load characteristic and good effects of energy saving. (author)

  18. Two Stage Anaerobic Reactor Design and Treatment To Produce Biogas From Mixed Liquor of Vegetable Waste

    Science.gov (United States)

    Budiastuti, H.; Ghozali, M.; Wicaksono, H. K.; Hadiansyah, R.

    2018-01-01

    Municipal solid waste has become a common challenged problem to be solved for developing countries including Indonesia. Municipal solid waste generating is always bigger than its treatment to reduce affect of environmental pollution. This research tries to contribute to provide an alternative solution to treat municipal solid waste to produce biogas. Vegetable waste was obtained from Gedebage Market, Bandung and starter as a source of anaerobic microorganisms was cow dung obtained from a cow farm in Lembang. A two stage anaerobic reactor was designed and built to treat the vegetable waste in a batch run. The capacity of each reactor is 20 liters but its active volume in each reactor is 15 liters. Reactor 1 (R1) was fed up with mixture of filtered blended vegetable waste and water at ratio of 1:1 whereas Reactor 2 (R2) was filled with filtered mixed liquor of cow dung and water at ratio of 1:1. Both mixtures were left overnight before use. Into R1 it was added EM-4 at concentration of 10%. pH in R1 was maintained at 5 - 6.5 whereas pH in R1 was maintained at 6.5 - 7.5. Temperature of reactors was not maintained to imitate the real environmental temperature. Parameters taken during experiment were pH, temperature, COD, MLVSS, and composition of biogas. The performance of reactor built was shown from COD efficiencies reduction obtained of about 60% both in R1 and R2, pH average in R1 of 4.5 ± 1 and R2 of 7 ± 0.6, average temperature in both reactors of 25 ± 2°C. About 1L gas produced was obtained during the last 6 days of experiment in which CH4 obtained was 8.951 ppm and CO2 of 1.087 ppm. The maximum increase of MLVSS in R1 reached 156% and R2 reached 89%.

  19. Analysis of the key enzymes of butyric and acetic acid fermentation in biogas reactors

    Science.gov (United States)

    Gabris, Christina; Bengelsdorf, Frank R; Dürre, Peter

    2015-01-01

    This study aimed at the investigation of the mechanisms of acidogenesis, which is a key process during anaerobic digestion. To expose possible bottlenecks, specific activities of the key enzymes of acidification, such as acetate kinase (Ack, 0.23–0.99 U mg−1 protein), butyrate kinase (Buk, biogas reactor content from three different biogas reactors. Furthermore, the detection of Ack was successful via Western blot analysis. Quantification of corresponding functional genes encoding Buk (buk) and But (but) was not feasible, although an amplification was possible. Thus, phylogenetic trees were constructed based on respective gene fragments. Four new clades of possible butyrate-producing bacteria were postulated, as well as bacteria of the genera Roseburia or Clostridium identified. The low Buk activity was in contrast to the high specific But activity in the analysed samples. Butyrate formation via Buk activity does barely occur in the investigated biogas reactor. Specific enzyme activities (Ack, Buk and But) in samples drawn from three different biogas reactors correlated with ammonia and ammonium concentrations (NH3 and NH4+-N), and a negative dependency can be postulated. Thus, high concentrations of NH3 and NH4+-N may lead to a bottleneck in acidogenesis due to decreased specific acidogenic enzyme activities. PMID:26086956

  20. Computer Aided Analysis and Prototype Testing of an Improved Biogas Reactor For Biomass System

    Directory of Open Access Journals (Sweden)

    Jeremy (Zheng Li

    2015-05-01

    Full Text Available The alternative fuel resources substituting for conventional fuels are required due to less availability of fuel resources than demand in the market. A large amount of crude oil and petroleum products are required to be imported in many countries over the world. Also the environmental pollution is another serious problem when use petroleum products. Biogas, with the composition of 54.5% CH4, 39.5% CO2, and 6% other elements (i.e., H2, N2, H2S, and O2, is a clear green fuel that can substitute the regular petroleum fuels to reduce the pollutant elements. Biogas can be produced by performing enriching, scrubbing, and bottling processes. The purification process can be further applied to take away the pollutants in biogas. The pure biogas process analyzed in this research is compressed to 2950 psi while being filled into gas cylinder. The daily produced biogas capacity is around 5480 ft3 and the processing efficacy is affected by surrounding environment and other factors. The design and development of this biogas system is assisted through mathematical analysis, 3D modeling, computational simulation, and prototype testing. Both computer aided analysis and prototype testing show close results which validate the feasibility of this biogas system in biomass applications.

  1. Biological biogas upgrading capacity of a hydrogenotrophic community in a trickle-bed reactor

    International Nuclear Information System (INIS)

    Rachbauer, Lydia; Voitl, Gregor; Bochmann, Günther; Fuchs, Werner

    2016-01-01

    Highlights: • Data on long term operation of a system supplied with real biogas are presented. • Ex-situ biological methanation is feasible for biogas upgrading. • Gas quality obtained complies with strictest direct grid injection criteria. • Biomethane can act as flexible storage for renewable surplus electricity. - Abstract: The current study reports on biological biogas upgrading by means of hydrogen addition to obtain biomethane. A mesophilic (37 °C) 0.058 m"3 trickle-bed reactor with an immobilized hydrogenotrophic enrichment culture was operated for a period of 8 months using a substrate mix of molecular hydrogen (H_2) and biogas (36–42% CO_2). Complete CO_2 conversion (> 96%) was achieved up to a H_2 loading rate of 6.5 m_n"3 H_2/m"3_r_e_a_c_t_o_r _v_o_l_. × d, corresponding to 2.3 h gas retention time. The optimum H_2/CO_2 ratio was determined to be between 3.67 and 4.15. CH_4 concentrations above 96% were achieved with less than 0.1% residual H_2. This gas quality complies even with tightest standards for grid injection without the need for additional CO_2 removal. If less rigid standards must be fulfilled H_2 loading rates can be almost doubled (10.95 versus 6.5 m_n"3 H_2/m"3_r_e_a_c_t_o_r _v_o_l_. × d) making the process even more attractive. At this H_2 loading the achieved methane productivity was 2.52 m_n"3 CH_4/m"3_r_e_a_c_t_o_r _v_o_l_. × d. In terms of biogas this corresponds to an upgrading capacity of 6.9 m_n"3 biogas/m"3_r_e_a_c_t_o_r _v_o_l_. × d. The conducted experiments demonstrate that biological methanation in an external reactor is well feasible for biogas upgrading under the prerequisite that an adequate H_2 source is available.

  2. 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...

  3. 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.

  4. Syntrophic microbial communities on straw as biofilm carrier increase the methane yield of a biowaste-digesting biogas reactor

    Directory of Open Access Journals (Sweden)

    Frank R. Bengelsdorf

    2015-08-01

    Full Text Available Biogas from biowaste can be an important source of renewable energy, but the fermentation process of low-structure waste is often unstable. The present study uses a full-scale biogas reactor to test the hypothesis that straw as an additional biofilm carrier will increase methane yield; and this effect is mirrored in a specific microbial community attached to the straw. Better reactor performance after addition of straw, at simultaneously higher organic loading rate and specific methane yield confirmed the hypothesis. The microbial communities on straw as a biofilm carrier and of the liquid reactor content were investigated using 16S rDNA amplicon sequencing by means of 454 pyrosequencing technology. The results revealed high diversity of the bacterial communities in the liquid reactor content as well as the biofilms on the straw. The most abundant archaea in all samples belonged to the genera Methanoculleus and Methanosarcina. Addition of straw resulted in a significantly different microbial community attached to the biofilm carrier. The bacterium Candidatus Cloacamonas acidaminovorans and methanogenic archaea of the genus Methanoculleus dominated the biofilm on straw. Syntrophic interactions between the hydrogenotrophic Methanoculleus sp. and members of the hydrogen-producing bacterial community within biofilms may explain the improved methane yield. Thus, straw addition can be used to improve and to stabilize the anaerobic process in substrates lacking biofilm-supporting structures.

  5. Valorization of biogas into liquid hydrocarbons in plasma-catalyst reactor

    Science.gov (United States)

    Nikravech, Mehrdad; Rahmani, Abdelkader; Labidi, Sana; Saintini, Noiric

    2016-09-01

    Biogas represents an important source of renewable energy issued from biological degradation of biomass. It is planned to produce in Europe the amount of biogas equivalent to 6400 kWh electricity and 4500 kteo (kilo tons equivalent oil) in 2020. Currently the biogas is used in cogeneration engines to produce heat and electricity directly in farms or it is injected in gas networks after purification and odorisation. The aim of this work is to propose a third option that consists of valorization of biogas by transformation into liquid hydrocarbons like acetone, methanol, ethanol, acetic acid etc. These chemicals, among the most important feed materials for chemical industries, retain CO2 molecules participating to reduce the greenhouse gas emissions and have high storage energy capacity. We developed a low temperature atmospheric plasma-catalyst reactor (surface dielectric barrier discharge) to transform biogas into chemicals. The conversion rates of CH4 and CO2 are respectively about 50% and 30% depending on operational conditions. The energetic cost is 25 eV/molecule. The yields of liquid hydrocarbon reaches currently 10% wt. More the 11 liquid chemicals are observed in the liquid fraction. Acknowledgements are due to SPC Programme Energie de demain.

  6. Temperature increases from 55 to 75 C in a two-phase biogas reactor result in fundamental alterations within the bacterial and archaeal community structure

    Energy Technology Data Exchange (ETDEWEB)

    Rademacher, Antje [Leibniz-Institut fuer Agrartechnik Potsdam-Bornim e.V. (ATB), Potsdam (Germany). Abt. Bioverfahrenstechnik; Technische Univ. Berlin (Germany). Inst. fuer Technischen Umweltschutz; Nolte, Christine; Schoenberg, Mandy; Klocke, Michael [Leibniz-Institut fuer Agrartechnik Potsdam-Bornim e.V. (ATB), Potsdam (Germany). Abt. Bioverfahrenstechnik

    2012-10-15

    Agricultural biogas plants were operated in most cases below their optimal performance. An increase in the fermentation temperature and a spatial separation of hydrolysis/acetogenesis and methanogenesis are known strategies in improving and stabilizing biogas production. In this study, the dynamic variability of the bacterial and archaeal community was monitored within a two-phase leach bed biogas reactor supplied with rye silage and straw during a stepwise temperature increase from 55 to 75 C within the leach bed reactor (LBR), using TRFLP analyses. To identify the terminal restriction fragments that were obtained, bacterial and archaeal 16S rRNA gene libraries were constructed. Above 65 C, the bacterial community structure changed from being Clostridiales-dominated toward being dominated by members of the Bacteroidales, Clostridiales, and Thermotogales orders. Simultaneously, several changes occurred, including a decrease in the total cell count, degradation rate, and biogas yield along with alterations in the intermediate production. A bioaugmentation with compost at 70 C led to slight improvements in the reactor performance; these did not persist at 75 C. However, the archaeal community within the downstream anaerobic filter reactor (AF), operated constantly at 55 C, altered by the temperature increase in the LBR. At an LBR temperature of 55 C, members of the Methanobacteriales order were prevalent in the AF, whereas at higher LBR temperatures Methanosarcinales prevailed. Altogether, the best performance of this two-phase reactor was achieved at an LBR temperature of below 65 C, which indicates that this temperature range has a favorable effect on the microbial community responsible for the production of biogas. (orig.)

  7. Biogas composition and engine performance, including database and biogas property model

    NARCIS (Netherlands)

    Bruijstens, A.J.; Beuman, W.P.H.; Molen, M. van der; Rijke, J. de; Cloudt, R.P.M.; Kadijk, G.; Camp, O.M.G.C. op den; Bleuanus, W.A.J.

    2008-01-01

    In order to enable this evaluation of the current biogas quality situation in the EU; results are presented in a biogas database. Furthermore the key gas parameter Sonic Bievo Index (influence on open loop A/F-ratio) is defined and other key gas parameters like the Methane Number (knock resistance)

  8. Assessing the Environmental Performance of Integrated Ethanol and Biogas Production

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Michael; Svensson, Niclas; Fonseca, Jorge (Linkoeping Univ., Environmental Technology and Management, Linkoeping (Sweden)), e-mail: michael.martin@liu.se

    2011-06-15

    As the production of biofuels continues to expand worldwide, criticism about, e.g. the energy output versus input and the competition with food has been questioned. However, biofuels may be optimized to increase the environmental performance through the concepts of industrial symbiosis. This paper offers a quantification of the environmental performance of industrial symbiosis in the biofuel industry through integration of biogas and ethanol processes using a life cycle approach. Results show that although increasing integration is assumed to produce environmental benefits in industrial symbiosis, not all impact categories have achieved this and the results depend upon the allocation methods chosen

  9. 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...

  10. Biogas everywhere

    International Nuclear Information System (INIS)

    Couturier, Ch.; Pegret-Rosa, A.S.; Leca, Ch.; Adlec, E.

    2009-01-01

    Since the publication in July 2006 of the new purchase tariff of electricity produced by biogas, the methanation channel is increasing. In the past ten years the number of biogas plants from domestic wastes, passed from 1 to 20. This document presents an economic analysis of the different sources of biogas, the performances and the injection of biogas in the public network of the gas utilities. (A.L.B.)

  11. Performance and emissions of an engine fuelled by biogas of palm oil mill effluent

    Science.gov (United States)

    Arjuna, J.; Sitorus, T. B.; Ambarita, H.; Abda, S.

    2018-02-01

    This research investigates the performance and emissions of an engine by biogas and gasoline. The experiments use biogas of palm oil mill effluent (POME) with turbocharger at engine loading conditions (100, 200, 300, 400, and 500 Watt). Specific fuel consumption and thermal efficiency are used to compare engine performance, and emission analysis is based on parameters such as carbon monoxide (CO), hydrocarbon (HC), carbon dioxide (CO2) and oxide (O2). The experimental data show that the maximum thermal efficiency when engine use biogas and gasoline is 20.44% and 22.22% respectively. However, there was CO emission reduction significantly when the engine using POME biogas.

  12. Ex-situ biogas upgrading and enhancement in different reactor systems.

    Science.gov (United States)

    Kougias, Panagiotis G; Treu, Laura; Benavente, Daniela Peñailillo; Boe, Kanokwan; Campanaro, Stefano; Angelidaki, Irini

    2017-02-01

    Biogas upgrading is envisioned as a key process for clean energy production. The current study evaluates the efficiency of different reactor configurations for ex-situ biogas upgrading and enhancement, in which externally provided hydrogen and carbon dioxide were biologically converted to methane by the action of hydrogenotrophic methanogens. The methane content in the output gas of the most efficient configuration was >98%, allowing its exploitation as substitute to natural gas. Additionally, use of digestate from biogas plants as a cost efficient method to provide all the necessary nutrients for microbial growth was successful. High-throughput 16S rRNA sequencing revealed that the microbial community was resided by novel phylotypes belonging to the uncultured order MBA08 and to Bacteroidales. Moreover, only hydrogenotrophic methanogens were identified belonging to Methanothermobacter and Methanoculleus genera. Methanothermobacter thermautotrophicus was the predominant methanogen in the biofilm formed on top of the diffuser surface in the bubble column reactor. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Different substrates and starter inocula govern microbial community structures in biogas reactors.

    Science.gov (United States)

    Satpathy, Preseela; Steinigeweg, Sven; Cypionka, Heribert; Engelen, Bert

    2016-01-01

    The influence of different starter inocula on the microbial communities in biogas batch reactors fed with fresh maize and maize silage as substrates was investigated. Molecular biological analysis by Denaturing Gradient Gel Electrophoresis (DGGE) of 16S rRNA gene fragments showed that each inoculum bore specific microbial communities with varying predominant phylotypes. Both, bacterial and archaeal DGGE profiles displayed three distinct communities that developed depending on the type of inoculum. Although maize and silage are similar substrates, different communities dominated the lactate-rich silage compared to lactate-free fresh maize. Cluster analysis of DGGE gels showed the communities of the same substrates to be stable with their respective inoculum. Bacteria-specific DGGE analysis revealed a rich diversity with Firmicutes being predominant. The other abundant phylotypes were Bacteroidetes and Synergistetes. Archaea-specific DGGE analysis displayed less diverse community structures, identifying members of the Methanosarcinales as the dominant methanogens present in all the three biogas digesters. In general, the source of inoculum played a significant role in shaping microbial communities. Adaptability of the inoculum to the substrates fed also influenced community compositions which further impacted the rates of biogas production.

  14. Key factors affecting performance of biogas latrines in urban ...

    African Journals Online (AJOL)

    Pre-tested questionnaires were administered to users, owners and construction technicians/masons of the biogas latrines. Field observations were also undertaken to assess physical conditions of the biogas latrines. Principal component analysis was then used to establish correlation between variables of design, ...

  15. Energy potential and alternative usages of biogas and sludge from UASB reactors: case study of the Laboreaux wastewater treatment plant.

    Science.gov (United States)

    Rosa, A P; Conesa, J A; Fullana, A; Melo, G C B; Borges, J M; Chernicharo, C A L

    2016-01-01

    This work assessed the energy potential and alternative usages of biogas and sludge generated in upflow anaerobic sludge blanket reactors at the Laboreaux sewage treatment plant (STP), Brazil. Two scenarios were considered: (i) priority use of biogas for the thermal drying of dehydrated sludge and the use of the excess biogas for electricity generation in an ICE (internal combustion engine); and (ii) priority use of biogas for electricity generation and the use of the heat of the engine exhaust gases for the thermal drying of the sludge. Scenario 1 showed that the electricity generated is able to supply 22.2% of the STP power demand, but the thermal drying process enables a greater reduction or even elimination of the final volume of sludge to be disposed. In Scenario 2, the electricity generated is able to supply 57.6% of the STP power demand; however, the heat in the exhaust gases is not enough to dry the total amount of dehydrated sludge.

  16. 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

  17. Changing Feeding Regimes To Demonstrate Flexible Biogas Production: Effects on Process Performance, Microbial Community Structure, and Methanogenesis Pathways

    Science.gov (United States)

    Mulat, Daniel Girma; Jacobi, H. Fabian; Feilberg, Anders; Adamsen, Anders Peter S.; Richnow, Hans-Hermann

    2015-01-01

    Flexible biogas production that adapts biogas output to energy demand can be regulated by changing feeding regimes. In this study, the effect of changes in feeding intervals on process performance, microbial community structure, and the methanogenesis pathway was investigated. Three different feeding regimes (once daily, every second day, and every 2 h) at the same organic loading rate were studied in continuously stirred tank reactors treating distiller's dried grains with solubles. A larger amount of biogas was produced after feeding in the reactors fed less frequently (once per day and every second day), whereas the amount remained constant in the reactor fed more frequently (every 2 h), indicating the suitability of the former for the flexible production of biogas. Compared to the conventional more frequent feeding regimes, a methane yield that was up to 14% higher and an improved stability of the process against organic overloading were achieved by employing less frequent feeding regimes. The community structures of bacteria and methanogenic archaea were monitored by terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rRNA and mcrA genes, respectively. The results showed that the composition of the bacterial community varied under the different feeding regimes, and the observed T-RFLP patterns were best explained by the differences in the total ammonia nitrogen concentrations, H2 levels, and pH values. However, the methanogenic community remained stable under all feeding regimes, with the dominance of the Methanosarcina genus followed by that of the Methanobacterium genus. Stable isotope analysis showed that the average amount of methane produced during each feeding event by acetoclastic and hydrogenotrophic methanogenesis was not influenced by the three different feeding regimes. PMID:26497462

  18. Changing Feeding Regimes To Demonstrate Flexible Biogas Production: Effects on Process Performance, Microbial Community Structure, and Methanogenesis Pathways.

    Science.gov (United States)

    Mulat, Daniel Girma; Jacobi, H Fabian; Feilberg, Anders; Adamsen, Anders Peter S; Richnow, Hans-Hermann; Nikolausz, Marcell

    2016-01-15

    Flexible biogas production that adapts biogas output to energy demand can be regulated by changing feeding regimes. In this study, the effect of changes in feeding intervals on process performance, microbial community structure, and the methanogenesis pathway was investigated. Three different feeding regimes (once daily, every second day, and every 2 h) at the same organic loading rate were studied in continuously stirred tank reactors treating distiller's dried grains with solubles. A larger amount of biogas was produced after feeding in the reactors fed less frequently (once per day and every second day), whereas the amount remained constant in the reactor fed more frequently (every 2 h), indicating the suitability of the former for the flexible production of biogas. Compared to the conventional more frequent feeding regimes, a methane yield that was up to 14% higher and an improved stability of the process against organic overloading were achieved by employing less frequent feeding regimes. The community structures of bacteria and methanogenic archaea were monitored by terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rRNA and mcrA genes, respectively. The results showed that the composition of the bacterial community varied under the different feeding regimes, and the observed T-RFLP patterns were best explained by the differences in the total ammonia nitrogen concentrations, H2 levels, and pH values. However, the methanogenic community remained stable under all feeding regimes, with the dominance of the Methanosarcina genus followed by that of the Methanobacterium genus. Stable isotope analysis showed that the average amount of methane produced during each feeding event by acetoclastic and hydrogenotrophic methanogenesis was not influenced by the three different feeding regimes. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  19. The feasibility of trace element supplementation for stable operation of wheat stillage-fed biogas tank reactors.

    Science.gov (United States)

    Gustavsson, J; Svensson, B H; Karlsson, A

    2011-01-01

    The aim of this study was to investigate the effect of trace element supplementation on operation of wheat stillage-fed biogas tank reactors. The stillage used was a residue from bio-ethanol production, containing high levels of sulfate. In biogas production, high sulfate content has been associated with poor process stability in terms of low methane production and accumulation of process intermediates. However, the results of the present study show that this problem can be overcome by trace element supplementations. Four lab-scale wheat stillage-fed biogas tank reactors were operated for 345 days at a hydraulic retention time of 20 days (37 degrees C). It was concluded that daily supplementation with Co (0.5 mg L(-1)), Ni (0.2 mg L(-1)) and Fe (0.5 g L(-1)) were required for maintaining process stability at the organic loading rate of 4.0 g volatile solids L(-1) day(-1).

  20. Acetate conversion in anaerobic biogas reactors: Traditional and molecular tools for studying this important group of anaerobic microorganisms

    DEFF Research Database (Denmark)

    Schmidt, Jens Ejbye; Mladenovska, Zuzana; Lange, Marianne

    2000-01-01

    Different methods were applied to study the role of aceticlastic methanogens in biogas reactors treating solid waste and wastewater. We used traditional microbiological methods, immunological and 16S rRNA ribosomal probes for detection of the methanogens. Using this approach we identified the met...

  1. In-situ biogas upgrading in thermophilic granular UASB reactor: key factors affecting the hydrogen mass transfer rate

    DEFF Research Database (Denmark)

    Bassani, Ilaria; Kougias, Panagiotis; Angelidaki, Irini

    2016-01-01

    in the biogas into CH4, via hydrogenotrophic methanogenesis. The setup consisted of a granular reactor connected to a separate chamber, where H2 was injected. Different packing materials (rashig rings and alumina ceramic sponge) were tested to increase gas-liquid mass transfer. This aspect was optimized...

  2. Functionally redundant but dissimilar microbial communities within biogas reactors treating maize silage in co-fermentation with sugar beet silage

    Science.gov (United States)

    Langer, Susanne G; Ahmed, Sharif; Einfalt, Daniel; Bengelsdorf, Frank R; Kazda, Marian

    2015-01-01

    Numerous observations indicate a high flexibility of microbial communities in different biogas reactors during anaerobic digestion. Here, we describe the functional redundancy and structural changes of involved microbial communities in four lab-scale continuously stirred tank reactors (CSTRs, 39°C, 12 L volume) supplied with different mixtures of maize silage (MS) and sugar beet silage (SBS) over 80 days. Continuously stirred tank reactors were fed with mixtures of MS and SBS in volatile solid ratios of 1:0 (Continuous Fermenter (CF) 1), 6:1 (CF2), 3:1 (CF3), 1:3 (CF4) with equal organic loading rates (OLR 1.25 kgVS m−3 d−1) and showed similar biogas production rates in all reactors. The compositions of bacterial and archaeal communities were analysed by 454 amplicon sequencing approach based on 16S rRNA genes. Both bacterial and archaeal communities shifted with increasing amounts of SBS. Especially pronounced were changes in the archaeal composition towards Methanosarcina with increasing proportion of SBS, while Methanosaeta declined simultaneously. Compositional shifts within the microbial communities did not influence the respective biogas production rates indicating that these communities adapted to environmental conditions induced by different feedstock mixtures. The diverse microbial communities optimized their metabolism in a way that ensured efficient biogas production. PMID:26200922

  3. In-situ biogas upgrading in thermophilic granular UASB reactor: key factors affecting the hydrogen mass transfer rate.

    Science.gov (United States)

    Bassani, Ilaria; Kougias, Panagiotis G; Angelidaki, Irini

    2016-12-01

    Biological biogas upgrading coupling CO 2 with external H 2 to form biomethane opens new avenues for sustainable biofuel production. For developing this technology, efficient H 2 to liquid transfer is fundamental. This study proposes an innovative setup for in-situ biogas upgrading converting the CO 2 in the biogas into CH 4 , via hydrogenotrophic methanogenesis. The setup consisted of a granular reactor connected to a separate chamber, where H 2 was injected. Different packing materials (rashig rings and alumina ceramic sponge) were tested to increase gas-liquid mass transfer. This aspect was optimized by liquid and gas recirculation and chamber configuration. It was shown that by distributing H 2 through a metallic diffuser followed by ceramic sponge in a separate chamber, having a volume of 25% of the reactor, and by applying a mild gas recirculation, CO 2 content in the biogas dropped from 42 to 10% and the final biogas was upgraded from 58 to 82% CH 4 content. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Integration of Cleaner Production and Waste Water Treatment on Tofu Small Industry for Biogas Production using AnSBR Reactor

    Science.gov (United States)

    Rahayu, Suparni Setyowati; Budiyono; Purwanto

    2018-02-01

    A research on developing a system that integrates clean production and waste water treatment for biogas production in tofu small industry has been conducted. In this research, tofu waste water was turned into biogas using an AnSBR reactor. Mud from the sewage system serves as the inoculums. This research involved: (1) workshop; (2) supervising; (3) technical meeting; (4) network meeting, and (5) technical application. Implementation of clean production integrated with waste water treatment reduced the amount of waste water to be treated in a treatment plant. This means less cost for construction and operation of waste water treatment plants, as inherent limitations associated with such plants like lack of fund, limited area, and technological issues are inevitable. Implementation of clean production prior to waste water treatment reduces pollution figures down to certain levels that limitations in waste water treatment plants can be covered. Results show that biogas in 16 days HRT in an AnSBR reactor contains CH4(78.26 %) and CO2 (20.16 %). Meanwhile, treatments using a conventional bio-digester result in biogas with 72.16 % CH4 and 18.12 % CO2. Hence, biogas efficiency for the AnSBR system is 2.14 times greater than that of a conventional bio-digester.

  5. Performance of the biogas project in Ziyang sugar factory

    Energy Technology Data Exchange (ETDEWEB)

    Dezhao He [Chengdu Biogas Research Inst., Chengdu (China)

    2000-07-01

    Located in Houjiaping town, Ziyang county, Ziyang Sugar Factory was installed in 1958 as a state enterprise, which mainly processes sugar cane to produce sugar. Sideline products include alcohol and paper. Nowadays, its daily capacity of sugar cane extraction is 1,000 tons and potable alcohol production is 15 - 20 tons. Its annual output value is 25 million Yuan. This plant is one of the backbones in Sichuan sugar cane processing enterprises. The biogas project of the Ziyang Sugar Factory was one of the large biogas installations in China, completed during the Seventh Five-year Plan. The distillery wastewater (slops) from the alcoholic fermentation process of starch (fresh potato, dry potato, kernel and Chinese sorghum) and sugar molasses as substrates is disposed of. The slop has a low pH, a high organic concentration, a high content of suspended solids, a dark colour and a high temperature. Its daily discharge quantity is 200 tons corresponding to 2/3 of total wastewater in that plant. It is a serious source of water pollution when it is directly discharged into Tuojiang River. Therefore, due to its high concentration of polluting substances, anaerobic treatment of distillery wastewater has been decided. This is the first case of wastewater treatment in Nudging city. The construction of this biogas installation started in July 1987. On November 25, 1988, the digester began to produce biogas. Up to now, the digesters have properly operated for more than one year. Besides its use as daily household fuel for the 810 employees, biogas is also supplied to the plant cafeteria as cooking fuel and to some production purposes within the plant, which has achieved obvious economic benefits. The designed capacity of daily biogas production for this biogas plant is 3,000 - 4,000 m{sup 3}. (orig.)

  6. Optimization of biogas production from manure

    DEFF Research Database (Denmark)

    Kaparaju, Prasad Laxmi-Narasimha; Boe, Kanokwan; Buendia, Inmaculada M.

    -scale studies showed that serial digestion with 77/23% volume distribution produced 1.9-6.1% more biogas compared to that obtained during one-step CSTR operation. However, temperature was found to have a strong influence on the methane production and process performance of the second reactor of a serial CSTR......The main objective of the project was to improve biogas production from manures. This objective was addressed by investigating 1) the effect of different reactor configurations, 2) operational procedures, aiming to selectively retain/return degradable material in the reactor and 3) different...... process at 90/10, 80/20, 70/30, 50/50 or 30/70% volume distribution could produce 11-17.8% more biogas compared to single CSTR process under similar operating conditions. The increased biogas production was mainly from the second reactor of the serial process, which accounted for 16-18% of the total...

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

    Directory of Open Access Journals (Sweden)

    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 %.

  8. Performance analysis of a biogas-fueled micro gas turbine using a validated thermodynamic model

    International Nuclear Information System (INIS)

    Nikpey Somehsaraei, Homam; Mansouri Majoumerd, Mohammad; Breuhaus, Peter; Assadi, Mohsen

    2014-01-01

    This study focuses on an investigation of the fuel flexibility and performance analysis of micro gas turbines (MGTs) in biogas application. For this purpose, a steady state thermodynamic model of an MGT was developed and validated by experimental data obtained from a 100 kW MGT test rig. Quite good agreement was obtained between the measurements and the simulation results. A wide range of biogas compositions with varying methane content was simulated for this study. Necessary minor modifications to fuel valves and compressor were assumed to allow engine operation with the simulated biogas composition. The effects of biogas on the engine performance were fully analyzed at various operational conditions by changing the power demand and also the ambient temperature. Compared to the natural gas fueled case, the mass flow and pressure ratio in the MGT decreased, which resulted in a slight reduction of the surge margin. This effect became more severe, however, at low power loads and/or low ambient temperatures. For all operational conditions, the electrical efficiency decreased with decreasing methane content of the biogas. The results also indicated the negative effect of the biogas on the heat recovery in the recuperator, which lowered as the methane content of the fuel decreased. - Highlights: •The MGT performance and fuel flexibility were investigated in biogas application. •A thermodynamic model of the MGT was developed and validated with experimental data. •Changes in performance and operating conditions of components were studied. •The results showed the viability of the MGT for use in biogas application

  9. Effects of varying composition of biogas on performance and emission characteristics of compression ignition engine using exergy analysis

    International Nuclear Information System (INIS)

    Verma, Saket; Das, L.M.; Kaushik, S.C.

    2017-01-01

    Highlights: • Different compositions of biogas have been studied in dual fuel mode using exergy analysis. • Diesel substitution by biogas decreases with higher CO_2 fractions in biogas. • Exergy efficiency decreases with higher CO_2 fractions in biogas. • With low CO_2 fractions in biogas equitable performance can be obtained in dual fuel mode. • Engine modifications are needed to utilize high CO_2 containing biogas. - Abstract: Growing energy demands and environmental degradation with uncontrolled exploitation of fossil fuels have compelled the world to look for the alternatives. In this context, biogas is a promising candidate, which can easily be utilized in IC engines for vehicular as well as decentralized power generation applications. Primary constituents of raw biogas are methane (CH_4) that defines its heating value, and carbon dioxide (CO_2) that acts like a diluent. This dilution effect reduces the flame speed and heating value of biogas, eventually deteriorating the engine performances. Present article focuses on experimental evaluation and quantification of these variations of the engine performance. Three compositions of biogas: BG93, BG84 and BG75 (containing 93%, 84% and 75% of CH_4 by volume respectively) were studied on a small CI engine in dual fuel mode. Moreover, to evaluate individual process inefficiencies, exergy analysis based on second-law of thermodynamics is implemented. Exergy balances for different compositions of biogas are presented. Biogas dual fuel operation showed 80–90% diesel substitution at lower engine loads. At higher loads, total irreversibility of the engine was increased from 59.56% for diesel operation to 61.44%, 64.18% and 64.64% for BG93, BG84 and BG75 biogas compositions respectively. Furthermore, combustion irreversibility was found to be decreasing with higher CO_2 concentrations in biogas. BG93 showed comparable results to that of diesel operation with 26.9% and 27.4% second-law efficiencies respectively.

  10. Utilization of biogas released from palm oil mill effluent for power generation using self-preheated reactor

    International Nuclear Information System (INIS)

    Hosseini, Seyed Ehsan; Wahid, Mazlan Abdul

    2015-01-01

    Highlights: • A lab-scale reactor called self-preheating flameless combustion (SPFC) system is experimented. • Feasibility of power generation by POME biogas is modeled using SPFC system. • 4 MW power is available by POME biogas utilization in a typical palm oil mill with 300,000 tons production. • The rate of power generation increases when 2% hydrogen is added to POME biogas ingredients. - Abstract: In palm oil mills, for one ton crude palm oil (CPO) production, 70 m"3 biogas is released from palm oil mill effluent (POME) which can endanger the environment. Palm oil mills without appropriate strategies for biogas collection can participate in greenhouse gases (GHGs) generation actively. In this paper, a typical palm oil mill with annual capacity of 300,000 ton oil palm production and 3 MW electricity demand is considered as a pilot plant and feasibility of power generation by POME biogas is modeled by Aspen Plus considering flameless mode in combustion system. A new design of lab-scale flameless reactor called self-preheated flameless combustion (SPFC) system is presented and employed in power generation modeling. In SPFC system, the flameless chamber is employed as a heater to preheat an oxidizer over the self-ignition temperature of the fuel. A helical stainless steel pipe (called self-preheating pipe) is installed inside the chamber to conduct the oxidizer from exhaust zone to the combustion zone inside the chamber and preheat oxidizer. In the flameless mode, the diluted oxidizer is injected to the helical pipe from the exhaust zone and the preheated oxidizer at the burner is conducted to the flameless furnace through a distributor. In SPFC system external heater for preheating oxidizer is removed and the rate of power generation increases. The results show that 10.8 MW power could be generated in ultra-lean POME biogas SPFC. However, the rate of pollutant especially CO_2 and NO_x is high in this circumstances. In stoichiometric condition, 4 MW power

  11. Evaluation of the rotary drum reactor process as pretreatment technology of municipal solid waste for thermophilic anaerobic digestion and biogas production.

    Science.gov (United States)

    Gikas, Petros; Zhu, Baoning; Batistatos, Nicolas Ion; Zhang, Ruihong

    2018-06-15

    Municipal solid waste (MSW) contains a large fraction of biodegradable organic materials. When disposed in landfills, these materials can cause adverse environmental impact due to gaseous emissions and leachate generation. This study was performed with an aim of effectively separating the biodegradable materials from a Mechanical Biological Treatment (MBT) facility and treating them in well-controlled anaerobic digesters for biogas production. The rotary drum reactor (RDR) process (a sub-process of the MBT facilities studied in the present work) was evaluated as an MSW pretreatment technology for separating and preparing the biodegradable materials in MSW to be used as feedstock for anaerobic digestion. The RDR processes used in six commercial MSW treatment plants located in the USA were surveyed and sampled. The samples of the biodegradable materials produced by the RDR process were analyzed for chemical and physical characteristics as well as anaerobically digested in the laboratory using batch reactors under thermophilic conditions. The moisture content, TS, VS and C/N of the samples varied between 64.7 and 44.4%, 55.6 to 35.3%, 27.0 to 41.3% and 24.5 to 42.7, respectively. The biogas yield was measured to be between 533.0 and 675.6 mL g -1 VS after 20 days of digestion. Approximately 90% of the biogas was produced during the first 13 days. The average methane content of the biogas was between 58.0 and 59.9%. The results indicated that the biodegradable materials separated from MSW using the RDR processes could be used as an excellent feedstock for anaerobic digestion. The digester residues may be further processed for compost production or further energy recovery by using thermal conversion processes such as combustion or gasification. Copyright © 2017. Published by Elsevier Ltd.

  12. Enhancing wastewater degradation and biogas production by intermittent operation of UASB reactors

    International Nuclear Information System (INIS)

    Nadais, Helena; Barbosa, Marta; Capela, Isabel; Arroja, Luis; Ramos, Christian G.; Grilo, Andre; Sousa, Silvia A.; Leitao, Jorge H.

    2011-01-01

    The present work establishes intermittent operation of UASB reactors as a novel form of enhancing the anaerobic degradation of complex wastewaters and its conversion to usable biogas. Results show that the average methane production rate is 25% higher with the intermittent operation than with the continuous mode, meaning that it could produce 25% more electricity or heat. The methanization efficiency obtained in intermittent UASB reactors is around 20% higher than in the continuous systems, confirming a higher biological degradation of the substrates. It has been suggested that intermittent operation causes a forced adaptation of the biomass towards the degradation of complex substrates and results from morphological analyses of the biomass developed in intermittent and continuous UASB reactors showed marked differences between them. In order to gain a deeper knowledge on how microbial populations are affected by these operational parameters, a strategy involving the amplification, cloning, and analysis of the nucleotide sequences of genes encoding the 16S ribosomal RNA was undertaken and is described in this work. This strategy allowed the identification of a total of 49 different sequences. Results from the molecular characterization of the microbial populations are consistent with the higher methanization efficiency of the intermittent mode of operation.

  13. 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

  14. Thermodynamic simulation model for predicting the performance of spark ignition engines using biogas as fuel

    International Nuclear Information System (INIS)

    Nunes de Faria, Mário M.; Vargas Machuca Bueno, Juan P.; Ayad, Sami M.M. Elmassalami; Belchior, Carlos R. Pereira

    2017-01-01

    Highlights: • A 0-D model for performance prediction of SI ICE fueled with biogas is proposed. • Relative difference between simulated and experimental values was under 5%. • Can be adapted for different biogas compositions and operating ranges. • Could be a valuable tool for predicting trends and guiding experimentation. • Is suitable for use with biogas supplies in developing regions. - Abstract: Biogas found its way from developing countries and is now an alternative to fossil fuels in internal combustion engines and with the advantage of lower greenhouse gas emissions. However, its use in gas engines requires engine modifications or adaptations that may be costly. This paper reports the results of experimental performance and emissions tests of an engine-generator unit fueled with biogas produced in a sewage plant in Brazil, operating under different loads, and with suitable engine modifications. These emissions and performance results were in agreement with the literature and it was confirmed that the penalties to engine performance were more significant than emission reduction in the operating range tested. Furthermore, a zero dimensional simulation model was employed to predict performance characteristics. Moreover, a differential thermodynamic equation system was solved, obtaining the pressure inside the cylinder as a function of the crank angle for different engine conditions. Mean effective pressure and indicated power were also obtained. The results of simulation and experimental tests of the engine in similar conditions were compared and the model validated. Although several simplifying assumptions were adopted and empirical correlations were used for Wiebe function, the model was adequate in predicting engine performance as the relative difference between simulated and experimental values was lower than 5%. The model can be adapted for use with different raw or enriched biogas compositions and could prove to be a valuable tool to guide

  15. Performance study of four stroke S.I. engine using upgraded biogas fuel

    Directory of Open Access Journals (Sweden)

    Jai Prakash

    2016-09-01

    Full Text Available In resent year, increased environmental awareness and energy shortages have encouraged researchers to investigate the possibility of using alternate fuels. The purpose of finding the alternate sources is to minimize the consumption of conventional fossil fuels and in turn to reduce the degradation of environmental quality to a great extent. The use of bio-based fuels like biogas produced from biomass and bio-wastes is a valuable energy source which is sustainable that can be manufactured from locally available waste streams thereby solving the local waste problem. Local wastes (organic wastes contain enough energy to contribute significantly to energy supply especially the rural regions of developing countries. Biogas is a clean and environment friendly fuel produced from anaerobic digestion of agro, animal or human wastes. The biogas has about 60 % methane and 40 % carbon dioxide with small traces of H2S. The use of H2S leads to formation of SO2 which combines with the water vapor to form acids and hence corrode the metals. Thus, raw biogas as such cannot be used for powering vehicular I.C engine. In the present work, an attempt has been made to upgrade the quality of raw biogas by removing CO2 and H2S, thus enriching its methane content up to the natural gas level and to study the performance of four stroke S.I engine aspirating upgraded biogas as primary fuel and its emission characteristics.

  16. Experimental comparison of MCFC performance using three different biogas types and methane

    Science.gov (United States)

    Bove, Roberto; Lunghi, Piero

    Biogas recovery is an environmentally friendly and cost-effective practice that is getting consensus in both the scientific and industrial community, as the growing number of projects demonstrate. The use of fuel cells as energy conversion systems increases the conversion efficiency, as well as the environmental benefits. Molten carbonate fuel cells (MCFC) operate at a temperature of about 650 °C, thus presenting a high fuel flexibility, compared to low temperature fuel cells. Aim of the present study is to compare the performance of an MCFC single cell, fuelled with different biogas types as well as methane. The biogases considered are derived from the following processes: (1) steam gasification in an entrained flow gasifier; (2) steam gasification in a duel interconnect fluidized bed gasifier; (3) biogas from an anaerobic digestion process. The performances are evaluated for different fuel utilization and current densities. The results are an essential starting point for a complete system design and demonstration.

  17. 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.

  18. 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

  19. 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)

  20. A fuzzy-logic-based model to predict biogas and methane production rates in a pilot-scale mesophilic UASB reactor treating molasses wastewater

    International Nuclear Information System (INIS)

    Turkdogan-Aydinol, F. Ilter; Yetilmezsoy, Kaan

    2010-01-01

    A MIMO (multiple inputs and multiple outputs) fuzzy-logic-based model was developed to predict biogas and methane production rates in a pilot-scale 90-L mesophilic up-flow anaerobic sludge blanket (UASB) reactor treating molasses wastewater. Five input variables such as volumetric organic loading rate (OLR), volumetric total chemical oxygen demand (TCOD) removal rate (R V ), influent alkalinity, influent pH and effluent pH were fuzzified by the use of an artificial intelligence-based approach. Trapezoidal membership functions with eight levels were conducted for the fuzzy subsets, and a Mamdani-type fuzzy inference system was used to implement a total of 134 rules in the IF-THEN format. The product (prod) and the centre of gravity (COG, centroid) methods were employed as the inference operator and defuzzification methods, respectively. Fuzzy-logic predicted results were compared with the outputs of two exponential non-linear regression models derived in this study. The UASB reactor showed a remarkable performance on the treatment of molasses wastewater, with an average TCOD removal efficiency of 93 (±3)% and an average volumetric TCOD removal rate of 6.87 (±3.93) kg TCOD removed /m 3 -day, respectively. Findings of this study clearly indicated that, compared to non-linear regression models, the proposed MIMO fuzzy-logic-based model produced smaller deviations and exhibited a superior predictive performance on forecasting of both biogas and methane production rates with satisfactory determination coefficients over 0.98.

  1. Reactor performance calculations for water reactors

    International Nuclear Information System (INIS)

    Hicks, D.

    1970-04-01

    The principles of nuclear, thermal and hydraulic performance calculations for water cooled reactors are discussed. The principles are illustrated by describing their implementation in the UKAEA PATRIARCH scheme of computer codes. This material was originally delivered as a course of lectures at the Technical University of Helsinki in Summer of 1969.

  2. Serial completely stirred tank reactors for improving biogas production and substance degradation during anaerobic digestion of corn stover.

    Science.gov (United States)

    Li, YuQian; Liu, ChunMei; Wachemo, Akiber Chufo; Yuan, HaiRong; Zou, DeXun; Liu, YanPing; Li, XiuJin

    2017-07-01

    Several completely stirred tank reactors (CSTR) connected in series for anaerobic digestion of corn stover were investigated in laboratory scale. Serial anaerobic digestion systems operated at a total HRT of 40days, and distribution of HRT are 10+30days (HRT10+30d), 20+20days (HRT20+20d), and 30+10days (HRT30+10d) were compared to a conventional one-step CSTR at the same HRT of 40d. The results showed that in HRT10+30d serial system, the process became very unstable at organic load of 50gTS·L -1 . The HRT20+20d and HRT30+10d serial systems improved methane production by 8.3-14.6% compared to the one-step system in all loads of 50, 70, 90gTS·L -1 . The conversion rates of total solid, cellulose, and hemicellulose were increased in serial anaerobic digestion systems compared to single system. The serial systems showed more stable process performance in high organic load. HRT30+10d system showed the best biogas production and conversions among all systems. Copyright © 2017. Published by Elsevier Ltd.

  3. Performance Evaluation on Otto Engine Generator Using Gasoline and Biogas from Palm Oil Mill Effluent

    Science.gov (United States)

    Irvan; Trisakti, B.; Husaini, T.; Sitio, A.; Sitorus, TB

    2017-06-01

    Biogas is a flammable gas produced from the fermentation of organic materials by anaerobic bacteria originating from household waste manure and organic waste including palm oil mill effluent (POME). POME is mainly discharged from the sterilization unit of palm oil processing into crude palm oil. This study utilized biogas produced from liquid waste palm oil for use as fuel in the Otto engine generator 4 - stroke, type STARKE GFH1900LX with a peak power of 1.3 kW, 1.0 kW average power, bore 55 mm, stroke 40 mm, Vd 95 × 10-6 m3, Vc 10 × 10-6 m3, compression ratio of 10.5 : 1, and the number of cylinders = 1. The objective of this study is to evaluate the performance of Otto engine generator fueled with biogas that generated from POME, then comparing its performance fueled by gasoline. The performance included power, torque, specific fuel consumption, thermal efficiency, and the air-fuel ratio. Experiment was conducted by using a variation of the lamp load of 100, 200, 300, 400, and 500 W. The results revealed that the use of biogas as fuel decreased in power, torque, brake thermal efficiency, and air fuel ratio (AFR), while there is an increasing of value specific fuel consumption (SFC).

  4. Performance of a cycle Otto engine using biogas; Desempenho de um motor ciclo Otto utilizando biogas como combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Juliano de [Universidade Estadual do Oeste do Parana (UNIOESTE), Cascavel, PR (Brazil). Centro de Ciencias Exatas e Tecnologicas], e-mail: jsouza@unioeste.br; Souza, Samuel N. Melegari de, [Universidade Estadual do Oeste do Parana (UNIOESTE), Cascavel, PR (Brazil); Machado, Paulo Romeu M [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Dept. de Engenharia Mecanica

    2004-07-01

    The rising of the oil prices is increasing the search for alternative fuels. Brazil has a great availability of biogas from anaerobic digestion in the rural area, urban waste in the landfills and treatment of the municipal sewer. In this work were evaluated in dynamometer a cycle Otto engine using biogas, and were obtained the characteristics curves of torque and power. First was done the evidence test with gasoline, biogas and natural gas, using commercial systems for this fuels, using as comparison for other tests. After has been done tests for some combinations of ignition point, mixer of gas and compression tax. By the analysis of the results has been concluded that the better results for power and torque using biogas as fuel were with a tax compression of 12,5:1, gas mixer long and ignition point advanced in 45 deg. (author)

  5. Influence of dissolved product gas on organism retention in biogas tower reactors; Der Einfluss geloester Produktgase auf den Organismenrueckhalt in Biogas-Turmreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Pietsch, T.; Maerkl, H. [Technische Univ. Hamburg-Harburg, Hamburg (Germany). Arbeitsbereich Bioprozess- und Bioverfahrenstechnik

    1999-07-01

    In biogas tower reactors, considerable oversaturations of CO{sub 2} dissolved in molecular form in the liquid phase can occur, compared to the thermodynamic steady state with the gas phase. In buildings of low height, upflow designs cause biological CO{sub 2} production along the reactor to saturate the liquid phase with carbonic acid, and also cause the pH value increasing from acid degradation to bind CO{sub 2} in the form of hydrogen carbonate HCO{sup -}{sub 3}. Where buildings are very high, the liquid phase becomes degassed through a decrease in CO{sub 2} partial pressure because of decreasing hydrostatic pressure along the length of the reactor. Rising gas bubbles in the liquid phase as well as enclosed gas bubbles in biomass particles slow down their sedimentation considerably and can result in flotation of biomass particles owing to gas expansion from declining hydrostatic pressure. A sedimentation characteristics for biomass under decreasing hydrostatic pressure is given. Conditions critical to biomass retention are energy input into CO{sub 2}-oversaturated liquids as well as dynamically rapid drops in pH value owing to associated CO{sub 2} degassing. (orig.) [German] In Biogas-Turmreaktoren koennen erhebliche Uebersaettigungen von molekular geloestem CO{sub 2} in der Fluessigphase gegenueber dem thermodynamischen Gleichgewichtszustand mit der Gasphase auftreten. Bei geringer Bauhoehe fuehrt bei upflow-Konzepten die biologische CO{sub 2}-Produktion entlang des Reaktors zu einer Aufsaettigung der Fluessigphase mit Kohlensaeure und der durch Saeureabbau ansteigende pH-Wert zu einer Bindung des CO{sub 2} in Form des Hydrogencarbonats HCO{sub 3}{sup -}. Sehr grosse Bauhoehen fuehren zu einer Entgasung der Fluessigphase durch Abnahme des CO{sub 2}-Partialdruckes aufgrund des abnehmenden hydrostatischen Druckes entlang der Reaktorhoehe. Aufsteigende Gasblasen in der Fluessigphase sowie eingeschlossene Gasblasen in Biomassepartikeln mindern deren

  6. 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.

  7. Performance of semi-continuous membrane bioreactor in biogas production from toxic feedstock containing D-Limonene.

    Science.gov (United States)

    Wikandari, Rachma; Youngsukkasem, Supansa; Millati, Ria; Taherzadeh, Mohammad J

    2014-10-01

    A novel membrane bioreactor configuration containing both free and encased cells in a single reactor was proposed in this work. The reactor consisted of 120g/L of free cells and 120g/L of encased cells in a polyvinylidene fluoride membrane. Microcrystalline cellulose (Avicel) and d-Limonene were used as the models of substrate and inhibitor for biogas production, respectively. Different concentrations of d-Limonene i.e., 1, 5, and 10g/L were tested, and an experiment without the addition of d-Limonene was prepared as control. The digestion was performed in a semi-continuous thermophilic reactor for 75 days. The result showed that daily methane production in the reactor with the addition of 1g/L d-Limonene was similar to that of control. A lag phase was observed in the presence of 5g/L d-Limonene; however, after 10 days, the methane production increased and reached a similar production to that of the control after 15 days. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Comparative analysis of taxonomic, functional, and metabolic patterns of microbiomes from 14 full-scale biogas reactors by metagenomic sequencing and radioisotopic analysis.

    Science.gov (United States)

    Luo, Gang; Fotidis, Ioannis A; Angelidaki, Irini

    2016-01-01

    Biogas production is a very complex process due to the high complexity in diversity and interactions of the microorganisms mediating it, and only limited and diffuse knowledge exists about the variation of taxonomic and functional patterns of microbiomes across different biogas reactors, and their relationships with the metabolic patterns. The present study used metagenomic sequencing and radioisotopic analysis to assess the taxonomic, functional, and metabolic patterns of microbiomes from 14 full-scale biogas reactors operated under various conditions treating either sludge or manure. The results from metagenomic analysis showed that the dominant methanogenic pathway revealed by radioisotopic analysis was not always correlated with the taxonomic and functional compositions. It was found by radioisotopic experiments that the aceticlastic methanogenic pathway was dominant, while metagenomics analysis showed higher relative abundance of hydrogenotrophic methanogens. Principal coordinates analysis showed the sludge-based samples were clearly distinct from the manure-based samples for both taxonomic and functional patterns, and canonical correspondence analysis showed that the both temperature and free ammonia were crucial environmental variables shaping the taxonomic and functional patterns. The study further the overall patterns of functional genes were strongly correlated with overall patterns of taxonomic composition across different biogas reactors. The discrepancy between the metabolic patterns determined by metagenomic analysis and metabolic pathways determined by radioisotopic analysis was found. Besides, a clear correlation between taxonomic and functional patterns was demonstrated for biogas reactors, and also the environmental factors that shaping both taxonomic and functional genes patterns were identified.

  9. Adaptation of continuous biogas reactors operating under wet fermentation conditions to dry conditions with corn stover as substrate.

    Science.gov (United States)

    Kakuk, Balázs; Kovács, Kornél L; Szuhaj, Márk; Rákhely, Gábor; Bagi, Zoltán

    2017-08-01

    Corn stover (CS) is the agricultural by-product of maize cultivation. Due to its high abundance and high energy content it is a promising substrate for the bioenergy sector. However, it is currently neglected in industrial scale biogas plants, because of its slow decomposition and hydrophobic character. To assess the maximum biomethane potential of CS, long-term batch fermentations were carried out with various substrate concentrations and particle sizes for 72 days. In separate experiments we adapted the biogas producing microbial community in wet fermentation arrangement first to the lignocellulosic substrate, in Continuous Stirred Tank Reactor (CSTR), then subsequently, by continuously elevating the feed-in concentration, to dry conditions in solid state fermenters (SS-AD). In the batch tests, the CSTR experiment, the daily substrate loading was gradually increased from 1 to 2 g vs /L/day until the system produced signs of overloading. Then the biomass was transferred to SS-AD reactors and the adaptation process was studied. Although the specific methane yields were lower in the SS-AD arrangement (177 mL CH 4 /g vs in CSTR vs. 105 mL in SS-AD), the benefits of process operational parameters, i.e. lower energy consumption, smaller reactor volume, digestate amount generated and simpler configuration, may compensate the somewhat lower yield. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. dynamic performance of research reactors

    International Nuclear Information System (INIS)

    Abo elnor, A.G.M.

    2007-01-01

    this work studies the dynamic performance of material testing reactor (MTR), where the dynamic performance of any reactor reflects its safety behavior and it should enhance its intrinsic characteristics s ystem corrects itself internally without introducing external corrective action . the present work analyzes and studies the dynamic performance of mtr through the transfer function. the servo system parameters can be changed to fit the system demand. the servo system is an excellent approximation to some of the practical servo system currently use in reactor control system, and a quadratic form of this sort should closely approximate the behavior of almost any type of physical equipment which might be chosen to drive a control rod. proposed changes in servo system parameters could enhance the dynamic performance of the system , but the suitable parameters can be evaluated by using the automatic reactor power control system model

  11. 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)

  12. 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...

  13. Reactor core performance calculating device

    International Nuclear Information System (INIS)

    Tominaga, Kenji; Bando, Masaru; Sano, Hiroki; Maruyama, Hiromi.

    1995-01-01

    The device of the present invention can calculate a power distribution efficiently at high speed by a plurality of calculation means while taking an amount of the reactor state into consideration. Namely, an input device takes data from a measuring device for the amount of the reactor core state such as a large number of neutron detectors disposed in the reactor core for monitoring the reactor state during operation. An input data distribution device comprises a state recognition section and a data distribution section. The state recognition section recognizes the kind and amount of the inputted data and information of the calculation means. The data distribution section analyzes the characteristic of the inputted data, divides them into a several groups, allocates them to each of the calculation means for the purpose of calculating the reactor core performance efficiently at high speed based on the information from the state recognition section. A plurality of the calculation means calculate power distribution of each of regions based on the allocated inputted data, to determine the power distribution of the entire reactor core. As a result, the reactor core can be evaluated at high accuracy and at high speed irrespective of the whole reactor core or partial region. (I.S.)

  14. Improving biogas production from anaerobic co-digestion of Thickened Waste Activated Sludge (TWAS) and fat, oil and grease (FOG) using a dual-stage hyper-thermophilic/thermophilic semi-continuous reactor.

    Science.gov (United States)

    Alqaralleh, Rania Mona; Kennedy, Kevin; Delatolla, Robert

    2018-07-01

    This paper investigates the feasibility and advantages of using a dual-stage hyper-thermophilic/thermophilic semi-continuous reactor system for the co-digestion of Thickened Waste Activated Sludge (TWAS) and Fat, Oil and Grease (FOG) to produce biogas in high quantity and quality. The performance of the dual-stage hyper-thermophilic (70°C)/thermophilic (55°C) anaerobic co-digestion system is evaluated and compared to the performance of a single-stage thermophilic (55°C) reactor that was used to co-digest the same FOG-TWAS mixtures. Both co-digestion reactors were compared to a control reactor (the control reactor was a single-stage thermophilic reactor that only digested TWAS). The effect of FOG% in the co-digestion mixture (based on total volatile solids) and the reactor hydraulic retention time (HRT) on the biogas/methane production and the reactors' performance were thoroughly investigated. The FOG% that led to the maximum methane yield with a stable reactor performance was determined for both reactors. The maximum FOG% obtained for the single-stage thermophilic reactor at 15 days HRT was found to be 65%. This 65% FOG resulted in 88.3% higher methane yield compared to the control reactor. However, the dual-stage hyper-thermophilic/thermophilic co-digestion reactor proved to be more efficient than the single-stage thermophilic co-digestion reactor, as it was able to digest up to 70% FOG with a stable reactor performance. The 70% FOG in the co-digestion mixture resulted in 148.2% higher methane yield compared to the control at 15 days HRT. 70% FOG (based on total volatile solids) is so far the highest FOG% that has been proved to be useful and safe for semi-continuous reactor application in the open literature. Finally, the dual-stage hyper-thermophilic/thermophilic co-digestion reactor also proved to be efficient and stable in co-digesting 40% FOG mixtures at lower HRTs (i.e., 9 and 12 days) and still produce high methane yields and Class A effluents

  15. Performance of polydimethylsiloxane membrane contactor process for selective hydrogen sulfide removal from biogas.

    Science.gov (United States)

    Tilahun, Ebrahim; Bayrakdar, Alper; Sahinkaya, Erkan; Çalli, Bariş

    2017-03-01

    H 2 S in biogas affects the co-generation performance adversely by corroding some critical components within the engine and it has to be removed in order to improve the biogas quality. This work presents the use of polydimethylsiloxane (PDMS) membrane contactor for selective removal of H 2 S from the biogas. Experiments were carried out to evaluate the effects of different pH of absorption liquid, biogas flowrate and temperature on the absorption performances. The results revealed that at the lowest loading rate (91mg H 2 S/m 2 ·h) more than 98% H 2 S and 59% CO 2 absorption efficiencies were achieved. The CH 4 content in the treated gas increased from 60 to 80% with nearly 5% CH 4 loss. Increasing the pH (7-10) and loading rate (91-355mg H 2 S/m 2 ·h) enhanced the H 2 S absorption capacity, and the maximum H 2 S/CO 2 and H 2 S/CH 4 selectivity factors were 2.5 and 58, respectively. Temperature played a key role in the process and lower temperature was beneficial for intensifying H 2 S absorption performance. The highest H 2 S fluxes at pH 10 and 7 were 3.4g/m 2 ·d and 1.8g/m 2 ·d with overall mass transfer coefficients of 6.91×10 -6 and 4.99×10 -6 m/s, respectively. The results showed that moderately high H 2 S fluxes with low CH 4 loss may be achieved by using a robust and cost-effective membrane based absorption process for desulfurization of biogas. A tubular PDMS membrane contactor was tested for the first time to remove H 2 S from biogas under slightly alkaline conditions and the suggested process could be a promising for real scale applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Demonstration of Software Application Biogas Optimizer at the Haendeloe Biogas Site

    Energy Technology Data Exchange (ETDEWEB)

    Cook, Kristofer (Bioprocess Control Sweden AB, Lund (SE))

    2008-04-15

    There is a growing interest in the utilisation of process optimisation technologies within the biogas industry. This trend is being driven by new and growing market opportunities as well as an interest to improve the overall profitability of commercial biogas processes. Biogas Optimizer, developed by Bioprocess Control Sweden AB based in Lund, Sweden, represents one such process optimisation technology, utilising a supervisory and control approach to improve both biogas production efficiency and process stability. A demonstration project was conducted over a nine month period during 2007 at the Haendeloe biogas plant in Norrkoeping, Sweden, owned and operated by Svensk Biogas AB, to provide an indication of the potential of Biogas Optimizer to improve the competitiveness of biogas producers. The demonstration project attempted to satisfy 3 goals, namely; 1) to obtain baseline production information regarding the average Organic Loading Rate (OLR) and average Biogas Production Rate (BPR), 2) to demonstrate that the technology behind Biogas Optimizer works under full-scale production conditions, and 3) to verify that significant/notable production efficiency improvements can be achieved utilising Biogas Optimizer when compared to baseline production information, and that biogas production can be optimised for maximising the utilisation of reactor capacity while still leaving a comfortable safety margin so as to avoid reactor overloading. The collection of baseline production information during three months resulted in an average OLR of 4.0 Kg VS/m3/day and average BPR of 2.6 Nm3/m3/day being selected as baseline data from which to compare the performance of Biogas Optimizer. The full-scale demonstration of Biogas Optimizer was conducted over a 40 day period. During these 40 days, OLR recommendations from Biogas Optimizer, and the resulting manual adjustment of the OLR by the plant operator, resulted in an increase in the average OLR from 4.0 to 4.7 Kg/m3/day and

  17. 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...

  18. Effect of operating conditions and reactor configuration on efficiency of full-scale biogas plants

    DEFF Research Database (Denmark)

    Angelidaki, Irini; Boe, Kanokwan; Ellegaard, L.

    2005-01-01

    A study on 18 full-scale centralized biogas plants was carried out in order to find significant operational factors influencing productivity and stability of the plants. It was found that the most plants were operating relatively stable with volatile fatty acids (VFA) concentration below 1.5 g....../l. VFA concentration increase was observed in occasions with dramatic overloading or other disturbances such as operational temperature changes. Ammonia was found to be a significant factor for stability. A correlation between increased residual biogas production and high ammonia was found. When ammonia...

  19. A fuzzy-logic-based model to predict biogas and methane production rates in a pilot-scale mesophilic UASB reactor treating molasses wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Turkdogan-Aydinol, F. Ilter, E-mail: aydin@yildiz.edu.tr [Yildiz Technical University, Faculty of Civil Engineering, Department of Environmental Engineering, 34220 Davutpasa, Esenler, Istanbul (Turkey); Yetilmezsoy, Kaan, E-mail: yetilmez@yildiz.edu.tr [Yildiz Technical University, Faculty of Civil Engineering, Department of Environmental Engineering, 34220 Davutpasa, Esenler, Istanbul (Turkey)

    2010-10-15

    A MIMO (multiple inputs and multiple outputs) fuzzy-logic-based model was developed to predict biogas and methane production rates in a pilot-scale 90-L mesophilic up-flow anaerobic sludge blanket (UASB) reactor treating molasses wastewater. Five input variables such as volumetric organic loading rate (OLR), volumetric total chemical oxygen demand (TCOD) removal rate (R{sub V}), influent alkalinity, influent pH and effluent pH were fuzzified by the use of an artificial intelligence-based approach. Trapezoidal membership functions with eight levels were conducted for the fuzzy subsets, and a Mamdani-type fuzzy inference system was used to implement a total of 134 rules in the IF-THEN format. The product (prod) and the centre of gravity (COG, centroid) methods were employed as the inference operator and defuzzification methods, respectively. Fuzzy-logic predicted results were compared with the outputs of two exponential non-linear regression models derived in this study. The UASB reactor showed a remarkable performance on the treatment of molasses wastewater, with an average TCOD removal efficiency of 93 ({+-}3)% and an average volumetric TCOD removal rate of 6.87 ({+-}3.93) kg TCOD{sub removed}/m{sup 3}-day, respectively. Findings of this study clearly indicated that, compared to non-linear regression models, the proposed MIMO fuzzy-logic-based model produced smaller deviations and exhibited a superior predictive performance on forecasting of both biogas and methane production rates with satisfactory determination coefficients over 0.98.

  20. Reactor core performance estimating device

    International Nuclear Information System (INIS)

    Tanabe, Akira; Yamamoto, Toru; Shinpuku, Kimihiro; Chuzen, Takuji; Nishide, Fusayo.

    1995-01-01

    The present invention can autonomously simplify a neural net model thereby enabling to conveniently estimate various amounts which represents reactor core performances by a simple calculation in a short period of time. Namely, a reactor core performance estimation device comprises a nerve circuit net which divides the reactor core into a large number of spacial regions, and receives various physical amounts for each region as input signals for input nerve cells and outputs estimation values of each amount representing the reactor core performances as output signals of output nerve cells. In this case, the nerve circuit net (1) has a structure of extended multi-layered model having direct coupling from an upper stream layer to each of downstream layers, (2) has a forgetting constant q in a corrected equation for a joined load value ω using an inverse error propagation method, (3) learns various amounts representing reactor core performances determined using the physical models as teacher signals, (4) determines the joined load value ω decreased as '0' when it is to less than a predetermined value upon learning described above, and (5) eliminates elements of the nerve circuit net having all of the joined load value decreased to 0. As a result, the neural net model comprises an autonomously simplifying means. (I.S.)

  1. Aerobic desulfurization of biogas by acidic biotrickling filtration in a randomly packed reactor

    International Nuclear Information System (INIS)

    Montebello, Andrea M.; Mora, Mabel; López, Luis R.; Bezerra, Tercia; Gamisans, Xavier; Lafuente, Javier; Baeza, Mireia; Gabriel, David

    2014-01-01

    Highlights: • Desulfurization of high loads of H 2 S is feasible by acidic biotrickling filtration. • Robustness of the process is demonstrated in the long-term (550 d). • Biosulfur to sulfate oxidation under H 2 S starvation was successfully performed. • Lower sulfate production found at acidic pH compared to that at neutral pH. • Plastic material is recommended for long-term acidic biotrickling filtration. - Abstract: Biotrickling filters for biogas desulfurization still must prove their stability and robustness in the long run under extreme conditions. Long-term desulfurization of high loads of H 2 S under acidic pH was studied in a lab-scale aerobic biotrickling filter packed with metallic Pall rings. Reference operating conditions at steady-state corresponded to an empty bed residence time (EBRT) of 130 s, H 2 S loading rate of 52 g S–H 2 S m −3 h −1 and pH 2.50–2.75. The EBRT reduction showed that the critical EBRT was 75 s and the maximum EC 100 g S–H 2 S m −3 h −1 . Stepwise increases of the inlet H 2 S concentration up to 10,000 ppm v lead to a maximum EC of 220 g S–H 2 S m −3 h −1 . The H 2 S removal profile along the filter bed indicated that the first third of the filter bed was responsible for 70–80% of the total H 2 S removal. The oxidation rate of solid sulfur accumulated inside the bioreactor during periodical H 2 S starvation episodes was verified under acidic operating conditions. The performance under acidic pH was comparable to that under neutral pH in terms of H 2 S removal capacity. However, bioleaching of the metallic packing used as support and chemical precipitation of sulfide/sulfur salts occurred

  2. CANDU reactor experience: fuel performance

    International Nuclear Information System (INIS)

    Truant, P.T.; Hastings, I.J.

    1985-07-01

    Ontario Hydro has more than 126 reactor-years experience in operating CANDU reactors. Fuel performance has been excellent with 47 000 channel fuelling operations successfully completed and 99.9 percent of the more than 380 000 bundles irradiated operating as designed. Fuel performance limits and fuel defects have had a negligible effect on station safety, reliability, the environment and cost. The actual incapability charged to fuel is less than 0.1 percent over the stations' lifetimes, and more recently has been zero

  3. 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

  4. 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

  5. Metagenomic analysis on thermophilic biogas reactors fed with high load of Long Chain Fatty Acids (LCFA)

    DEFF Research Database (Denmark)

    Zhu, Xinyu; De Francisci, Davide; Treu, Laura

    In anaerobic digestion systems, the accumulation of long chain fatty acids (LCFA) leads to process instability and decrease of the methane production. This detrimental condition is known to be reversible depending on the concentration of the accumulated LCFAs and mainly on the microbial consortium...... due to LCFA increase in the feedstock composition. The result shows that the addition of sodium oleate caused a reversible inhibition of reactor. The correlation between the microbial community’s profile and the reactors performance indicated that Syntrophomonas was the genus most likely involved...... in sodium oleate degradation. Other genera that were found abundant are Pseudomonas, Clostridium XI and Clostridium III. The relative abundance of these genera was not significantly affected by the addition of sodium oleate, and this indicates that they are probably involved in later steps of degradation...

  6. 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.)

  7. Aerobic desulfurization of biogas by acidic biotrickling filtration in a randomly packed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Montebello, Andrea M.; Mora, Mabel; López, Luis R.; Bezerra, Tercia [Department of Chemical Engineering, School of Engineering, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Gamisans, Xavier [Department of Mining Engineering and Natural Resources, Universitat Politècnica de Catalunya, Bases de Manresa 61-73, 08240 Manresa (Spain); Lafuente, Javier [Department of Chemical Engineering, School of Engineering, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Baeza, Mireia [Department of Chemistry, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Gabriel, David, E-mail: david.gabriel@uab.cat [Department of Chemical Engineering, School of Engineering, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)

    2014-09-15

    Highlights: • Desulfurization of high loads of H{sub 2}S is feasible by acidic biotrickling filtration. • Robustness of the process is demonstrated in the long-term (550 d). • Biosulfur to sulfate oxidation under H{sub 2}S starvation was successfully performed. • Lower sulfate production found at acidic pH compared to that at neutral pH. • Plastic material is recommended for long-term acidic biotrickling filtration. - Abstract: Biotrickling filters for biogas desulfurization still must prove their stability and robustness in the long run under extreme conditions. Long-term desulfurization of high loads of H{sub 2}S under acidic pH was studied in a lab-scale aerobic biotrickling filter packed with metallic Pall rings. Reference operating conditions at steady-state corresponded to an empty bed residence time (EBRT) of 130 s, H{sub 2}S loading rate of 52 g S–H{sub 2}S m{sup −3} h{sup −1} and pH 2.50–2.75. The EBRT reduction showed that the critical EBRT was 75 s and the maximum EC 100 g S–H{sub 2}S m{sup −3} h{sup −1}. Stepwise increases of the inlet H{sub 2}S concentration up to 10,000 ppm{sub v} lead to a maximum EC of 220 g S–H{sub 2}S m{sup −3} h{sup −1}. The H{sub 2}S removal profile along the filter bed indicated that the first third of the filter bed was responsible for 70–80% of the total H{sub 2}S removal. The oxidation rate of solid sulfur accumulated inside the bioreactor during periodical H{sub 2}S starvation episodes was verified under acidic operating conditions. The performance under acidic pH was comparable to that under neutral pH in terms of H{sub 2}S removal capacity. However, bioleaching of the metallic packing used as support and chemical precipitation of sulfide/sulfur salts occurred.

  8. COD biological removal and biogas production in anaerobic reactor treating cassava wastewater industry; Remocao biologica de DQO e producao de biogas em reator anaerobio tratando efluente de fecularia de madioca

    Energy Technology Data Exchange (ETDEWEB)

    Watthier, Elisangela [Universidade Estadual do Oeste do Parana (UNIOESTE), Cascavel, PR (Brazil). Curso de Mestrado em Engenharia Agricola; Andreani, Cristiane Lurdes [Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brasilia, DF (Brazil); Gomes, Simone Damasceno [Universidade Estadual do Oeste do Parana (PGEAGRI/UNIOESTE), Cascavel, PR (Brazil). Programa de Pos-Graduacao em Engenharia Agricola; Moreschi, Roberson; Rufino, Mauricio de Oliveira [Universidade Estadual do Oeste do Parana (UNIOESTE), Cascavel, PR (Brazil). Curso de Engenharia Agricola

    2010-07-01

    The effluent from the cassava industry cause damage to the environment if released without treatment. One alternative is the implementation of anaerobic reactors, which also add value through the production of biogas. The support means increases the contact surface of micro-organisms and enhance their setting. The purpose of this study was to evaluate the reduction of organic matter (DQO) and biogas production in a reactor of PVC with 90 cm long and 15 cm in diameter, through support rings of bamboo, 10 cm in length and diameter ranged from 1.7 to 2.5 cm, with a volume of 6 L. The organic loading used were 4,357, 4,708, 5,601 and 6,126 g DQO.L-1.day-1, corresponding to hydraulic retention time (TRH) of 3,5, 2,8, 3,25 and 2,7 days, respectively. It was observed that with the increase of organic load was increased production of biogas, the largest observed for a load of 6.126 g DQO.L-1.day-1 with an average of 9.146 L.day-1. Regarding the removal of organic matter were achieved values of 98.35, 99.09, 99.33 and 98.55% respectively for each load applied, with the highest efficiency observed in charge of 5.601 g COD. L-1. day-1, but without significant differences. (author)

  9. Biogas and reduction of organic matter in anaerobic reactor with continuous flow means support; Producao de biogas e reducao de materia organica em reatores anaerobicos de fluxo continuo com meio suporte

    Energy Technology Data Exchange (ETDEWEB)

    Kunzler, Kathia Regina; Gomes, Simone Damasceno; Goncalves, Jefferson Luiz; Kuczman, Osvaldo [Universidade Estadual do Oeste do Parana (PGEAGRI/UNIOESTE), Cascavel, PR (Brazil). Programa de Pos-Graduacao em Engenharia Agricola], Emails: kathiark@yahoo.com.br, simoned@unioeste.br; Piana, Pitagoras Augusto [Universidade Estadual do Oeste do Parana (UNIOESTE), Toledo, PR (Brazil)

    2010-07-01

    Starch processing industries are to obtain cassava starch. Its main residue is the effluent resulting from pressing the roots, Manipueira, high organic load and toxic. In this study, we compared the removal efficiency of organic loading and biogas production in anaerobic reactors, with the support means bamboo in different relations width: height. The first lesion diameter of 15 cm and a length of 90 cm, a ratio 1:6 and the second with a diameter of 20 cm and 60 cm long, ratio of 1:3. The support medium consisted of rings of bamboo with 10 cm length and diameters between 1.7 and 2.5 cm. The loads applied were 0.519, 1.156, 1.471, 3.813, 4.347, 4.708 and 5.601gDQO/L.day. To evaluate the removal efficiency of organic matter, the samples were subjected to analysis of DQO biogas production was assessed in terms of organic load removed. Bamboo as a support allowed the application of higher loads. The higher efficiency in the production of biogas was produced in the reactor with the highest ratio width: height, being more significant for the organic load of 5, 601 gCOD/L.day, showing more stability this. (author)

  10. Environmental Performance of Miscanthus, Switchgrass and Maize: Can C4 Perennials Increase the Sustainability of Biogas Production?

    Directory of Open Access Journals (Sweden)

    Andreas Kiesel

    2016-12-01

    Full Text Available Biogas is considered a promising option for complementing the fluctuating energy supply from other renewable sources. Maize is currently the dominant biogas crop, but its environmental performance is questionable. Through its replacement with high-yielding and nutrient-efficient perennial C4 grasses, the environmental impact of biogas could be considerably improved. The objective of this paper is to assess and compare the environmental performance of the biogas production and utilization of perennial miscanthus and switchgrass and annual maize. An LCA was performed using data from field trials, assessing the impact in the five categories: climate change (CC, fossil fuel depletion (FFD, terrestrial acidification (TA, freshwater eutrophication (FE and marine eutrophication (ME. A system expansion approach was adopted to include a fossil reference. All three crops showed significantly lower CC and FFD potentials than the fossil reference, but higher TA and FE potentials, with nitrogen fertilizer production and fertilizer-induced emissions identified as hot spots. Miscanthus performed best and changing the input substrate from maize to miscanthus led to average reductions of −66% CC; −74% FFD; −63% FE; −60% ME and −21% TA. These results show that perennial C4 grasses and miscanthus in particular have the potential to improve the sustainability of the biogas sector.

  11. Experimental and numerical analysis of the performance and exhaust gas emissions of a biogas/n-heptane fueled HCCI engine

    KAUST Repository

    Kozarac, Darko; Taritas, Ivan; Vuilleumier, David; Saxena, Samveg; Dibble, Robert W.

    2016-01-01

    The use of highly reactive fuel as an ignition promoter enables operation of biogas fueled homogeneous charge compression ignition (HCCI) engine at low intake temperatures with practical control of combustion phasing. In order to gain some insight into this operation mode the influence of addition of n-heptane on combustion, performance, emissions and control of combustion phasing of a biogas fueled HCCI engine is experimentally researched and presented in this paper. Additionally, the performance analysis of the practical engine solution for such operation is estimated by using the numerical simulation of entire engine. The results showed that the introduction of highly reactive fuel results with a significant change in operating conditions and with a change in optimum combustion phasing. The addition of n-heptane resulted in lower nitrogen oxides and increased carbon monoxide emissions, while the unburned hydrocarbons emissions were strongly influenced by combustion phasing and at optimal conditions are lowered compared to pure biogas operation. The results also showed a practical operation range for strategies that use equivalence ratio as a control of load. Simulation results showed that the difference in performance between pure biogas and n-heptane/biogas operation is even greater when the practical engine solution is taken into account.

  12. Experimental and numerical analysis of the performance and exhaust gas emissions of a biogas/n-heptane fueled HCCI engine

    KAUST Repository

    Kozarac, Darko

    2016-09-12

    The use of highly reactive fuel as an ignition promoter enables operation of biogas fueled homogeneous charge compression ignition (HCCI) engine at low intake temperatures with practical control of combustion phasing. In order to gain some insight into this operation mode the influence of addition of n-heptane on combustion, performance, emissions and control of combustion phasing of a biogas fueled HCCI engine is experimentally researched and presented in this paper. Additionally, the performance analysis of the practical engine solution for such operation is estimated by using the numerical simulation of entire engine. The results showed that the introduction of highly reactive fuel results with a significant change in operating conditions and with a change in optimum combustion phasing. The addition of n-heptane resulted in lower nitrogen oxides and increased carbon monoxide emissions, while the unburned hydrocarbons emissions were strongly influenced by combustion phasing and at optimal conditions are lowered compared to pure biogas operation. The results also showed a practical operation range for strategies that use equivalence ratio as a control of load. Simulation results showed that the difference in performance between pure biogas and n-heptane/biogas operation is even greater when the practical engine solution is taken into account.

  13. 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.

  14. An innovative bioelectrochemical-anaerobic digestion-coupled system for in-situ ammonia recovery and biogas enhancement: process performance and microbial ecology

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Angelidaki, Irini

    (SMRC) and a continuous stirred tank reactor (CSTR), to prevent ammonia toxicity during anaerobic digestion by in-situ ammonia recovery and electricity production. In batch experiment, the ammonia concentration in the CSTR decreased from 6 to 0.7 g-N/L with an average recovery rate of 0.18 g-N/L(CSTR...... performance was enhanced. In addition, the coexistence of other cations in CSTR or cathode had no negative effect on the ammonia transportation. In continuous reactor operation, 112% extra biogas production was achieved due to ammonia recovery. High-throughput molecular sequencing analysis showed an impact...... of ammonia recovery on the microbial community composition in the integrated system. Results clearly indicate the great potential of the SMRC-CSTR-coupled system for efficient and cost-effective ammonia recovery, energy production and treatment of ammonia-rich residues....

  15. Microbial diversity and dynamicity of biogas reactors due to radical changes of feedstock composition

    DEFF Research Database (Denmark)

    De Francisci, Davide; Kougias, Panagiotis; Treu, Laura

    2015-01-01

    substrate change. The greatest increase in diversity was observed in the reactor supplemented with carbohydrates and the microbial community became dominated by lactobacilli, while the lowest corresponded to the reactor overfed with proteins, where only Desulfotomaculum showed significant increase...

  16. Performance Analysis of a MCFC/MGT Hybrid Power System Bi-Fueled by City Gas and Biogas

    Directory of Open Access Journals (Sweden)

    Hongyu Huang

    2015-06-01

    Full Text Available This study evaluates the performance of a molten carbonate fuel cell and micro gas turbine (MCFC/MGT hybrid power system bi-fueled by city gas and biogas. The performance of the MCFC/MGT hybrid power system and MFCF/MGT hybrid power system response have been investigated experimentally and numerically. Results show that the MCFC, steam reformer, and catalytic combustor models are in agreement with the experimental results of the system fueled by city gas only and the system bi-fueled by city gas and biogas. The MFCF/MGT hybrid power system can have manifest operation with the addition of biogas at a flow rate of up to 150.0 Nm3·h−1, which is about 50% of the overall input heat value. In addition, the MCFC and MGT outputs decrease with the increase in the flow rate of added biogas, with an overall power generation efficiency ranging from 39.0% to 42.0%. Furthermore, the MCFC/MGT hybrid power system can be operated stably both at low amplitude with slow current change and large amplitude with rapid power conditions. Finally, the MCFC/MGT hybrid system bi-fueled by city gas and biogas may be applicable to the energy supply of the micro–grid network.

  17. Performance evaluation of restaurant food waste and biowaste to biogas pilot projects in China and implications for national policy.

    Science.gov (United States)

    De Clercq, Djavan; Wen, Zongguo; Fan, Fei

    2017-03-15

    The objective of this research was to conduct a performance evaluation of three food waste/biowaste-to-biogas pilot projects across 7 scenarios in China based on multi-criteria decision analysis (MCDA) methodology. The projects ranked included a food waste-biogas project in Beijing, a food waste-biogas project in Suzhou and a co-digestion project producing biomethane in Hainan. The projects were ranked from best to worst based on technical, economic and environmental criteria under the MCDA framework. The results demonstrated that some projects are encountering operational problems. Based on these findings, six national policy recommendations were provided: (1) shift away from capital investment subsidies to performance-based subsidies; (2) re-design feed in tariffs; (3) promote bio-methane and project clustering; (4) improve collection efficiency by incentivizing FW producers to direct waste to biogas projects; (5) incentivize biogas projects to produce multiple outputs; (6) incentivize food waste-based projects to co-digest food waste with other substrates for higher gas output. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Assessment of energy performance in the life-cycle of biogas production

    International Nuclear Information System (INIS)

    Berglund, Maria; Boerjesson, Pal

    2006-01-01

    Energy balances are analysed from a life-cycle perspective for biogas systems based on 8 different raw materials. The analysis is based on published data and relates to Swedish conditions. The results show that the energy input into biogas systems (i.e. large-scale biogas plants) overall corresponds to 20-40% (on average approximately 30%) of the energy content in the biogas produced. The net energy output turns negative when transport distances exceed approximately 200 km (manure), or up to 700 km (slaughterhouse waste). Large variations exist in energy efficiency among the biogas systems studied. These variations depend both on the properties of the raw materials studied and on the system design and allocation methods chosen. The net energy output from biogas systems based on raw materials that have high water content and low biogas yield (e.g. manure) is relatively low. When energy-demanding handling of the raw materials is required, the energy input increases significantly. For instance, in a ley crop-based biogas system, the ley cropping alone corresponds to approximately 40% of the energy input. Overall, operation of the biogas plant is the most energy-demanding process, corresponding to 40-80% of the energy input into the systems. Thus, the results are substantially affected by the assumptions made about the allocation of a plant's entire energy demand among raw materials, e.g. regarding biogas yield or need of additional water for dilution

  19. Performance indicators for power reactors

    International Nuclear Information System (INIS)

    Gillies, C.; White, M.

    1995-11-01

    A review of Canadian and worldwide performance indicator definitions and data was performed to identify a set of indicators that could be used for comparison of performance among nuclear power plants. The results of this review are to be used as input to an AECB team developing a consistent set of performance indicators for measuring Canadian power reactor safety performance. To support the identification of performance indicators, a set of criteria was developed to assess the effectiveness of each indicator for meaningful comparison of performance information. The project identified a recommended set of performance indicators that could be used by AECB staff to compare the performance of Canadian nuclear power plants among themselves, and with international performance. The basis for selection of the recommended set and exclusion of others is provided. This report provides definitions and calculation methods for each recommended performance indicator. In addition, a spreadsheet has been developed for comparison and trending for the recommended set of indicators. Example trend graphs are included to demonstrate the use of the spreadsheet. (author). 50 refs., 11 tabs., 3 figs

  20. Optimization of biogas production from wheat straw stillage in UASB reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kaparaju, Prasad; Serrano, Maria; Angelidaki, Irini [Institute of Environment and Resources, Technical University of Denmark, Building 115, DK-2800 Kgs. Lyngby (Denmark)

    2010-12-15

    In the present study, thermophilic anaerobic digestion of wheat straw stillage was investigated. Methane potential of stillage was determined in batch experiments at two different substrate concentrations. Results showed that higher methane yields of 324 ml/g-(volatile solids) VS{sub added} were obtained at stillage concentrations of 12.8 g-VS/L than at 25.6 g-VS/l. Continuous anaerobic digestion of stillage was performed in an up-flow anaerobic sludge blanket (UASB) reactor at 55 C with 2 days hydraulic retention time. Results showed that both substrate concentration and organic loading rate (OLR) influenced process performance and methane yields. Maximum methane yield of 155 ml CH{sub 4}/g-COD was obtained at stillage mixtures with water of 25% (v/v) in the feed and at an OLR of 17.1 g-COD/(l.d). Soluble chemical oxygen demand (SCOD) removal at this OLR was 76% (w/w). Increase in OLR to 41.2 g-COD/(l.d) and/or stillage concentration in the feed to 33-50% (v/v) resulted in low methane yields or complete process failure. The results showed that thermophilic anaerobic digestion of wheat straw stillage alone for methane production is feasible in UASB reactor at an OLR of 17.1 g-COD/(l.d) and at substrate concentration of 25% in the feed. The produced methane could improve the process energy and economics of a bioethanol plant and also enable to utilize the stillage in a sustainable manner. (author)

  1. Optimization of biogas production from wheat straw stillage in UASB reactor

    International Nuclear Information System (INIS)

    Kaparaju, Prasad; Serrano, Maria; Angelidaki, Irini

    2010-01-01

    In the present study, thermophilic anaerobic digestion of wheat straw stillage was investigated. Methane potential of stillage was determined in batch experiments at two different substrate concentrations. Results showed that higher methane yields of 324 ml/g-(volatile solids) VS added were obtained at stillage concentrations of 12.8 g-VS/L than at 25.6 g-VS/l. Continuous anaerobic digestion of stillage was performed in an up-flow anaerobic sludge blanket (UASB) reactor at 55 o C with 2 days hydraulic retention time. Results showed that both substrate concentration and organic loading rate (OLR) influenced process performance and methane yields. Maximum methane yield of 155 ml CH 4 /g-COD was obtained at stillage mixtures with water of 25% (v/v) in the feed and at an OLR of 17.1 g-COD/(l.d). Soluble chemical oxygen demand (SCOD) removal at this OLR was 76% (w/w). Increase in OLR to 41.2 g-COD/(l.d) and/or stillage concentration in the feed to 33-50% (v/v) resulted in low methane yields or complete process failure. The results showed that thermophilic anaerobic digestion of wheat straw stillage alone for methane production is feasible in UASB reactor at an OLR of 17.1 g-COD/(l.d) and at substrate concentration of 25% in the feed. The produced methane could improve the process energy and economics of a bioethanol plant and also enable to utilize the stillage in a sustainable manner.

  2. Importance of reduced sulfur for the equilibrium chemistry and kinetics of Fe(II), Co(II) and Ni(II) supplemented to semi-continuous stirred tank biogas reactors fed with stillage

    International Nuclear Information System (INIS)

    Shakeri Yekta, Sepehr; Lindmark, Amanda; Skyllberg, Ulf; Danielsson, Åsa; Svensson, Bo H.

    2014-01-01

    Highlights: • Thermodynamics and kinetics of Fe, Co and Ni added to biogas reactors were studied. • Formation of Fe-sulfide and Fe-thiol aqueous complexes controlled the Fe solubility. • Cobalt solubility was controlled by processes independent of Co-sulfide interaction. • Iron added to the biogas reactors effected the Ni speciation and solubility. - Abstract: The objective of the present study was to assess major chemical reactions and chemical forms contributing to solubility and speciation of Fe(II), Co(II), and Ni(II) during anaerobic digestion of sulfur (S)-rich stillage in semi-continuous stirred tank biogas reactors (SCSTR). These metals are essential supplements for efficient and stable performance of stillage-fed SCSTR. In particular, the influence of reduced inorganic and organic S species on kinetics and thermodynamics of the metals and their partitioning between aqueous and solid phases were investigated. Solid phase S speciation was determined by use of S K-edge X-ray absorption near-edge spectroscopy. Results demonstrated that the solubility and speciation of supplemented Fe were controlled by precipitation of FeS(s) and formation of the aqueous complexes of Fe-sulfide and Fe-thiol. The relatively high solubility of Co (∼20% of total Co content) was attributed to the formation of compounds other than Co-sulfide and Co-thiol, presumably of microbial origin. Nickel had lower solubility than Co and its speciation was regulated by interactions with FeS(s) (e.g. co-precipitation, adsorption, and ion substitution) in addition to precipitation/dissolution of discrete NiS(s) phase and formation of aqueous Ni-sulfide complexes

  3. Importance of reduced sulfur for the equilibrium chemistry and kinetics of Fe(II), Co(II) and Ni(II) supplemented to semi-continuous stirred tank biogas reactors fed with stillage

    Energy Technology Data Exchange (ETDEWEB)

    Shakeri Yekta, Sepehr, E-mail: sepehr.shakeri.yekta@liu.se [Department of Thematic Studies – Water and Environmental Studies, Linköping University, SE-581 83 Linköping (Sweden); Lindmark, Amanda [Department of Thematic Studies – Water and Environmental Studies, Linköping University, SE-581 83 Linköping (Sweden); Skyllberg, Ulf [Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83 Umeå (Sweden); Danielsson, Åsa; Svensson, Bo H. [Department of Thematic Studies – Water and Environmental Studies, Linköping University, SE-581 83 Linköping (Sweden)

    2014-03-01

    Highlights: • Thermodynamics and kinetics of Fe, Co and Ni added to biogas reactors were studied. • Formation of Fe-sulfide and Fe-thiol aqueous complexes controlled the Fe solubility. • Cobalt solubility was controlled by processes independent of Co-sulfide interaction. • Iron added to the biogas reactors effected the Ni speciation and solubility. - Abstract: The objective of the present study was to assess major chemical reactions and chemical forms contributing to solubility and speciation of Fe(II), Co(II), and Ni(II) during anaerobic digestion of sulfur (S)-rich stillage in semi-continuous stirred tank biogas reactors (SCSTR). These metals are essential supplements for efficient and stable performance of stillage-fed SCSTR. In particular, the influence of reduced inorganic and organic S species on kinetics and thermodynamics of the metals and their partitioning between aqueous and solid phases were investigated. Solid phase S speciation was determined by use of S K-edge X-ray absorption near-edge spectroscopy. Results demonstrated that the solubility and speciation of supplemented Fe were controlled by precipitation of FeS(s) and formation of the aqueous complexes of Fe-sulfide and Fe-thiol. The relatively high solubility of Co (∼20% of total Co content) was attributed to the formation of compounds other than Co-sulfide and Co-thiol, presumably of microbial origin. Nickel had lower solubility than Co and its speciation was regulated by interactions with FeS(s) (e.g. co-precipitation, adsorption, and ion substitution) in addition to precipitation/dissolution of discrete NiS(s) phase and formation of aqueous Ni-sulfide complexes.

  4. 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

  5. Submerged anaerobic membrane bioreactor (SAnMBR) performance on sewage treatment: removal efficiencies, biogas production and membrane fouling.

    Science.gov (United States)

    Chen, Rong; Nie, Yulun; Ji, Jiayuan; Utashiro, Tetsuya; Li, Qian; Komori, Daisuke; Li, Yu-You

    2017-09-01

    A submerged anaerobic membrane reactor (SAnMBR) was employed for comprehensive evaluation of sewage treatment at 25 °C and its performance in removal efficiency, biogas production and membrane fouling. Average 89% methanogenic degradation efficiency as well as 90%, 94% and 96% removal of total chemical oxygen demand (TCOD), biochemical oxygen demand (BOD) and nonionic surfactant were obtained, while nitrogen and phosphorus were only subjected to small removals. Results suggest that SAnMBRs can effectively decouple organic degradation and nutrients disposal, and reserve all the nitrogen and phosphorus in the effluent for further possible recovery. Small biomass yields of 0.11 g mixed liquor volatile suspended solids (MLVSS)/gCOD were achieved, coupled to excellent methane production efficiencies of 0.338 NLCH 4 /gCOD, making SAnMBR an attractive technology characterized by low excess sludge production and high bioenergy recovery. Batch tests revealed the SAnMBR appeared to have the potential to bear a high food-to-microorganism ratio (F/M) of 1.54 gCOD/gMLVSS without any inhibition effect, and maximum methane production rate occurred at F/M 0.7 gCOD/gMLVSS. Pore blocking dominated the membrane fouling behaviour at a relative long hydraulic retention time (HRT), i.e. >12 hours, while cake layer dominated significantly at shorter HRTs, i.e. <8 hours.

  6. 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...

  7. 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.

  8. MAPLE research reactor beam-tube performance

    International Nuclear Information System (INIS)

    Lee, A.G.; Lidstone, R.F.; Gillespie, G.E.

    1989-05-01

    Atomic Energy of Canada Limited (AECL) has been developing the MAPLE (Multipurpose Applied Physics Lattice Experimental) reactor concept as a medium-flux neutron source to meet contemporary research reactor applications. This paper gives a brief description of the MAPLE reactor and presents some results of computer simulations used to analyze the neutronic performance. The computer simulations were performed to identify how the MAPLE reactor may be adapted to beam-tube applications such as neutron radiography

  9. High performance light water reactor

    International Nuclear Information System (INIS)

    Squarer, D.; Schulenberg, T.; Struwe, D.; Oka, Y.; Bittermann, D.; Aksan, N.; Maraczy, C.; Kyrki-Rajamaeki, R.; Souyri, A.; Dumaz, P.

    2003-01-01

    The objective of the high performance light water reactor (HPLWR) project is to assess the merit and economic feasibility of a high efficiency LWR operating at thermodynamically supercritical regime. An efficiency of approximately 44% is expected. To accomplish this objective, a highly qualified team of European research institutes and industrial partners together with the University of Tokyo is assessing the major issues pertaining to a new reactor concept, under the co-sponsorship of the European Commission. The assessment has emphasized the recent advancement achieved in this area by Japan. Additionally, it accounts for advanced European reactor design requirements, recent improvements, practical design aspects, availability of plant components and the availability of high temperature materials. The final objective of this project is to reach a conclusion on the potential of the HPLWR to help sustain the nuclear option, by supplying competitively priced electricity, as well as to continue the nuclear competence in LWR technology. The following is a brief summary of the main project achievements:-A state-of-the-art review of supercritical water-cooled reactors has been performed for the HPLWR project.-Extensive studies have been performed in the last 10 years by the University of Tokyo. Therefore, a 'reference design', developed by the University of Tokyo, was selected in order to assess the available technological tools (i.e. computer codes, analyses, advanced materials, water chemistry, etc.). Design data and results of the analysis were supplied by the University of Tokyo. A benchmark problem, based on the 'reference design' was defined for neutronics calculations and several partners of the HPLWR project carried out independent analyses. The results of these analyses, which in addition help to 'calibrate' the codes, have guided the assessment of the core and the design of an improved HPLWR fuel assembly. Preliminary selection was made for the HPLWR scale

  10. Co-digestion of manure and whey for in situ biogas upgrading by the addition of H2: process performance and microbial insights

    DEFF Research Database (Denmark)

    Luo, Gang; Angelidaki, Irini

    2013-01-01

    composition. The best biogas composition (75:6.6:18.4) was obtained at stirring speed 150 rpmand using ceramic diffuser, while the biogas in the control reactor consisted of CH4 and CO2 at a ratio of 55:45. The consumed hydrogen was almost completely converted to CH4, and there was no significant accumulation......In situ biogas upgrading was conducted by introducing H2 directly to the anaerobic reactor. As H2 addition is associated with consumption of the CO2 in the biogas reactor, pH increased to higher than 8.0 when manure alone was used as substrate. By co-digestion of manure with acidic whey, the p......H in the anaerobic reactor with the addition of hydrogen could be maintained below 8.0, which did not have inhibition to the anaerobic process. The H2 distribution systems (diffusers with different pore sizes) and liquid mixing intensities were demonstrated to affect the gas-liquid mass transfer of H2 and the biogas...

  11. Process performance and comparative metagenomic analysis during co-digestion of manure and lignocellulosic biomass for biogas production

    International Nuclear Information System (INIS)

    Tsapekos, P.; Kougias, P.G.; Treu, L.; Campanaro, S.; Angelidaki, I.

    2017-01-01

    Highlights: • Pig manure and ensiled meadow grass were examined in co-digestion process. • Mechanical pretreatment increased the methane yield by 6.4%. • Coprothermobacter proteolyticus was firmly bounded to the digested grass. • Clostridium thermocellum was enriched in the firmly attached grass samples. • The abundance of methanogens was higher in the liquid fraction of digestate. - Abstract: Mechanical pretreatment is considered to be a fast and easily applicable method to prepare the biomass for anaerobic digestion. In the present study, the effect of mechanical pretreatment on lignocellulosic silages biodegradability was elucidated in batch reactors. Moreover, co-digestion of the silages with pig manure in continuously fed biogas reactors was examined. Metagenomic analysis for determining the microbial communities in the pig manure digestion system was performed by analysing unassembled shotgun genomic sequences. A comparative analysis allowed to identify the microbial species firmly attached to the digested grass particles and to distinguish them from the planktonic microbes floating in the liquid medium. It was shown that the methane yield of ensiled grass was significantly increased by 12.3% due to mechanical pretreatment in batch experiments. Similarly, the increment of the methane yield in the co-digestion system reached 6.4%. Regarding the metagenomic study, species similar to Coprothermobacter proteolyticus and to Clostridium thermocellum, known for high proteolytic and cellulolytic activity respectively, were found firmly attached to the solid fraction of digested feedstock. Results from liquid samples revealed clear differences in microbial community composition, mainly dominated by Proteobacteria. The archaeal community was found in higher relative abundance in the liquid fraction of co-digestion experiment compared to the solid fraction. Finally, an unclassified Alkaliphilus sp. was found in high relative abundance in all samples.

  12. Performance of a UASB reactor treating coffee wet wastewater

    International Nuclear Information System (INIS)

    Guardia Puebla, Yans; Rodríguez Pérez, Suyén; Janet Jiménez Hernández; Sánchez Girón, Víctor

    2014-01-01

    The present work shows the results obtained in the anaerobic digestion process of coffee wet wastewater processing. An UASB anaerobic reactor was operated in single-stage in mesophilic temperature controlled conditions (37±1ºC). The effect of both organic loading rate (OLR) and hydraulic retention time (HRT) in the anaerobic digestion of coffee wet wastewater was investigated. The OLR values considered in the single-stage UASB reactor varied in a range of 3,6-4,1 kgCOD m-3 d-1 and the HRT stayed in a range of 21,5-15,5 hours. The evaluation results show that the best performance of UASB reactor in single-stage was obtained at OLR of 3,6 kg COD m-3 d-1 with an average value of total and soluble COD removal of 77,2% and 83,4%, respectively, and average methane concentration in biogas of 61%. The present study suggests that the anaerobic digestion is suitable to treating coffee wet wastewater. (author)

  13. Production of biogas from plant materials

    Energy Technology Data Exchange (ETDEWEB)

    Zuer, J.

    1980-12-01

    Different crop residues from agriculture and horticulture were investigated for feasibility of producing biogas. The anaerobic fermentation has been performed in batch system fermentation reactors (5 liters) at mesophilic conditions (35 degrees C). Content of volatile solids (VS/TS) in raw materials varied from 78.5 percent in silage from top of sugar beet to 97.3 percent in straw of rye. The highest content of lignin was found in stalks of Jerusalem artichoke (49.6 percent), stalks of horse bean (47.6 percent) and the lowest in leaves of cauliflower (9.5 percent), top of sugar beet and leaves of cabbage (11 percent) in both. Ratio of carbon to nitrogen was the highest in the straw of rye (60) and the lowest in silage from top of sugar beet (11) and in leaves of cauliflower (11). Rate of biogas production during the first 13 days of fermentation was about 27 liters per kg TS per day, achieved from top of sugar beet. Typical mean rate of biogas production, about 9 liters per kg TS per day, was performed during the first 40 days of retention time from straw of wheat and stalks of rape. Top of sugar beet and manure slurry have had the shortest effective retention time ca 20 days. Maximum total yield of biogas (427.0 liters per kg TS) was achieved from top of sugar beet. From manure slurry 257.5 liters biogas per kg TS was obtained. Methane content in biogas produced during the final 7 days of retention time was the highest from silage from top of artichoke (72.8 percent), stalks of horse bean (71.6 percent) and straw of wheat (71.0 percent). The lowest percentage of methane (59.0 percent) was found in biogas from top of sugar beet.

  14. 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 ...

  15. Diversity of archaea and bacteria in a biogas reactor fed with ...

    African Journals Online (AJOL)

    1College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, 2School of Food Science and. Engineering ... rumen microbes in artificial reactors for the conversion of ..... feed additive due to the high digestibility of the.

  16. Purification of bioethanol effluent in an UASB reactor system with simultaneous biogas formation

    DEFF Research Database (Denmark)

    Torry-Smith, Mads Peter; Sommer, Peter; Ahring, Birgitte Kiær

    2003-01-01

    of these compounds were removed from the BEE in the reactor. Implementation of a UASB purification step was found to be a promising approach to detoxify process water from bioethanol production allowing for recirculation of the process water and reduced production costs.......In this study, the prospect of using an Upflow Anaerobic Sludge Blanket (UASB) reactor for detoxification of process water derived from bioethanol production has been investigated. The bioethanol effluent (BEE) originated from wet oxidized wheat straw fermented by Saccharomyces cerevisiae...

  17. Evaluation of silage-fed biogas process performance using microbiological and kinetic methods

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, Aa

    1996-10-01

    In this study, different kinetic and microbiological methods were used to evaluate the growth and activity of key groups of bacteria degrading ley silage in one-phase and two-phase biogas processes. Emphasis was placed on studying the dynamic behaviour of different trophic groups resulting from the initiation of liquid recirculation in the processes. The microbiological methods included microscopy and most probable number (MPN) counts with different substrates. The kinetic methods included measurements of specific methanogenic activity (SMA) with acetate and H{sub 2}/CO{sub 2} as substrates, batch assays with trace element additions and measurement of conversion rates of mannitol and lactate in the digesters. In general, the initiation of liquid recirculation at first promoted the growth and/or activity of several trophic groups of bacteria, such as butyrate and propionate degraders and acetotrophic and hydrogenotrophic methanogens in the liquefaction/acidogenesis reactors of the two-phase processes. This was probably mainly due to the increased pH. However, after some time of liquid recirculation, an inhibition of some bacterial groups occurred, such as propionate degraders and methanogens in the methanogenic reactors of two-phase processes. This was probably due to increased concentrations of salts and free ammonia. The batch assays proved to be valuable tools in process optimization by the addition of trace elements. Here, the addition of cobalt significantly increased methane production from acetate. In this study, a more comprehensive understanding of the process behaviour in response to the initiation of liquid recirculation was achieved which could not have been obtained by only monitoring routine parameters such as pH, methane production and concentrations of organic acids and salts. 120 refs, 4 figs, 1 tab

  18. The economic performance of combined heat and power from biogas produced from manure in Sweden – A comparison of different CHP technologies

    International Nuclear Information System (INIS)

    Lantz, Mikael

    2012-01-01

    Highlights: ► Interest in biogas from manure is increasing rapidly due to its climate benefits. ► Farm-scale production of CHP from manure-based biogas is not profitable in Sweden. ► Minor changes in energy prices or suggested production subsidies will make it profitable. ► Profitability is also affected by efficiency of scale and introduction of thermophilic conditions. -- Abstract: Interest in the generation of biogas from agricultural residues is increasing rapidly due to its climate benefits. In this study, an evaluation of the economic feasibility of various technologies, also on different scales, for the production of combined heat and power from manure-based biogas in Sweden is presented. The overall conclusion is that such production is not profitable under current conditions. Thus, the gap between the calculated biogas production cost and the acceptable cost for break-even must be bridged by, for example, different policy instruments. In general, efficiency of scale favors large-scale plants compared to individual farm-scale ones. However, a large, centralized biogas plant, using manure from numerous farms, is not always more cost efficient than a large, farm-scale plant treating manure from a few neighboring farms. The utilization of the produced heat, electricity prices, and political incentives, all have a significant impact on the economic outcome, whereas the value of the digestate as fertilizer is currently having a minor impact. Utilization of heat is, however, often limited by the lack of local heat sinks, in which case the implementation of a biogas process operating under thermophilic conditions could increase the profitability due to a more efficient utilization of reactor volume by using more process heat. The results from this study could be utilized by policy makers when implementing policy instruments considering biogas production from manure as well as companies involved in production and utilization of biogas.

  19. 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)

  20. MODIFIKASI KARBON AKTIF SEBAGAI ADSORBEN UNTUK PEMURNIAN BIOGAS

    Directory of Open Access Journals (Sweden)

    Heru Susanto

    2012-08-01

    Full Text Available The use of biogas as an environmentally friendly fuel is limited by the presence of CO2 and water vapor asimpurities. Therefore, biogas purification for CO2 and water vapor removal is very important step during biogasapplication. This paper presents a process for biogas purification by means of adsorption using either modifiedor unmodified activated carbon as an adsorbent. The modification was performed by passing a pure ammoniagas into activated carbon in a quartz reactor. The results showed that the adsorption process using modifiedactivated carbon decreases CO2 content in biogas up to 67.5% whereas for unmodified activated carbon was of43%. Further, the modification increased CO2 adsorption capacity from ~28 to ~38 mg CO2/g adsorbent. Theincrease in feed temperature decreases CO2 adsorption capacity.

  1. The biogas

    International Nuclear Information System (INIS)

    Rigaud, Ch.; Laffargue, C.; Zebboud, I.

    2007-01-01

    Mixed of methane and carbon dioxide the biogas can be produced by many sources for the heat or the electricity production and the fuel production. This document aims to better understand the biogas, its characteristics, its valorization, the plants concerned, the installations and the regulation. It provides also an example of a biogas power plant and the biogas use in the farms. (A.L.B.)

  2. Effect of swirl on the performance and combustion of a biogas fuelled spark ignition engine

    International Nuclear Information System (INIS)

    Porpatham, E.; Ramesh, A.; Nagalingam, B.

    2013-01-01

    Highlights: • Tests were conducted on a biogas fuelled SI engine with normal and masked valve. • Improvement in brake power and brake thermal efficiency with masked valve. • Lean misfire limit is extended with enhanced swirl from 0.68 to 0.65. • Enhanced swirl decreases HC level from1530 ppm to 1340 ppm and increases NO emission from 2250 ppm to 3440 ppm. • The reduction in ignition delay and higher heat release rate with enhanced swirl. - Abstract: The influence of swirl on the performance, emissions and combustion in a constant speed Spark Ignition (SI) engine was studied experimentally. A single cylinder diesel engine was modified to operate as a biogas operated spark ignition engine. The engine was operated at 1500 rpm at throttle opening of 25% and 100% at various equivalence ratios. The tests covered a range of equivalence ratios from rich to lean operating limits and also at an optimum compression ratio of 13:1 with normal and masked intake valve to enhance swirl. The spark timing was set to MBT (Minimum advance for Best Torque). It was found that masked valve configuration enhanced the power output and brake thermal efficiency at full throttle. The lean limit of combustion also got extended. Heat release rates indicated enhanced combustion rates with masked valve, which are mainly responsible for the improvement in thermal efficiency. NO level increased with masked valve as compared to normal configuration. The spark timings were to be retarded by about 6 °CA and 4 °CA when compared to normal configuration at 25% and 100% throttle respectively

  3. 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)

  4. Investigation of the prospect of energy self-sufficiency and technical performance of an integrated PEMFC (proton exchange membrane fuel cell), dairy farm and biogas plant system

    International Nuclear Information System (INIS)

    Guan, Tingting; Alvfors, Per; Lindbergh, Göran

    2014-01-01

    Highlights: • A PEMFC stack with a 40% of electrical efficiency will make the integrated PEMFC-CHP, biogas plant and dairy farm self-sufficient. • The quality of the reformate gas is good enough to support normal operation of the PEMFC-CHP. • The methane conversion rate and the content of the CH 4 in the biogas need to be balanced in order to obtain the best system performance. • Compared with a coal-fired CHP plant, the integrated system can avoid coal consumption and CO 2 emissions. - Abstract: A PEMFC fuelled with hydrogen is known for its high efficiency and low local emissions. However, the generation of hydrogen is always a controversial issue for the application of the PEMFC due to the use of fossil fuel and the possible carbon dioxide emissions. Presently, the PEMFC-CHP fed with renewable fuels, such as biogas, appears to be the most attractive energy converter–fuel combination. In this paper, an integrated PEMFC-CHP, a dairy farm and a biogas plant are studied. A PEMFC-CHP fed with reformate gas from the biogas plant generates electricity and heat to a dairy farm and a biogas plant, while the dairy farm delivers wet manure to the biogas plant as the feedstock for biogas production. This integrated system has been modelled for steady-state conditions by using Aspen Plus®. The results indicate that the wet manure production of a dairy farm with 300 milked cows can support a biogas plant to give 1280 MW h of biogas annually. Based on the biogas production, a PEMFC-CHP with a stack having an electrical efficiency of 40% generates 360 MW h electricity and 680 MW h heat per year, which is enough to cover the energy demand of the whole system while the total efficiency of the PEMFC-CHP system is 82%. The integrated PEMFC-CHP, dairy farm and biogas plant could make the dairy farm and the biogas plant self-sufficient in a sustainable way provided the PEMFC-CHP has the electrical efficiency stated above. The effect of the methane conversion rate and the

  5. Performance and emission characteristics of biogas used in diesel engine operation

    International Nuclear Information System (INIS)

    Makareviciene, Violeta; Sendzikiene, Egle; Pukalskas, Saugirdas; Rimkus, Alfredas; Vegneris, Ricardas

    2013-01-01

    Highlights: • Biogas is an environmentally friendly biofuel for diesel engines. • Results of diesel engine tests when fuelling with biogas are presented. • Engine and environmental characteristics depends on carbon dioxide content in biogas. • Using biogas in a diesel engine requires certain operational modifications. - Abstract: The objective of this study it to evaluate the impact of the carbon dioxide concentration in biogas on the operating characteristics and exhaust gas emissions of a diesel engine running on a mixture of biogas and mineral diesel fuel. The tests were carried out in two stages. In the first stage, the impact of different biogas compositions and the exhaust gas recirculation system (EGR) on the engine parameters was determined. Lower pollutant levels were measured in the studies without the EGR system, except for the nitrogen oxides NO x levels. The NO x concentration decrease was directly proportional to the concentration of methane in the common fuel mixture. In the second stage, the gas with the highest methane content was used to determine the impact of the start of injection timing on the engine operating parameters. As the methane content in the common fuel mixture increased, the start of injection timing had to be progressively advanced to increase the thermal efficiency and to lower the fuel consumption, the CO and HC concentrations and the smokiness of the exhaust; however, advancing the start of injection timing increased NO x pollution

  6. Biogas production from wheat straw in batch and UASB reactors: the roles of pretreatment and seaweed hydrolysate as a co-substrate.

    Science.gov (United States)

    Nkemka, Valentine Nkongndem; Murto, Marika

    2013-01-01

    This research evaluated biogas production in batch and UASB reactors from pilot-scale acid catalysed steam pretreated and enzymatic hydrolysed wheat straw. The results showed that the pretreatment was efficient and, a sugar yield of 95% was obtained. The pretreatment improved the methane yield (0.28 m(3)/kg VS(added)) by 57% compared to untreated straw. Treatment of the straw hydrolysate with nutrient supplementation in a UASB reactor resulted in a high methane production rate, 2.70 m(3)/m(3).d at a sustainable OLR of 10.4 kg COD/m(3).d and with a COD reduction of 94%. Alternatively, co-digestion of the straw and seaweed hydrolysates in a UASB reactor also maintained a stable anaerobic process and can thus reduce the cost of nutrients addition. We have shown that biogas production from wheat straw can be competitive by pretreatment, high methane production rate in UASB reactors and also by co-digestion with seaweed hydrolysate. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Optimization of hydrogen dispersion in thermophilic up-flow reactors for ex situ biogas upgrading

    DEFF Research Database (Denmark)

    Bassani, Ilaria; Kougias, Panagiotis; Treu, Laura

    2017-01-01

    and CO2, up to 3.6L/LREACTOR·d H2 loading rate. Specifically, reactors' CH4 content increased from 23 to 96% and the CH4 yield reached 0.25LCH4/LH2. High throughput 16S rRNA gene sequencing revealed predominance of bacteria belonging to Anaerobaculum genus and to uncultured order MBA08. Additionally...

  8. Low-temperature upgrading of low-calorific biogas for CO2 mitigation using DBD-catalyst hybrid reactor

    Science.gov (United States)

    Nozaki, Tomohiro; Tsukijihara, Hiroyuki; Fukui, Wataru; Okazaki, Ken

    2006-10-01

    Although huge amounts of biogas, which consists of 20-60% of CH4 in CO2/N2, can be obtained from landfills, coal mines, and agricultural residues, most of them are simply flared and wasted: because global warming potential of biogas is 5-15 times as potent as CO2. Poor combustibility of such biogas makes it difficult to utilize in conventional energy system. The purpose of this project is to promote the profitable recovery of methane from poor biogas via non-thermal plasma technology. We propose low-temperature steam reforming of biogas using DBD generated in catalyst beds. Methane is partially converted into hydrogen, and then fed into internal combustion engines for improved ignition stability as well as efficient operation. Low-temperature steam reforming is beneficial because exhaust gas from an engine can be used to activate catalyst beds. Space velocity (3600-15000 hr-1), reaction temperature (300-650^oC), and energy cost (30-150 kJ per mol CH4) have been investigated with simulated biogas (20-60% CH4 in mixtures of CO2/N2). The DBD enhances reaction rate of CH4 by a factor of ten at given catalyst temperatures, which is a rate-determining step of methane steam reforming, while species concentration of upgraded biogas was governed by thermodynamic equilibrium in the presence of catalyst.

  9. Performance evaluation of a completely stirred anaerobic reactor treating pig manure at a low range of mesophilic conditions

    International Nuclear Information System (INIS)

    Guo, Jianbin; Dong, Renjie; Clemens, Joachim; Wang, Wei

    2013-01-01

    Highlights: • The biogas process can run stably at 20 °C at extremely low OLR after long-term acclimation of bacteria. • A biogas plant running at 28 °C seems as efficient as that operated at 38 °C at low OLR of 1.3 g ODM L −1 d −1 . • Lower temperature operation is inadvisable for the commercial biogas plant running at rather high OLR. • The estimated sludge yield at 28 °C is higher than that at 38 °C. - Abstract: Many Chinese biogas plants run in the lower range of mesophilic conditions. This study evaluated the performance of a completely stirred anaerobic reactor treating pig manure at different temperatures (20, 28 and 38 °C). The start-up phase of the reactor at 20 °C was very long and extremely poor performance was observed with increasing organic loading rate (OLR). At an OLR of 4.3 g ODM L −1 d −1 , methane production at 28 °C was comparable (3% less) with that at 38 °C, but the risk of acidification was high at 28 °C. At low OLR (1.3 g ODM L −1 d −1 ), the biogas process appeared stable at 28 °C and gave same methane yields as compared to the reactor operating at 38 °C. The estimated sludge yield at 28 °C was 0.065 g VSS g −1 COD removed, which was higher than that at 38 °C (0.016 g VSS g −1 COD removed )

  10. 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

  11. 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

  12. Inhibitory effect of coumarin on syntrophic fatty acid-oxidizing and methanogenic cultures and biogas reactor microbiomes

    NARCIS (Netherlands)

    Popp, Denny; Plugge, Caroline M.; Kleinsteuber, Sabine; Harms, Hauke; Sträuber, Heike

    2017-01-01

    Coumarins are widely found in plants as natural constituents having antimicrobial activity. When considering plants that are rich in coumarins for biogas production, adverse effects on microorganisms driving the anaerobic digestion process are expected. Furthermore, coumarin derivatives, like

  13. Nuclear fuel performance in boiling water reactors

    International Nuclear Information System (INIS)

    Elkins, R.B.; Baily, W.E.; Proebstle, R.A.; Armijo, J.S.; Klepfer, H.H.

    1981-01-01

    A major development program is described to improve the performance of Boiling Water Reactor fuel. This sustained program is described in four parts: 1) performance monitoring, 2) fuel design changes, 3) plant operating recommendations, and 4) advanced fuel programs

  14. Strategies for recovering inhibition caused by long chain fatty acids on anaerobic thermophilic biogas reactors

    DEFF Research Database (Denmark)

    Palatsi, J.; Laureni, M.; Andres, M.V.

    2009-01-01

    patterns, dilution and addition of adsorbents, in order to determine the most appropriate strategy for fast recovery of the reactor activity in manure based plants inhibited by LCFA. Dilution with active inoculum for increasing the biomass/LCFA ratio, or addition of adsorbents for adsorbing the LCFA...... biomass to an inhibitory concentration of LCFA improved the recovery ability of the system, indicated as increasing degradation rates from 0.04 to 0.16 g COD_CH4/g VS day. The incubation time between subsequent pulses, or discontinuous LCFA pulses, seems to be a decisive process parameter to tackle LCFA...

  15. Biogas barometer

    International Nuclear Information System (INIS)

    2014-01-01

    The energy recovery of biogas has kept on increasing in the European Union in 2013: +10.2%. Almost 13.4 million tep (tonnes of oil equivalent) of biogas primary energy was produced but the growth of the biogas sector is decreasing (it was 16.9% between 2011 and 2012). The growth for the coming years is expected to fall further because of political decisions in some countries to limit the use of land for farming purposes and to manage the biogas sector more efficiently. Germany ranks first for the production of biogas primary energy with 6717 ktep followed by United Kingdom with 1824 ktep. 2 tables give the production of electricity and heat from biogas in the E.U. member states in 2012 and 2013. The total production of electricity and heat from biogas in the E.U. in 2013 reached 53327 GWh and 432 ktep respectively. A list reviews the most significant companies working in Europe in the sector of methanation, 10 companies are listed among which 2 are Italian: AB Energy (Gruppo AB), BTS Italia and 8 are German: MT Energie, Envitec Biogas AG, Biogas Weser-Ems, Planet Biogastechnik, Schmack Biogas GmbH, Weltec Biopower GmbH, UTS Biogastechnik (Anaergia Group), Bioconstruct and BTS Italia. (A.C.)

  16. Space reactor fuels performance and development issues

    International Nuclear Information System (INIS)

    Wewerka, E.M.

    1984-01-01

    Three compact reactor concepts are now under consideration by the US Space Nuclear Power Program (the SP-100 Program) as candidates for the first 100-kWe-class space reactor. Each of these reactor designs puts unique constraints and requirements on the fuels system, and raises issues of fuel systems feasibility and performance. This paper presents a brief overview of the fuel requirements for the proposed space reactor designs, a delineation of the technical feasibility issues that each raises, and a description of the fuel systems development and testing program that has been established to address key technical issues

  17. 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.

  18. 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.

  19. Short-term effect of acetate and ethanol on methane formation in biogas sludge.

    Science.gov (United States)

    Refai, Sarah; Wassmann, Kati; Deppenmeier, Uwe

    2014-08-01

    Biochemical processes in biogas plants are still not fully understood. Especially, the identification of possible bottlenecks in the complex fermentation processes during biogas production might provide potential to increase the performance of biogas plants. To shed light on the question which group of organism constitutes the limiting factor in the anaerobic breakdown of organic material, biogas sludge from different mesophilic biogas plants was examined under various conditions. Therefore, biogas sludge was incubated and analyzed in anaerobic serum flasks under an atmosphere of N2/CO2. The batch reactors mirrored the conditions and the performance of the full-scale biogas plants and were suitable test systems for a period of 24 h. Methane production rates were compared after supplementation with substrates for syntrophic bacteria, such as butyrate, propionate, or ethanol, as well as with acetate and H2+CO2 as substrates for methanogenic archaea. Methane formation rates increased significantly by 35 to 126 % when sludge from different biogas plants was supplemented with acetate or ethanol. The stability of important process parameters such as concentration of volatile fatty acids and pH indicate that ethanol and acetate increase biogas formation without affecting normally occurring fermentation processes. In contrast to ethanol or acetate, other fermentation products such as propionate, butyrate, or H2 did not result in increased methane formation rates. These results provide evidence that aceticlastic methanogenesis and ethanol-oxidizing syntrophic bacteria are not the limiting factor during biogas formation, respectively, and that biogas plant optimization is possible with special focus on methanogenesis from acetate.

  20. Performance evaluation of oxygen, air and nitrate for the microaerobic removal of hydrogen sulphide in biogas from sludge digestion.

    Science.gov (United States)

    Díaz, I; Lopes, A C; Pérez, S I; Fdz-Polanco, M

    2010-10-01

    The removal performance of hydrogen sulphide in severely polluted biogas produced during the anaerobic digestion of sludge was studied by employing pure oxygen, air and nitrate as oxidant reactives supplied to the biodigester. Research was performed in a 200-L digester with an hydraulic retention time (HRT) of ∼20 days under mesophilic conditions. The oxygen supply (0.25 N m³/m³ feed) to the bioreactor successfully reduced the hydrogen sulphide content from 15,811 mg/N m³ to less than 400 mg/N m³. The introduction of air (1.27 N m³/m³ feed) removed more than 99% of the hydrogen sulphide content, with a final concentration of ∼55 mg/N m³. COD removal, VS reduction and methane yield were not affected under microaerobic conditions; however, methane concentration in the biogas decreased when air was employed as a result of nitrogen dilution. The nitrate addition was not effective for hydrogen sulphide removal in the biogas. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Biogas in the natural gas distribution network; Biogas til nettet

    Energy Technology Data Exchange (ETDEWEB)

    Kvist Jensen, T.

    2009-05-15

    With the Danish 'Thorsoe Biogas Plant' as reference case, an assessment of the possibility of using the existing natural gas distribution network for distributing biogas was carried out. Technologies for and cost of upgrading biogas to natural gas quality are presented. Furthermore, a socio-economic analysis has been performed, including the Danish financial conditions, the market models, and the role of the natural gas distribution companies.

  2. Biogas Filter Based on Local Natural Zeolite Materials

    OpenAIRE

    Krido Wahono, Satriyo; Anggo Rizal, Wahyu

    2014-01-01

    UPT BPPTK LIPI has created a biogas filter tool to improve the purity of methane in the biogas. The device shaped cylindrical tube containing absorbent materials which based on local natural zeolite of Indonesia. The absorbent has been activated and modified with other materials. This absorbtion material has multi-adsorption capacity for almost impurities gas of biogas. The biogas  filter increase methane content of biogas for 5-20%. The biogas filter improve the biogas’s performance such as ...

  3. System for obtaining biogas. System zur Gewinnung von Biogas

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1985-01-17

    The invention refers to a system for obtaining biogas from organic substances in at least one drum reactor, which is situated in a container accepting a liquid and which is driven so that it rotates preferably around its horizontal drum axis. It is distinguished by the fact that for at least one drum reactor acting as the main reactor there is at least one further reactor ahead of it for the pre-treatment or pre-fermentation of the substances.

  4. Evaluation of the efficiency of a plug-flow digester to produce biogas from swine waste water; Avaliacao da eficiencia de um biodigestor tubular na producao de biogas a partir de aguas residuarias de suinocultura

    Energy Technology Data Exchange (ETDEWEB)

    Feiden, Armin [Universidade Estadual do Oeste do Parana (UNIOESTE), Marechal Candido Rondon, PR (Brazil). Centro de Ciencias Agrarias; Reichl, Johann [Escola de Energia Biolsolar, Quatro Pontes, PR (Brazil); Schwab, Jair; Schwab, Vera [Colegio Estadual Entre Rios do Oeste, PR (Brazil)

    2004-07-01

    The performance of a plug-flow digester, type Reichl, was evaluated with and without mixing. The digester, treating swine wastewater, had a capacity of 800 m{sup 3} and were operated at a loading rate of 0,931 kg and 0,634 kg of total solids and volatile solids per day, respectively. With mixing, the daily average biogas production was 289,50 m{sup 3} day{sup -1}, the specific volume production of 0,362 m{sup 3} biogas m{sup -3} reactor day{sup -1} and a specific biogas production of 0,389 m{sup 3} and 0,571 m{sup 3} biogas kg{sup -1} total solids and volatile solids added, respectively. Without mixing, was observed a reduction of 17,69% on the daily average biogas production, to only 238,30 m{sup 3} day{sup -1}. It correspond to a specific volume production of 0,298 m{sup 3} biogas m{sup -3} reactor day{sup -1} and a specific biogas production of 0,320 m{sup 3} and 0,470 m{sup 3} biogas kg{sup -1} total solids and volatile solids added, respectively. With mixing, a reduction of 68,67% total solids was achieved, compared to 52,11% without mixing. Considering volatile solids, it was achieved 80,16% with mixing, compared to 58,77% without mixing. (author)

  5. Biogas barometer

    International Nuclear Information System (INIS)

    Anon.

    2004-01-01

    Unlike the other renewable energy sectors, biogas production did not result from concerns over energy but rather from environmental preoccupations (elimination of pollution, treatment of waste, control of greenhouse gas emissions). Biogas produced in this manner constitutes a sizeable and renewable deposit, with European production (EU 15) in the region of 3219 ktoe in 2003. (author)

  6. 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

  7. 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

  8. Biogas performance from co-digestion of Taihu algae and kitchen wastes

    International Nuclear Information System (INIS)

    Zhao, Ming-Xing; Ruan, Wen-Quan

    2013-01-01

    Highlights: • Co-digestion mode improves the biogas yield of Taihu algae and kitchen wastes. • Neutral protease enzyme reached maximum in algae only group. • The activity of dehydrogenase enzyme in mixed substrate groups was higher than that of algae and kitchen wastes only group. - Abstract: Co-digestion of Taihu algae with high carbon content substrate can balance the nutrients in the fermentation process. In this study, optimal mixing ratio for co-digestion of Taihu algae and kitchen wastes were investigated in order to improve biogas production potential. The results indicated that the biogas yield reached 388.6 mL/gTS at C/N15:1 group, which was 1.29 and 1.18 times of algae and kitchen wastes only. The maximum concentration of VFA reached 4239 mg/L on 8th day in kitchen wastes group, which was 1.21 times of algae group. Neutral protease enzyme activity in algae group reached maximum of 904.2 μg/(gTS h), while dehydrogenase enzyme at C/N 15:1 group reached maximum of 3402.2 μgTF/(gTS h). The feasibility of adjusting the C/N with co-digestion of Taihu algae and kitchen wastes to increase biogas production was demonstrated. Remarkably, the C/N of 15:1 was found to be the most appropriate ratio

  9. Effects of organic loading rate on biogas production from macroalgae: Performance and microbial community structure.

    Science.gov (United States)

    Sun, Meng-Ting; Fan, Xiao-Lei; Zhao, Xiao-Xian; Fu, Shan-Fei; He, Shuai; Manasa, M R K; Guo, Rong-Bo

    2017-07-01

    Macroalgae biomass has been considered as a promising feedstock for biogas production. In order to improve the efficiency of anaerobic digestion (AD) of macroalgae, semi-continuous fermentation was conducted to examine the effects of organic loading rate (OLR) on biogas production from Macrocystis pyrifer. Results showed that, under OLRs of 1.37, 2.74, 4.12 and 6.85kgVS substrate /(m 3 ·d), the average unit biogas yields were 438.9, 477.3, 480.1 and 188.7mL/(gVS substrate d), respectively. It indicated that biogas production was promoted by the increased OLR in an appropriate range while inhibited by the OLR beyond the appropriate range. The investigation on physical-chemical parameters revealed that unfavorable VFAs concentration, pH and salinity might be the main causes for system failure due to the overrange OLR, while the total phenols failed to reach the inhibitory concentration. Microbial community analysis demonstrated that several bacterial and archaeal phyla altered with increase in OLR apparently. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Effect of fermented biogas residue on growth performance, serum biochemical parameters, and meat quality in pigs

    Directory of Open Access Journals (Sweden)

    Xiang Xu

    2017-10-01

    Full Text Available Objective This study investigated the effect of fermented biogas residue (FBR of wheat on the performance, serum biochemical parameters, and meat quality in pigs. Methods We selected 128 pigs (the mean initial body weight was 40.24±3.08 kg and randomly allocated them to 4 groups (1 control group and 3 treatment groups with 4 replicates per group and 8 pigs per pen in a randomized complete block design based on initial body weight and sex. The control group received a corn-soybean meal-based diet, the treatment group fed diets containing 5%, 10%, and 15% FBR, respectively (abbreviated as FBR5, FBR10, and FBR15, respectively. Every group received equivalent-energy and nitrogen diets. The test lasted 60 days and was divided into early and late stages. Blood and carcass samples were obtained on 60 d. Meat quality was collected from two pigs per pen. Results During the late stage, the average daily feed intake and average daily gain of the treatment groups was greater than that of the control group (p<0.05. During the entire experiment, the average daily gain of the treatment groups was higher than that of the control group (p<0.05. Fermented biomass residue did not significantly affect serum biochemical parameters or meat quality, but did affect amino acid profiles in pork. The contents of Asp, Arg, Tyr, Phe, Leu, Thr, Ser, Lys, Pro, Ala, essential amino acids, non-essential amino acids, and total amino acids in pork of FBR5 and FBR10 were greater than those of the control group (p<0.05. Conclusion These combined results suggest that feeding FBR could increase the average daily gain and average daily feed intake in pigs and the content of several flavor-promoting amino acids.

  11. Reactor shutdown: nuclear power plant performance

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    The article essentially looks at the performance of nine of Sweden's nuclear reactors. A table lists the percentage of time for the first three quarters of 1981 that the reactors were operating, and the number of hours out of service for planned or other reasons. In particular, one station - Ringhals 3 - was out of action because of a damaged tube in the associated steam generator. The same fault occurred with another reactor - Ringhals 4 - before this was brought into service. The reasons for the failure and its importance are briefly discussed. (G.P.)

  12. Enhancing biogas production from vinasse in sugarcane biorefineries: Effects of urea and trace elements supplementation on process performance and stability.

    Science.gov (United States)

    Janke, Leandro; Leite, Athaydes F; Batista, Karla; Silva, Witan; Nikolausz, Marcell; Nelles, Michael; Stinner, Walter

    2016-10-01

    In this study, the effects of nitrogen, phosphate and trace elements supplementation were investigated in a semi-continuously operated upflow anaerobic sludge blanket system to enhance process stability and biogas production from sugarcane vinasse. Phosphate in form of KH2PO4 induced volatile fatty acids accumulation possibly due to potassium inhibition of the methanogenesis. Although nitrogen in form of urea increased the reactor's alkalinity, the process was overloaded with an organic loading rate of 6.1gCODL(-1)d(-1) and a hydraulic retention time of 3.6days. However, by supplementing urea and trace elements a stable operation even at an organic loading rate of 9.6gCODL(-1)d(-1) and a hydraulic retention time of 2.5days was possible, resulting in 79% higher methane production rate with a stable specific methane production of 239mLgCOD(-1). Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Biogas combined-heat-and-power-unit in practice: emission behaviour and performance behaviour; Biogas-BHKW in der Praxis: Emissions- und Leistungsverhalten

    Energy Technology Data Exchange (ETDEWEB)

    Aschmann, V.; Kissel, R.; Gronauer, A. [Bayerische Landesanstalt fuer Landwirtschaft (LfL), Freising-Weihenstephan (Germany). Inst. fuer Landtechnik und Tierhaltung

    2007-07-01

    The electrical power output of the combined-heat-and-power-unit (CHPU) is prioritized when biogas is used for electricity production. However, during servicing and adjusting of engines, beside power output, exhaust gas emissions should also be taken into consideration. Investigations at several biogas driven CHPU prior to maintenance revealed NO{sub x}-levels in the exhaust gas that were in part considerably in excess of respective limit values. The limit values could be met by servicing and adjusting the engine, but this resulted in decreased electrical efficiency and power output. (orig.)

  14. Different approaches to assess the environmental performance of a cow manure biogas plant

    Science.gov (United States)

    Torrellas, Marta; Burgos, Laura; Tey, Laura; Noguerol, Joan; Riau, Victor; Palatsi, Jordi; Antón, Assumpció; Flotats, Xavier; Bonmatí, August

    2018-03-01

    In intensive livestock production areas, farmers must apply manure management systems to comply with governmental regulations. Biogas plants, as a source of renewable energy, have the potential to reduce environmental impacts comparing with other manure management practices. Nevertheless, manure processing at biogas plants also incurs in non-desired gas emissions that should be considered. At present, available emission calculation methods cover partially emissions produced at a biogas plant, with the subsequent difficulty in the preparation of life cycle inventories. The objective of this study is to characterise gaseous emissions: ammonia (NH3-N), methane (CH4), nitrous oxide (N2Oindirect, and N2Odirect) and hydrogen sulphide (H2S) from the anaerobic co-digestion of cow manure by using different approaches for preparing gaseous emission inventories, and to compare the different methodologies used. The chosen scenario for the study is a biogas plant located next to a dairy farm in the North of Catalonia, Spain. Emissions were calculated by two methods: field measurements and estimation, following international guidelines. International Panel on Climate Change (IPCC) guidelines were adapted to estimate emissions for the specific situation according to Tier 1, Tier 2 and Tier 3 approaches. Total air emissions at the biogas plant were calculated from the emissions produced at the three main manure storage facilities on the plant: influent storage, liquid fraction storage, and the solid fraction storage of the digestate. Results showed that most of the emissions were produced in the liquid fraction storage. Comparing measured emissions with estimated emissions, NH3, CH4, N2Oindirect and H2S total emission results were in the same order of magnitude for both methodologies, while, N2Odirect total measured emissions were one order of magnitude higher than the estimates. A Monte Carlo analysis was carried out to examine the uncertainties of emissions determined from

  15. 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

  16. Sicilian potential biogas production

    Directory of Open Access Journals (Sweden)

    Antonio Comparetti

    2013-09-01

    Full Text Available This study is aimed at predicting the Sicilian potential biogas production, using the Organic Fraction of Municipal Solid Waste (OFMSW, animal manure and food industry by-products, in a region where only one biogas plant using MSW and one co-digestion plant are nowadays available. The statistical data about OFMSW, the number of animals bred in medium and large farms and the amounts of by-products of food processing industries were evaluated, in order to compute the Sicilian potential biogas and energy production. The OFMSW produced in Sicily, that is 0.8 million tons ca. per year (37% of MSW, could be used in a bio-reactor, together with other raw materials, for Anaerobic Digestion (AD process, producing biogas and “digestate”. Moreover, 3.03 million tons ca. of manure, collected in medium and large animal husbandry farms (where cows, pigs and poultry are bred, and 350 thousand tons ca. of by-products, collected in food processing industries (pomace from olive oil mills and grape marc from wineries, might be used for AD process. The Sicilian potential biogas production from the AD of the above raw materials is 170.2 millions of m3, that is equal to 1023.4 GWh of energy per year, of which 484 GWh from animal manure, 303 GWh from OFMSW and 236.4 GWh from food industry by-products. The highest biogas production is in the province of Palermo (35.6 millions of m3, Ragusa (30.8 millions of m3 and Catania (22.8 millions of m3, having a potential energy production of 213.8, 185 and 137 GWh, respectively.

  17. BEAP profiles as rapid test system for status analysis and early detection of process incidents in biogas plants.

    Science.gov (United States)

    Refai, Sarah; Berger, Stefanie; Wassmann, Kati; Hecht, Melanie; Dickhaus, Thomas; Deppenmeier, Uwe

    2017-03-01

    A method was developed to quantify the performance of microorganisms involved in different digestion levels in biogas plants. The test system was based on the addition of butyrate (BCON), ethanol (ECON), acetate (ACON) or propionate (PCON) to biogas sludge samples and the subsequent analysis of CH 4 formation in comparison to control samples. The combination of the four values was referred to as BEAP profile. Determination of BEAP profiles enabled rapid testing of a biogas plant's metabolic state within 24 h and an accurate mapping of all degradation levels in a lab-scale experimental setup. Furthermore, it was possible to distinguish between specific BEAP profiles for standard biogas plants and for biogas reactors with process incidents (beginning of NH 4 + -N inhibition, start of acidification, insufficient hydrolysis and potential mycotoxin effects). Finally, BEAP profiles also functioned as a warning system for the early prediction of critical NH 4 + -N concentrations leading to a drop of CH 4 formation.

  18. 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...

  19. Experimental Study on Productivity Performance of Household Combined Thermal Power and Biogas System in Northwest China

    Directory of Open Access Journals (Sweden)

    Jian Kang

    2018-01-01

    Full Text Available Ample quantities of solar and local biomass energy are available in the rural regions of northwest China to satisfy the energy needs of farmers. In this work, low-temperature solar thermal collectors, photovoltaic solar power generators, and solar-powered thermostatic biogas digesters were combined to create a heat, electricity, and biogas cogeneration system and were experimentally studied through two buildings in a farming village in northwestern China. The results indicated that the floor heater had the best heating effect. And the fraction of the energy produced by the solar elements of the system was 60.3%. The photovoltaic power-generation system achieved photovoltaic (PV conversion efficiencies of 8.3% and 8.1% during the first and second season, respectively. The intrinsic power consumption of the system was 143.4 kW·h, and 115.7 kW·h of electrical power was generated by the system in each season. The average volume of biogas produced daily was approximately 1.0 m3. Even though the ambient temperature reached −25°C, the temperature of the biogas digester was maintained at 27°C ± 2 for thermostatic fermentation. After optimization, the energy-saving rate improved from 66.2% to 85.5%. The installation reduced CO2 emissions by approximately 27.03 t, and the static payback period was 3.1 yr. Therefore, the system is highly economical, energy efficient, and beneficial for the environment.

  20. Experimental Study on Productivity Performance of Household Combined Thermal Power and Biogas System in Northwest China

    Science.gov (United States)

    Zhen, Xiaofei; Osman, Yassir Idris Abdalla; Feng, Rong; Si, Zetian

    2018-01-01

    Ample quantities of solar and local biomass energy are available in the rural regions of northwest China to satisfy the energy needs of farmers. In this work, low-temperature solar thermal collectors, photovoltaic solar power generators, and solar-powered thermostatic biogas digesters were combined to create a heat, electricity, and biogas cogeneration system and were experimentally studied through two buildings in a farming village in northwestern China. The results indicated that the floor heater had the best heating effect. And the fraction of the energy produced by the solar elements of the system was 60.3%. The photovoltaic power-generation system achieved photovoltaic (PV) conversion efficiencies of 8.3% and 8.1% during the first and second season, respectively. The intrinsic power consumption of the system was 143.4 kW·h, and 115.7 kW·h of electrical power was generated by the system in each season. The average volume of biogas produced daily was approximately 1.0 m3. Even though the ambient temperature reached −25°C, the temperature of the biogas digester was maintained at 27°C ± 2 for thermostatic fermentation. After optimization, the energy-saving rate improved from 66.2% to 85.5%. The installation reduced CO2 emissions by approximately 27.03 t, and the static payback period was 3.1 yr. Therefore, the system is highly economical, energy efficient, and beneficial for the environment. PMID:29862289

  1. Performance Indicators of Operating Reactors

    Data.gov (United States)

    Nuclear Regulatory Commission — A list of Performance Indicators (PI) that are reported to the NRC by licensees at the end of each quarter in accordance with Inspection Manual Chapters (IMC) 0608,...

  2. 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)

  3. Thermal performance of milk chilling units in remote villages working with the combination of biomass, biogas and solar energies

    International Nuclear Information System (INIS)

    Edwin, M.; Sekhar, S. Joseph

    2015-01-01

    The milk processing and preservation is a fast growing business in developing countries and it is facing problems due to high energy cost and environmental concerns in using conventional energy sources. The energy tapped from renewable energy sources through the technological innovations would be one of the best options to implement the milk preservation strategies at village level. In rural areas, bioenergy is one of the most versatile energy-generating options. Because of the diversity in feed stock and conversion technologies, suitable study is needed to implement renewable energy base technologies to provide a continuous flow of energy services. In this paper, the use of locally available renewable energy sources, in various combinations, to operate a milk chilling plant at village level has been analysed using the Matlab software. The effect of variations in the combination of renewable energy sources on the overall system COP has been studied. The study predicts that the best possible overall system COPs in hilly, rubber cultivation, paddy and seashore regions are 0.26, 0.25, 0.235 and 0.24 respectively. Moreover, suitable combinations identified in the aforementioned regions are Biomass/Gobar gas (0.7:0.3), Biomass/Biogas/Gobar gas (0.7:0.1:0.2), Biogas/Biomass/Gobar gas (0.6:0.15:0.25) and Biomass/Gobar gas/Biogas/Solar (0.5:0.25:0.125:0.125) respectively. - Highlights: • Hybrid energy based milk cooling system for remote regions. • Performance studies on cooling systems with the combination of renewable energy sources is carried out. • Renewable energy sources available in remote villages to meet the short term milk preservation needs. • Identification of suitable combinations of renewable energy sources to give maximum thermodynamic performance. • Identification of appropriate combinations of renewable energy sources to meet the milk cooling needs in remote regions.

  4. Water Reactor Fuel Performance Meeting 2008

    International Nuclear Information System (INIS)

    2008-10-01

    This meeting contains articles of the Water Reactor Fuel Performance Meeting 2008 of Korean Nuclear Society, Atomic Energy Society of Japan, Chinese Nuclear Society, European Nuclear Society and American Nuclear Society. It was held on Oct. 19-23, 2008 in Seoul, Korea and subject of Meeting is 'New Clear' Fuel - A green energy solution. This proceedings is comprised of 5 tracks. The main topic titles of track are as follows: Advances in water reactor fuel technology, Fuel performance and operational experience, Transient fuel behavior and safety-related issues, Fuel cycle, spent fuel storage and transportations and Fuel modeling and analysis. (Yi, J. H.)

  5. 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.

  6. 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)

  7. Reactor performance and microbial community dynamics during anaerobic co-digestion of municipal wastewater sludge with restaurant grease waste at steady state and overloading stages.

    Science.gov (United States)

    Razaviarani, Vahid; Buchanan, Ian D

    2014-11-01

    Linkage between reactor performance and microbial community dynamics was investigated during mesophilic anaerobic co-digestion of restaurant grease waste (GTW) with municipal wastewater sludge (MWS) using 10L completely mixed reactors and a 20day SRT. Test reactors received a mixture of GTW and MWS while control reactors received only MWS. Addition of GTW to the test reactors enhanced the biogas production and methane yield by up to 65% and 120%, respectively. Pyrosequencing revealed that Methanosaeta and Methanomicrobium were the dominant acetoclastic and hydrogenotrophic methanogen genera, respectively, during stable reactor operation. The number of Methanosarcina and Methanomicrobium sequences increased and that of Methanosaeta declined when the proportion of GTW in the feed was increased to cause an overload condition. Under this overload condition, the pH, alkalinity and methane production decreased and VFA concentrations increased dramatically. Candidatus cloacamonas, affiliated within phylum Spirochaetes, were the dominant bacterial genus at all reactor loadings. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Biogas generation apple pulp.

    Science.gov (United States)

    Llaneza Coalla, H; Blanco Fernández, J M; Morís Morán, M A; López Bobo, M R

    2009-09-01

    In view of the pressing problem that appears in our region (Asturias, north of Spain) with the residues from the cider production, it was decided to test this kind of material as a co-substrate joint with slaughterhouse waste in a laboratory unit. The anaerobic digestion of apple pulp was investigated for biogas production. This paper presents the results where apple pulp was co-digested with slaughterhouse waste (pig intestine and bovine stomach content) in a biogas laboratory unit (10 l CSTR reactor). The production of biogas has reached very satisfactory values during the whole test (0.8m(3)kg(-1)OTS), verifying that the process is kept in stable conditions of pH (near 8.0), and the volatile fatty acids was always underneath 3000 mg/l, when the pulp amount was lower than 100g in mesophilic conditions. The fat concentration into the digester remained always below the value that causes inhibition of the methanogenic bacteria, 500 mg/l. Finally, methane concentration (77-80%) and H(2)S concentration (400 ppm) in the biogas, they were similar to those obtained when the test was run out in the absence of apple pulp. The process efficiency with respect to COD removal was high, near 80% of the total COD. Finally, inhibitory effects of methanogenic bacteria were observed when pulp concentration was around 10% in the input material.

  9. Sustainable operation of submerged Anammox membrane bioreactor with recycling biogas sparging for alleviating membrane fouling.

    Science.gov (United States)

    Li, Ziyin; Xu, Xindi; Xu, Xiaochen; Yang, FengLin; Zhang, ShuShen

    2015-12-01

    A submerged anaerobic ammonium oxidizing (Anammox) membrane bioreactor with recycling biogas sparging for alleviating membrane fouling has been successfully operated for 100d. Based on the batch tests, a recycling biogas sparging rate at 0.2m(3)h(-1) was fixed as an ultimate value for the sustainable operation. The mixed liquor volatile suspended solid (VSS) of the inoculum for the long operation was around 3000mgL(-1). With recycling biogas sparging rate increasing stepwise from 0 to 0.2m(3)h(-1), the reactor reached an influent total nitrogen (TN) up to 1.7gL(-1), a stable TN removal efficiency of 83% and a maximum specific Anammox activity (SAA) of 0.56kg TNkg(-1) VSSd(-1). With recycling biogas sparging rate at 0.2 m(3) h(-1) (corresponding to an aeration intensity of 118m(3)m(-2)h(-1)), the membrane operation circle could prolong by around 20 times compared to that without gas sparging. Furthermore, mechanism of membrane fouling was proposed. And with recycling biogas sparging, the VSS and EPS content increasing rate in cake layer were far less than the ones without biogas sparging. The TN removal performance and sustainable membrane operation of this system showed the appealing potential of the submerged Anammox MBR with recycling biogas sparging in treating high-strength nitrogen-containing wastewaters. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Biogas technology in Pakistan

    International Nuclear Information System (INIS)

    Ahmed, M.

    1997-02-01

    Although biomethanation is a mature technology its implementation is paradoxically only partly a success in Pakistan. Biogas plants on family farms can be economical but seldom are so in Pakistan. Either the investment cost has been high or satisfactory performance of the process could not be maintained or in some case for a short period of time only. It is, however, concluded that biogas plants, if correctly operated and maintained, may prove to be appropriate to the technical abilities and economic capacity of Pakistani farmers. It can get a change to be disseminated in rural areas. Biogas technology is appropriate to the ecological and economic demands of the future. With the potential from existing cattle population only, 3 to 4 million family size biogas plants may be installed in Pakistan which can substitute of considerable part of rural fuel wood demand for their daily household energy requirements. A large amount of dung is burnt every year by households which if put in the biogas plant, may provide a considerable amount of energy along with organic fertilizer could be saved from being burned at the same time. On the basis of available data from the livestock excluding agriculture residue (50% collectivity-1991), in terms of fuel substitution, this would be equivalent to 1200 million litres of kerosene at worth economic value of 9021 million rupees saving in the form of gas and 821 million rupees as additional fertilizer value annually. (LN)

  11. SOFC Operation with Real Biogas

    DEFF Research Database (Denmark)

    Hagen, Anke; Winiwarter, Anna; Langnickel, Hendrik

    2017-01-01

    Biogas is a valuable energy source and will be available in future in systems relying on renewables. It is an attractive fuel for solid oxide fuel cells (SOFC), which are able to utilize the carbon contained in the biogas and which produce electricity with high efficiency. In the current paper......, state‐of‐the‐art SOFCs were studied regarding performance and durability in relation to biogas as fuel and considering important contaminants, specifically sulfur. First, the catalytic behavior in relevant synthetic biogas mixtures was studied and the potential of dry reforming was demonstrated....... Successful long term operation of an SOFC under both, conditions of steam and dry reforming, i.e., addition of steam or CO2 to avoid carbon formation was shown. For the steam reforming case a remarkable period of 3,500 h, hereof 3,000 h in the presence of H2S was achieved. Finally, a real biogas from...

  12. Biogas recirculation for simultaneous calcium removal and biogas purification within an expanded granular sludge bed system treating leachate.

    Science.gov (United States)

    Luo, Jinghuan; Lu, Xueqin; Liu, Jianyong; Qian, Guangren; Lu, Yongsheng

    2014-12-01

    Biogas, generated from an expanded granular sludge bed (EGSB) reactor treating municipal solid waste (MSW) leachate, was recirculated for calcium removal from the leachate via a carbonation process with simultaneous biogas purification. Batch trials were performed to optimize the solution pH and imported biogas (CO2) for CaCO3 precipitation. With applicable pH of 10-11 obtained, continuous trials achieved final calcium concentrations of 181-375 mg/L (removal efficiencies≈92.8-96.5%) in the leachate and methane contents of 87.1-91.4% (purification efficiencies≈65.4-82.2%) in the biogas. Calcium-balance study indicates that 23-986 mg Ca/d was released from the bio-system under the carbonized condition where CaCO3 precipitating was moved outside the bioreactor, whereas 7918-9517 mg Ca/d was trapped into the system for the controlled one. These findings demonstrate that carbonation removal of calcium by biogas recirculation could be a promising alternative to pretreat calcium-rich MSW leachate and synergistically to improve methane content. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Quantification of syntrophic fatty acid-beta-oxidizing bacteria in a mesophilic biogas reactor by oligonucleotide probe hybridization

    DEFF Research Database (Denmark)

    Hansen, K.W.; Ahring, Birgitte Kiær; Raskin, L.

    1999-01-01

    Small-subunit rRNA sequences were obtained for two saturated fatty acid-beta-oxidizing syntrophic bacteria, Syntrophomonas sapovorans and Syntrophomonas wolfei LYE, and sequence analysis confirmed their classification as members of the family Syntrophomonadaceae. S, wolfei LYE was closely related...... fatty acid-beta-oxidizing syntrophic bacteria in methanogenic environments, the microbial community structure of a sample from a full-scale biogas plant was determined. Hybridization results with probes for syntrophic bacteria-and methanogens were compared to specific methanogenic activities...

  14. Effect of engine load and biogas flow rate to the performance of a compression ignition engine run in dual-fuel (dieselbiogas) mode

    Science.gov (United States)

    Ambarita, H.

    2018-02-01

    The Government of Indonesia (GoI) has released a target on reduction Green Houses Gases emissions (GHG) by 26% from level business-as-usual by 2020, and the target can be up to 41% by international supports. In the energy sector, this target can be reached effectively by promoting fossil fuel replacement or blending with biofuel. One of the potential solutions is operating compression ignition (CI) engine in dual-fuel (diesel-biogas) mode. In this study effects of engine load and biogas flow rate on the performance and exhaust gas emissions of a compression ignition engine run in dual-fuel mode are investigated. In the present study, the used biogas is refined with methane content 70% of volume. The objectives are to explore the optimum operating condition of the CI engine run in dual-fuel mode. The experiments are performed on a four-strokes CI engine with rated output power of 4.41 kW. The engine is tested at constant speed 1500 rpm. The engine load varied from 600W to 1500W and biogas flow rate varied from 0 L/min to 6 L/min. The results show brake thermal efficiency of the engine run in dual-fuel mode is better than pure diesel mode if the biogas flow rates are 2 L/min and 4 L/min. It is recommended to operate the present engine in a dual-fuel mode with biogas flow rate of 4 L/min. The consumption of diesel fuel can be replaced up to 50%.

  15. Comparative life cycle assessment of biogas plant configurations for a demand oriented biogas supply for flexible power generation.

    Science.gov (United States)

    Hahn, Henning; Hartmann, Kilian; Bühle, Lutz; Wachendorf, Michael

    2015-03-01

    The environmental performance of biogas plant configurations for a demand - oriented biogas supply for flexible power generation is comparatively assessed in this study. Those configurations indicate an increased energy demand to operate the operational enhancements compared to conventional biogas plants supplying biogas for baseload power generation. However, findings show that in contrast to an alternative supply of power generators with natural gas, biogas supplied on demand by adapted biogas plant configurations saves greenhouse gas emissions by 54-65 g CO(2-eq) MJ(-1) and primary energy by about 1.17 MJ MJ(-1). In this regard, configurations with flexible biogas production profit from reduced biogas storage requirements and achieve higher savings compared to configurations with continuous biogas production. Using thicker biogas storage sheeting material reduces the methane permeability of up to 6m(3) d(-1) which equals a reduction of 8% of the configuration's total methane emissions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Synthesis, performance and regeneration of carbon membranes for biogas upgrading - a future energy carrier

    Energy Technology Data Exchange (ETDEWEB)

    Lie, Jon Arvid

    2005-07-01

    The focus of the current work was to find a low-cost precursor for carbon molecular sieve (CMS) membranes for biogas upgrading (i.e. CO{sub 2}/CH{sub 4} separation to meet vehicle fuel criteria), and a simple way of producing them. Wood pulp from spruce and pine containing a majority of cellulose resulted in carbons with CO{sub 2}/CH{sub 4} separation performance at the same level as those derived from specialty polymers like polyimides. Pulp has the advantage of being widespread and cheap. Cellulose hydrolysis with trifluoroacetic acid (TFA), that is gentle enough to preserve the monosaccharides, provided an anticipative route to carbon membrane formation. Increasing the hydrolysis time, resulted in reduced weight loss during carbonization, and better separation performance for the gas pair CO{sub 2}/CH{sub 4}. The results indicated that furans are a key intermediate in forming microporosity with high separation performance. For the separation of CO2 from CH{sub 4} the optimum carbon formation temperature seemed to be near 650{sup d}eg C (single gas tests at 30{sup d}eg C and 2 bar feed pressure). In addition, several ways of modifying a carbon material are described. The modification method used in this study was metal doping of carbon. CMS membranes were formed by vacuum carbonization of hydrolyzed cellulose and metal loaded hydrolyzed cellulose. Metal additives include oxides of Ca, Mg, Fe(III) and Si, and nitrates of Ag, Cu and Fe(III). The carbon membrane containing Fe-nitrate has promising separation performance for the gas pairs 02/N2 and CO{sub 2}/CH{sub 4}. The CO{sub 2}/CH{sub 4} selectivity was typically larger than 100, with a CO2 permeability of about 300 Barrer (single gas tests). Carbon containing nitrates of Cu or Ag showed high selectivity, but reduced 02 and CO2 permeability compared to carbon with Fe-nitrate. Element analysis indicated that Cu migrates to the carbon surface, creating an extra layer resistance to gas transport. A silver mirror

  17. EU Agro Biogas Project

    NARCIS (Netherlands)

    Amon, T.; Mayr, H.; Eder, M.; Hobbs, P.; Rao Ravella, S.; Roth, U.; Niebaum, A.; Doehler, H.; Weiland, P.; Abdoun, E.; Moser, A.; Lyson, M.; Heiermann, M.; Plöchl, M.; Budde, J.; Schattauer, A.; Suarez, T.; Möller, H.; Ward, A.; Hillen, F.; Sulima, P.; Oniszk-Polplawska, A.; Krampe, P.; Pastorek, Z.; Kara, J.; Mazancova, J.; Dooren, van H.J.C.; Wim, C.; Gioelli, F.; Balsari, P.

    2009-01-01

    EU-AGRO-BIOGAS is a European Biogas initiative to improve the yield of agricultural biogas plants in Europe, to optimise biogas technology and processes and to improve the efficiency in all parts of the production chain from feedstock to biogas utilisation. Leading European research institutions and

  18. Numerical investigation: Performances of a standard biogas in a 100 kWe MGT

    Directory of Open Access Journals (Sweden)

    Vincenza Liguori

    2016-11-01

    For reasons related to the design economies, the preliminary numerical investigations such as that of the work in question on a model of combustor of a 100 kWe MGT are essential. To limit nitrogen oxides production, established lean premixed conditions. It is studied the behavior of a standard biogas M65 starting from the mouth of flame, through the laminar model up to the whole combustor but through the model k-ε, at different adducted flows. It is liked also to submit a hint related to the variation of thermal profiles or of concentrations in the combustor when the supplied natural gases have different composition, as well as at different flows and when adopted simplified kinetic paths of model to understand a sort of acceptable degree of simplification, for studies of first approximation.

  19. Thermodynamic Performance Analysis of a Biogas-Fuelled Micro-Gas Turbine with a Bottoming Organic Rankine Cycle for Sewage Sludge and Food Waste Treatment Plants

    Directory of Open Access Journals (Sweden)

    Sunhee Kim

    2017-02-01

    Full Text Available In the Republic of Korea, efficient biogas-fuelled power systems are needed to use the excess biogas that is currently burned due to a lack of suitable power technology. We examined the performance of a biogas-fuelled micro-gas turbine (MGT system and a bottoming organic Rankine cycle (ORC. The MGT provides robust operation with low-grade biogas, and the exhaust can be used for heating the biodigester. Similarly, the bottoming ORC generates additional power output with the exhaust gas. We selected a 1000-kW MGT for four co-digestion plants with 28,000-m3 capacity. A 150-kW ORC system was selected for the MGT exhaust gas. We analysed the effects of the system size, methane concentration, and ORC operating conditions. Based on the system performance, we analysed the annual performance of the MGT with a combined heat and power (CHP system, bottoming ORC, or both a bottoming ORC and CHP system. The annual net power outputs for each system were 7.4, 8.5, and 9.0 MWh per year, respectively.

  20. Responses of the biogas process to pulses of oleate in reactors treating mixtures of cattle and pig manure

    DEFF Research Database (Denmark)

    Nielsen, Henrik Bjørn; Ahring, Birgitte Kiær

    2006-01-01

    The effect of oleate on the anaerobic digestion process was investigated. Two thermophilic continuously stirred tank reactors (CSTR) were fed with mixtures of cattle and pig manure with different total solid (TS) and volatile solid (VS) content. The reactors were subjected to increasing pulses...

  1. Taxonomy and functional roles of biogas microbiota binned from multiple metagenomes of anaerobic digestion systems

    DEFF Research Database (Denmark)

    Angelidaki, Irini; Treu, Laura; Campanaro, Stefano

    Anaerobic digestion, a biologically mediated process, is a worldwide spread technology for biogas production. This work represents the first comprehensive catalogue of microbial genomes populating mesophilic and thermophilic biogas reactors treating manure, agro-industrial organic residues. High ...

  2. Metagenomic analysis and functional characterization of the biogas microbiome using high throughput shotgun sequencing and a novel binning strategy

    DEFF Research Database (Denmark)

    Campanaro, Stefano; Treu, Laura; Kougias, Panagiotis

    2016-01-01

    Biogas production is an economically attractive technology that has gained momentum worldwide over the past years. Biogas is produced by a biologically mediated process, widely known as "anaerobic digestion." This process is performed by a specialized and complex microbial community, in which...... performed using >400 proteins revealed that the biogas community is a trove of new species. A new approach based on functional properties as per network representation was developed to assign roles to the microbial species. The organization of the anaerobic digestion microbiome is resembled by a funnel...... on the phylogenetic and functional characterization of the microbial community populating biogas reactors. By applying for the first time high-throughput sequencing and a novel binning strategy, the identified genes were anchored to single genomes providing a clear understanding of their metabolic pathways...

  3. What does the hydrolysis perform in the fermentation of biogas? Biogas, hydrolysis, fermenter biology, multistage process operation; Was kann die Hydrolyse bei der Biogasvergaerung leisten? Biogas, Hydrolyse, Fermenterbiologie, mehrphasige Prozessfuehrung

    Energy Technology Data Exchange (ETDEWEB)

    Oechsner, H.; Lemmer, A. [Landesanstalt fuer Agrartechnik und Bioenergie, Univ. Hohenheim, Stuttgart (Germany)

    2009-07-01

    Nowadays renewable primary products are normally favored for fermentation in agricultural biogas plants. Since this substrate has to be cultivated for biogas fermentation in particular and hence causes production costs, the energy content of the material should be dissipated in biogas completely. For this the fermentation process has to run as efficient as possible. In case of one-phase process management with high space loading there is a risk of imbalance and maybe even collapse of process biology in the fermenter. In case of high space loading and short retention time the substrate won't be fermented completely. The aim is to create good conditions for microorganism participating in the process by a two-phase process management which integrates a stage of hydrolysis. In the stage of hydrolysis the microorganisms and enzymes metabolize the organic matter into readily biodegradable carbonic acids, which can be supplied targeted in the following methanisation as substrate for methanogenic bacteria. The hydrolysis proceeds under various terms and conditions (aerobic/anaerobic, different pH-value, different temperature level). This necessitates a safe control of operation and process parameters, which is often difficult to ensure in practice. In a malfunctioning hydrolysis also methane can be produced, that causes energy losses and environmental damage when emitted in atmosphere. Hydrogen can be produced in the hydrolysis as well what can involve a safety risk. Urgent need for research exists concerning the two-phase fermentation of renewable primary products. By systematic laboratory analysis the knowledge should be expanded, to improve the planning reliability in this field. (orig.)

  4. Performance of a biogas upgrading process based on alkali absorption with regeneration using air pollution control residues.

    Science.gov (United States)

    Baciocchi, Renato; Carnevale, Ennio; Costa, Giulia; Gavasci, Renato; Lombardi, Lidia; Olivieri, Tommaso; Zanchi, Laura; Zingaretti, Daniela

    2013-12-01

    This work analyzes the performance of an innovative biogas upgrading method, Alkali absorption with Regeneration (AwR) that employs industrial residues and allows to permanently store the separated CO2. This process consists in a first stage in which CO2 is removed from the biogas by means of chemical absorption with KOH or NaOH solutions followed by a second stage in which the spent absorption solution is contacted with waste incineration Air Pollution Control (APC) residues. The latter reaction leads to the regeneration of the alkali reagent in the solution and to the precipitation of calcium carbonate and hence allows to reuse the regenerated solution in the absorption process and to permanently store the separated CO2 in solid form. In addition, the final solid product is characterized by an improved environmental behavior compared to the untreated residues. In this paper the results obtained by AwR tests carried out in purposely designed demonstrative units installed in a landfill site are presented and discussed with the aim of verifying the feasibility of this process at pilot-scale and of identifying the conditions that allow to achieve all of the goals targeted by the proposed treatment. Specifically, the CO2 removal efficiency achieved in the absorption stage, the yield of alkali regeneration and CO2 uptake resulting for the regeneration stage, as well as the leaching behavior of the solid product are analyzed as a function of the type and concentration of the alkali reagent employed for the absorption reaction. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. EU Agro Biogas Project

    OpenAIRE

    Amon, T.; Mayr, H.; Eder, M.; Hobbs, P.; Rao Ravella, S.; Roth, U.; Niebaum, A.; Doehler, H.; Weiland, P.; Abdoun, E.; Moser, A.; Lyson, M.; Heiermann, M.; Plöchl, M.; Budde, J.

    2009-01-01

    EU-AGRO-BIOGAS is a European Biogas initiative to improve the yield of agricultural biogas plants in Europe, to optimise biogas technology and processes and to improve the efficiency in all parts of the production chain from feedstock to biogas utilisation. Leading European research institutions and universities are cooperating with key industry partners in order to work towards sustainable biogas production in Europe. Fourteen partners from eight European countries are involved in the EU-AGR...

  6. 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...

  7. DUPIC fuel performance from reactor physics viewpoint

    International Nuclear Information System (INIS)

    Choi, H.; Rhee, B.W.; Park, H.

    1995-01-01

    A preliminary study was performed for the evaluation of Stress Corrosion Cracking (SCC) parameters of nominal DUPIC fuel in CANDU reactor. For the reference 2-bundle shift refueling scheme, the predicted ramped power and power increase of the 43-element DUPIC fuel in the equilibrium core are below the SCC thresholds of CANDU natural uranium fuel. For 4-bundle shift refueling scheme, the envelope of element ramped power and power increase upon refueling are 8% and 44% higher than those of 2-bundle shift refueling scheme on the average, respectively, and both schemes are not expected to cause SCC failures. (author)

  8. Hydrogen production via reforming of biogas over nanostructured Ni/Y catalyst: Effect of ultrasound irradiation and Ni-content on catalyst properties and performance

    Energy Technology Data Exchange (ETDEWEB)

    Sharifi, Mahdi [Chemical Engineering Faculty, Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz (Iran, Islamic Republic of); Reactor and Catalysis Research Center (RCRC), Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz (Iran, Islamic Republic of); Haghighi, Mohammad, E-mail: haghighi@sut.ac.ir [Chemical Engineering Faculty, Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz (Iran, Islamic Republic of); Reactor and Catalysis Research Center (RCRC), Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz (Iran, Islamic Republic of); Abdollahifar, Mozaffar [Chemical Engineering Faculty, Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz (Iran, Islamic Republic of); Reactor and Catalysis Research Center (RCRC), Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz (Iran, Islamic Republic of)

    2014-12-15

    Highlights: • Synthesis of nanostructured Ni/Y catalyst by sonochemical and impregnation methods. • Enhancement of size distribution and active phase dispersion by employing sonochemical method. • Evaluation of biogas reforming over Ni/Y catalyst with different Ni-loadings. • Preparation of highly active and stable catalyst with low Ni content for biogas reforming. • Getting H{sub 2}/CO very close to equilibrium ratio by employing sonochemical method. - Abstract: The effect of ultrasound irradiation and various Ni-loadings on dispersion of active phase over zeolite Y were evaluated in biogas reforming for hydrogen production. X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray, Brunauer–Emmett–Teller, Fourier transform infrared analysis and TEM analysis were employed to observe the characteristics of nanostructured catalysts. The characterizations implied that utilization of ultrasound irradiation enhanced catalyst physicochemical properties including high dispersion of Ni on support, smallest particles size and high catalyst surface area. The reforming reactions were carried out at GHSV = 24 l/g.h, P = 1 atm, CH{sub 4}/CO{sub 2} = 1 and temperature range of 550–850 °C. Activity test displayed that ultrasound irradiated Ni(5 wt.%)/Y had the best performance and the activity remained stable during 600 min. Furthermore, the proposed reaction mechanism showed that there are three major reaction channels in biogas reforming.

  9. Performance tests for integral reactor nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Dong-Seong; Yim, Jeong-Sik; Lee, Chong-Tak; Kim, Han-Soo; Koo, Yang-Hyun; Lee, Byung-Ho; Cheon, Jin-Sik; Oh, Je-Yong

    2006-02-15

    An integral type reactor SMART plans to utilize metallic Zr-U fuel which is Zr-based alloy with 34{approx}38 wt% U. In order to verify the technologies for the design and manufacturing of the fuel and get a license, performance tests were carried out. Experimental Fuel Assembly (EFA) manufactured in KAERI is being successfully irradiated in the MIR reactor of RIAR from September 4 2004, and it has achieved burnup of 0.21 g/cc as of January 25 2006. Thermal properties of irradiated Zr-U fuel were measured. Up to the phase transformation temperature, thermal diffusivity increased linearly in proportion to temperature. However its dependence on the burnup was not significant. RIA tests with 4 unirradiated Zr-U fuel rods were performed in Kurchatov Institute to establish a safety criterion. In the case of the un-irradiated Zr-U fuel, the energy deposition during the control rod ejection accident should be less than 172 cal/g to prevent the failure accompanying fuel fragmentation and dispersal. Finally the irradiation tests of fuel rods have been performed at HANARO. The HITE-2 test was successfully completed up to a burnup of 0.31 g/cc. The HITE-3 test began in February 2004 and will be continued up to a target burnup of 0.6 g/cc.

  10. Spark ignition engine performance and emissions in a high compression engine using biogas and methane mixtures without knock occurrence

    Directory of Open Access Journals (Sweden)

    Gómez Montoya Juan Pablo

    2015-01-01

    Full Text Available With the purpose to use biogas in an internal combustion engine with high compression ratio and in order to get a high output thermal efficiency, this investigation used a diesel engine with a maximum output power 8.5 kW, which was converted to spark ignition mode to use it with gaseous fuels. Three fuels were used: Simulated biogas, biogas enriched with 25% and 50% methane by volume. After conversion, the output power of the engine decreased by 17.64% when using only biogas, where 7 kW was the new maximum output power of the engine. The compression ratio was kept at 15.5:1, and knocking did not occur during engine operation. Output thermal efficiency operating the engine in SI mode with biogas enriched with 50% methane was almost the same compared with the engine running in diesel-biogas dual mode at full load and was greater at part loads. The dependence of the diesel pilot was eliminated when biogas was used in the engine converted in SI mode. The optimum condition of experiment for the engine without knocking was using biogas enriched with 50% methane, with 12 degrees of spark timing advance and equivalence ratio of 0.95, larger output powers and higher values of methane concentration lead the engine to knock operation. The presence of CO2 allows operating engines at high compression ratios with normal combustion conditions. Emissions of nitrogen oxides, carbon monoxide and unburnt methane all in g/kWh decreased when the biogas was enriched with 50% methane.

  11. Reactor fuel performance data file, 1985 edition

    International Nuclear Information System (INIS)

    Harayama, Yasuo; Fujita, Misao; Watanabe, Kohji.

    1986-07-01

    In safety evaluation and integrity studies of reactor fuel, data on fuel performance are the most basic materials. The Fuel Reliability Laboratory No.1 has obtained the fuel performance data by joining in some international programs to study the safety and integrity of fuel. Those data have only used for the studies in the above two fields. However, if the data are rearranged and compiled in a easily usable form, they can be utilized in other field of studies. Then, a 'data file' on fuel performance is beeing compiled by adding data from open literatures to those obtained in international programs. The present report is prepared on the basis of the data file compiled by March in 1986. (author)

  12. Enhancement of biogas production from food waste and sewage sludge - Environmental and economic life cycle performance.

    Science.gov (United States)

    Eriksson, Ola; Bisaillon, Mattias; Haraldsson, Mårten; Sundberg, Johan

    2016-06-15

    Management of municipal solid waste is an efficient method to increase resource efficiency, as well as to replace fossil fuels with renewable energy sources due to that (1) waste to a large extent is renewable as it consists of food waste, paper, wood etc. and (2) when energy and materials are recovered from waste treatment, fossil fuels can be substituted. In this paper results from a comprehensive system study of future biological treatment of readily degradable waste in two Swedish regions are presented. Different collection and separation systems for food waste in households have been applied as well as technical improvements of the biogas process as to reduce environmental impact. The results show that central sorting of a mixed fraction into recyclables, combustibles, biowaste and inert is a competitive option compared to source separation. Use of pellets is beneficial compared to direct spreading as fertiliser. Fuel pellets seem to be the most favourable option, which to a large extent depends on the circumstances in the energy system. Separation and utilisation of nitrogen in the wet part of the digestion residue is made possible with a number of technologies which decreases environmental impact drastically, however to a substantial cost in some cases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Decentralized power generation from biogas

    International Nuclear Information System (INIS)

    2008-01-01

    Areva Bioenergies proposes ready-to-use biogas production and valorization units that use industrial effluents (liquid effluents, spent water, solid wastes). Biogas valorization is performed through cogeneration plants with an output power of 500 kW to 10 MW. This brochure presents Areva's global offer in methanation projects (support, engineering, optimization). Areva Bioenergies counts 20 dual-purpose power plants in operation or under construction in the world which represent an installed power of 220 MW

  14. Biomass storage for further energy use through biogas production

    Energy Technology Data Exchange (ETDEWEB)

    Atem, A.D. [Instituto CEDIAC, Facultad de Ingenieria, Universidad Nacional de Cuyo, Centro Universitario, 5500 Mendoza (Argentina); Instituto de Medio Ambiente, Facultad de Ingenieria, Universidad Nacional de Cuyo, Centro Universitario, 5500 Mendoza (Argentina); Instituto de Energia, Universidad Nacional de Cuyo, Centro Universitario, 5500 Mendoza (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas - CONICET, Mendoza (Argentina); Indiveri, M.E. [Instituto de Medio Ambiente, Facultad de Ingenieria, Universidad Nacional de Cuyo, Centro Universitario, 5500 Mendoza (Argentina); Instituto de Energia, Universidad Nacional de Cuyo, Centro Universitario, 5500 Mendoza (Argentina); Llamas, S. [Instituto de Medio Ambiente, Facultad de Ingenieria, Universidad Nacional de Cuyo, Centro Universitario, 5500 Mendoza (Argentina)

    2010-06-15

    The present work approaches the residual biomass conservation for later digestion in an anaerobic batch reactor. Twenty 4 L capacity PET reactors were used. A measuring device was constructed to quantify the biogas production. As substrate were used tomato wastes from local industry and rumen fluid as inoculum. Digestion start up was able to be controlled by varying the temperature, during a period of 118 days was not verified biogas production. After re-inoculated with rumen fluid stabilized for 34 days, biogas production was verified. They were obtained 0.10 m{sup 3} of biogas per kilogram of volatile solids, with 50% of methane content. (author)

  15. 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...

  16. The Influences of Stirring and Cow Manure Added on Biogas Production From Vegetable Waste Using Anaerobic Digester

    Science.gov (United States)

    Abdullah, N. O.; Pandebesie, E. S.

    2018-03-01

    Based on Indonesian Government Regulation number 18, 2008, solid waste management should be conducted from the source to minimize the amount of waste. The process includes the waste from domestic, commercial, and institution. This also includes in 3R program (reduce, reuse, and recycle). Vegetable waste from market is a potential material to produce biogas due to its chemical composition (hemi-cellulose, cellulose, and lignin) which transform the biomass to be the raw material of biogas. Acid substance of vegetable becomes an obstacle in process of producing biogas. There has to be buffer material which can improve the performance of biogas process. Cow manure is a material which can be easily obtained as buffer. This research used 24 biogas reactor in volume 6 L by batch method. Biogas volume is measured by checking the preferment in manometer. Methane measurement is conducted by using Gas Chromatography (GC) Hewlett Packard (HP-series 6890) in day 15 and 30. The research was started by sample characterization, sample test by total solid analysis, volatile solid, lignin, ratio C/N, ammonium, and ash. Analysis of pH, temperature, and biogas volume is conducted every day.

  17. Quantification of syntrophic fatty acid-{beta}-oxidizing bacteria in a mesophilic biogas reactor by oligonucleotide probe hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, K.H.; Ahring, B.K.; Raskin, L.

    1999-11-01

    Small-subunit rRNA sequences were obtained for two saturated fatty acid-{beta}-oxidizing syntrophic bacteria, Syntrophomonas sapovorans and Syntrophomonas wolfei LYB, and sequence analysis confirmed their classification as members of the family Syntrophomonadaceae. S.wolfei LYB was closely related to S.wolfei subsp. solfei, but S. sapovorans did not cluster with the other members of the genus Syntrophomonas. Five oligonucleotide probes targeting the small-subunit rRNA of different groups within the family Syntrophomonadaceae, which contains all currently known saturated fatty acid-{beta}-oxidizing syntrophic bacteria, were developed and characterized. The probes were designed to be specific at the family, genus, and species levels and were characterized by temperature-of-dissociation and specificity studies. To demonstrate the usefulness of the probes for the detection and quantification of saturated fatty acid-{beta}-oxidizing syntrophic bacteria in methanogenic environments, the microbial community structure of a sample from a full-scale biogas plant was determined. Hybridization results with probes for syntrophic bacteria and methanogens were compared to specific methanogenic activities and microbial numbers determined with most-probable-number estimates. Most of the methanogenic rRNA was comprised of Methanomicrobiales rRNA, suggesting that members of this order served as the main hydrogen-utilizing microorganisms. Between 0.2 and 1% of the rRNA was attributed to the Syntrophomonadaceae, or which the majority was accounted for by the genus Syntrophomonas.

  18. Importance of reduced sulfur for the equilibrium chemistry and kinetics of Fe(II), Co(II) and Ni(II) supplemented to semi-continuous stirred tank biogas reactors fed with stillage.

    Science.gov (United States)

    Shakeri Yekta, Sepehr; Lindmark, Amanda; Skyllberg, Ulf; Danielsson, Asa; Svensson, Bo H

    2014-03-30

    The objective of the present study was to assess major chemical reactions and chemical forms contributing to solubility and speciation of Fe(II), Co(II), and Ni(II) during anaerobic digestion of sulfur (S)-rich stillage in semi-continuous stirred tank biogas reactors (SCSTR). These metals are essential supplements for efficient and stable performance of stillage-fed SCSTR. In particular, the influence of reduced inorganic and organic S species on kinetics and thermodynamics of the metals and their partitioning between aqueous and solid phases were investigated. Solid phase S speciation was determined by use of S K-edge X-ray absorption near-edge spectroscopy. Results demonstrated that the solubility and speciation of supplemented Fe were controlled by precipitation of FeS(s) and formation of the aqueous complexes of Fe-sulfide and Fe-thiol. The relatively high solubility of Co (∼ 20% of total Co content) was attributed to the formation of compounds other than Co-sulfide and Co-thiol, presumably of microbial origin. Nickel had lower solubility than Co and its speciation was regulated by interactions with FeS(s) (e.g. co-precipitation, adsorption, and ion substitution) in addition to precipitation/dissolution of discrete NiS(s) phase and formation of aqueous Ni-sulfide complexes. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. The need for high performance breeder reactors

    International Nuclear Information System (INIS)

    Vaughan, R.D.; Chermanne, J.

    1977-01-01

    It can be easily demonstrated, on the basis of realistic estimates of continued high oil costs, that an increasing portion of the growth in energy demand must be supplied by nuclear power and that this one might account for 20% of all the energy production by the end of the century. Such assumptions lead very quickly to the conclusion that the discovery, extraction and processing of the uranium will not be able to follow the demand; the bottleneck will essentially be related to the rate at which the ore can be discovered and extracted, and not to the existing quantities nor their grade. Figures as high as 150.000 T/annum and more would be quickly reached, and it is necessary to wonder already now if enough capital can be attracted to meet these requirements. There is only one solution to this problem: improve the conversion ratio of the nuclear system and quickly reach the breeding; this would lead to the reduction of the natural uranium consumption by a factor of about 50. However, this condition is not sufficient; the commercial breeder must have a breeding gain as high as possible because the Pu out-of-pile time and the Pu losses in the cycle could lead to an unacceptable doubling time for the system, if the breeding gain is too low. That is the reason why it is vital to develop high performance breeder reactors. The present paper indicates how the Gas-cooled Breeder Reactor [GBR] can meet the problems mentioned above, on the basis of recent and realistic studies. It briefly describes the present status of GBR development, from the predecessors in the gas cooled reactor line, particularly the AGR. It shows how the GBR fuel takes mostly profit from the LMFBR fuel irradiation experience. It compares the GBR performance on a consistent basis with that of the LMFBR. The GBR capital and fuel cycle costs are compared with those of thermal and fast reactors respectively. The conclusion is, based on a cost-benefit study, that the GBR must be quickly developed in order

  20. Automated surveillance of reactor coolant pump performance

    International Nuclear Information System (INIS)

    Gross, K.C.; Singer, R.M.; Humenik, K.E.

    1992-01-01

    An artificial intelligence based expert system has been developed for continuous surveillance and diagnosis of centrifugal-type reactor coolant pump (RCP) performance and operability. The expert system continuously monitors digitized signals from a variety of physical variables (speed, vibration level, motor power, discharge pressure) associated with RCP performance for annunciation of the incipience or onset of off-normal operation. The system employs an extremely sensitive pattern-recognition technique, the sequential probability ratio test (SPRT) for rapid identification of pump operability degradation. The sequential statistical analysis of the signal noise has been shown to provide the theoretically shortest sampling time to detect disturbances and thus has the potential of providing incipient fault detection information to operators sufficiently early to avoid forced plant shutdowns. The sensitivity and response time of the expert system are analyzed in this paper using monte carlo simulation techniques

  1. Biogas Filter Based on Local Natural Zeolite Materials

    Directory of Open Access Journals (Sweden)

    Satriyo Krido Wahono

    2014-02-01

    Full Text Available UPT BPPTK LIPI has created a biogas filter tool to improve the purity of methane in the biogas. The device shaped cylindrical tube containing absorbent materials which based on local natural zeolite of Indonesia. The absorbent has been activated and modified with other materials. This absorbtion material has multi-adsorption capacity for almost impurities gas of biogas. The biogas  filter increase methane content of biogas for 5-20%. The biogas filter improve the biogas’s performance such as increasing methane contents, increasing heating value, reduction of odors, reduction of corrosion potential, increasing the efficiency and stability of the generator.

  2. Valorizing waste iron powder in biogas production: Hydrogen sulfide control and process performances.

    Science.gov (United States)

    Andriamanohiarisoamanana, Fetra J; Shirai, Tomoya; Yamashiro, Takaki; Yasui, Seiichi; Iwasaki, Masahiro; Ihara, Ikko; Nishida, Takehiro; Tangtaweewipat, Suchon; Umetsu, Kazutaka

    2018-02-15

    Biogas is composed of different gases including hydrogen sulfide (H 2 S), which is a hazardous gas that damages pipes and generators in anaerobic digestion system. The objective of this study was to control H 2 S by waste iron powder produced by laser cutting machine in a steel and iron industry. Waste iron powder was mixed with dairy manure at a concentration between 2.0 and 20.0 g/L in batch experiments, while the concentration was varied between 1.0 and 4.0 g/L in bench experiment. In batch experiment, a reduction of up to 93% of H 2 S was observed at waste iron powder of 2.0 g/L (T1), while the reduction was of more than 99% at waste iron powder beyond 8.0 g/L (T4 ∼ T6). The total sulfide concentration (S T ) increased together with waste iron powder concentration and was fitted with a quadratic equation with a maximum S T of 208.0 mg/L at waste iron powder of 20.2 g/L. Waste iron powder did not have significant effect on methane yield in batch and bench experiments. However, hydrolysis rate constant was increased by almost 100%, while the lag-phase period was reduced to half in test digesters compared to that in control digester. In bench experiment, H 2 S concentration was reduced by 89% at 2.0 g/L, while 50% at 1.0 g/L. Therefore, waste iron powder was effectively removed H 2 S and did not affect negatively anaerobic digestion process. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Parameter estimation and long-term process simulation of a biogas reactor operated under trace elements limitation

    International Nuclear Information System (INIS)

    Lübken, Manfred; Koch, Konrad; Gehring, Tito; Horn, Harald; Wichern, Marc

    2015-01-01

    Highlights: • Estimation of ADM1 parameter uncertainty by nonlinear, correlated parameter analysis. • Unbounded confidence regions were obtained for single hydrolysis rate constants. • ADM1 carbohydrates were divided into a slowly and readily degradable part. • Bioavailability of trace metals explained discrepancies between modeled and measured data. - Abstract: The Anaerobic Digestion Model No. 1 (ADM1) was modified to describe the long-term process stability of a two-stage agricultural biogas system operated for 494 days with a mono-substrate. The ADM1 model fraction for carbohydrates was divided into a slowly and readily degradable part. Significant different hydrolysis rate constants were found for proteins and single fractions of carbohydrates in batch experiments. Degradation of starch, xylan (hemicellulose), cellulose and zein (protein) were modeled with first order hydrolysis rate coefficients of 1.20 d −1 , 0.70 d −1 , 0.18 d −1 and 0.30 d −1 , respectively. While the hydrolysis rate coefficients found in batch experiments could be used for predicting continuous process data, the statistically calculated confidence regions (nonlinear parameter estimation) showed that the upper limits were unbounded. Single discrepancies between measured and modeled process data of the two-stage pilot system could be explained by the lack of bioavailability of trace elements. Addition of iron, as Fe(III)Cl 3 , allowed stable process conditions for an organic loading rate (OLR) up to 2.5 g VS L −1 d −1 . Additional supplement of trace elements was necessary for process operation at OLRs above 2.5 g VS L −1 d −1

  4. 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.

  5. Analysis of fast reactor steam generator performance

    International Nuclear Information System (INIS)

    Hulme, G.; Curzon, A.F.

    1992-01-01

    A computer model for the prediction of flow and temperature fields within a fast reactor steam generator unit is described. The model combines a commercially available computational fluid dynamics (CFD) solver (PHOENICS) with a steam-tube calculation and provides solutions for the fully coupled flow and temperature fields on both the shell side and the tube side. The model includes the inlet and outlet headers and the bottom end stagnant zone. It also accounts for the effects of support grids and edge-gaps. Two and three dimensional and transient calculations have been performed for both straight tube and J-tube units. Examples of the application of the model are presented. (7 figures) (Author)

  6. Design and performance of subgrade biogeochemical reactors.

    Science.gov (United States)

    Gamlin, Jeff; Downey, Doug; Shearer, Brad; Favara, Paul

    2017-12-15

    Subgrade biogeochemical reactors (SBGRs), also commonly referred to as in situ bioreactors, are a unique technology for treatment of contaminant source areas and groundwater plume hot spots. SBGRs have most commonly been configured for enhanced reductive dechlorination (ERD) applications for chlorinated solvent treatment. However, they have also been designed for other contaminant classes using alternative treatment media. The SBGR technology typically consists of removal of contaminated soil via excavation or large-diameter augers, and backfill of the soil void with gravel and treatment amendments tailored to the target contaminant(s). In most cases SBGRs include installation of infiltration piping and a low-flow pumping system (typically solar-powered) to recirculate contaminated groundwater through the SBGR for treatment. SBGRs have been constructed in multiple configurations, including designs capable of meeting limited access restrictions at heavily industrialized sites, and at sites with restrictions on surface disturbance due to sensitive species or habitat issues. Typical performance results for ERD applications include 85 to 90 percent total molar reduction of chlorinated volatile organic compounds (CVOCs) near the SBGR and rapid clean-up of adjacent dissolved contaminant source areas. Based on a review of the literature and CH2M's field-scale results from over a dozen SBGRs with a least one year of performance data, important site-specific design considerations include: 1) hydraulic residence time should be long enough for sufficient treatment but not too long to create depressed pH and stagnant conditions (e.g., typically between 10 and 60 days), 2) reactor material should balance appropriate organic mulch as optimal bacterial growth media along with other organic additives that provide bioavailable organic carbon, 3) a variety of native bacteria are important to the treatment process, and 4) biologically mediated generation of iron sulfides along with

  7. Effect of compression ratio on performance, combustion and emission characteristics of a dual fuel diesel engine run on raw biogas

    International Nuclear Information System (INIS)

    Bora, Bhaskor J.; Saha, Ujjwal K.; Chatterjee, Soumya; Veer, Vijay

    2014-01-01

    Highlights: • Maximum brake thermal efficiency of 20.04% was obtained in dual fuel mode. • Compression ratio of 18 produced the maximum brake thermal efficiency. • Maximum replacement of diesel was found to be 79.46% at a compression ratio of 18. • CO gets reduced by 26.22% with the increase of compression ratio from 16 to18. • HC gets reduced by 41.97% with the increase of compression ratio from 16 to18. - Abstract: The energy consumption of the world is increasing at a staggering rate due to population explosion. The extensive use of energy has led to fossil fuel depletion and the rise in pollution. Renewable energy holds the key solution to these aforementioned problems. Biogas, one such renewable fuel, can be used in a diesel engine under dual fuel mode for the generation of power. This work attempts to unfold the effect of compression ratio on the performance, combustion and emission characteristics of a dual fuel diesel engine run on raw biogas. For this investigation, a 3.5 kW single cylinder, direct injection, water cooled, variable compression ratio diesel engine is converted into a biogas run dual fuel diesel engine by connecting a venturi gas mixer at the inlet manifold. Experiments have been conducted at various compression ratios (18, 17.5, 17 and 16) and under different loading conditions fixing the standard injection timing at 23° before top dead centre. At 100% load, the brake thermal efficiencies of the dual fuel mode are found to be 20.04%, 18.25%, 17.07% and 16.42% at compression ratios of 18, 17.5, 17 and 16, respectively, whereas at the same load, the diesel mode shows an efficiency of 27.76% at a compression ratio of 17.5. The maximum replacement of the precious fossil fuel is found to be 79.46%, 76.1%, 74% and 72% at compression ratios of 18, 17.5, 17 and 16, respectively at 100% load. For the dual fuel mode, on an average, there is a reduction in carbon monoxide as well as hydrocarbon emission by 26.22% and 41.97% when compression

  8. Research about reactor operator's personality characteristics and performance

    International Nuclear Information System (INIS)

    Wei Li; He Xuhong; Zhao Bingquan

    2003-01-01

    To predict and evaluate the reactor operator's performance by personality characteristics is an important part of reactor operator safety assessment. Using related psychological theory combined with the Chinese operator's fact and considering the effect of environmental factors to personality analysis, paper does the research about the about the relationships between reactor operator's performance and personality characteristics, and offers the reference for operator's selection, using and performance in the future. (author)

  9. Online monitoring and control of the biogas process

    Energy Technology Data Exchange (ETDEWEB)

    Boe, K.

    2006-07-01

    The demand for online monitoring and control of biogas process is increasing, since better monitoring and control system can improve process stability and enhance process performance for better economy of the biogas plants. A number of parameters in both the liquid and the gas phase have been suggested as process indicators. These include gas production, pH, alkalinity, volatile fatty acids (VFA) and hydrogen. Of these, VFA is the most widely recognised as a direct, relevant measure of stability. The individual, rather than collective VFA concentrations are recognised as providing significantly more information for diagnosis. However, classic on-line measurement is based on filtration, which suffers from fouling, especially in particulate or slurry wastes. In this project, a new online VFA monitoring system has been developed using gas-phase VFA extraction to avoid sample filtration. The liquid sample is pumped into a sampling chamber, acidified, added with salt and heated to extract VFA into the gas phase before analysis by GC-FID. This allows easy application to manure. Sample and analysis time of the system varies from 25-40 min. depending on the washing duration. The sampling frequency is fast enough for the dynamic of a manure digester, which is in the range of several hours. This system has been validated over more than 6 months and had shown good agreement with offline VFA measurement. Response from this sensor was compared with other process parameters such as biogas production, pH and dissolved hydrogen during overload situations in a laboratory-scale digester, to investigate the suitability of each measure as a process indicator. VFA was most reliable for indicating process imbalance, and propionate was most persistent. However, when coupling the online VFA monitoring with a simple control for automatic controlling propionate level in a digester, it was found that propionate decreased so slow that the biogas production fluctuated. Therefore, it is more

  10. In-situ biogas sparging enhances the performance of an anaerobic membrane bioreactor (AnMBR) with mesh filter in low-strength wastewater treatment.

    Science.gov (United States)

    Li, Na; Hu, Yi; Lu, Yong-Ze; Zeng, Raymond J; Sheng, Guo-Ping

    2016-07-01

    In the recent years, anaerobic membrane bioreactor (AnMBR) technology is being considered as a very attractive alternative for wastewater treatment due to the striking advantages such as upgraded effluent quality. However, fouling control is still a problem for the application of AnMBR. This study investigated the performance of an AnMBR using mesh filter as support material to treat low-strength wastewater via in-situ biogas sparging. It was found that mesh AnMBR exhibited high and stable chemical oxygen demand (COD) removal efficiencies with values of 95 ± 5 % and an average methane yield of 0.24 L CH4/g CODremoved. Variation of transmembrane pressure (TMP) during operation indicated that mesh fouling was mitigated by in-situ biogas sparging and the fouling rate was comparable to that of aerobic membrane bioreactor with mesh filter reported in previous researches. The fouling layer formed on the mesh exhibited non-uniform structure; the porosity became larger from bottom layer to top layer. Biogas sparging could not change the composition but make thinner thickness of cake layer, which might be benefit for reducing membrane fouling rate. It was also found that ultrasonic cleaning of fouled mesh was able to remove most foulants on the surface or pores. This study demonstrated that in-situ biogas sparging enhanced the performance of AnMBRs with mesh filter in low-strength wastewater treatment. Apparently, AnMBRs with mesh filter can be used as a promising and sustainable technology for wastewater treatment.

  11. Performance of metallic fuels in liquid-metal fast reactors

    International Nuclear Information System (INIS)

    Seidel, B.R.; Walters, L.C.; Kittel, J.H.

    1984-01-01

    Interest in metallic fuels for liquid-metal fast reactors has come full circle. Metallic fuels are once again a viable alternative for fast reactors because reactor outlet temperature of interest to industry are well within the range where metallic fuels have demonstrated high burnup and reliable performance. In addition, metallic fuel is very tolerant of off-normal events of its high thermal conductivity and fuel behavior. Futhermore, metallic fuels lend themselves to compact and simplified reprocessing and refabrication technologies, a key feature in a new concept for deployment of fast reactors called the Integral Fast Reactor (IFR). The IFR concept is a metallic-fueled pool reactor(s) coupled to an integral-remote reprocessing and fabrication facility. The purpose of this paper is to review recent metallic fuel performance, much of which was tested and proven during the twenty years of EBR-II operation

  12. 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.

  13. 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.

  14. Energy Crop-Based Biogas as Vehicle Fuel—The Impact of Crop Selection on Energy Efficiency and Greenhouse Gas Performance

    Directory of Open Access Journals (Sweden)

    Pål Börjesson

    2015-06-01

    Full Text Available The production of biogas from six agricultural crops was analysed regarding energy efficiency and greenhouse gas (GHG performance for vehicle fuel from a field-to-tank perspective, with focus on critical parameters and on calculation methods. The energy efficiency varied from 35% to 44%, expressed as primary energy input per energy unit vehicle gas produced. The GHG reduction varied from 70% to 120%, compared with fossil liquid fuels, when the GHG credit of the digestate produced was included through system expansion according to the calculation methodology in the ISO 14044 standard of life cycle assessment. Ley crop-based biogas systems led to the highest GHG reduction, due to the significant soil carbon accumulation, followed by maize, wheat, hemp, triticale and sugar beet. Critical parameters are biogenic nitrous oxide emissions from crop cultivation, for which specific emission factors for digestate are missing today, and methane leakage from biogas production. The GHG benefits were reduced and the interrelation between the crops changed, when the GHG calculations were instead based on the methodology stated in the EU Renewable Energy Directive, where crop contribution to soil carbon accumulation is disregarded. All systems could still reach a 60% GHG reduction, due to the improved agricultural management when digestate replaces mineral fertilisers.

  15. Performance of pressure tubes in CANDU reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, D.; Griffiths, M.; Bickel, G.; Buyers, A.; Coleman, C.; Nordin, H.; St Lawrence, S. [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)

    2016-06-15

    The pressure tubes in CANDU reactors typically operate for times up to about 30 years prior to refurbishment. The in-reactor performance of Zr-2.5Nb pressure tubes has been evaluated by sampling and periodic inspection. This paper describes the behavior and discusses the factors controlling the behaviour of these components. The Zr–2.5Nb pressure tubes are nominally extruded at 815{sup o}C, cold worked nominally 27%, and stress relieved at 400 {sup o}C for 24 hours, resulting in a structure consisting of elongated grains of hexagonal close-packed alpha-Zr, partially surrounded by a thin network of filaments of body-centred-cubic beta-Zr. These beta-Zr filaments are meta-stable and contain about 20% Nb after extrusion. The stress-relief treatment results in partial decomposition of the beta-Zr filaments with the formation of hexagonal close-packed alpha-phase particles that are low in Nb, surrounded by a Nb-enriched beta-Zr matrix. The material properties of pressure tubes are determined by variations in alpha-phase texture, alpha-phase grain structure, network dislocation density, beta-phase decomposition, and impurity concentration that are a function of manufacturing variables. The pressure tubes operate at temperatures between 250 {sup o}C and 310 {sup o}C with coolant pressures up to about 11 MPa in fast neutron fluxes up to 4 x 10{sup 17} n·m{sup -2}·s{sup -1} (E > 1 MeV) and the properties are modified by these conditions. The properties of the pressure tubes in an operating reactor are therefore a function of both manufacturing and operating condition variables. The ultimate tensile strength, fracture toughness, and delayed hydride-cracking properties (velocity (V) and threshold stress intensity factor (K{sub IH})) change with irradiation, but all reach a nearly limiting value at a fluence of less than 10{sup 25} n·m{sup -2} (E > 1 MeV). At this point the ultimate tensile strength is raised about 200 MPa, toughness is reduced by about 50%, V increases

  16. A model to describe the performance of the UASB reactor.

    Science.gov (United States)

    Rodríguez-Gómez, Raúl; Renman, Gunno; Moreno, Luis; Liu, Longcheng

    2014-04-01

    A dynamic model to describe the performance of the Upflow Anaerobic Sludge Blanket (UASB) reactor was developed. It includes dispersion, advection, and reaction terms, as well as the resistances through which the substrate passes before its biotransformation. The UASB reactor is viewed as several continuous stirred tank reactors connected in series. The good agreement between experimental and simulated results shows that the model is able to predict the performance of the UASB reactor (i.e. substrate concentration, biomass concentration, granule size, and height of the sludge bed).

  17. Reactor coolant pump seals: improving their performance

    International Nuclear Information System (INIS)

    Pothier, N.E.; Metcalfe, R.

    1986-06-01

    Large CANDU plants are benefitting from transient-resistant four-year reliable reactor coolant pump seal lifetimes, a direct result of AECL's 20-year comprehensive seal improvement program involving R and D staff, manufacturers, and plant designers and operators. An overview of this program is presented, which covers seal modification design, testing, post-service examination, specialized maintenance and quality control. The relevancy of this technology to Light Water Reactor Coolant Pump Seals is also discussed

  18. Study on Reactor Performance of Online Power Monitoring in PUSPATI TRIGA Reactor (RTP)

    International Nuclear Information System (INIS)

    Zareen Khan Abdul Jalil Khan; Ridzuan Abdul Mutalib; Mohd Sabri Minhat

    2014-01-01

    The Reactor TRIGA PUSPATI (RTP) at Malaysia Nuclear Agency is a TRIGA Mark II type reactor and pool type cooled by natural circulation of light water. This paper describe on reactor performance of online power monitoring based on various parameter of reactor such as log power, linear power, period, Fuel and coolant temperature and reactivity parameter with using neutronic and other instrumentation system of reactor. Methodology of online power estimation and monitoring is to evaluate and analysis of reactor power which is important of reactor safety and control. Neutronic instrumentation system will use to estimate power measurement, differential of log and linear power and period during reactor operation .This study also focus on noise fluctuation from fission chamber during reactor operation .This work will present result of online power monitoring from RTP which indicated the safety parameter identification and initiate safety action on crossing the threshold set point trip. Conclude that optimization of online power monitoring will improved the reactor control and safety parameter of reactor during operation. (author)

  19. A Preliminary Analysis of Reactor Performance Test (LOEP) for a Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyeonil; Park, Su-Ki [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The final phase of commissioning is reactor performance test, which is to prove the integrated performance and safety of the research reactor at full power with fuel loaded such as neutron power calibration, Control Absorber Rod/Second Shutdown Rod drop time, InC function test, Criticality, Rod worth, Core heat removal with natural mechanism, and so forth. The last test will be safety-related one to assure the result of the safety analysis of the research reactor is marginal enough to be sure about the nuclear safety by showing the reactor satisfies the acceptance criteria of the safety functions such as for reactivity control, maintenance of auxiliaries, reactor pool water inventory control, core heat removal, and confinement isolation. After all, the fuel integrity will be ensured by verifying there is no meaningful change in the radiation levels. To confirm the performance of safety equipment, loss of normal electric power (LOEP), possibly categorized as Anticipated Operational Occurrence (AOO), is selected as a key experiment to figure out how safe the research reactor is before turning over the research reactor to the owner. This paper presents a preliminary analysis of the reactor performance test (LOEP) for a research reactor. The results showed how different the transient between conservative estimate and best estimate will look. Preliminary analyses have shown all probable thermal-hydraulic transient behavior of importance as to opening of flap valve, minimum critical heat flux ratio, the change of flow direction, and important values of thermal-hydraulic parameters.

  20. Performance of a multipurpose research electrochemical reactor

    International Nuclear Information System (INIS)

    Henquin, E.R.; Bisang, J.M.

    2011-01-01

    Highlights: → For this reactor configuration the current distribution is uniform. → For this reactor configuration with bipolar connection the leakage current is small. → The mass-transfer conditions are closely uniform along the electrode. → The fluidodynamic behaviour can be represented by the dispersion model. → This reactor represents a suitable device for laboratory trials. - Abstract: This paper reports on a multipurpose research electrochemical reactor with an innovative design feature, which is based on a filter press arrangement with inclined segmented electrodes and under a modular assembly. Under bipolar connection, the fraction of leakage current is lower than 4%, depending on the bipolar Wagner number, and the current distribution is closely uniform. When a turbulence promoter is used, the local mass-transfer coefficient shows a variation of ±10% with respect to its mean value. The fluidodynamics of the reactor responds to the dispersion model with a Peclet number higher than 10. It is concluded that this reactor is convenient for laboratory research.

  1. Simultaneous wastewater treatment and biogas production using integrated anaerobic baffled reactor granular activated carbon from baker's yeast wastewater.

    Science.gov (United States)

    Pirsaheb, Meghdad; Mohamadi, Samira; Rahmatabadi, Sama; Hossini, Hooshyar; Motteran, Fabrício

    2017-08-30

    In this study, simultaneous degradation of organic matter and color removal from food processing industries wastewater using an integrated anaerobic baffled reactor granular activated carbon (IABRGAC) was investigated. Theretofore, effective parameters such as hydraulic retention time (HRT) and granular activated carbon (GAC) filling ratio were studied. The bioreactor was operated at 3, 4 and 5 d of HRT and GAC filling ratio of 20%, 35% and 50%. To analyze and optimize the independent operating variables, response surface methodology was applied. Operating condition was optimized for HRT (4 d) and GAC filling ratio (50%). Better COD (94.6%) and BOD (93.7%) removal efficiency occurred with loading COD of 15,000 mg/L, with diminished wastewater color around 54% and turbidity to 54 NTU. In addition, methane production, methane yielding rate (Y m ) and specific methanogenic activity (SMA) test in an integrated system were investigated. The system IABRGAC was able to generate a volumetric rate about 0.31 and 0.44 L/g COD removed d at the experimental condition. The Y m was between 0.31 and 0.44 L/g COD removed .d and SMA was between 0.13 and 0.38 g COD/g volatile suspended solid. Based on results it can be concluded that the IABRGAC to be a successful pretreatment for highstrength wastewater before discharging the final effluent to sewerage and aerobic treating processes.

  2. 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

  3. Biogas Production from Sugarcane Waste: Assessment on Kinetic Challenges for Process Designing

    Science.gov (United States)

    Janke, Leandro; Leite, Athaydes; Nikolausz, Marcell; Schmidt, Thomas; Liebetrau, Jan; Nelles, Michael; Stinner, Walter

    2015-01-01

    Biogas production from sugarcane waste has large potential for energy generation, however, to enable the optimization of the anaerobic digestion (AD) process each substrate characteristic should be carefully evaluated. In this study, the kinetic challenges for biogas production from different types of sugarcane waste were assessed. Samples of vinasse, filter cake, bagasse, and straw were analyzed in terms of total and volatile solids, chemical oxygen demand, macronutrients, trace elements, and nutritional value. Biochemical methane potential assays were performed to evaluate the energy potential of the substrates according to different types of sugarcane plants. Methane yields varied considerably (5–181 Nm3·tonFM−1), mainly due to the different substrate characteristics and sugar and/or ethanol production processes. Therefore, for the optimization of AD on a large-scale, continuous stirred-tank reactor with long hydraulic retention times (>35 days) should be used for biogas production from bagasse and straw, coupled with pre-treatment process to enhance the degradation of the fibrous carbohydrates. Biomass immobilization systems are recommended in case vinasse is used as substrate, due to its low solid content, while filter cake could complement the biogas production from vinasse during the sugarcane offseason, providing a higher utilization of the biogas system during the entire year. PMID:26404248

  4. Improved biogas production from rice straw by co-digestion with kitchen waste and pig manure

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Jingqing [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China); School of Environmental Sciences and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Li, Dong; Sun, Yongming [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China); Wang, Guohui [School of Environmental Sciences and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Yuan, Zhenhong, E-mail: yuanzh@ms.giec.ac.cn [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China); Zhen, Feng; Wang, Yao [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2013-12-15

    Highlights: • Biogas production was enhanced by co-digestion of rice straw with other materials. • The optimal ratio of kitchen waste, pig manure and rice straw is 0.4:1.6:1. • The maximum biogas yield of 674.4 L/kg VS was obtained. • VFA inhibition occurred when kitchen waste content was more than 26%. • The dominant VFA were propionate and acetate in successful reactors. - Abstract: In order to investigate the effect of feedstock ratios in biogas production, anaerobic co-digestions of rice straw with kitchen waste and pig manure were carried out. A series of single-stage batch mesophilic (37 ± 1 °C) anaerobic digestions were performed at a substrate concentration of 54 g/L based on volatile solids (VS). The results showed that the optimal ratio of kitchen waste, pig manure, and rice straw was 0.4:1.6:1, for which the C/N ratio was 21.7. The methane content was 45.9–70.0% and rate of VS reduction was 55.8%. The biogas yield of 674.4 L/kg VS was higher than that of the digestion of rice straw or pig manure alone by 71.67% and 10.41%, respectively. Inhibition of biogas production by volatile fatty acids (VFA) occurred when the addition of kitchen waste was greater than 26%. The VFA analysis showed that, in the reactors that successfully produced biogas, the dominant intermediate metabolites were propionate and acetate, while they were lactic acid, acetate, and propionate in the others.

  5. Improved biogas production from rice straw by co-digestion with kitchen waste and pig manure

    International Nuclear Information System (INIS)

    Ye, Jingqing; Li, Dong; Sun, Yongming; Wang, Guohui; Yuan, Zhenhong; Zhen, Feng; Wang, Yao

    2013-01-01

    Highlights: • Biogas production was enhanced by co-digestion of rice straw with other materials. • The optimal ratio of kitchen waste, pig manure and rice straw is 0.4:1.6:1. • The maximum biogas yield of 674.4 L/kg VS was obtained. • VFA inhibition occurred when kitchen waste content was more than 26%. • The dominant VFA were propionate and acetate in successful reactors. - Abstract: In order to investigate the effect of feedstock ratios in biogas production, anaerobic co-digestions of rice straw with kitchen waste and pig manure were carried out. A series of single-stage batch mesophilic (37 ± 1 °C) anaerobic digestions were performed at a substrate concentration of 54 g/L based on volatile solids (VS). The results showed that the optimal ratio of kitchen waste, pig manure, and rice straw was 0.4:1.6:1, for which the C/N ratio was 21.7. The methane content was 45.9–70.0% and rate of VS reduction was 55.8%. The biogas yield of 674.4 L/kg VS was higher than that of the digestion of rice straw or pig manure alone by 71.67% and 10.41%, respectively. Inhibition of biogas production by volatile fatty acids (VFA) occurred when the addition of kitchen waste was greater than 26%. The VFA analysis showed that, in the reactors that successfully produced biogas, the dominant intermediate metabolites were propionate and acetate, while they were lactic acid, acetate, and propionate in the others

  6. Biogas handbook (pilot edition)

    Energy Technology Data Exchange (ETDEWEB)

    Mazumdar, A [comp.

    1982-01-01

    The theory of biogas production; factors affecting digester design; details of several biogas plants of India and China including their construction, operation, and maintenance; designs of biogas utilization devices; and the use of digested sludge as fertilizer or animal feed are discussed. Included is a section listing the causes and known solutions of technical problems associated with the construction and operation of biogas plants and appliances. (CK)

  7. Utilization of biogas

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, J L; Ross, C C; Smith, M S; Harper, S R [Georgia Tech Research Corp., Atlanta, GA (USA)

    1989-01-01

    A comprehensive study of the systems and equipment required to convert biogas into useful thermal and/or electrical energy was conducted, and the results published in the Handbook on Biogas Utilization (Walsh et al., Georgia Institute of Technology, Atlanta, GA, 1988). The physical, chemical and combustion characteristics of biogas, and the impact of these characteristics on both new and modified combustion equipment, were considered. The study also included consideration of auxiliary equipment for biogas collection, clean-up, compression and storage. (author).

  8. Comparison of Pickering NGS performance with world power reactors, 1977

    International Nuclear Information System (INIS)

    Buhay, S.

    Pickering NGS performance is compared, in highly graphic form, with the perfomance of other nuclear power plants around the world. The four Pickering reactors score in the top six, rated by gross capacity factor. Major system suppliers for world power reactors above 500 MW are cataloged. (E.C.B.)

  9. Mixing and scale affect moving bed biofilm reactor (MBBR) performance

    NARCIS (Netherlands)

    Kamstra, Andries; Blom, Ewout; Terjesen, Bendik Fyhn

    2017-01-01

    Moving Bed Biofilm Reactors (MBBR) are used increasingly in closed systems for farming of fish. Scaling, i.e. design of units of increasing size, is an important issue in general bio-reactor design since mixing behaviour will differ between small and large scale. Research is mostly performed on

  10. Aspects of biogas utilisation

    International Nuclear Information System (INIS)

    Luning, L.

    1992-01-01

    Utilisation of biogas has received considerable attention over the last decade, its full potential has not been reached however. The paper discusses various options for utilisation of biogas and the limitations that may occur as far as they are associated with the characteristics of biogas. As a result the prospects for the future are presented. (au)

  11. INDIAN POINT REACTOR STARTUP AND PERFORMANCE

    Energy Technology Data Exchange (ETDEWEB)

    Deddens, J. C.; Batch, M. L.

    1963-09-15

    The testing program for the Indian Point Reactor is discussed. The thermal and hydraulic evaluation of the primary coolant system is discussed. Analyses of fuel loading and initial criticality, measurement of operating coefficients of reactivity, control rod group reactivity worths, and xenon evaluation are presented. (R.E.U.)

  12. Influence of alkalinity and VFAs on the performance of an UASB reactor with recirculation for the treatment of Tequila vinasses.

    Science.gov (United States)

    López-López, Alberto; León-Becerril, Elizabeth; Rosales-Contreras, María Elena; Villegas-García, Edgardo

    2015-01-01

    The main problem linked to the stability of upflow anaerobic sludge blanket (UASB) reactors during the treatment of Tequila vinasse is the high acidity and the null alkalinity present in this effluent. This research evaluates the effect of alkalinity and volatile fatty acids (VFAs) concentration on the performance of an UASB reactor with recirculation of the effluent for removing organic matter and biogas production from Tequila vinasses. Recirculation of the effluent reduces the impact of VFAs and organic matter concentration present in the influent, inducing the stability of the reactor. The UASB reactor was operated during 235 days at organic loading rates from 2.5 to 20.0 kg m(-3) d(-1), attaining a removal efficiency of COD greater than 75% with a methane yield of 335 ml CH4 g(-1) COD at SPT, maintaining a ratio of VFAs/Alk ≤ 0.5. Therefore, an optimal ratio of VFAs/Alk was established for the system operating in stable conditions for the treatment of Tequila vinasses. Under these conditions, the alkalinity was recuperated by the system itself, without the addition of external alkalinity.

  13. Research and development into power reactor fuel performance

    International Nuclear Information System (INIS)

    Notley, M.J.F.

    1983-07-01

    The nuclear fuel in a power reactor must perform reliably during normal operation, and the consequences of abnormal events must be researched and assessed. The present highly reliable operation of the natural UO 2 in the CANDU power reactors has reduced the need for further work in this area; however a core of expertise must be retained for purposes such as training of new staff, retaining the capability of reacting to unforeseen circumstances, and participating in the commercial development of new ideas. The assessment of fuel performance during accidents requires research into many aspects of materials, fuel and fission product behaviour, and the consolidation of that knowledge into computer codes used to evaluate the consequences of any particular accident. This work is growing in scope, much is known from out-reactor work at temperatures up to about 1500 degreesC, but the need for in-reactor verification and investigation of higher-temperature accidents has necessitated the construction of a major new in-reactor test loop and the initiation of the associated out-reactor support programs. Since many of the programs on normal and accident-related performance are generic in nature, they will be applicable to advanced fuel cycles. Work will therefore be gradually transferred from the present, committed power reactor system to support the next generation of thorium-based reactor cycles

  14. Performance evaluation of a mesophilic (37 deg. C) upflow anaerobic sludge blanket reactor in treating distiller's grains wastewater

    International Nuclear Information System (INIS)

    Gao Mengchun; She Zonglian; Jin Chunji

    2007-01-01

    The performance of a laboratory-scale upflow anaerobic sludge blanket (UASB) reactor treating distiller's grains wastewater was investigated for 420 days at 37 deg. C. After a successful start-up, 80-97.3% chemical oxygen demand (COD) removal efficiencies were achieved at hydraulic retention times (HRT) of 82-11 h with organic loading rates (OLR) of 5-48.3 kg COD m -3 d -1 . The biogas mainly consisted of methane and carbon dioxide, and the methane and carbon dioxide content in the biogas was 57-60 and 38-41%, respectively. The yield coefficient of methane production was 0.3182 l CH 4 g -1 COD removed until OLR at 33.3 kg COD m -3 d -1 , but afterwards began to decrease. The volatile fatty acid (VFA) in the effluent mainly consisted of acetate and propionate, accounting for more than 95% of total VFA as COD, and other VFA was detected at insignificant concentrations. The mesophilic granules developed in this study showed an excellent specific methanogenic activity (SMA) at 0.91 and 1.12 g methane COD g -1 VSS -1 d -1 using sucrose and acetate as individual substrates on day 200, respectively

  15. Special file: biogas

    International Nuclear Information System (INIS)

    Signoret, Stephane; Mary, Olivier; Zebboudj, Idir; Mounissamy, Alice; Sandrin-Deforge, Armelle; Petitot, Pauline; De Santis, Audrey

    2015-01-01

    With some graphs indicating the number and types of existing and projected biogas production units, a first article outlines that the development rate is presently too low to be able to reach objectives defined for 2020. A second article comments the results of a benchmark study performed by the ADEME on the biogas sector status in European countries (a map indicates the levels of production and electricity purchase tariffs, the evolution of development conditions, and the types of financial support). In an interview, a GrDF manager in charge of strategy discusses the GrDF strategy on biomethane, the future management of gas networks, the operation of existing biomethane injection sites, future projects, the management of consumption variations, and the issue of biomethane injection tariff. An article then presents an experiment made by farmers in western France who gathered about a methanization site with a unit of injection of biomethane into the natural gas network. The assessment of another experiment (a Methanea methanization unit operated by two farmers in the Ain district) is then presented. The next article gives an overview of the various possibilities proposed by the legal framework for the contract between input providers and the methanization unit operator. Different assessment tools are then presented: Flash BMP (a fast and affordable method of measurement of the biochemical methane potential or BMP to perform feasibility studies), and a software for the precise assessment of the profitability of a methanization unit. In an interview, a member of Weltec Biopower proposes a brief overview of services and products proposed by this company which installs biogas and bio-methanization every where in the world. A last article addresses the recent evolutions and progress of certification of French digestates

  16. Monitoring and control of the biogas process based on propionate concentration using online VFA measurement.

    Science.gov (United States)

    Boe, Kanokwan; Steyer, Jean-Philippe; Angelidaki, Irini

    2008-01-01

    Simple logic control algorithms were tested for automatic control of a lab-scale CSTR manure digester. Using an online VFA monitoring system, propionate concentration in the reactor was used as parameter for control of the biogas process. The propionate concentration was kept below a threshold of 10 mM by manipulating the feed flow. Other online parameters such as pH, biogas production, total VFA, and other individual VFA were also measured to examine process performance. The experimental results showed that a simple logic control can successfully prevent the reactor from overload, but with fluctuations of the propionate level due to the nature of control approach. The fluctuation of propionate concentration could be reduced, by adding a lower feed flow limit into the control algorithm to prevent undershooting of propionate response. It was found that use of the biogas production as a main control parameter, rather than propionate can give a more stable process, since propionate was very persistent and only responded very slowly to the decrease of the feed flow which lead to high fluctuation of biogas production. Propionate, however, was still an excellent parameter to indicate process stress under gradual overload and thus recommended as an alarm in the control algorithm. Copyright IWA Publishing 2008.

  17. Numerical investigation of biogas flameless combustion

    International Nuclear Information System (INIS)

    Hosseini, Seyed Ehsan; Bagheri, Ghobad; Wahid, Mazlan Abdul

    2014-01-01

    Highlights: • Fuel consumption decreases from 3.24 g/s in biogas conventional combustion to 1.07 g/s in flameless mode. • The differences between reactants and products temperature intensifies irreversibility in traditional combustion. • The temperature inside the chamber is uniform in biogas flameless mode and exergy loss decreases in this technique. • Low O 2 concentration in the flameless mode confirms a complete and quick combustion process in flameless regime. - Abstract: The purpose of this investigation is to analyze combustion characteristics of biogas flameless mode based on clean technology development strategies. A three dimensional (3D) computational fluid dynamic (CFD) study has been performed to illustrate various priorities of biogas flameless combustion compared to the conventional mode. The effects of preheated temperature and wall temperature, reaction zone and pollutant formation are observed and the impacts of combustion and turbulence models on numerical results are discussed. Although preheated conventional combustion could be effective in terms of fuel consumption reduction, NO x formation increases. It has been found that biogas is not eligible to be applied in furnace heat up due to its low calorific value (LCV) and it is necessary to utilize a high calorific value fuel to preheat the furnace. The required enthalpy for biogas auto-ignition temperature is supplied by enthalpy of preheated oxidizer. In biogas flameless combustion, the mean temperature of the furnace is lower than traditional combustion throughout the chamber. Compared to the biogas flameless combustion with uniform temperature, very high and fluctuated temperatures are recorded in conventional combustion. Since high entropy generation intensifies irreversibility, exergy loss is higher in biogas conventional combustion compared to the biogas flameless regime. Entropy generation minimization in flameless mode is attributed to the uniform temperature inside the chamber

  18. A new high performance research reactor

    International Nuclear Information System (INIS)

    Abbate, Pablo M.

    2002-01-01

    A contract for the design, construction and commissioning of the Replacement Research Reactor was signed in July 2000 between Australia authorities and INVAP from Argentina. Since then the detailed design has been completed, an application for a construction license was made in May 2001 and the construction authorisation was issued on 4 th April 2002. This paper explains the safety philosophy embedded into the design together with the approach taken for main elements of the design and their relation to the proposed applications of the reactor. Also information is provided on the suit of neutron beam facilities and irradiation facilities being constructed. Finally it is presented an outline of the project management organisation, project planing and schedule. (author)

  19. Australia's new high performance research reactor

    International Nuclear Information System (INIS)

    Miller, R.; Abbate, P.M.

    2003-01-01

    A contract for the design and construction of the Replacement Research Reactor was signed in July 2000 between ANSTO and INVAP from Argentina. Since then the detailed design has been completed, a construction authorization has been obtained, and construction has commenced. The reactor design embodies modern safety thinking together with innovative solutions to ensure a highly safe and reliable plant. Also significant effort has been placed on providing the facility with diverse and ample facilities to maximize its use for irradiating material for radioisotope production as well as providing high neutron fluxes for neutron beam research. The project management organization and planing is commensurate with the complexity of the project and the number of players involved. (author)

  20. Neutronic Core Performance of CAREM-25 Reactor

    International Nuclear Information System (INIS)

    Villarino, Eduardo; Hergenreder, Daniel; Matzkin, S

    2000-01-01

    The actual design state of core of CAREM-25 reactor is presented.It is shown that the core design complains with the safety and operation established requirements.It is analyzed the behavior of the reactor safety and control systems (single failure of the fast shut down system, single failure of the shut down system, single failure of the second shut down system, reactivity worth of the adjust and control system in normal operation and hot shut down, reactivity worth of the adjust and control system and the scheme of movement of the control rod during the operation cycle).It is shown the burnup profile of fuel elements with the proposed scheme of refueling and the burnup and power density distribution at different moments of the operation cycle.The power peaking factor of the equilibrium core is 2.56, the minimum DNBR is 1.90 and its average is 2.09 during the operation cycle

  1. Dynamic simulation platform to verify the performance of the reactor regulating system for a research reactor

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-07-01

    Digital instrumentation and controls system technique is being introduced in new constructed research reactor or life extension of older research reactor. Digital systems are easy to change and optimize but the validated process for them is required. Also, to reduce project risk or cost, we have to make it sure that configuration and control functions is right before the commissioning phase on research reactor. For this purpose, simulators have been widely used in developing control systems in automotive and aerospace industries. In these literatures, however, very few of these can be found regarding test on the control system of research reactor with simulator. Therefore, this paper proposes a simulation platform to verify the performance of RRS (Reactor Regulating System) for research reactor. This simulation platform consists of the reactor simulation model and the interface module. This simulation platform is applied to I and C upgrade project of TRIGA reactor, and many problems of RRS configuration were found and solved. And it proved that the dynamic performance testing based on simulator enables significant time saving and improves economics and quality for RRS in the system test phase. (authors)

  2. Economical and ecological benchmarking of biogas plant configurations for flexible power generation in future power supply systems

    International Nuclear Information System (INIS)

    Hahn, Henning

    2016-01-01

    With the share of intermittent renewable energies within the electricity system rising, balancing services from dispatchable power plants are of increasing importance. This study comparatively assesses the environmental and economic performance of biogas plant configurations, supplying biogas on demand for flexible power generation. A cost analysis of five configurations based on biogas storing and flexible biogas production concepts has been carried out. Results show that additional flexibility costs for a biogas supply of 8 hours per day range between 2 Euro to 11 Euro MWh -1 and for a 72 hour period without biogas demand from 9 Euro to 19 Euro MWh -1 . While biogas storage concepts were identified as favorable short-term supply configurations, flexible biogas production concepts profit from reduced storage requirements at plants with large biogas production capacities or for longer periods without biogas demand [1, 2]. Flexible biogas plant configurations indicate an increased energy demand to operate the operational enhancements compared to conventional biogas plants supplying biogas for baseload power generation. However, findings show that in contrast to an alternative supply of power generators with natural gas, biogas supplied on demand by adapted biogas plant configurations saves greenhouse gas emissions by 54 to 65 g CO 2-eq MJ -1 and primary energy by about 1.17 MJ MJ -1 . In this regard, configurations with flexible biogas production profit from reduced biogas storage requirements and achieve higher savings compared to configurations with continuous biogas production [1, 3].

  3. Biogas from lignocellulosic biomass

    Energy Technology Data Exchange (ETDEWEB)

    Berglund Odhner, Peter; Schabbauer, Anna [Grontmij AB, Stockholm (Sweden); Sarvari Horvath, Ilona; Mohseni Kabir, Maryam [Hoegskolan i Boraas, Boraas (Sweden)

    2012-01-15

    Grontmij AB has cooperated with the University of Boraas to evaluate the technological and economical possibilities for biogas production from substrates containing lignocellulose, such as forest residues, straw and paper. The state of knowledge regarding biogas production from cellulosic biomass has been summarized. The research in the field has been described, especially focusing on pretreatment methods and their results on increased gas yields. An investigation concerning commercially available pretreatment methods and the cost of these technologies has been performed. An economic evaluation of biogas production from lignocellulosic materials has provided answers to questions regarding the profitability of these processes. Pretreatment with steam explosion was economically evaluated for three feedstocks - wood, straw and paper - and a combination of steam explosion and addition of NaOH for paper. The presented costs pertain to costs for the pretreatment step as it, in this study, was assumed that the pretreatment would be added to an existing plant and the lignocellulosic substrates would be part of a co-digestion process. The results of the investigation indicate that it is difficult to provide a positive net result when comparing the cost of pretreatment versus the gas yield (value) for two of the feedstocks - forest residues and straw. This is mainly due to the high cost of the raw material. For forest residues the steam pretreatment cost exceeded the gas yield by over 50 %, mainly due to the high cost of the raw material. For straw, the production cost was similar to the value of the gas. Paper showed the best economic result. The gas yield (value) for paper exceeded the pretreatment cost by 15 %, which makes it interesting to study paper further.

  4. Desempenho de um conjunto motogerador adaptado a biogás Performance of a motogenerator adapted for biogas

    Directory of Open Access Journals (Sweden)

    Rodrigo G. Souza

    2010-02-01

    Full Text Available O presente trabalho foi desenvolvido na Estação de Produção e Uso de Biogás, da Universidade Federal de Lavras. O objetivo foi desenvolver e avaliar um sistema de alimentação de um motor estacionário com biogás. Foi utilizado um motor de 4 tempos com 4077 W de potência nominal à rotação de 4200 rpm acoplado a um gerador de 2400 W com rotação operacional de 3600 rpm. O biogás utilizado foi produzido em um biodigestor modelo indiano a partir de esterco bovino, contendo, em média, 63 % de metano. Os experimentos foram realizados com o motor operando, inicialmente, a gasolina na sua versão original e, posteriormente, com o sistema de alimentação a biogás. Para os ensaios foram medidas as rotações e o consumo energético do motor, além da tensão e corrente gerada para alimentar três potências resistivas iguais a 1000, 1200 e 1500 W. Para o conjunto motogerador alimentado a gasolina na sua versão original, observou-se uma potência média gerada de 840,2 W com tensão de 109 volts e eficiência do conjunto de 12,14 %. Para o conjunto motogerador operando a biogás utilizando o sistema de alimentação desenvolvido, observou-se uma potência média de 934,59 W, tensão 100,90 volts e eficiência de 8,22 %. Foi possível operar estavelmente o conjunto motogerador com combustível alternativo, biogás, utilizando o sistema de alimentação desenvolvido, substituindo em 100% o uso de gasolina.The present work was conducted at the Unity of Production and Use of Biogas of Lavras Federal University. Its objective was to develop and to evaluate the biogas powering system in a stationary motor using biogas. A four-timing stationary motor with 4077 W nominal potency at a 4200 rpm rotation was used coupled to a generator of 2400 W with operational rotation of 3600 rpm. The biogas used in the experiment was produced in an Indian model biodigestor operated with bovine manure, containing an average of 63% methane. The experiments were

  5. Cooling Performance of Natural Circulation for a Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Park, Suki; Chun, J. H.; Yum, S. B. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    This paper deals with the core cooling performance by natural circulation during normal operation and a flow channel blockage event in an open tank-in-pool type research reactor. The cooling performance is predicted by using the RELAP5/ MOD3.3 code. The core decay heat is usually removed by natural circulation to the reactor pool water in open tank-in-pool type research reactors with the thermal power less than several megawatts. Therefore, these reactors have generally no active core cooling system against a loss of normal forced flow. In reactors with the thermal power less than around one megawatt, the reactor core can be cooled down by natural circulation even during normal full power operation. The cooling performance of natural circulation in an open tank-in-pool type research reactor has been investigated during the normal natural circulation and a flow channel blockage event. It is found that the maximum powers without void generation at the hot channel are around 1.16 MW and 820 kW, respectively, for the normal natural circulation and the flow channel blockage event.

  6. Transient two-phase performance of LOFT reactor coolant pumps

    International Nuclear Information System (INIS)

    Chen, T.H.; Modro, S.M.

    1983-01-01

    Performance characteristics of Loss-of-Fluid Test (LOFT) reactor coolant pumps under transient two-phase flow conditions were obtained based on the analysis of two large and small break loss-of-coolant experiments conducted at the LOFT facility. Emphasis is placed on the evaluation of the transient two-phase flow effects on the LOFT reactor coolant pump performance during the first quadrant operation. The measured pump characteristics are presented as functions of pump void fraction which was determined based on the measured density. The calculated pump characteristics such as pump head, torque (or hydraulic torque), and efficiency are also determined as functions of pump void fractions. The importance of accurate modeling of the reactor coolant pump performance under two-phase conditions is addressed. The analytical pump model, currently used in most reactor analysis codes to predict transient two-phase pump behavior, is assessed

  7. Energy from whey - comparison of the biogas and bioethanol processes

    International Nuclear Information System (INIS)

    Fruteau de Laclos, H.; Membrez, Y.

    2004-01-01

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a project which investigated how energy could be generated from the whey produced in the cheese-making process. The first part of the project aimed to validate a concept for on-site production and use of biogas at a medium-sized cheese factory. The results of the first step, an experimental study carried out using a down-flow fixed-film bio-reactor, are discussed. This allowed the determination of the optimal working parameters as well as providing an estimate of the performance of the process. The second part of the project aimed to compare the bio-ethanol and biogas production processes. It was carried out in collaboration with AlcoSuisse and the Energy Systems Laboratory at the Swiss Federal Institute of Technology (EPFL) in Lausanne. The results of a life-cycle assessment (LCA) are discussed, which compared the two processes from an environmental point of view. Here, two impacts were considered: fossil fuel consumption and greenhouse effect. The replacement of fuel-oil with biogas for heat production and the replacement of conventional petrol with mixture including 5% bio-ethanol were examined. The results are presented that show that there was no significant difference between the two processes. According to the authors, the treatment of one cubic meter of cheese-whey allows savings of more than 20 litres of oil equivalent and 60 kg of CO 2 emissions

  8. Performance improvement of the Annular Core Pulse Reactor for reactor safety experiments

    International Nuclear Information System (INIS)

    Reuscher, J.A.; Pickard, P.S.

    1976-01-01

    The Annular Core Pulse Reactor (ACPR) is a TRIGA type reactor which has been in operation at Sandia Laboratories since 1967. The reactor is utilized in a wide variety of experimental programs which include radiation effects, neutron radiography, activation analysis, and fast reactor safety. During the past several years, the ACPR has become an important experimental facility for the United States Fast Reactor Safety Research Program and questions of interest to the safety of the LMFBR are being addressed. In order to enhance the capabilities of the ACPR for reactor safety experiments, a project to improve the performance of the reactor was initiated. It is anticipated that the pulse fluence can be increased by a factor of 2.0 to 2.5 utilizing a two-region core concept with high heat capacity fuel elements around the central irradiation cavity. In addition, the steady-state power of the reactor will be increased by about a factor of two. The new features of the improvements are described

  9. Core design concepts for high performance light water reactors

    International Nuclear Information System (INIS)

    Schulenberg, T.; Starflinger, J.

    2007-01-01

    Light water reactors operated under supercritical pressure conditions have been selected as one of the promising future reactor concepts to be studied by the Generation IV International Forum. Whereas the steam cycle of such reactors can be derived from modern fossil fired power plants, the reactor itself, and in particular the reactor core, still need to be developed. Different core design concepts shall be described here to outline the strategy. A first option for near future applications is a pressurized water reactor with 380 .deg. C core exit temperature, having a closed primary loop and achieving 2% pts. higher net efficiency and 24% higher specific turbine power than latest pressurized water reactors. More efficiency and turbine power can be gained from core exit temperatures around 500 .deg. C, which require a multi step heat up process in the core with intermediate coolant mixing, achieving up to 44% net efficiency. The paper summarizes different core and assembly design approaches which have been studied recently for such High Performance Light Water Reactors

  10. Characteristics of on-demand biogas production by using sugar beet silage.

    Science.gov (United States)

    Ahmed, Sharif; Kazda, Marian

    2017-08-01

    On-demand electricity generation can be achieved by just-in-time biogas production instantly utilized in co-generation units. For this goal, easily degradable substrates like sugar beet silage have a high potential. Potential for on-demand biogas production from co-digestion of sugar beet silage (SS) with grass silage (GS) was evaluated in two experiments at organic loading rates (OLRs) of 1.5 kgVS m -3 day -1 and 2.5 kgVS m -3 day -1 , respectively. Each experiment was fed with intermittent feeding system at 8 hrs interval at the same feedstock ratios (volatile solids based) of GS:SS-1:0, 3:1 and 1:3, respectively. Modelling by Gaussian equation was performed in order to understand the effects of SS on biogas production. Addition of sugar beet silage led to maximum biogas production within a short time, but it differed significantly depending on feedstock ratios and OLRs, respectively. At OLR 1.5 kgVS m -3 day -1 , during mono fermentation of grass silage maximum biogas production rate of 0.27 l N hr -1 was reached at 2.74 hrs. Production rate did not change at feedstock ratio of GS:SS-3:1 but increased to 0.64 l N hr -1 at GS:SS-1:3 within a shorter time span (1.58 hrs). On the contrary, at OLR of 2.5 kgVS m -3 day -1 time span between feedstock input and maximum biogas production did not differ significantly (p > 0.05) among the reactors. Biogas production rates were 0.60 l N hr -1 within 2.27 hrs and 0.82 l N hr -1 within 2.30 hrs at GS:SS-3:1 and GS:SS-1:3, respectively. Surprisingly, there was no time lag between maximum biogas and methane production rates, irrespectively of OLR. This implies that once the whole microbial community is adapted to intermittent substrate input, the metabolic products are instantly utilized through the all steps of anaerobic substrate degradation. Applying this finding opens new perspectives for on-demand biogas energy production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Effect of beta limits on reactor performance in EBT

    International Nuclear Information System (INIS)

    Uckan, N.A.; Spong, D.A.; Nelson, D.B.

    1981-01-01

    Because of uncertainties in extrapolating results of simplified models to a reactor plasma, the parameters that influence the beta limits cannot be determined accurately at the present time. Also, the reasonable changes within the models and/or assumptions are seen to affect the core beta limits by almost an order of magnitde. Hence, at the present, these limits cannot be used as a rigid (and reliable) requirement for ELMO Bumpy Torus (EBT) reactor engineering considerations. However, sensitivity studies can be carried out to determine the boundaries of the operating regime and to demonstrate the effects of various modes, assumptions, and models on reactor performance (Q value). First, the modes believed to limit the core β and ring plasma performance are discussed, and the simplifications and/or assumptions involved in deriving these limits are highlighted. Then, the implications of these limits for a reactor are given

  12. Internally Heated Screw Pyrolysis Reactor (IHSPR) heat transfer performance study

    Science.gov (United States)

    Teo, S. H.; Gan, H. L.; Alias, A.; Gan, L. M.

    2018-04-01

    1.5 billion end-of-life tyres (ELT) were discarded globally each year and pyrolysis is considered the best solution to convert the ELT into valuable high energy-density products. Among all pyrolysis technologies, screw reactor is favourable. However, conventional screw reactor risks plugging issue due to its lacklustre heat transfer performance. An internally heated screw pyrolysis reactor (IHSPR) was developed by local renewable energy industry, which serves as the research subject for heat transfer performance study of this particular paper. Zero-load heating test (ZLHT) was first carried out to obtain the operational parameters of the reactor, followed by the one dimensional steady-state heat transfer analysis carried out using SolidWorks Flow Simulation 2016. Experiments with feed rate manipulations and pyrolysis products analyses were conducted last to conclude the study.

  13. Biogas Production: Microbiology and Technology.

    Science.gov (United States)

    Schnürer, Anna

    Biogas, containing energy-rich methane, is produced by microbial decomposition of organic material under anaerobic conditions. Under controlled conditions, this process can be used for the production of energy and a nutrient-rich residue suitable for use as a fertilising agent. The biogas can be used for production of heat, electricity or vehicle fuel. Different substrates can be used in the process and, depending on substrate character, various reactor technologies are available. The microbiological process leading to methane production is complex and involves many different types of microorganisms, often operating in close relationships because of the limited amount of energy available for growth. The microbial community structure is shaped by the incoming material, but also by operating parameters such as process temperature. Factors leading to an imbalance in the microbial community can result in process instability or even complete process failure. To ensure stable operation, different key parameters, such as levels of degradation intermediates and gas quality, are often monitored. Despite the fact that the anaerobic digestion process has long been used for industrial production of biogas, many questions need still to be resolved to achieve optimal management and gas yields and to exploit the great energy and nutrient potential available in waste material. This chapter discusses the different aspects that need to be taken into consideration to achieve optimal degradation and gas production, with particular focus on operation management and microbiology.

  14. Development of empirical models for performance evaluation of UASB reactors treating poultry manure wastewater under different operational conditions

    International Nuclear Information System (INIS)

    Yetilmezsoy, Kaan; Sakar, Suleyman

    2008-01-01

    A nonlinear modeling study was carried out to evaluate the performance of UASB reactors treating poultry manure wastewater under different organic and hydraulic loading conditions. Two identical pilot scale up-flow anaerobic sludge blanket (UASB) reactors (15.7 L) were run at mesophilic conditions (30-35 deg. C) in a temperature-controlled environment with three hydraulic retention times (θ) of 15.7, 12 and 8.0 days. Imposed volumetric organic loading rates (L V ) ranged from 0.65 to 4.257 kg COD/(m 3 day). The pH of the feed varied between 6.68 and 7.82. The hydraulic loading rates (L H ) were controlled between 0.105 and 0.21 m 3 /(m 2 day). The daily biogas production rates ranged between 4.2 and 29.4 L/day. High volumetric COD removal rates (R V ) ranging from 0.546 to 3.779 kg COD removed /(m 3 day) were achieved. On the basis of experimental results, two empirical models having a satisfactory correlation coefficient of about 0.9954 and 0.9416 were developed to predict daily biogas production (Q g ) and effluent COD concentration (S e ), respectively. Findings of this modeling study showed that optimal COD removals ranging from 86.3% to 90.6% were predicted with HRTs of 7.9, 9.5, 11.2, 12.6, 13.7 and 14.3 days, and L V of 1.27, 1.58, 1.78, 1.99, 2.20 and 2.45 kg COD/(m 3 day) for the corresponding influent substrate concentrations (S i ) of 10,000, 15,000, 20,000, 25,000, 30,000 and 35,000 mg/L, respectively

  15. Towards novel biogas upgrading processes

    Energy Technology Data Exchange (ETDEWEB)

    Privalova, E.

    2013-06-01

    Biogas production has considerable development possibilities not only in Finland but all over the world since it it the easiest way of creating value out of various waste fractions and represents an alternative source of renewable energy. Development of efficient biogas upgrading technology has become an important issue since it improves the quality of biogas and for example facilitating its injection into the natural gas pipelines. Moreover, such upgrading contributes to resolving the issue of increasing CO{sub 2} emissions and addresses the increasing climate change concerns. Together with traditional CO{sub 2} capturing technologies a new class of recently emerged sorbents such as ionic liquids is claimed as promising media for gas separations. In this thesis, an extensive comparison of the performance of different solvents in terms of CO{sub 2} capture has been performed. The focus of the present study was on aqueous amine solutions and their mixtures, traditional ionic liquids, 'switchable' ionic liquids and poly(ionic liquid)s in order to reveal the best option for biogas upgrading. The CO{sub 2} capturing efficiency for the most promising solvents achieved values around 50-60 L CO{sub 2}/L absorbent. These values are superior to currently widely applied water wash biogas upgrading system. Regeneration of the solvent mixtures appeared to be challenging since the loss of initial efficiency upon CO{sub 2} release was in excess of 20-40 vol %, especially in the case of aqueous amine solutions. In contrast, some of the ionic liquids displayed reversible behavior. Thus, for selected 'switchable' ionic and poly(ionic liquid)s the CO{sub 2} absorption/regeneration cycles were performed 3-4 times without any notable efficiency decrease. The viscosity issue, typical for ionic liquids upon CO{sub 2} saturation, was addressed and the information obtained was evaluated and related to the ionic interactions. The occurrence of volatile organic compounds

  16. Residual biogas yield of digestate from agricultural biogas plants; Restgaspotenzial in Gaerresten aus landwirtschaftlichen Biogasanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Lehner, Andreas; Effenberger, Mathias; Kissel, Rainer; Gronauer, Andreas [Bayerische Landesanstalt fuer Landwirtschaft, Freising (Germany). Arbeitsgruppe Biogastechnologie und Reststoffmanagement

    2009-07-01

    To evaluate the residual biogas yield during storage, biogas tests at a temperature of 22 C were performed with samples of liquid digested residue from 15 agricultural biogas plants (BGP). Values of residual biogas yield between 0.3 and 1.3 % with respect to the biogas yield from the raw input materials were measured. For the two one-stage BGP, the value was about 1.2 %. For the two-stage plants, a residual biogas yield (RBY) of 0.9 % was determined as opposed to 0.4 % for the three-stage plants. With a single exception, the RBY was clearly below 1.0 % if the overall hydraulic retention time in the BGP was equal to or larger than 100 days. For the majority of samples, the residual biogas yield showed a positive correlation with the level of volatile fatty acids in the digestate. Since the real conditions in storage tanks cannot be simulated with a simple batch-test, the results are not representative for the actual biogas production and potential methane emissions from the digestate during open storage. (orig.)

  17. Future European biogas

    DEFF Research Database (Denmark)

    Meyer, A. K.P.; Ehimen, E. A.; Holm-Nielsen, J. B.

    2018-01-01

    Biogas is expected to play an important role in reaching the future energy policy targets of the European Union (EU). The sustainability of biogas substrates has however been recently critically discussed due to the increasing shares of agricultural land used for energy crop production.The aim...... of this study was to project and map the biomass and biogas energy potential from a selection of potentially sustainable agricultural residues, which have been documented to improve in biogas yields when co-digested in biogas production, for the EU28 in year 2030. The investigated types of residual biomasses...... were animal manure, straw by-products from cereal production, and excess grass from rotational and permanent grasslands and meadows. The biogas energy potential from the investigated biomass was projected to range from 1.2·103 to 2.3·103 PJ y-1 in year 2030 in the EU28, depending on the biomass...

  18. A highly concentrated diet increases biogas production and the agronomic value of young bull's manure.

    Science.gov (United States)

    Mendonça Costa, Mônica Sarolli Silva de; Lucas, Jorge de; Mendonça Costa, Luiz Antonio de; Orrico, Ana Carolina Amorim

    2016-02-01

    The increasing demand for animal protein has driven significant changes in cattle breeding systems, mainly in feedlots, with the use of young bulls fed on diets richer in concentrate (C) than in forage (F). These changes are likely to affect animal manure, demanding re-evaluation of the biogas production per kg of TS and VS added, as well as of its agronomic value as a biofertilizer, after anaerobic digestion. Here, we determined the biogas production and agronomic value (i.e., the macronutrient concentration in the final biofertilizer) of the manure of young bulls fed on diets with more (80% C+20% F; 'HighC' diet) or less (65% C+35% F; 'LowC' diet) concentrate, evaluating the effects of temperature (25, 35, and 40°C) and the use of an inoculum, during anaerobic digestion. A total of 24 benchtop reactors were used, operating in a semi-continuous system, with a 40-day hydraulic retention time (HRT). The manure from animals given the HighC diet had the greatest potential for biogas production, when digested with the use of an inoculum and at 35 or 40°C (0.6326 and 0.6207m(3)biogas/kg volatile solids, or VS, respectively). We observed the highest levels of the macronutrients N, P, and K in the biofertilizer from the manure of animals given HighC. Our results show that the manure of young bulls achieves its highest potential for biogas production and agronomic value when animals are fed diets richer in concentrate, and that biogas production increases if digestion is performed at higher temperatures, and with the use of an inoculum. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Energy recovering and biogas

    International Nuclear Information System (INIS)

    2005-11-01

    In spite of the advantages of the methanation and the biogas valorization, the France is one of the european countries where these energy recovery techniques have less developed. Liquid industrial effluents, sewage sludges, waste waters, oils or vinification residues can be processed to produce biogas. In this innovative context biogas combustion installations will have to anticipate the regulations on CO 2 emissions. (A.L.B.)

  20. Microbial electrochemical separation of CO2 for biogas upgrading

    DEFF Research Database (Denmark)

    Kokkoli, Argyro; Zhang, Yifeng; Angelidaki, Irini

    2018-01-01

    was obtained at 1.2 V, inlet biogas rate of 0.088 mL/h/mL reactor and NaCl concentration of 100 mM at a 5-day operation. Meanwhile, the organic matter of the domestic wastewater in the anode was almost completely removed at the end. The study demonstrated a new sustainable way to simultaneously upgrade biogas......Biogas upgrading to natural gas quality has been under focus the recent years for increasing the utilization potential of biogas. Conventional methods for CO2 removal are expensive and have environmental challenges, such as increased emissions of methane in the atmosphere with serious greenhouse...... impact. In this study, an innovative microbial electrochemical separation cell (MESC) was developed to in-situ separate and regenerate CO2 via alkali and acid regeneration. The MESC was tested under different applied voltages, inlet biogas rates and electrolyte concentrations. Pure biomethane...

  1. Basic Data on Biogas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Renewable gases such as biogas and biomethane are considered as key energy carrier when the society is replacing fossil fuels with renewable alternatives. In Sweden, almost 80 % of the fossil fuels are used in the transport sector. Therefore, the focus in Sweden has been to use the produced biogas in this sector as vehicle gas. Basic Data on Biogas contains an overview of production, utilisation, climate effects etc. of biogas from a Swedish perspective. The purpose is to give an easy overview of the current situation in Sweden for politicians, decision makers and interested public. 1.4 TWh of biogas is produced annually in Sweden at approximately 230 facilities. The 135 wastewater treatment plants that produce biogas contribute with around half of the production. In order to reduce the sludge volume, biogas has been produced at wastewater treatment plants for decades. New biogas plants are mainly co-digestion plants and farm plants. The land filling of organic waste has been banned since 2005, thus the biogas produced in landfills is decreasing.

  2. Performance tests of the reactor containment structures of HTTR

    International Nuclear Information System (INIS)

    Sakaba, Nariaki; Iigaki, Kazuhiko; Kawaji, Satoshi; Iyoku, Tatsuo

    1998-03-01

    The containment structures of the HTTR consist of the reactor containment vessel (CV), service area (SA) and emergency air purification system, which minimize the release of FPs in the postulated accidents with FP release from the reactor facilities. The CV is designed to withstand the temperature and pressure transients and to be leak-tight within the specified leakage limit even in the case of a rupture of the primary concentric hot gas duct. The pressure of inside of the SA should be maintained slightly lower than that of atmosphere by the emergency air purification system. The radioactive materials are released from the stack to environment via the emergency air purification system under the accident condition. Then the emergency air purification system should remove airborne radio-activities and should maintain proper pressure in the SA. We established the method to measure leak rate of the CV with closed reactor coolant pressure boundary although it is normally measured under opened reactor coolant pressure boundary as employed in LWRs. The CV leak rate test was carried out by the newly developed method and the expected performance was obtained. The SA and emergency air purification system were also confirmed by the performance test. We concluded that the reactor containment structures were fabricated to minimize the release of FPs in the postulated accidents with FP release from the reactor facilities. (author)

  3. Contour analysis of steady state tokamak reactor performance

    International Nuclear Information System (INIS)

    Devoto, R.S.; Fenstermacher, M.E.

    1990-01-01

    A new method of analysis for presenting the possible operating space for steady state, non-ignited tokamak reactors is proposed. The method uses contours of reactor performance and plasma characteristics, fusion power gain, wall neutron flux, current drive power, etc., plotted on a two-dimensional grid, the axes of which are the plasma current I p and the normalized beta, β n = β/(I p /aB 0 ), to show possible operating points. These steady state operating contour plots are called SOPCONS. This technique is illustrated in an application to a design for the International Thermonuclear Experimental Reactor (ITER) with neutral beam, lower hybrid and bootstrap current drive. The utility of the SOPCON plots for pointing out some of the non-intuitive considerations in steady state reactor design is shown. (author). Letter-to-the-editor. 16 refs, 3 figs, 1 tab

  4. Comparison of Ontario Hydro's performance with world power reactors - 1981

    International Nuclear Information System (INIS)

    Dumka, B.R.

    1982-04-01

    The performance of Ontario Hydro's CANDU reactors in 1981 is compared with that of 123 world nuclear power reactors rated at 500 MW(e) or greater. The report is based on data extracted from publications, as well as correspondence with a number of utilities. The basis used is the gross capacity factor, which is defined as gross unit generation divided by the perfect gross output for the period of interest. The lowest of the published turbine and generator design ratings is used to determine the perfect gross output, unless the unit has been proven capable of consistently exceeding this value. The first six reactors in the rankings were CANDU reactors operated by Ontario Hydro

  5. Description of Measurements on Biogas Stations

    Directory of Open Access Journals (Sweden)

    Ladislav Novosád

    2016-08-01

    Full Text Available This paper focuses mainly on performance analysis for three biogas stations situated within the territory of the Czech Republic. This paper contains basic details of the individual biogas stations as well as description of their types. It also refers to the general description of the measurement gauge involved, with specifications of its potential use. The final part of this paper deals with the analysis of course data obtained, with special regard to voltage, current, active power and reactive power data.

  6. Biogas Production from Water Hyacinth (Eichhornia Crassipes): The Effect of F/M Ratio

    Science.gov (United States)

    Nugraha, W. D.; Syafrudin; Pradita, L. L.; Matin, H. H. A.; Budiyono

    2018-05-01

    Distribution of water hyacinth (Eichhornia crassipes), generally considered as a water weed, that has been a problem which can harm the environment, irrigation system, and agriculture. However water hyacinth can be used in biogas production because it has large enough amount of hemicellulose contents. The purpose of this study was to know the effect of F/M ratio to biogas production from water hyacinth waste with Liquid Anaerobic Digestion (LAD) method. A series of laboratory experiments using biodigester were performed in batch anaerobic operation at room temperature. F/M ratio that used in each reactor was 39.76, 20.03, 13.32, and 10.01. Degradation process was done in 60 days. The result showed that F/M ratio effects to the biogas production. The best performance of biogas production from this research will be obtained if F/M ratio is in the range of 10.01-20.03 (correspond to 25%-50% of rumen fluid) with water hyacinth as the main substrate.

  7. Thermal performances of an insulating structure for a reactor vessel

    International Nuclear Information System (INIS)

    Aranovitch, E.; Crutzen, S.; Le Det, M.; Denis, R.

    1974-12-01

    This report describes the thermal and technological tests performed on a multilayer thermal insulation system for high temperature gas reactors. It includes the description of test facilities, global tests, interpretation of data, and technological tests. Results obtained make it possible to predetermine with a satisfactory precision thermal performances under various nominal conditions

  8. Performance of the prism reactor's passive decay heat removal system

    International Nuclear Information System (INIS)

    Magee, P.M.; Hunsbedt, A.

    1989-01-01

    The PRISM modular reactor concept has a totally passive safety-grade decay heat removal system referred to as the Reactor Vessel Auxiliary Cooling System (RVACS) that rejects heat from the reactor by radiation and natural convection of air. The system is inherently reliable and is not subject to the failure modes commonly associated with active cooling systems. The thermal performance of RVACS exceeds requirements and significant thermal margins exist. RVACS has been shown to perform its function under many postulated accident conditions. The PRISM power plant is equipped with three methods for shutdown: condenser cooling in conjunction with intermediate sodium and steam generator systems, and auxiliary cooling system (ACS) which removes heat from the steam generator by natural convection of air and transport of heat from the core by natural convection in the primary and intermediate systems, and a safety- grade reactor vessel auxiliary cooling system (RVACS) which removes heat passively from the reactor containment vessel by natural convection of air. The combination of one active and two passive systems provides a highly reliable and economical shutdown heat removal system. This paper provides a summary of the RVACS thermal performance for expected operating conditions and postulated accident events. The supporting experimental work, which substantiates the performance predictions, is also summarized

  9. The Improvement of Carburater Efficiency Using Biogas-based Venturi

    Directory of Open Access Journals (Sweden)

    Lasmi Ni Ketut

    2016-01-01

    Full Text Available The elimination of the fossil fuel subsidy by the Indonesian government has caused an increase in fuel prices, and a solution to find a relatively cheap and environmentally friendly alternative energy is needed. Biogas is one of the sources of renewable energy that has a potential to be developed, especially in farming area where the abundant animal excrement is not yet optimally used and causes environmental problems. Addressing this issue, we have developed an innovation by making a biogas and air mixer instrument through venturi pipe, using the basic theory of fluid mechanism in order to increase the use of biogas as an electricity source. Usually, biogas-based electric generators use dual fuel system such as fossil fuel and biogas to perform combustion due to the low octane contained in the biogas. By replacing the readily available manufactured venturi with the modified venturi, optimal combustion can be reached with using only single fuel of biogas. The results of the experiments show that the biogas debit on carburetor increases from 13 to 439 watts consuming biogas fuel from 0.22 to 4.96 liter/minute, respectively. The amount of combusted biogas depends on the value of the load power. Within the scope of our results, the maximum voltage reached is about 211.13 – 211.76 volts which is feasible to use for 220 volts electrical appliances

  10. Design of laboratory cyclone separator for biogas purification

    Directory of Open Access Journals (Sweden)

    Marián Fodora

    2013-01-01

    Full Text Available This article deals with calculation of a cyclone separator for biogas purification using physical and chemical methods. There is presented a methodology for determination of operating dimensions of the cyclone separator and description of principal features of the cyclone separator model. Calculations have been performed for the diameter of the cylindrical part of cyclone separator 175 mm and for the biogas volume flow rate 6.9∙10−5 m3∙s−1. The calculations can be used in practice for the design of cyclone separator depending on the flow rate of biogas, size of the biogas plants respectively. The developed cyclone separator has been used for the cleaning of biogas in operating conditions at the biogas plant in Kolinany (Slovakia. The presented method of biogas purification has been used for the removing of hydrogen sulphide, particulate matter and carbon dioxide from the raw biogas at the biogas plant. Removal of these undesirable impurities from the biogas is an important step in the production of a fully valued fuel, biomethane.

  11. Study on biogas premixed charge diesel dual fuelled engine

    International Nuclear Information System (INIS)

    Duc, Phan Minh; Wattanavichien, Kanit

    2007-01-01

    This paper presents an experimental investigation of a small IDI biogas premixed charge diesel dual fuelled CI engine used in agricultural applications. Engine performance, diesel fuel substitution, energy consumption and long term use have been concerned. The attained results show that biogas-diesel dual fuelling of this engine revealed almost no deterioration in engine performance but lower energy conversion efficiency which was offset by the reduced fuel cost of biogas over diesel. The long term use of this engine with biogas-diesel dual fuelling is feasible with some considerations

  12. 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.

  13. 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.

  14. Farm Biogas Handbook; Gaardsbiogashandbok

    Energy Technology Data Exchange (ETDEWEB)

    Christensson, Kjell; Bjoernsson, Lovisa; Dahlgren, Stefan; Eriksson, Peter; Lantz, Mikael; Lindstroem, Johanna; Mickelaaker, Maria

    2009-04-15

    A very large share of the total raw material potential for biogas production will be found within the agriculture. The raw material potential of manure in Sweden amounts to 4 - 6 TWh. Within the agriculture there is moreover a big potential in the form of residues from plant cultivation and non-food crops (approximately 7 TWh) that can to be used for biogas production. The potential for biogas production from only residues and manure is around 8-10 TWh. An increased biogas production within the agriculture would give significant environmental effects. Among other things manure, that today is leaking methane gas to the atmosphere, can be fermented, and trough this process the methane losses will be reduced. When the produced biogas replaces fossil fuel, an overall environmental effect will be reached, that is highly significant. This manual deals with biogas plants for agriculture and such plants that do not have extensive transports of different raw materials, as manure, wastes etc. One of the starting points for this manual's set-up is a course plan that Biogas Syd made for the courses they give to farmers, advisors and others. The manual illustrates important aspects in planning and construction of biogas plants, from raw material and technology to dimensioning of plant, use of biogas and planning of local gas grids. We also think it is important to illustrate the legislation that encompasses construction work and operation of a biogas plant. Investment costs are also illustrated, but the book does not give any extensive economic calculations, since we believe that such calculations need their own manual in the form of calculation examples, based on various conditions. The final section is called 'Biogas on farm - from idea to reality' where the entire process from analysis and pre-planning to monitoring and control of plant during operation is briefly described

  15. Desempenho de um aquecedor de água a biogás Performance of a water heater by biogas

    Directory of Open Access Journals (Sweden)

    Fabio M. da Silva

    2005-12-01

    Full Text Available Estudos foram desenvolvidos para dimensionar e adaptar o injetor do queimador principal de um aquecedor de água tipo acumulação de 75 L. O diâmetro do injetor foi redimensionado em função da pressão de serviço de 100 mm H2O e poder calorífico inferior do biogás de 21.600 kJ m-3 n, garantindo a manutenção da potência calorífica do equipamento de 20.900 kJ h-1. Os resultados demonstraram que o queimador adaptado operou com biogás adequadamente, com chama estável. A eficiência média do aquecedor foi de 68%, para ganho térmico de 36,7 ºC, correspondendo à temperatura final da água igual a 62,7 ºC, sendo consumido 0,796 m³n de biogás, aquecendo 75 L de água em 72 minutos.Studies had been developed to project and to adapt the injector of the main burner of water heater accumulated type of 75 L. The diameter of the injector was project in function of the pressure of service of 100 mm H2O and inferior calorific power of biogas of 21,600 kJ m-3 n, having guaranteed the maintenance of the calorific power of the equipment of 20,900 of kJ h-1 .The results had demonstrated that the adapted burner to operate with biogas operated adequately with a steady flame. The average efficiency of the heater was of 68%, for a thermal profit of 36.7 ºC, corresponding the final temperature of the water of 62.7 ºC being consumed 0.796 m³ n of biogas, heating 75 L of water in 72 minutes.

  16. A technical survey of power generation from biogas

    International Nuclear Information System (INIS)

    1996-01-01

    The objectives of this survey are: to review the use of biogas (ie landfill gas, sewage gas and farm gas) for power generation, mainly in the UK. To assess the performance of prime movers and the status and need for biogas pre-treatment. To review legislation with regard to emissions both in the UK and overseas. To provide a framework of good practice for choosing prime movers fuelled by biogas. (author)

  17. Influence of Inoculum Content on Performance of Anaerobic Reactors for Treating Cattle Manure using Rumen Fluid Inoculum

    OpenAIRE

    Sunarso; S. Johari; I N. Widiasa; Budiyono

    2009-01-01

    Biogas productions of cattle manure using rumen fluid inoculums were determined using batch anaerobic digesters at mesophilic temperatures (room and 38.5 oC). The aim of this paper was to analyze the influence of rumen fluid contents on biogas yield from cattle manure using fluid rumen inoculums. A series of laboratory experiments using 400 ml biodigester were performed in batch operation mode. Given 100 grams of fresh cattle manure (M) was fed to each biodigester and mixed with rumen fluid (...

  18. Modern control technology for improved nuclear reactor performance

    International Nuclear Information System (INIS)

    Oakes, L.C.

    1986-01-01

    One of the main complaints leveled at reactor control systems by utility spokesmen is complexity. One only has to look inside a power reactor control room to appreciate this viewpoint. The high reliability and versatility of modern microprocessors makes possible distributed control systems with only performance data and abnormal conditions being relayed to the control room. In a sense, this emulates the human-body control system where routine repetitive actions are handled in an involuntary manner. The significance of expert systems to the nuclear reactor control and safety systems is their ability to capture human and other expertise and make it available, upon demand, and under almost all circumstances. Thus, human problem-solving skills acquired by the learning process over a long period of time can be captured and employed with the reliability inherent in computers. This is especially important in nuclear plants when human operators are burdened by stress and emotional factors that have a dramatic effect on performance level

  19. Transient safety performance of the PRISM innovative liquid metal reactor

    International Nuclear Information System (INIS)

    Magee, P.M.; Dubberley, A.E.; Rhow, S.K.; Wu, T.

    1988-01-01

    The PRISM sodium-cooled reactor concept utilizes passive safety characteristics and modularity to increase performance margins, improve licensability, reduce owner's risk and reduce costs. The relatively small size of each reactor module (471 MWt) facilitates the use of passive self-shutdown and shutdown heat removal features, which permit design simplification and reduction of safety-related systems. Key to the transient performance is the inherent negative reactivity feedback characteristics of the core design resulting from the use of metal (U-Pu-Zr) swing, and very low control rod runout worth. Selected beyond design basis events relying only on these core design features are analyzed and the design margins summarized to demonstrate the advancement in reactor safety achieved with the PRISM design concept

  20. 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...

  1. Trenton Biogas LLC

    Energy Technology Data Exchange (ETDEWEB)

    Blair, William Brian [Trenton Biogas LLC, Trenton, NJ (United States)

    2017-06-13

    During the total period of funding, the project objectives changed. The initial objective of the project was to research the health and efficacy of two commercial derivative products of levulinic acid extracted from food waste and to optimize conversion methods for manufacturing. Unfortunately, and prior to any final conclusions, the scientist performing the studies passed away leaving much of the work incomplete. Analysis of the initial work product suggested that the process for commercializing levulinic acid from the food waste product was cost prohibitive mostly due to the market readiness for the levulinic acid product. The second phase of funding research period focused on utilizing the food waste (which had already been researched from phase 1) for other sources of energy. The focus and objectives of this phase were more focused on the technology transfer necessary to commercialize anaerobic digestion of food waste in a somewhat urban environment. During this transition, the project name changed from Trenton Fuel Works to Trenton Biogas.

  2. Electricity from biogas

    International Nuclear Information System (INIS)

    Augenstein, D.; Benemann, J.; Hughes, E.

    1994-01-01

    Biogas is a medium-Btu methane and carbon dioxide mix produced by bacterial decomposition of organic matter. Its sources include landfills, waste water sludges, and animal wastes. It can fuel energy applications, of which electricity generation is a frequently-preferred option. The greatest current U.S. biogas recovery and energy use is at landfills, where biogas at about 80 landfill sites fuels a total of approximately 300 MWe. Wastewater treatment plants and confined animal waste management systems support additional electric power production. Generation of electricity from biogas can present difficulties due to the generally small scale of the generating facility, variable energy content of the gas, fluctuating availability, contaminant problems, and often-demanding control needs. However, such difficulties are being successfully addressed and economics for electricity generation are often favorable as biogas can be essentially open-quotes freeclose quotes fuel. Biogas recovery and use has the additional advantage of mitigating a potent greenhouse gas. Biogas from U.S. landfills alone could fuel about 1% of U.S. electrical generation while giving climate change benefit equivalent to reducing CO 2 emissions in the electricity sector by more than 10%. Growth in landfill gas use will be facilitated by recent regulations, advances in equipment, and improved management techniques such as open-quotes controlled landfillingclose quotes. The potential for biogas recovery and electricity production from sewage sludges, animal wastes and other organic resources such as agricultural residues is uncertain but probably exceeds the estimate for landfills

  3. Biogas plant control system

    International Nuclear Information System (INIS)

    Balasevicius, L.; Dervinis, G.; Macerauskas, V.

    2002-01-01

    This paper presents intelligent control system for the pig farm biogas production process. The system uses a fuzzy logic models based on knowledge of experts and operators. Four fuzzy models are introduced. The adequacy of fuzzy models is verified using real data and MATLAB simulation. Proposed expert system is implemented into traditional SCADA system for biogas process prediction and failure analyzing. (authors)

  4. The impact of CO2-costs on biogas usage

    DEFF Research Database (Denmark)

    Jensen, Ida Græsted; Nielsen, Lise Skovsgaard

    2017-01-01

    The Danish government has set a target of being fossil fuel independent by 2050 implying that a high degree of inflexible renewable energy will be included in the energy system; biogas can add flexibility and potentially has a negative CO2-emission. In this paper, we investigate the socioeconomic...... system costs of reaching a Danish biogas target of 3.8 PJ in the energy system, and how CO2 costs affect the system costs and biogas usage. We perform our analysis using the energy systems model, Balmorel, and expand the model with a common target for raw biogas and upgraded biogas (biomethane). Raw...... biogas can be used directly in heat and power production, while biomethane has the same properties as natural gas. Balmorel is altered such that natural gas and biomethane can be used in the same technologies. Several CO2-cost estimates are investigated; hereunder a high estimate for the expected CO2...

  5. Analysis of tandem mirror reactor performance

    International Nuclear Information System (INIS)

    Wu, K.F.; Campbell, R.B.; Peng, Y.K.M.

    1984-11-01

    Parametric studies are performed using a tandem mirror plasma point model to evaluate the wall loading GAMMA and the physics figure of merit, Q (fusion power/injected power). We explore the relationship among several dominant parameters and determine the impact on the plasma performance of electron cyclotron resonance heating in the plug region. These global particle and energy balance studies were carried out under the constraints of magnetohydrodynamic (MHD) equilibrium and stability and constant magnetic flux, assuming a fixed end-cell geometry. We found that the higher the choke coil fields, the higher the Q, wall loading, and fusion power due to the combination of the increased central-cell field B/sub c/ and density n/sub c/ and the reduced central-cell beta β/sub c/. The MHD stability requirement of constant B/sub c/ 2 β/sub c/ causes the reduction in β/sub c/. In addition, a higher value of fusion power can also be obtained, at a fixed central-cell length, by operating at a lower value of B/sub c/ and a higher value of β/sub c/

  6. The Performance of Structured Packings in Trickle-Bed Reactors

    NARCIS (Netherlands)

    Frank, M.J.W.; Kuipers, J.A.M.; Versteeg, G.F.; Swaaij, W.P.M. van

    1999-01-01

    An experimental study was carried out to investigate whether the use of structured packings might improve the mass transfer characteristics and the catalyst effectiveness of a trickle-bed reactor. Therefore, the performances of a structured packing, consisting of KATAPAK elements, and a dumped

  7. An analysis of CDTN performance in the reactors technology area

    International Nuclear Information System (INIS)

    Pinheiro, R.B.

    1985-01-01

    The author makes an analysis of CDTN (Centro de Desenvolvimento da Tecnologia Nuclear) performance in the reactors technology area, showing difficulties and failures, but emphasizing the particular competence and capacity acquired in this area, as for example: the capacity in codes and methods are of neutronic calculations and nuclear projects, experimental thermohydraulic program, tests services in components and the others. (C.M.) [pt

  8. Density dependence of reactor performance with thermal confinement scalings

    International Nuclear Information System (INIS)

    Stotler, D.P.

    1992-03-01

    Energy confinement scalings for the thermal component of the plasma published thus far have a different dependence on plasma density and input power than do scalings for the total plasma energy. With such thermal scalings, reactor performance (measured by Q, the ratio of the fusion power to the sum of the ohmic and auxiliary input powers) worsens with increasing density. This dependence is the opposite of that found using scalings based on the total plasma energy, indicating that reactor operation concepts may need to be altered if this density dependence is confirmed in future research

  9. Performance and safety design of the advanced liquid metal reactor

    International Nuclear Information System (INIS)

    Berglund, R.C.; Magee, P.M.; Boardman, C.E.; Gyorey, G.L.

    1991-01-01

    The Advanced Liquid Metal Reactor (ALMR) program led by General Electric is developing, under U.S. Department of Energy sponsorship, a conceptual design for an advanced sodium-cooled liquid metal reactor plant. This design is intended to improve the already excellent level of plant safety achieved by the nuclear power industry while at the same time providing significant reductions in plant construction and operating costs. In this paper, the plant design and performance are reviewed, with emphasis on the ALMR's unique passive design safety features and its capability to utilize as fuel the actinides in LWR spent fuel

  10. Performance demonstration experience for reactor pressure vessel shell ultrasonic testing

    International Nuclear Information System (INIS)

    Zado, V.

    1998-01-01

    The most ultrasonic testing techniques used by many vendors for pressurized water reactor (PWR) examinations were based on American Society of Mechanical Engineers 'Boiler and Pressurized Vessel Code' (ASME B and PV Code) Sections XI and V. The Addenda of ASME B and PV Code Section XI, Edition 1989 introduced Appendix VIII - 'Performance Demonstration for Ultrasonic Examination Systems'. In an effort to increase confidence in performance of ultrasonic testing of the operating nuclear power plants in United States, the ultrasonic testing performance demonstration examination of reactor vessel welds is performed in accordance with Performance Demonstration Initiative (PDI) program which is based on ASME Code Section XI, Appendix VIII requirements. This article provides information regarding extensive qualification preparation works performed prior EPRI guided performance demonstration exam of reactor vessel shell welds accomplished in January 1997 for the scope of Appendix VIII, Supplements IV and VI. Additionally, an overview of the procedures based on requirements of ASME Code Section XI and V in comparison to procedure prepared for Appendix VIII examination is given and discussed. The samples of ultrasonic signals obtained from artificial flaws implanted in vessel material are presented and results of ultrasonic testing are compared to actual flaw sizes. (author)

  11. 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

  12. Biogas in agriculture. Status and prospects. Proceedings; Biogas in der Landwirtschaft. Stand und Perspektiven. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    emissions and optimization of the humus balance (Kurt Moeller); (18) Evaluation of greenhouse gases from agricultural biogas plants by means of emission measurements (Jan Liebetrau); (19) Greenhouse gas balances and CO{sub 2}-eq abatement costs of agricultural biogas plants (Ursula Roth); (20) Mixtures of wild plants for production of biogas (Birgit Vollrath); (21) Utilization of straw as a fermentation substrate by means of digestion of straw (Stefan Droege); (22) Biogas from algae, seaweed and seagrass? (Helga Schneider); (23) Common project of farmers and public utilities - Feeding of biogas with amine purification (Johannes Steinhauer); (23) Feeding bio methan from the view of a plant operator (Thomas Balling); (24) Potentials for an optimized and resources carefully delivery of bio methan - Guidelines for a further expansion for biogas utilization (Wolfgang Urban); (25) Repowering of biogas plants (Anton Baumann); (26) Repowering of biogas plants for enhancing the process efficiency (Matthias Effenberger); (27) From troubled kid to star performers - On the repowering of a biogas plant (Hans-Werner Gress). Furthermore, 55 posters were presented.

  13. Kinetic analysis of nitric oxide reduction using biogas as reburning fuel

    African Journals Online (AJOL)

    Biogas was suggested more suitable as reburning fuel to reduce NO emission and Miller-Bowan's mechanism was performed to analyze the effect of reaction environment in the process of biogas reburning. Results show that the NO reduction efficiency increased with the increase of hydrocarbon in biogas, reburning fuel ...

  14. Stimulation of the hydrolytic stage for biogas production from cattle manure in an electrochemical bioreactor.

    Science.gov (United States)

    Samani, Saeed; Abdoli, Mohammad Ali; Karbassi, Abdolreza; Amin, Mohammad Mehdi

    Electrical current in the hydrolytic phase of the biogas process might affect biogas yield. In this study, four 1,150 mL single membrane-less chamber electrochemical bioreactors, containing two parallel titanium plates were connected to the electrical source with voltages of 0, -0.5, -1 and -1.5 V, respectively. Reactor 1 with 0 V was considered as a control reactor. The trend of biogas production was precisely checked against pH, oxidation reduction potential and electrical power at a temperature of 37 ± 0.5°C amid cattle manure as substrate for 120 days. Biogas production increased by voltage applied to Reactors 2 and 3 when compared with the control reactor. In addition, the electricity in Reactors 2 and 3 caused more biogas production than Reactor 4. Acetogenic phase occurred more quickly in Reactor 3 than in the other reactors. The obtained results from Reactor 4 were indicative of acidogenic domination and its continuous behavior under electrical stimulation. The results of the present investigation clearly revealed that phasic electrical current could enhance the efficiency of biogas production.

  15. Optimization of biogas production from olive-oil mill wastewater, by codigesting with diluted poultry-manure

    International Nuclear Information System (INIS)

    Gelegenis, John; Georgakakis, Dimitris; Angelidaki, Irini; Christopoulou, Nicholetta; Goumenaki, Maria

    2007-01-01

    Optimization of biogas production from olive-mill wastewater (OMW) was attempted by codigesting with diluted poultry-manure (DPM) at mesophilic conditions. A series of laboratory experiments were performed in continuously-operating reactors, fed with mixtures of OMW and DPM at various concentrations. It was concluded that codigestion of OMW with DPM is possible without any dilution of OMW or addition of any chemicals. Biogas production was slightly higher when OMW was added to DPM up to a critical concentration (about 40%, expressed as contribution of OMW to the volatile solids of the mixture), after which production is decreased. The results were further verified by scaling up to a continuously-operating pilot-plant reactor digesting DPM, and confirmed that no negative impact was imposed by adding OMW up to the above critical value

  16. 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

  17. 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.

  18. Proteotyping of laboratory-scale biogas plants reveals multiple steady-states in community composition.

    Science.gov (United States)

    Kohrs, F; Heyer, R; Bissinger, T; Kottler, R; Schallert, K; Püttker, S; Behne, A; Rapp, E; Benndorf, D; Reichl, U

    2017-08-01

    Complex microbial communities are the functional core of anaerobic digestion processes taking place in biogas plants (BGP). So far, however, a comprehensive characterization of the microbiomes involved in methane formation is technically challenging. As an alternative, enriched communities from laboratory-scale experiments can be investigated that have a reduced number of organisms and are easier to characterize by state of the art mass spectrometric-based (MS) metaproteomic workflows. Six parallel laboratory digesters were inoculated with sludge from a full-scale BGP to study the development of enriched microbial communities under defined conditions. During the first three month of cultivation, all reactors (R1-R6) were functionally comparable regarding biogas productions (375-625 NL L reactor volume -1 d -1 ), methane yields (50-60%), pH values (7.1-7.3), and volatile fatty acids (VFA, 1 gNH 3 L -1 ) showed an increase to pH 7.5-8.0, accumulation of acetate (>10 mM), and decreasing biogas production (<125 NL L reactor volume -1 d -1 ). Tandem MS (MS/MS)-based proteotyping allowed the identification of taxonomic abundances and biological processes. Although all reactors showed similar performances, proteotyping and terminal restriction fragment length polymorphisms (T-RFLP) fingerprinting revealed significant differences in the composition of individual microbial communities, indicating multiple steady-states. Furthermore, cellulolytic enzymes and cellulosomal proteins of Clostridium thermocellum were identified to be specific markers for the thermophilic reactors (R3, R4). Metaproteins found in R3 indicated hydrogenothrophic methanogenesis, whereas metaproteins of acetoclastic methanogenesis were identified in R4. This suggests not only an individual evolution of microbial communities even for the case that BGPs are started at the same initial conditions under well controlled environmental conditions, but also a high compositional variance of microbiomes under

  19. Influence of different practices on biogas sustainability

    International Nuclear Information System (INIS)

    Boulamanti, Aikaterini K.; Donida Maglio, Sara; Giuntoli, Jacopo; Agostini, Alessandro

    2013-01-01

    Biogas production and use are generally regarded as a sustainable practice that can guarantee high greenhouse gas (GHG) savings. However, the actual carbon footprint of biogas is strongly influenced by several factors. The aim of this study is to analyse the environmental performance of different biogas to electricity scenarios. Two criticalities are identified as important: the choice of feedstock and the operational practice concerning the digestate. Maize, manure and co-digestion of them are the different feedstocks chosen. Maize has higher yields, but its cultivation has to be accounted for, which consists of 28–42% of the GHG emissions of the whole process of producing electricity. Manure is considered a residue and as a result benefits from no production stage, but also from avoided emissions from the normal agricultural practice of storing it in the farm and spreading it as fertiliser, but has lower methane yields. Co-digestion combines the benefits and disadvantages of the two different feedstocks. Digestate storage in open or closed tanks and further use as fertiliser is analysed. The environmental impact analysis shows that a substantial reduction of GHG emissions can be achieved with closed digestate storage. The GHG emissions savings vary from about 3% in the maize pathways with open storage up to 330% in the manure pathway with closed storage. The biogas pathways, though, have worse environmental performances in all other environmental impacts considered but ozone depletion potential when compared to the European electricity average mix. -- Highlights: ► Biogas sustainability depends on the feedstock and the digestate management. ► Closed storage is strongly recommended. ► Taking into consideration credits is recommended. ► The biogas pathways GHG emissions can be lower than the ones of the reference system. ► Biogas pathways have higher impact in eutrophication, ecotoxicity and PM potentials

  20. Effect of Waste Paper on Biogas Production from Co-digestion of ...

    African Journals Online (AJOL)

    The effect of waste paper on biogas production from the co-digestion of fixed amount of cow dung and water hyacinth was studied at room temperature in five batch reactor for over 60 days. Waste paper addition was varied for a fixed amount of cow dung and water hyacinth until maximum biogas production was achieved.

  1. WWER reactor fuel performance, modelling and experimental support. Proceedings

    International Nuclear Information System (INIS)

    Stefanova, S.; Chantoin, P.; Kolev, I.

    1994-01-01

    This publication is a compilation of 36 papers presented at the International Seminar on WWER Reactor Fuel Performance, Modelling and Experimental Support, organised by the Institute for Nuclear Research and Nuclear Energy (BG), in cooperation with the International Atomic Energy Agency. The Seminar was attended by 76 participants from 16 countries, including representatives of all major Russian plants and institutions responsible for WWER reactor fuel manufacturing, design and research. The reports are grouped in four chapters: 1) WWER Fuel Performance and Economics: Status and Improvement Prospects: 2) WWER Fuel Behaviour Modelling and Experimental Support; 3) Licensing of WWER Fuel and Fuel Analysis Codes; 4) Spent Fuel of WWER Plants. The reports from the corresponding four panel discussion sessions are also included. All individual papers are recorded in INIS as separate items

  2. Fuel performance and fission product behaviour in gas cooled reactors

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    The Co-ordinated Research Programme (CRP) on Validation of Predictive Methods for Fuel and Fission Product Behaviour was organized within the frame of the International Working Group on Gas Cooled Reactors. This International Working Group serves as a forum for exchange of information on national programmes, provides advice to the IAEA on international co-operative activities in advanced technologies of gas cooled reactors (GCRs), and supports the conduct of these activities. The objectives of this CRP were to review and document the status of the experimental data base and of the predictive methods for GCR fuel performance and fission product behaviour; and to verify and validate methodologies for the prediction of fuel performance and fission product transport. Refs, figs, tabs.

  3. Fuel performance and fission product behaviour in gas cooled reactors

    International Nuclear Information System (INIS)

    1997-11-01

    The Co-ordinated Research Programme (CRP) on Validation of Predictive Methods for Fuel and Fission Product Behaviour was organized within the frame of the International Working Group on Gas Cooled Reactors. This International Working Group serves as a forum for exchange of information on national programmes, provides advice to the IAEA on international co-operative activities in advanced technologies of gas cooled reactors (GCRs), and supports the conduct of these activities. The objectives of this CRP were to review and document the status of the experimental data base and of the predictive methods for GCR fuel performance and fission product behaviour; and to verify and validate methodologies for the prediction of fuel performance and fission product transport

  4. Fuel performance at high burnup for water reactors

    International Nuclear Information System (INIS)

    1991-02-01

    The present meeting was scheduled by the International Atomic Energy Agency, upon proposal of the Members of the International Working Group on Water Reactor Fuel Performance and Technology. The purpose of this meeting was to review the ''state-of-the-art'' in the area of Fuel Performance at High Burnup for Water Reactors. Previous IAEA meetings on this topic were held in Mol in 1981 and 1984 and on related topics in Stockholm and Lyon in 1987. Fifty-five participants from 16 countries and two international organizations attended the meeting and 28 papers were presented and discussed. The papers were presented in five sub-sessions and during the meeting, working groups composed of the session chairmen and paper authors prepared the summary of each session with conclusions and recommendations for future work. A separate abstract was prepared for each of these papers. Refs, figs and tabs

  5. WWER reactor fuel performance, modelling and experimental support. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Stefanova, S; Chantoin, P; Kolev, I [eds.

    1994-12-31

    This publication is a compilation of 36 papers presented at the International Seminar on WWER Reactor Fuel Performance, Modelling and Experimental Support, organised by the Institute for Nuclear Research and Nuclear Energy (BG), in cooperation with the International Atomic Energy Agency. The Seminar was attended by 76 participants from 16 countries, including representatives of all major Russian plants and institutions responsible for WWER reactor fuel manufacturing, design and research. The reports are grouped in four chapters: (1) WWER Fuel Performance and Economics: Status and Improvement Prospects: (2) WWER Fuel Behaviour Modelling and Experimental Support; (3) Licensing of WWER Fuel and Fuel Analysis Codes; (4) Spent Fuel of WWER Plants. The reports from the corresponding four panel discussion sessions are also included. All individual papers are recorded in INIS as separate items.

  6. Fabrication of high performance components for Indian nuclear reactors

    International Nuclear Information System (INIS)

    Jayaraj, R.N.

    2011-01-01

    Nuclear Fuel Complex (NFC), a Unit of the Department of Atomic Energy (DAE) has been engaged for well over three-and-half decades in the manufacture of fuels for Pressurized Heavy Water Reactors (PHWRs) and Boiling Water Reactors (BWRs). All the fuel assembly components, like, fuel clad tubes, end plugs, spacers, spacer grids etc. are also being manufactured at NFC in Zirconium alloy material. Apart from the regular production of these components and finished fuel assemblies, NFC has also been engaged in the production of Zirconium alloy reactor core structurals, like, pressure tubes, calandria tubes, garter springs and reactivity control mechanisms for PHWRs and square channels for BWRs. While all these structural components are produced through standardized flow sheets, there have been continuous innovations carried out in the processes to meet the ever increasing end-use characteristics laid down by the utilities. The paper enumerates various aspects of different technologies developed at NFC for the manufacture of high performance components for reactor applications

  7. Process performance and comparative metagenomic analysis during co-digestion of manure and lignocellulosic biomass for biogas production

    DEFF Research Database (Denmark)

    Tsapekos, Panagiotis; Kougias, Panagiotis; Treu, Laura

    2017-01-01

    Mechanical pretreatment is considered to be a fast and easily applicable method to prepare the biomass for anaerobic digestion. In the present study, the effect of mechanical pretreatment on lignocellulosic silages biodegradability was elucidated in batch reactors. Moreover, co-digestion of the s......Mechanical pretreatment is considered to be a fast and easily applicable method to prepare the biomass for anaerobic digestion. In the present study, the effect of mechanical pretreatment on lignocellulosic silages biodegradability was elucidated in batch reactors. Moreover, co...

  8. Dynamic biogas upgrading based on the Sabatier process

    DEFF Research Database (Denmark)

    Jurgensen, Lars; Ehimen, Ehiazesebhor Augustine; Born, Jens

    2015-01-01

    index, CO2 content and calorific value were found to be controllable by the H2/CO2 ratio fed the methanation reactor. An optimal H2/CO2 ratio of 3.45–3.7 was seen to result in a product gas with high calorific value and Wobbe index. The dynamic reactor simulation verified that the process start......This study aimed to investigate the feasibility of substitute natural gas (SNG) generation using biogas from anaerobic digestion and hydrogen from renewable energy systems. Using thermodynamic equilibrium analysis, kinetic reactor modeling and transient simulation, an integrated approach...... for the operation of a biogas-based Sabatier process was put forward, which was then verified using a lab scale heterogenous methanation reactor. The process simulation using a kinetic reactor model demonstrated the feasibility of the production of SNG at gas grid standards using a single reactor setup. The Wobbe...

  9. Experimental Facilities for Performance Evaluation of Fast Reactor Components

    International Nuclear Information System (INIS)

    Chandramouli, S.; Kumar, V.A. Suresh; Shanmugavel, M.; Vijayakumar, G.; Vinod, V.; Noushad, I.B.; Babu, B.; Kumar, G. Padma; Nashine, B.K.; Rajan, K.K.

    2013-01-01

    Brief details about various experimental facilities catering to the testing and performance evaluation requirements of fast reactor components have been brought out. These facilities have been found to be immensely useful to continue research and development activities in the areas of component development and testing, sodium technology, thermal hydraulics and sodium instrumentation for the SFR’s. In addition new facilities which have been planned will be of great importance for the developmental activities related to future SFR’s

  10. Operational limitations of light water reactors relating to fuel performance

    International Nuclear Information System (INIS)

    Cheng, H.S.

    1976-07-01

    General aspects of fuel performance for typical Boiling and Pressurized Water Reactors are presented. Emphasis is placed on fuel failures in order to make clear important operational limitations. A discussion of fuel element designs is first given to provide the background information for the subsequent discussion of several fuel failure modes that have been identified. Fuel failure experiences through December 31, 1974, are summarized. The operational limitations that are required to mitigate the effects of fuel failures are discussed

  11. Biogas energy in India

    Energy Technology Data Exchange (ETDEWEB)

    Moulik, T K

    1982-01-01

    A socio-economic study of India's biogas energy program, a response to the oil crisis of the 1970's, reviews the impact of promoting large-scale community biogas plants as a way to reach the lowest income groups. A case study draws on the experiences of the community plant in Gujarat village, and explores the program's secondary benefits and impacts on life styles. 15 references, 5 figures, 37 tables. (DCK)

  12. Biogas programme in India

    International Nuclear Information System (INIS)

    De Castro, J.

    1996-01-01

    The National Project on Biogas Development (NPBD) of the Ministry of Non-conventional Energy Sources (MNES) was introduced in 1981-1982 to promote the use of biogas installations in households. Several systems have been introduced, all based on two basic designs: floating metal drum (Janata model) and fixed masonry dome (Deenbandhu model). An overview is given of the results, incentives of the Indian government and constraints so-far of the NPBD. 3 figs., 1 tab., 1 ills

  13. Janata biogas plant

    Energy Technology Data Exchange (ETDEWEB)

    Bahadur, S; Singh, K K

    1980-03-01

    The Janata biogas plant is based on the use of local materials and locally available skills only. It is a proven technology at low cost and easy maintenance which should facilitate its extension at a much faster pace especially among the low income groups. This technology is important at this time because of the current crisis in the availability of firewood and mineral fuels. This handbook explains in non-technical language the basic features, design, and construction of this biogas plant. (DC)

  14. Biogas feed analysis

    OpenAIRE

    Song, Yuan

    2008-01-01

    Biogas production is regarded as the best energy recovery process from wet organic solid wastes (WOSW). Feed composition, storage conditions and time will influence the compositions of feed to biogas processes. In this study, apple juice from Meierienes Juice factory was used as the model substrates to mimic the liquid phase that can be extracted from fruit or juice industry WOSW. A series of batch experiments were carried out with different initial feed concentrations (0, 1, 2, 5, 10 %) of a...

  15. Biogas production from Eichhornia crassipes aquatic plant; Producao de biogas a partir da planta aquatica Eichhornia crassipes

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Roberto Guimaraes; Silva, Jose Goncalves da; Fernandes Filho, Jorge; Pereira, Maria Cristina Duarte Eiras [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Engenharia Mecanica. Programa de Pos-Graduacao em Engenharia Mecanica]. E-mail: temrobe@vm.uff.br; Melo, Ricardo Bichara de [Light Servicos de Eletricidade S.A., Rio de Janeiro, RJ (Brazil)]. E-mail: rbmelo@light.com.br

    2004-07-01

    Virtually all plants and waste plants and animals may in some way be used as an energy source. The anaerobic digestion of these materials is an option, resulting in the biogas. Besides the gas obtained in the process, is produced, inside the biodigester, an excellent fertilizer. The aquatic plant Eichhornia crassipes is found in large quantities in various water bodies, such as reservoirs, lakes and ponds, becoming mostly often a big problem and it is necessary its systematic removal of water. The bench biodigester used in the experiment of biodigestion of aquatic plants is composed of a reactor containing the biomass, where the biogas is produced, and a reservoir to monitor the production of biogas. The reactor is located within a receptacle containing water that can be heated by an electrical resistance, with the purpose of maintaining the temperature inside the reactor around 35 deg C. The results of analysis of gas of the reactor made in a gas chromatograph to CG MASTER of double ionization detector with a flame and thermal conductivity, show a percentage of 50% of methane in the biogas. The process of biodigestion of aquatic plant Eichhornia crassipes shows potential to obtain biogas, with considerable levels of methane in order to make its exploitation. Also, were analyzed the biomass in the biodigester for determination of humid, total organic matter, mineral and organic carbon residue.

  16. Biodigestion of the aquatics plants mixtures and biogas production; Biodigestao de misturas de plantas aquaticas e producao de biogas

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Roberto Guimaraes; Abreu, Fernando Luiz Barbuda de; Fernandes Filho, Jorge; Pereira, Maria Cristina Duarte Eiras [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Engenharia Mecanica. Programa de Pos-Graduacao em Engenharia Mecanica]. E-mail: temrobe@vm.uff.br; Melo, Ricardo Bichara de [Light Servicos de Eletricidade S.A., Rio de Janeiro, RJ (Brazil). Gerencia de Estudos e Gestao de Geracao]. E-mail: rbmelo@light.com.br

    2004-07-01

    Several systems of generating electricity using water storage reservoirs. One problem that occurs constantly in these reservoirs is the accumulation of aquatic plants, such as Eichhornia crassipes, Eichhornia azurea, Pistia stratiotes and Salvinia that may cause serious problems for the system. Periodically, the biomass must be removed and disposed of appropriate form, so that does not cause contamination of soil, groundwater or allowing the proliferation of vectors. One possible destination is the use of biomass in a process of biodigestion, resulting in biogas. The bench of biodigester used in the experiment of biodigestion of aquatic plants is composed of a reactor containing the biomass, where the biogas is produced and a reservoir for the monitoring the production of biogas. The reactor is located inside a container containing water that can be heated by an electrical resistance, with the aim of maintaining the temperature inside the reactor around 35 deg C. The results of analysis of gas of the reactor was obtained using a gas chromatograph to CG MASTER of double ionization detector with a flame and thermal conductivity. These results show a percentage of 50% of methane in the biogas. Also, were analyzed the biomass in the biodigester for determination of humidity, total organic matter, waste mineral and organic carbon. The process of biodigestion of the mixture of aquatic plants: Eichhornia crassipes, Eichhornia azurea and Pistia stratiotes and Salvinia shows potential for obtaining biogas, with considerable levels of methane, in order to facilitate its recovery.

  17. Performance Evaluation of Metallic Dispersion Fuel for Advanced Research Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Ho Jin; Park, Jong Man; Kim, Chang Kyu; Chae, Hee Taek; Song, Kee Chan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Yeon Soo [Argonne National Laboratory, New York (United States)

    2007-07-01

    Uranium alloys with a high uranium density has been developed for high power research reactor fuel using low-enriched uranium (LEU). U-Mo alloys have been developed as candidate fuel material because of excellent irradiation behavior. Irradiation behavior of U-Mo/Al dispersion fuel has been investigated to develop high performance research reactor fuel as RERTR international research program. While plate-type and rod-type dispersion fuel elements are used for research reactors, HANARO uses rod-type dispersion fuel elements. PLATE code is developed by Argonne National Laboratory for the performance evaluation of plate-type dispersion fuel, but there is no counterpart for rod-type dispersion fuel. Especially, thermal conductivity of fuel meat decreases during the irradiation mainly because of interaction layer formation at the interface between the U-Mo fuel particle and Al matrix. The thermal conductivity of the interaction layer is not as high as the Al matrix. The growth of interaction layer is interactively affected by the temperature of fuel because it is associated with a diffusion reaction which is a thermally activated process. It is difficult to estimate the temperature profile during irradiation test due to the interdependency of fuel temperature and thermal conductivity changed by interaction layer growth. In this study, fuel performance of rod-type U-Mo/Al dispersion fuels during irradiation tests were estimated by considering the effect of interaction layer growth on the thermal conductivity of fuel meat.

  18. Performance Evaluation of Metallic Dispersion Fuel for Advanced Research Reactors

    International Nuclear Information System (INIS)

    Ryu, Ho Jin; Park, Jong Man; Kim, Chang Kyu; Chae, Hee Taek; Song, Kee Chan; Kim, Yeon Soo

    2007-01-01

    Uranium alloys with a high uranium density has been developed for high power research reactor fuel using low-enriched uranium (LEU). U-Mo alloys have been developed as candidate fuel material because of excellent irradiation behavior. Irradiation behavior of U-Mo/Al dispersion fuel has been investigated to develop high performance research reactor fuel as RERTR international research program. While plate-type and rod-type dispersion fuel elements are used for research reactors, HANARO uses rod-type dispersion fuel elements. PLATE code is developed by Argonne National Laboratory for the performance evaluation of plate-type dispersion fuel, but there is no counterpart for rod-type dispersion fuel. Especially, thermal conductivity of fuel meat decreases during the irradiation mainly because of interaction layer formation at the interface between the U-Mo fuel particle and Al matrix. The thermal conductivity of the interaction layer is not as high as the Al matrix. The growth of interaction layer is interactively affected by the temperature of fuel because it is associated with a diffusion reaction which is a thermally activated process. It is difficult to estimate the temperature profile during irradiation test due to the interdependency of fuel temperature and thermal conductivity changed by interaction layer growth. In this study, fuel performance of rod-type U-Mo/Al dispersion fuels during irradiation tests were estimated by considering the effect of interaction layer growth on the thermal conductivity of fuel meat

  19. 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 .

  20. Biogas in the agriculture. State of the art. Proceedings; Biogas in der Landwirtschaft. Stand und Perspektiven. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    Within the meeting of the Association for Technology and Structures in Agriculture (Darmstadt, Federal Republic of Germany) and the Agency for Renewable Resources (Guelzow, Federal Republic of Germany) between 15th and 16th September, 2009, in Weimar the following lectures were held: (1) Results of the actual biogas measurement II (Peter Weiland); (2) Agitators in biogas plants - Technology with central significance (Kay Rostalski); (3) How much energy is needed by a biogas fermenter? (Ludwig Heinloth); (4) The fermentation concept of Rueckert NatUrgas GmbH (Claus Rueckert, Dominique Pfeufer); (5) Experiences from the construction for the practice of the company MT-Energie GmbH (Bodo Drescher); (6) Fermenter/technology concept of Schmack Biogas AG (Thomas Moeeslinger); (7) Transport of biomass - How much does the logistics of Guelle and Co. cost? (Thore Toews); (8) Which factors determine the efficiency of biogas plants? (Gerd Reinhold); (9) Microbial diversity in biogas reactors in the fermentation of renewable raw materials (Michael Klocke et al.); (10) What do additives and ingredients contribute to the optimisation of the production of biogas? (Udo Hoelker); (11) Process optimisation - An interaction between technology and microbiology (Andreas Gronauer et al.); (12) Emissions at the production of biogas - an analysis if the environmental relevance (Joachim Clemens et al.); (13) Support systems for energy plants - Consequences to soil and environment (Matthias Willms et al.); (14) How ecological is biogas? (Sven Gaertner); (15) Biogas plant - Analysis of construction and operation from licensing view (Hans-Walter Schneichel); (16) Biogas plants - Analysis of construction and operation from contractual legal view (Florian Valentin); (17) Biogasplants - Analysis of construction and operation from remuneration legal view (Helmut Loibl); (18) Process and costs of treatment of residues of fermentation (Sebastian Wulf, Helmut Doehler); (19) How do residues of

  1. 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.

  2. Anaerobic degradation of coconut husk leachate using UASB-reactor.

    Science.gov (United States)

    Neena, C; Ambily, P S; Jisha, M S

    2007-07-01

    Reffing of coconut husk, the majorprocess in quality coir fibre extraction, causes serious pollution with brackish water lagoons of Kerala. An attempt is made to treat the coconut husk leachate by using a laboratory scale UASB-reactor The experiment was conducted with loading of leachate from 1 kg of fresh coconut husk. The anaerobic treatment was done continuously The parameters like VFA, pH, COD and polyphenols were analysed regularly during the evaluation of the reactor performance. The polyphenol, VFA and COD were diminished gradually with time. The pH of the reactor during the study was found to be in the range of 6-8. The biogas production was increased with loading and about 82% of the total COD/kg husk could be converted to biogas. The maximum polyphenol loading in the reactor was reached to about 298.51 mg/l of husk.

  3. High Performance Fuel Desing for Next Generation Pressurized Water Reactors

    International Nuclear Information System (INIS)

    Mujid S. Kazimi; Pavel Hejzlar

    2006-01-01

    The use of internally and externally cooled annular fuel rods for high power density Pressurized Water Reactors is assessed. The assessment included steady state and transient thermal conditions, neutronic and fuel management requirements, mechanical vibration issues, fuel performance issues, fuel fabrication methods and economic assessment. The investigation was conducted by a team from MIT, Westinghouse, Gamma Engineering, Framatome ANP, and AECL. The analyses led to the conclusion that raising the power density by 50% may be possible with this advanced fuel. Even at the 150% power level, the fuel temperature would be a few hundred degrees lower than the current fuel temperature. Significant economic and safety advantages can be obtained by using this fuel in new reactors. Switching to this type of fuel for existing reactors would yield safety advantages, but the economic return is dependent on the duration of plant shutdown to accommodate higher power production. The main feasibility issue for the high power performance appears to be the potential for uneven splitting of heat flux between the inner and outer fuel surfaces due to premature closure of the outer fuel-cladding gap. This could be overcome by using a very narrow gap for the inner fuel surface and/or the spraying of a crushable zirconium oxide film at the fuel pellet outer surface. An alternative fuel manufacturing approach using vobropacking was also investigated but appears to yield lower than desirable fuel density

  4. High Performance Fuel Desing for Next Generation Pressurized Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Mujid S. Kazimi; Pavel Hejzlar

    2006-01-31

    The use of internally and externally cooled annular fule rods for high power density Pressurized Water Reactors is assessed. The assessment included steady state and transient thermal conditions, neutronic and fuel management requirements, mechanical vibration issues, fuel performance issues, fuel fabrication methods and econmic assessment. The investigation was donducted by a team from MIT, Westinghouse, Gamma Engineering, Framatome ANP, and AECL. The analyses led to the conclusion that raising the power density by 50% may be possible with this advanced fuel. Even at the 150% power level, the fuel temperature would be a few hundred degrees lower than the current fuel temperatre. Significant economic and safety advantages can be obtained by using this fuel in new reactors. Switching to this type of fuel for existing reactors would yield safety advantages, but the economic return is dependent on the duration of plant shutdown to accommodate higher power production. The main feasiblity issue for the high power performance appears to be the potential for uneven splitting of heat flux between the inner and outer fuel surfaces due to premature closure of the outer fuel-cladding gap. This could be overcome by using a very narrow gap for the inner fuel surface and/or the spraying of a crushable zirconium oxide film at the fuel pellet outer surface. An alternative fuel manufacturing approach using vobropacking was also investigated but appears to yield lower than desirable fuel density.

  5. The effects of digestion temperature and temperature shock on the biogas yields from the mesophilic anaerobic digestion of swine manure.

    Science.gov (United States)

    Chae, K J; Jang, Am; Yim, S K; Kim, In S

    2008-01-01

    In order to obtain basic design criteria for anaerobic digesters of swine manure, the effects of different digesting temperatures, temperature shocks and feed loads, on the biogas yields and methane content were evaluated. The digester temperatures were set at 25, 30 and 35 degrees C, with four feed loads of 5%, 10%, 20% and 40% (feed volume/digester volume). At a temperature of 30 degrees C, the methane yield was reduced by only 3% compared to 35 degrees C, while a 17.4% reduction was observed when the digestion was performed at 25 degrees C. Ultimate methane yields of 327, 389 and 403 mL CH(4)/g VS(added) were obtained at 25, 30 and 35 degrees C, respectively; with moderate feed loads from 5% to 20% (V/V). From the elemental analysis of swine manure, the theoretical biogas and methane yields at standard temperature and pressure were 1.12L biogas/g VS(destroyed) and 0.724 L CH(4)/g VS(destroyed), respectively. Also, the methane content increased with increasing digestion temperatures, but only to a small degree. Temperature shocks from 35 to 30 degrees C and again from 30 to 32 degrees C led to a decrease in the biogas production rate, but it rapidly resumed the value of the control reactor. In addition, no lasting damage was observed for the digestion performance, once it had recovered.

  6. Theoretical and experimental analysis of fast reactor fuel performance

    International Nuclear Information System (INIS)

    Kummerer, K.R.; Freund, D.; Steiner, H.

    1982-09-01

    In order to predict behavior, performance, and capability of prototypic fuel pins a standard operational scheme for the SNR-300 fast breeder reactor is established considering besides normal operation unscheduled power changes and shutdowns. The behavior during the whole lifetime is calculated using the updated SATURN codes and - for special conditions as power transients and skewed fuel rod power - the new TRANSIENT and TEXDIF codes. The results of these calculations are compared to experimental findings. It is demonstrated that the level of modeling and the knowledge of material properties under irradiation are sufficient for a quantitative description of the fuel pin performance under the above mentioned conditions. (orig.) [de

  7. Impact of reactor water chemistry on cladding performance

    International Nuclear Information System (INIS)

    Cox, B.

    1997-01-01

    Water chemistry may have a major impact on fuel cladding performance in PWRs. If the saturation temperature on the surface of fuel cladding is exceeded, either because of the thermal hydraulics of the system, or because of crud deposition, then LiOH concentration can occur within thick porous oxide films on the cladding. This can degrade the protective film and accelerate the corrosion rate of the cladding. If sufficient boric acid is also present in the coolant then these effects may be mitigated. This is normally the case through most of any reactor fuel cycle. Extensive surface boiling may disrupt this equilibrium because of the volatility of boric acid in steam. Under such conditions severe cladding corrosion can ensue. The potential for such effects on high burnup cladding in CANDU reactors, where bone acid is not present in the primary coolant, is discussed. (author)

  8. Overcoming the effects of stress on reactor operator performance

    International Nuclear Information System (INIS)

    He Xuhong; Wei Li; Zhao Bingquan

    2003-01-01

    Reactor operators may be exposed to significant levels of stress during plant emergencies and their performance may be affected by the stress. This paper first identified the potential sources of stress in the nuclear power plant, then discussed the ways in which stress is likely to affect the reactor operators, and finally identified several training approaches for reducing or eliminating stress effects. The challenges for effective stress reducing training may seem daunting, yet the challenges are real and must be addressed. This paper reviewed researches in training design, knowledge and skill acquisition, and training transfer point to a number of strategies that can be used to address these challenges and lead to more effective training and development. (author)

  9. Impact of reactor water chemistry on cladding performance

    Energy Technology Data Exchange (ETDEWEB)

    Cox, B. [University of Toronto, Centre for Nuclear Engineering, Toronto, Ontario (Canada)

    1997-07-01

    Water chemistry may have a major impact on fuel cladding performance in PWRs. If the saturation temperature on the surface of fuel cladding is exceeded, either because of the thermal hydraulics of the system, or because of crud deposition, then LiOH concentration can occur within thick porous oxide films on the cladding. This can degrade the protective film and accelerate the corrosion rate of the cladding. If sufficient boric acid is also present in the coolant then these effects may be mitigated. This is normally the case through most of any reactor fuel cycle. Extensive surface boiling may disrupt this equilibrium because of the volatility of boric acid in steam. Under such conditions severe cladding corrosion can ensue. The potential for such effects on high burnup cladding in CANDU reactors, where bone acid is not present in the primary coolant, is discussed. (author)

  10. Value addition initiatives for CANDU reactor operation performance

    International Nuclear Information System (INIS)

    Chugh, V.; Parmar, R.; Schut, J.; Sherin, J.; Xie, H.; Zobin, D.

    2013-01-01

    Recently, AMEC NSS initiated projects for CANDU® station performance engineering with potentially high returns for the utilities. This paper discusses three initiatives. Firstly, optimization of instrument calibration interval from 1 to 3 years will reduce time commitments on the maintenance resources on top of financial savings ~$3,500 per instrument. Secondly, reactor thermal power uncertainty assessment shows the level of operation which is believed to have an over-conservative margin that can be used to increase power by up to 0.75%. Finally, as an alternative means for controlling Reactor Inlet Header Temperature (RIHT), physical modifications to the High Pressure (HP) feedwater heaters can be useful for partially recovering RIHT resulting in increased production by 10-12 MWe. (author)

  11. Thermal performance and efficiency of supercritical nuclear reactors

    International Nuclear Information System (INIS)

    Romney Duffey; Tracy Zhou; Hussam Khartabil

    2009-01-01

    The paper reviews the major advances and innovative aspects of the thermal performance of recent concepts for super-critical water-cooled nuclear reactors (SCWR). The concepts are based on the extensive experience in the thermal power industry with super and ultra-supercritical boilers and turbines. The challenges and goals of increased efficiency, reduced cost, enhanced safety and co-generation have been pursued over the last ten years, and have resulted both in viable concepts and a vibrant defined R and D effort. The supercritical concept has wide acceptance among industry, as it reflects standard engineering practices and current thermal plant technology that is being already deployed. The SCWR concept represents a continuous development of water-cooled reactor technology, which utilizes the best and latest advances made in the thermal power industry. (author)

  12. Performance of rotary kiln reactor for the elephant grass pyrolysis.

    Science.gov (United States)

    De Conto, D; Silvestre, W P; Baldasso, C; Godinho, M

    2016-10-01

    The influence of process conditions (rotary speed/temperature) on the performance of a rotary kiln reactor for non-catalytic pyrolysis of a perennial grass (elephant grass) was investigated. The product yields, the production of non-condensable gases as well as the biochar properties were evaluated. The maximum H2 yield was close to that observed for catalytic pyrolysis processes, while the bio-oil yield was higher than reported for pyrolysis of other biomass in rotary kiln reactors. A H2/CO ratio suitable for Fischer-Tropsch synthesis (FTS) was obtained. The biochars presented an alkaline pH (above 10) and interesting contents of nutrients, as well as low electrical conductivity, indicating a high potential as soil amendment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Overcoming the effects of stress on reactor operator performance

    Energy Technology Data Exchange (ETDEWEB)

    He Xuhong; Wei Li; Zhao Bingquan [Tsinghua Univ., Nuclear Power Plant Simulation Training Center, Beijing (China)

    2003-03-01

    Reactor operators may be exposed to significant levels of stress during plant emergencies and their performance may be affected by the stress. This paper first identified the potential sources of stress in the nuclear power plant, then discussed the ways in which stress is likely to affect the reactor operators, and finally identified several training approaches for reducing or eliminating stress effects. The challenges for effective stress reducing training may seem daunting, yet the challenges are real and must be addressed. This paper reviewed researches in training design, knowledge and skill acquisition, and training transfer point to a number of strategies that can be used to address these challenges and lead to more effective training and development. (author)

  14. Exergy analysis of the biogas sorption-enhanced chemical looping reforming process integrated with a high-temperature proton exchange membrane fuel cell

    International Nuclear Information System (INIS)

    Kasemanand, Sarunyou; Im-orb, Karittha; Tippawan, Phanicha; Wiyaratn, Wisitsree; Arpornwichanop, Amornchai

    2017-01-01

    Highlights: • A biogas reforming and fuel cell integrated process is considered. • Energy and exergy analyses of the integrated process are performed. • Increasing the nickel oxide-to-biogas ratio decreases the exergy efficiency. • The exergy destruction of the fuel cell increases with increasing cell temperature. • The exergy efficiency of the process is improved when heat integration is applied. - Abstract: A biogas sorption-enhanced chemical looping reforming process integrated with a high-temperature proton exchange membrane fuel cell is analyzed. Modeling of such an integrated process is performed by using a flowsheet simulator (Aspen plus). The exergy analysis is performed to evaluate the energy utilization efficiency of each unit and that of the integrated process. The effect of steam and nickel oxide to biogas ratios on the exergetic performance of the stand-alone biogas sorption-enhanced chemical looping reforming process is investigated. The total exergy destruction increases as the steam or nickel oxide to biogas ratio increases. The main exergy destruction is found at the air reactor. For the high-temperature proton exchange membrane fuel cell, the main exergy destruction is found at the cathode. The total exergy destruction increases when cell temperature increases, whereas the inverse effect is found when the current density is considered as a key parameter. Regarding the exergy efficiency, the results show opposite trend to the exergy destruction. The heat integration analysis is performed to improve the exergetic performance. It is found that the integrated process including the heat integration system can improve the exergy destruction and exergy efficiency of 48% and 60%, respectively.

  15. 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

    population social level raising; (20) Production of biogas with grassilage - when is this profitable?; (21) Biogas: Opportunity or threat for the agriculture; (22) Country report Cameroon; (23) Fruit wastes bioconversion for anaerobic co-digestion with pig manure. Process development for the recycling in decentralised farm scale plants; (24) A parameter estimation protocol for anaerobic digestion; (25) BABIU - a new process for production of biomethane from biogas; (26) Dry fermentation of organic wastes; (27) Biological production of hydrogen from agricultural raw materials and residual materials with subsequent methane step; (28) Two phase continuous digestion of solid manure on-farm; (29) Investigation and development of an optimal process of fermenentation of grassilage by a two-phase process operation; (30) Technical weak points at biogas plants - occasions, effects and measures; (31) Plant safety - a substantial component according to permission and availability of biogas plants; (32) Analysis and evaluation of alternative concepts of the energetic use of biogas and other biogenous gases; (33) Gas-side bundling of some biogas plants, gas processing and gas feeding; (34) Technical and economical demands to biogas production for feeding into the HD grid; (35) Thinking about the use of biogas from the view of heat utilization - development of concepts for bioenergy villages; (36) Biogas cogeneration plant in the practice: Behaviour of emission and performance; (37) The future of biogas in Europe: Visions and targets until 2020; (38) Two-stage dry-wet-fermentation - optimization of the hydrolysis for a short space-time-yields; (39) Manure-free fermentation of renewable raw materials; (40) Quantification of different microbial population in termophilic-dry anaerobic digestion; (41) The use of hydrolytic enzymes in agricultural biogas production; (42) A contribution to mobile online gas diagnostics according to the efficiency of biogas plants; (43) Genetic &apos

  16. 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

    level raising; (20) Production of biogas with grassilage - when is this profitable?; (21) Biogas: Opportunity or threat for the agriculture; (22) Country report Cameroon; (23) Fruit wastes bioconversion for anaerobic co-digestion with pig manure. Process development for the recycling in decentralised farm scale plants; (24) A parameter estimation protocol for anaerobic digestion; (25) BABIU - a new process for production of biomethane from biogas; (26) Dry fermentation of organic wastes; (27) Biological production of hydrogen from agricultural raw materials and residual materials with subsequent methane step; (28) Two phase continuous digestion of solid manure on-farm; (29) Investigation and development of an optimal process of fermenentation of grassilage by a two-phase process operation; (30) Technical weak points at biogas plants - occasions, effects and measures; (31) Plant safety - a substantial component according to permission and availability of biogas plants; (32) Analysis and evaluation of alternative concepts of the energetic use of biogas and other biogenous gases; (33) Gas-side bundling of some biogas plants, gas processing and gas feeding; (34) Technical and economical demands to biogas production for feeding into the HD grid; (35) Thinking about the use of biogas from the view of heat utilization - development of concepts for bioenergy villages; (36) Biogas cogeneration plant in the practice: Behaviour of emission and performance; (37) The future of biogas in Europe: Visions and targets until 2020; (38) Two-stage dry-wet-fermentation - optimization of the hydrolysis for a short space-time-yields; (39) Manure-free fermentation of renewable raw materials; (40) Quantification of different microbial population in termophilic-dry anaerobic digestion; (41) The use of hydrolytic enzymes in agricultural biogas production; (42) A contribution to mobile online gas diagnostics according to the efficiency of biogas plants; (43) Genetic 'fingerprints' to characterize

  17. THE ECONOMICS OF BIOGAS PRODUCTION

    Directory of Open Access Journals (Sweden)

    Kh. S. Karimov

    2013-11-01

    Full Text Available ABSTRACT: In this paper life-cycle cost analysis of three biogas digesters is presented. Results show that the cost of biogas depends on the construction of digesters, sizes of methane tank and possibility of heating of the slurry. Biogas and natural gas costs calaculated are observed and found to be comparable. It is recommended that the biogas digesters can be constructed and installed, in principle, for every family and there is no need to built long gas pipe lines. ABSTRAK: Kertaskerja ini membentangkan analisis kos kitar hayat tiga pencerna biogas. Keputusan menunjukkan kos biogas bergantung kepada pembinaan pencerna, saiz tangki metana dan kemungkinan pemanasan buburan. Pengiraan kos biogas dan gas asli diambil kira dan ianya didapati setanding. Adalah disarankan pencerna biogas boleh dibina dan dipasang secara teorinya, bagi setiap keluarga tanpa memerlukan pembinaan paip gas yang panjang.

  18. 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.

  19. Development of empirical models for performance evaluation of UASB reactors treating poultry manure wastewater under different operational conditions

    Energy Technology Data Exchange (ETDEWEB)

    Yetilmezsoy, Kaan [Department of Environmental Engineering, Yildiz Technical University, 34349 Yildiz, Besiktas, Istanbul (Turkey)], E-mail: yetilmez@yildiz.edu.tr; Sakar, Suleyman [Department of Environmental Engineering, Yildiz Technical University, 34349 Yildiz, Besiktas, Istanbul (Turkey)

    2008-05-01

    A nonlinear modeling study was carried out to evaluate the performance of UASB reactors treating poultry manure wastewater under different organic and hydraulic loading conditions. Two identical pilot scale up-flow anaerobic sludge blanket (UASB) reactors (15.7 L) were run at mesophilic conditions (30-35 deg. C) in a temperature-controlled environment with three hydraulic retention times ({theta}) of 15.7, 12 and 8.0 days. Imposed volumetric organic loading rates (L{sub V}) ranged from 0.65 to 4.257 kg COD/(m{sup 3} day). The pH of the feed varied between 6.68 and 7.82. The hydraulic loading rates (L{sub H}) were controlled between 0.105 and 0.21 m{sup 3}/(m{sup 2} day). The daily biogas production rates ranged between 4.2 and 29.4 L/day. High volumetric COD removal rates (R{sub V}) ranging from 0.546 to 3.779 kg COD{sub removed}/(m{sup 3} day) were achieved. On the basis of experimental results, two empirical models having a satisfactory correlation coefficient of about 0.9954 and 0.9416 were developed to predict daily biogas production (Q{sub g}) and effluent COD concentration (S{sub e}), respectively. Findings of this modeling study showed that optimal COD removals ranging from 86.3% to 90.6% were predicted with HRTs of 7.9, 9.5, 11.2, 12.6, 13.7 and 14.3 days, and L{sub V} of 1.27, 1.58, 1.78, 1.99, 2.20 and 2.45 kg COD/(m{sup 3} day) for the corresponding influent substrate concentrations (S{sub i}) of 10,000, 15,000, 20,000, 25,000, 30,000 and 35,000 mg/L, respectively.

  20. Terpenes removal from biogas; Terpenenverwijdering uit biogas

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, P.; Holstein, J.; De Haan, HR.; Vlap, H. [DNV KEMA, Arnhem (Netherlands)

    2013-06-15

    Biogas may contain unwanted and harmful components, including aromatic hydrocarbons such as terpenes. These terpenes (organic oils) are mainly present in citrus peel and plant residues; that is why especially raw biogas from organic waste digestion plants contains high concentrations of terpenes. If terpenes end up in the gas grid (with the injected biomethane) there is a risk that plastics (PE pipes) lose their mechanical properties by absorbing liquids or extracting ethereal plasticizers. This can lead to embrittlement greatly lowering the reliability of the piping. In addition, soft components are als o affected (gaskets and rubber O-rings). Besides the impact on the integrity of the gas grid, terpenes also mask the odor of natural gas odorants such as THT. This impedes the detection of gas leaks which is a significant security risk. Furthermore, the presence of terpenes in biogas leads to fouling of equipment used for the drying of biomethane, as well as contamination of adsorption liquids and membranes used in the upgrading process. Currently, terpenes are removed by activated carbon filters. The tool life of such a filter can be relatively short if terpene concentrations are high in the biogas; this results in a significant increase of the operational costs, due to the replacement of the carbon. This study looked at alternative techniques for removing much of the terpenes from biogas in a simple, efficient and cheap way. In a workshop with stakeholders two techniques were chosen to be tested on laboratory scale in order to demonstrate the proof of principle. These techniques are photo-oxydation and a gas scrubbing. Of all investigated techniques for the removal of limonene the application of UV radiation seems to be the most promising option because of the simplicity of the process, the high efficiency (up to 94%), the comparable operational costs with activated carbon (6.7 to 9.5 euro/kg limonene removed, compared to 10 euro/kg limonene removed for activated

  1. Innovative test method for the estimation of the foaming tendency of substrates for biogas plants.

    Science.gov (United States)

    Moeller, Lucie; Eismann, Frank; Wißmann, Daniel; Nägele, Hans-Joachim; Zielonka, Simon; Müller, Roland A; Zehnsdorf, Andreas

    2015-07-01

    Excessive foaming in anaerobic digestion occurs at many biogas plants and can cause problems including plugged gas pipes. Unfortunately, the majority of biogas plant operators are unable to identify the causes of foaming in their biogas reactor. The occurrence of foaming is often related to the chemical composition of substrates fed to the reactor. The consistency of the digestate itself is also a crucial part of the foam formation process. Thus, no specific recommendations concerning substrates can be given in order to prevent foam formation in biogas plants. The safest way to avoid foaming is to test the foaming tendency of substrates on-site. A possible solution is offered by an innovative foaming test. With the help of this tool, biogas plant operators can evaluate the foaming disposition of new substrates prior to use in order to adjust the composition of substrate mixes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. 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.

  3. 15. Annual Meeting on biogas and bioenergy in agriculture. Proceedings; 15. Jahrestagung Biogas und Bioenergie in der Landwirtschaft. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The volume contains besides the general statements on environmental protection and energy savings in the future and biogas as great potential for the rural development the following contributions in four parts: 1. political enveloping conditions: biogas usage within the frame of the the new EEG; state of biogas usage in Baden-Wuerttemberg; practical experiences end perspectives for the biogas development; renewable raw materials from the view of environmenmental protection; 2. gas utilization: the bioenergy village Mauenheim - model for the rural area; compression ignition gas engines with biogenic ignition oils; realization and economic performance of gas engines with biogas; microgasturbines - engineering and chances, gas processing and feeding into the gas network; 3. substrate: influence of the energy plant agriculture on the regional structures; biogas plants: substrate control by TS sensing; fermentation of fusaria contaminated corn; substrate contracts in the view of revenue and contract legacy; energy plants agriculture in Baden-Wuerttemberg; 4. process biology: comparison of dry and wet fermentation; fundamentals, process stability analytical possibilities; start-up of a biogas plant; biogas process with external hydrolysis; problems in the fermenter - inhibitors and auxiliaries.

  4. 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.

  5. Concept and basic performance of an in-pile experimental reactor for fast breeder reactors using fast driver core

    International Nuclear Information System (INIS)

    Obara, Toru; Sekimoto, Hiroshi

    1997-01-01

    The possibility of an in-pile experimental reactor for fast breeder reactors using a fast driver core is investigated. The driver core is composed of a particle bed with diluted fuel. The results of various basic analyses show that this reactor could perform as follows: (1) power peaking at the outer boundary of test core does not take place for large test core; (2) the radial power distribution in test fuel pin is expected to be the same as a real reactor; (3) the experiments with short half width pulse is possible; (4) for the ordinary MOX core, enough heating-up is possible for core damage experiments; (5) the positive effects after power burst can be seen directly. These are difficult for conventional thermal in-pile experimental reactors in large power excursion experiments. They are very attractive advantages in the in-pile experiments for fast breeder reactors. (author)

  6. Improved biogas production from whole stillage by co-digestion with cattle manure.

    Science.gov (United States)

    Westerholm, Maria; Hansson, Mikael; Schnürer, Anna

    2012-06-01

    Whole stillage, as sole substrate or co-digested with cattle manure, was evaluated as substrate for biogas production in five mesophilic laboratory-scale biogas reactors, operating semi-continuously for 640 days. The process performance was monitored by chemical parameters and by quantitative analysis of the methanogenic and acetogenic population. With whole stillage as sole substrate the process showed clear signs of instability after 120 days of operation. However, co-digestion with manure clearly improved biogas productivity and process stability and indicated increased methane yield compared with theoretical values. The methane yield at an organic loading rate (OLR) at 2.8 g VS/(L×day) and a hydraulic retention time (HRT) of 45 days with a substrate mixture 85% whole stillage and 15% manure (based on volatile solids [VS]) was 0.31 N L CH(4)/gVS. Surprisingly, the abundance of the methanogenic and acetogenic populations remained relatively stable throughout the whole operation and was not influenced by process performance. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. 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...

  8. Basic data biogas Germany. Solid fuels, biofuels, biogas; Basisdaten Bioenergie Deutschland. Festbrennstoffe, Biokraftstoffe, Biogas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-09-15

    The brochure ''Basic data biogas Germany'' gives statistical information about (a) renewable energies: primary energy consumption, power generation, energy supply, avoidance of greenhouse gases; (b) Solid fuels: energetic utilization, wood pellets, energy consumption, comparison to heating oil; (c) Biofuels: consumption, bioethanol, biodiesel, vegetable oils; (d) Biogas: biogas power plants, energy content, production, legal aspects.

  9. Basic data biogas Germany. Solid fuels, biofuels, biogas; Basisdaten Bioenergie Deutschland. Festbrennstoffe - Biokraftstoffe - Biogas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-08-15

    The brochure ''Basic data biogas Germany'' gives statistical information about (a) renewable energies: primary energy consumption, power generation, energy supply, avoidance of greenhouse gases; (b) Solid fuels: energetic utilization, wood pellets, energy consumption, comparison to heating oil; (c) Biofuels: consumption, bioethanol, biodiesel, vegetable oils; (d) Biogas: biogas power plants, energy content, production, legal aspects.

  10. A review on optimization production and upgrading biogas through CO2 removal using various techniques.

    Science.gov (United States)

    Andriani, Dian; Wresta, Arini; Atmaja, Tinton Dwi; Saepudin, Aep

    2014-02-01

    Biogas from anaerobic digestion of organic materials is a renewable energy resource that consists mainly of CH4 and CO2. Trace components that are often present in biogas are water vapor, hydrogen sulfide, siloxanes, hydrocarbons, ammonia, oxygen, carbon monoxide, and nitrogen. Considering the biogas is a clean and renewable form of energy that could well substitute the conventional source of energy (fossil fuels), the optimization of this type of energy becomes substantial. Various optimization techniques in biogas production process had been developed, including pretreatment, biotechnological approaches, co-digestion as well as the use of serial digester. For some application, the certain purity degree of biogas is needed. The presence of CO2 and other trace components in biogas could affect engine performance adversely. Reducing CO2 content will significantly upgrade the quality of biogas and enhancing the calorific value. Upgrading is generally performed in order to meet the standards for use as vehicle fuel or for injection in the natural gas grid. Different methods for biogas upgrading are used. They differ in functioning, the necessary quality conditions of the incoming gas, and the efficiency. Biogas can be purified from CO2 using pressure swing adsorption, membrane separation, physical or chemical CO2 absorption. This paper reviews the various techniques, which could be used to optimize the biogas production as well as to upgrade the biogas quality.

  11. Biogas in Botswana

    Energy Technology Data Exchange (ETDEWEB)

    MacGarry, B

    1981-01-01

    The experience gained in small-scale experiments with a 600-1 horizontal plug-flow digester, made from three 200-1 drums, was used to investigate the possibility of using biogas as a diesel-fuel substitute for powering pump engines at boreholes used for cattle in the arid areas of Botswana. A 10-m/sup 3/ Chinese-type digester was used in these tests. The terms of reference of the test and details of the operational plan are included. The use of biogas toilets as efficient low-cost sanitation devices are also being promoted.

  12. Biogas: quo vadis?

    International Nuclear Information System (INIS)

    Perch-Nielsen, S.

    2009-01-01

    This article takes a look at the situation in Switzerland with respect to the use of biogas and the potential available for its increased use. The sharp increase of biogas production in Switzerland and its use for the production of heat, electrical power and methane for the gas mains is reviewed. The large potential for additional biomass is discussed. The political will to increase the use of renewable forms of energy in Switzerland, security of supply and regional added value are discussed. The article discusses the current situation as well as trends concerning substrates, systems and products

  13. Prospects of biogas as dual fuel in small diesel engines

    International Nuclear Information System (INIS)

    Singh, Irvinder; Mittal, V.K.

    1992-01-01

    A study was conducted on diesel engines to find out the effect of induction rate of biogas on engine performance indices. The results of dual fuel engine performance was compared with diesel mode for various levels of biogas induction rate (0.3 to 7.2 l/s) engine load (20% to full load) and injection timing (20.6 to 48 before top dead centre). At full and 80% brake load, the best energy mix between diesel and biogas was 1.5:1 and 4:1 respectively. (author). 7 refs., 7 figs., 4 tabs

  14. Occurrence and abatement of volatile sulfur compounds during biogas production.

    Science.gov (United States)

    Andersson, Fräs Annika T; Karlsson, Anna; Svensson, Bo H; Ejlertsson, Jörgen

    2004-07-01

    Volatile sulfur compounds (VSCs) in biogas originating from a biogas production plant and from a municipal sewage water treatment plant were identified. Samples were taken at various stages of the biogas-producing process, including upgrading the gas to vehicle-fuel quality. Solid-phase microextraction was used for preconcentration of the VSCs, which were subsequently analyzed using gas chromatography in combination with mass spectrometry. Other volatile organic compounds present also were identified. The most commonly occurring VSCs in the biogas were hydrogen sulfide, carbonyl sulfide, methanethiol, dimethyl sulfide, and dimethyl disulfide, and hydrogen sulfide was not always the most abundant sulfur (S) compound. Besides VSCs, oxygenated organic compounds were commonly present (e.g., ketones, alcohols, and esters). The effect of adding iron chloride to the biogas reactor on the occurrence of VSCs also was investigated. It was found that additions of 500-g/m3 substrate gave an optimal removal of VSCs. Also, the use of a prefermentation step could reduce the amount of VSCs formed in the biogas process. Moreover, in the carbon dioxide scrubber used for upgrading the gas, VSCs were removed efficiently, leaving traces (ppbv levels). The scrubber also removed other organic compounds.

  15. From troubled kid to star performers - On the repowering of a biogas plant; Vom Sorgenkind zum Musterknaben. Ueber das Repowering einer Biogasanlage

    Energy Technology Data Exchange (ETDEWEB)

    Gress, Hans-Werner [ABO Wind AG, Wiesbaden (Germany)

    2011-07-01

    In 2001, the biogas plant in Samswegen (Federal Republic of Germany) has been successfully inaugurated. The plant proposed by Schmack AG (Schwandorf, Federal Republic of Germany) consisted of two horizontal plug flow digesters and three storage-flow digesters. Due to incidents this concept was not feasible in practical operation. Under this aspect, the author of the contribution under consideration reports on the repowering of a biogas plant. This includes a retrofit with necessary components such as a gas torch, a gas cooler and external desulfurization. Similarly, the solids metering was renewed. The recirculation could be reduced by 80 %.

  16. Experiences with biogas in Denmark

    DEFF Research Database (Denmark)

    Bundgaard, Sirid Sif; Kofoed-Wiuff, Anders

    This report is primarily based on the work of the Danish biogas task force, which was established as a result of the Energy Agreement of 22 March 2012. The purpose of the task force is to examine and support concrete biogas projects in order to facilitate the projected biogas development up to 2020....... The focus of the task force was on the practical integration of the new biogas production in energy system, including the utilization of gas, the necessary infrastructure and contractual relationships. The aim was to ensure effective and appropriate integration of biogas in the Danish energy supply, which...... was consistent with the policy objectives, both in regards to current challenges for specific biogas plants and the role of biogas flexible renewable energy form on longer term. The task force's final report was published in 2014....

  17. 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)

  18. Verification Test of Hydraulic Performance for Reactor Coolant Pump

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Jun; Kim, Jae Shin; Ryu, In Wan; Ko, Bok Seong; Song, Keun Myung [Samjin Ind. Co., Seoul (Korea, Republic of)

    2010-01-15

    According to this project, basic design for prototype pump and model pump of reactor coolant pump and test facilities has been completed. Basic design for prototype pump to establish structure, dimension and hydraulic performance has been completed and through primary flow analysis by computational fluid dynamics(CFD), flow characteristics and hydraulic performance have been established. This pump was designed with mixed flow pump having the following design requirements; specific velocity(Ns); 1080.9(rpm{center_dot}m{sup 3}/m{center_dot}m), capacity; 3115m{sup 3}/h, total head ; 26.3m, pump speed; 1710rpm, pump efficiency; 77.0%, Impeller out-diameter; 349mm, motor output; 360kw, design pressure; 17MPaG. The features of the pump are leakage free due to no mechanical seal on the pump shaft which insures reactor's safety and law noise level and low vibration due to no cooling fan on the motor which makes eco-friendly product. Model pump size was reduced to 44% of prototype pump for the verification test for hydraulic performance of reactor coolant pump and was designed with mixed flow pump and canned motor having the following design requirements; specific speed(NS); 1060.9(rpm{center_dot}m{sup 3}/m{center_dot}m), capacity; 539.4m{sup 3}/h, total head; 21.0m, pump speed; 3476rpm, pump efficiency; 72.9%, Impeller out-diameter; 154mm, motor output; 55kw, design pressure; 1.0MPaG. The test facilities were designed for verification test of hydraulic performance suitable for pump performance test, homologous test, NPSH test(cavitation), cost down test and pressure pulsation test of inlet and outlet ports. Test tank was designed with testing capacity enabling up to 2000m{sup 3}/h and design pressure 1.0MPaG. Auxiliary pump was designed with centrifugal pump having capacity; 1100m{sup 3}/h, total head; 42.0m, motor output; 190kw

  19. Economical and ecological benchmarking of biogas plant configurations for flexible power generation in future power supply systems; Oekonomisches und oekologisches Benchmarking von Biogasanlagenkonfigurationen zur flexiblen Verstromung in zukuenftigen Stromversorgungssystemen

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, Henning [Fraunhofer Institut fuer Windenergie und Energiesystemtechnik (IWES), Kassel (Germany). Bereich Energieverfahrenstechnik

    2016-08-01

    With the share of intermittent renewable energies within the electricity system rising, balancing services from dispatchable power plants are of increasing importance. This study comparatively assesses the environmental and economic performance of biogas plant configurations, supplying biogas on demand for flexible power generation. A cost analysis of five configurations based on biogas storing and flexible biogas production concepts has been carried out. Results show that additional flexibility costs for a biogas supply of 8 hours per day range between 2 Euro to 11 Euro MWh{sup -1} and for a 72 hour period without biogas demand from 9 Euro to 19 Euro MWh{sup -1}. While biogas storage concepts were identified as favorable short-term supply configurations, flexible biogas production concepts profit from reduced storage requirements at plants with large biogas production capacities or for longer periods without biogas demand [1, 2]. Flexible biogas plant configurations indicate an increased energy demand to operate the operational enhancements compared to conventional biogas plants supplying biogas for baseload power generation. However, findings show that in contrast to an alternative supply of power generators with natural gas, biogas supplied on demand by adapted biogas plant configurations saves greenhouse gas emissions by 54 to 65 g CO{sub 2-eq} MJ{sup -1} and primary energy by about 1.17 MJ MJ{sup -1}. In this regard, configurations with flexible biogas production profit from reduced biogas storage requirements and achieve higher savings compared to configurations with continuous biogas production [1, 3].

  20. Modeling and performance of the MHTGR [Modular High-Temperature Gas-Cooled Reactor] reactor cavity cooling system

    International Nuclear Information System (INIS)

    Conklin, J.C.

    1990-04-01

    The Reactor Cavity Cooling System (RCCS) of the Modular High- Temperature Gas-Cooled Reactor (MHTGR) proposed by the U.S. Department of Energy is designed to remove the nuclear afterheat passively in the event that neither the heat transport system nor the shutdown cooling circulator subsystem is available. A computer dynamic simulation for the physical and mathematical modeling of and RCCS is described here. Two conclusions can be made form computations performed under the assumption of a uniform reactor vessel temperature. First, the heat transferred across the annulus from the reactor vessel and then to ambient conditions is very dependent on the surface emissivities of the reactor vessel and RCCS panels. These emissivities should be periodically checked to ensure the safety function of the RCCS. Second, the heat transfer from the reactor vessel is reduced by a maximum of 10% by the presence of steam at 1 atm in the reactor cavity annulus for an assumed constant in the transmission of radiant energy across the annulus can be expected to result in an increase in the reactor vessel temperature for the MHTGR. Further investigation of participating radiation media, including small particles, in the reactor cavity annulus is warranted. 26 refs., 7 figs., 1 tab

  1. Blanket materials for fusion reactors: comparisons of thermochemical performance

    International Nuclear Information System (INIS)

    Johnson, C.E.; Fischer, A.K.; Tetenbaum, M.

    1984-01-01

    Thermodynamic calculations have been made to predict the thermochemical performance of the fusion reactor breeder materials, Li 2 O, LiAlO 2 , and Li 4 SiO 4 in the temperature range 900 to 1300 0 K and in the oxygen activity range 10 -25 to 10 -5 . Except for a portion of these ranges, the performance of LiAlO 2 is predicted to be better than that of Li 2 O and Li 4 SiO 4 . The protium purge technique for enhancing tritium release is explored for the Li 2 O system; it appears advantageous at higher temperatures but should be used cautiously at lower temperatures. Oxygen activity is an important variable in these systems and must be considered in executing and interpreting measurements on rates of tritium release, the form of released tritium, diffusion of tritiated species and their identities, retention of tritium in the condensed phase, and solubility of hydrogen isotope gases

  2. Empirical Model for Predicting Rate of Biogas Production | Adamu ...

    African Journals Online (AJOL)

    Rate of biogas production using cow manure as substrate was monitored in two laboratory scale batch reactors (13 liter and 108 liter capacities). Two empirical models based on the Gompertz and the modified logistic equations were used to fit the experimental data based on non-linear regression analysis using Solver tool ...

  3. 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 ...

  4. Distributed and micro-generation from biogas and agricultural application of sewage sludge: Comparative environmental performance analysis using life cycle approaches

    International Nuclear Information System (INIS)

    Sadhukhan, Jhuma

    2014-01-01

    Highlights: • 180,000 MJ biogas from 15.87 t sewage sludge supply 1 household electricity per year. • From the highest to the lowest avoided impacts: PEM FC 2 eq./MJ compared to natural gas. • 1 m 3 biogas production from ∼3.2 t sewage sludge AD can save 0.92 m 3 natural gas. • Digested matter causes eutrophication and toxicity potentials. - Abstract: The Feed-In-Tariff scheme in the UK has generated attractive economics in the investment for anaerobic digestion (AD) to convert sewage sludge into biogas and digested sludge for energy and agricultural applications, respectively. The biogas is a source of biomethane to replace natural gas in the gas grid system. Biogas can be utilised to generate combined heat and power (CHP) on-site, at household micro and distributed or community scales. These biogas CHP generation options can replace the equivalent natural gas based CHP generation options. Digested sludge can be transformed into fertiliser for agricultural application replacing inorganic N:P:K fertiliser. Biogas and digested matter yields are inter-dependent: when one increases, the other decreases. Hence, these various options need to be assessed for avoided life cycle impact potentials, to understand where greatest savings lie and in order to rank these options for informed decision making by water industries. To fill a gap in the information available to industry dealing with wastewater, the avoided emissions by various AD based technologies, in primary impact potentials that make a difference between various systems, have been provided in this paper. 1 m 3 biogas can save 0.92 m 3 natural gas. An average UK household (with a demand of 2 kWe) requires 180,000 MJ or 5000 Nm 3 or 4.76 t biogas per year, from 15.87 t sewage sludge processed through AD. The proton exchange membrane fuel cell (PEM FC) is suitable for building micro-generations; micro gas turbine (Micro GT), solid oxide fuel cell (SOFC) and SOFC-GT hybrid are suitable for distributed

  5. Thermodynamic performance of a gas-core fission reactor

    International Nuclear Information System (INIS)

    Klein, W.

    1987-01-01

    The purpose of this thesis was to investigate the thermodynamic behaviour of a critical quantity of gaseous uranium-fluorides in chemical equilibrium with a graphite wall. From the very beginning a container was considered with cooled walls. As it was evident that a nuclear reactor working with gaseous fuel should run at much higher temperatures than classical LWR or HTGR reactors, most of the investigations were performed for walls with a surface temperature of 1800 to 2000 K. It was supposed that such a surface temperature would be technologically possible for a heat load between 1 and 5 MWatt m -2 . Cooling with high pressure helium-gas has to keep balance with this heat flux. The technical construction of such a wall will be a problem in itself. It is thought that the experiences with re-entry-vessels in space-technology can be used. A basic assumption in all the calculations is that the U-C-F reactor gas 'sees' a graphite wall, possibly graphite tiles supported by heat resistant materials like SiN 2 , SiC 2 and at a lower temperature level by niobium-steel. Such a gastight compound-system is not necessarily of high-tensile strength materials. It has to be surrounded by a cooled neutron moderator-reflector which in its turn must be supported by a steel-wall at room temperature holding pressure of the order of 100 bar (10 MPa). The design of such a compound-wall is a task for the future. 116 refs.; 28 figs.; 29 tabs

  6. Biogenic Hydrogen Conversion of De-Oiled Jatropha Waste via Anaerobic Sequencing Batch Reactor Operation: Process Performance, Microbial Insights, and CO2 Reduction Efficiency

    Directory of Open Access Journals (Sweden)

    Gopalakrishnan Kumar

    2014-01-01

    Full Text Available We report the semicontinuous, direct (anaerobic sequencing batch reactor operation hydrogen fermentation of de-oiled jatropha waste (DJW. The effect of hydraulic retention time (HRT was studied and results show that the stable and peak hydrogen production rate of 1.48 L/L*d and hydrogen yield of 8.7 mL H2/g volatile solid added were attained when the reactor was operated at HRT 2 days (d with a DJW concentration of 200 g/L, temperature 55°C, and pH 6.5. Reduced HRT enhanced the production performance until 1.75 d. Further reduction has lowered the process efficiency in terms of biogas production and hydrogen gas content. The effluent from hydrogen fermentor was utilized for methane fermentation in batch reactors using pig slurry and cow dung as seed sources. The results revealed that pig slurry was a feasible seed source for methane generation. Peak methane production rate of 0.43 L CH4/L*d and methane yield of 20.5 mL CH4/g COD were observed at substrate concentration of 10 g COD/L, temperature 30°C, and pH 7.0. PCR-DGGE analysis revealed that combination of celluloytic and fermentative bacteria were present in the hydrogen producing ASBR.

  7. Biogas recovery from waste organic materials: a comparative experimental study

    International Nuclear Information System (INIS)

    Beschkov, V.; Angelov, I.; Petrova, P.

    2011-01-01

    Full text: Biogas production from organic waste is already traditional method for treatment of agricultural waste with simultaneous energy recovery in the form of biogas. However, biogas can also be produced efficiently treating organic waste from beverage industries and biodiesel production. In the latter case, huge amounts of crude glycerol are released posing severe problems with their treatment. The main obstacle to the efficient waste treatment by anaerobic digestion is the sensitivity of the methanogenic bacteria toward pH variations. When the digester is overloaded, high concentrations of organic acids are produced damping the activity of methanogenes. This problem can be overcome by separating the digester into different compartments, enabling the development of the consecutive processes of hydrolysis, acidogenesis and methanogenesis in different spaces.; In the present study results of biogas production from poultry litter, stillage from ethanol production, and crude glycerol from biodiesel manufacturing are presented. The experiments were carried out in a continuous baffled anaerobic reactor. It was established that the process with glycerol utilization was too sensitive toward the loading because of intensive acid formation as intermediates. The process with stillage as substrate was stable and well steered for months with very high biogas yield (350 I/kg COD) at high production rate, i.e. up to 4 wd ' . The microbial profiles, the pH values and the intermediate concentrations along the reactor were determined and correlated with the biogas yield. Different microbial strains and profiles for the different substrates were observed. In the case of glycerol digestion, almost one bacterial genus, i.e. Klebsiella sp., was detected besides the methanogenes, which enables to make speculations about the pathway of competitive intermediate, biogas, and final products formation

  8. Bioavailability of cobalt and nickel during anaerobic digestion of sulfur-rich stillage for biogas formation

    International Nuclear Information System (INIS)

    Gustavsson, Jenny; Shakeri Yekta, Sepehr; Sundberg, Carina; Karlsson, Anna; Ejlertsson, Jörgen; Skyllberg, Ulf; Svensson, Bo H.

    2013-01-01

    Highlights: ► We studied the effect of Co and Ni addition on biogas formation from stillage. ► Amendment with Co and Ni was necessary to maintain biogas process stability. ► 80–90% of Co and 100% of Ni was associated with organic matter/sulfides. ► The acetate-utilizing Methanosarcinales dominated during stable process. ► Co/Ni deficiency increased the number of the hydrogenotrophic Methanomicrobiales. - Abstract: Addition of Co and Ni often improves the production of biogas during digestion of organic matter, i.e. increasing CH 4 -production, process stability and substrate utilization which often opens for higher organic loading rates (OLRs). The effect of Co and Ni addition was evaluated by measuring methane production, volatile solids reduction, pH and concentration of volatile fatty acids (VFAs). A series of six lab.-scale semi-continuously fed biogas tank reactors were used for this purpose. The chemical forms and potential bioavailability of Co and Ni were examined by sequential extraction, acid volatile sulfide extraction (AVS) and simultaneously extracted metals. Furthermore, the sulfur speciation in solid phase was examined by sulfur X-ray absorption near edge structure spectroscopy. The effect of Co and Ni deficiency on the microbial community composition was analyzed using quantitative polymerase chain reaction and 454-pyrosequencing. The results showed that amendment with Co and Ni was necessary to maintain biogas process stability and resulted in increased CH 4 -production and substrate utilization efficiency. 10–20% of the total Co concentration was in dissolved form and should be regarded as easily accessible by the microorganisms. In contrast, Ni was entirely associated with organic matter/sulfides (mainly AVS) and regarded as very difficult to take up. Still Ni had stimulatory effects suggesting mechanisms such as dissolution of NiS to be involved in the regulation of Ni availability for the microorganisms. The microbial community

  9. 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.

  10. Performance Test for Neutron Detector and Associated System using Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seongwoo; Park, Sung Jae; Cho, Man Soon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Oh, Se Hyun [USERS, Daejeon (Korea, Republic of); Shin, Ho Cheol [KHNP CRI, Daejeon (Korea, Republic of)

    2016-10-15

    SPND (Self-Powered Neutron Detector) has been developed to extend its lifespan. ENFMS (Ex-Core Flux Monitoring System) of pressurized water reactor has been also improved. After the development and improvement, their performance must be verified under the neutron irradiation environment. We used a research reactor for the performance verification of neutron detector and associated system because the research reactor can meet the neutron flux level of commercial nuclear reactor. In this paper, we report the performance verification method and result for the SPND and ENFMS using the research reactor. The performance tests for the SPND and ENFMS were conducted using UCI TRIGA reactor. The test environment of commercial reactor’s neutron flux level must be required. However, it is difficult to perform the test in the commercial rector due to the constraint of time and space. The research reactor can be good alternative neutron source for the test of neutron detectors and associated system.

  11. Study for improvement of performance of the test and research reactors

    Energy Technology Data Exchange (ETDEWEB)

    Sakurai, Fumio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-03-01

    Current utilization needs for the test and research reactors become more advanced and diversified along with the advance of nuclear science and technology. Besides, the requested safety for the research and test reactors grows strictly every year as well as a case of the power reactors. Under this circumstance, every effort to improve reactor performance including its safety is necessary to be sustained for allowing more effective utilization of the test and research reactors as experimental apparatus for advanced researches. In this study, the following three themes i.e., JMTR high-performance fuel element, evaluation method of fast neutron irradiation dose in the JMTR, evaluation method of performance of siphon break valve as core covering system for water-cooled test and research reactors, were investigated respectively from the views of improvement of core performance as a neutron source, utilization performance as an experimental apparatus, and safety as a reactor plant. (author)

  12. Biogas technology in Cienfuegos: energy, environmental, economic and social impacts

    International Nuclear Information System (INIS)

    Costa Pérez, Inocente; Gutiérrez Benítez, Omar; Martínez Bermúdez, Guillermo; Padrón Padrón, Wilfredo; Águila Cabrera, Cira

    2015-01-01

    Promote the use of biogas is endorsed in the Guidelines 131 and 247 of the Economic and Social Policy of the Party and the Revolution element. The aim was to promote the construction and good practices in the use, operation and maintenance of biogas digesters in the province of Cienfuegos. The study of the design features of each type of digester, according to criteria of constructability, amount of manure, energy demand and geometry was performed. Un-practical theory for the design and construction of various types of biogas digesters compendium was prepared. Calculations for the conceptual and basic design fixed dome biogas digesters Circular Square and engineering were performed. The detailed engineering projects of different capacities biodigesters were developed. The results showed a progression of exponential growth in the number biodigesters for the past 4 years. This growth was accompanied by strong job training, technical advice and disclosure. Energy, environmental, economic and social impacts of the use of biogas in Cienfuegos were significant. At year end 2013, 80 biogas digesters in operation produced 429.1 m3 / day of biogas, which allowed replacing 78.3 t / year of fossil fuel equivalent disburse stop 43563.55 USD / year, stop pouring 3488.8 t / year of residual polluting the environment and stop emitting into the atmosphere 46.5 t / year of methane, equivalent to 1069.5 of carbon dioxide (CO 2 ) equivalent dioxide. (full text)

  13. Alternative policies to subsidize rural household biogas digesters

    International Nuclear Information System (INIS)

    Wang, Changbo; Zhang, Yaoqi; Zhang, Lixiao; Pang, Mingyue

    2016-01-01

    Existing policies of household biogas projects focus mainly on supports on construction, but less consider management and maintenance, resulting in high scrap rate and waste of resources. Alternative policies must be explored to balance construction and operation. Taking the costs and benefits from a typical rural household biogas project, this paper assesses the economic performance at three different subsidy levels, i.e., no subsidy, existing standard and positive externality based standard. Furthermore three subsidy alternatives, one-time, annual and combined option are applied to the externality based standard. The results show that household biogas digesters have unsatisfactory economic performance without any subsidy and even in current subsidy policies. Environmental benefits of the digester were estimated as 2732 Chinese Yuan, significantly larger than existing subsidy standard. To keep continuous work during the 20-year lifespans of digesters, the income disparity of farmers among regions must be considered for policy application. With the increasing of labor costs, the ratio of initial subsidies must be reduced. These results provide policy implications to the future development of biogas projects in terms of both their construction and follow-up management, reuse of the abandoned digesters as well as the exploitation of other emerging renewable energy projects. - Highlights: •Cost-benefit analysis of biogas was conducted involving its positive externalities. •Current subsidy level and scheme discourages sustained biogas use. •Biogas subsidy level should be raised based on the value of positive externalities. •Regionalized subsidy system is needed to address the current inefficiency.

  14. Metagenomic analysis and functional characterization of the biogas microbiome using high throughput shotgun sequencing and a novel binning strategy.

    Science.gov (United States)

    Campanaro, Stefano; Treu, Laura; Kougias, Panagiotis G; De Francisci, Davide; Valle, Giorgio; Angelidaki, Irini

    2016-01-01

    Biogas production is an economically attractive technology that has gained momentum worldwide over the past years. Biogas is produced by a biologically mediated process, widely known as "anaerobic digestion." This process is performed by a specialized and complex microbial community, in which different members have distinct roles in the establishment of a collective organization. Deciphering the complex microbial community engaged in this process is interesting both for unraveling the network of bacterial interactions and for applicability potential to the derived knowledge. In this study, we dissect the bioma involved in anaerobic digestion by means of high throughput Illumina sequencing (~51 gigabases of sequence data), disclosing nearly one million genes and extracting 106 microbial genomes by a novel strategy combining two binning processes. Microbial phylogeny and putative taxonomy performed using >400 proteins revealed that the biogas community is a trove of new species. A new approach based on functional properties as per network representation was developed to assign roles to the microbial species. The organization of the anaerobic digestion microbiome is resembled by a funnel concept, in which the microbial consortium presents a progressive functional specialization while reaching the final step of the process (i.e., methanogenesis). Key microbial genomes encoding enzymes involved in specific metabolic pathways, such as carbohydrates utilization, fatty acids degradation, amino acids fermentation, and syntrophic acetate oxidation, were identified. Additionally, the analysis identified a new uncultured archaeon that was putatively related to Methanomassiliicoccales but surprisingly having a methylotrophic methanogenic pathway. This study is a pioneer research on the phylogenetic and functional characterization of the microbial community populating biogas reactors. By applying for the first time high-throughput sequencing and a novel binning strategy, the

  15. Performance of an innovative multi-stage anaerobic reactor during ...

    African Journals Online (AJOL)

    Start-up of an anaerobic reactor is a relatively delicate process and depends on various factors such as wastewater composition, available inoculum, operating conditions and reactor configuration. Accordingly, systematized operational procedures are important, mainly during the start-up of an anaerobic reactor.

  16. PERFORMANCE IMPROVEMENT OF A CHEMICAL REACTOR BY NONLINEAR NATURAL OSCILLATIONS

    NARCIS (Netherlands)

    RAY, AK

    1995-01-01

    The dynamic behaviour of two coupled continuous stirred tank reactors in sequence is studied when the first reactor is being operated under limit cycle regimes producing self-sustained natural oscillations. The periodic output from the first reactor is then used as a forced input into the second

  17. Biogas as a fuel for solid oxide fuel cells and synthesis gas production: effects of ceria-doping and hydrogen sulfide on the performance of nickel-based anode materials.

    Science.gov (United States)

    Laycock, Christian J; Staniforth, John Z; Ormerod, R Mark

    2011-05-28

    tolerance of Ni/YSZ, however, in the presence of H(2)S ceria did not promote the reverse Boudouard reaction and at high temperatures carbon deposition was greater over ceria-doped Ni/YSZ. In order to further study the effects of ceria-doping, a solid oxide fuel cell (SOFC) was constructed with a ceria-doped anode cermet and its electrical performance on simulated biogas compared to hydrogen was tested. This fuel cell was subsequently ran for 1000 h on simulated biogas with no degradation in its overall electrical performance.

  18. High-Calorific Biogas Production by Selective CO2 Retention at Autogenerated Biogas Pressures up to 20 Bar

    NARCIS (Netherlands)

    Lindeboom, R.E.F.; Weijma, J.; Lier, van J.B.

    2012-01-01

    Autogenerative high pressure digestion (AHED) is a novel configuration of anaerobic digestion, in which micro-organisms produce autogenerated biogas pressures up to 90 bar with >90% CH4-content in a single step reactor. The less than 10% CO2-content was postulated to be resulting from

  19. Comparative review of foam formation in biogas plants and ruminant bloat

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Lucie; Goersch, Kati; Zehnsdorf, Andreas; Mueller, Roland Arno [UFZ - Helmholtz Centre for Environmental Research, Leipzig (Germany). Environmental and Biotechnology Centre; Neuhaus, Juergen [Leipzig Univ. (Germany). Inst. of Bacteriology and Mycology

    2012-12-15

    This review gives an overview of the current knowledge concerning the problem of foam formation in the process of anaerobic digestion in biogas plants that utilize renewable resources or biogenic waste material for biogas production. Process upsets in biogas production induced by foam formation can have a negative impact on the efficiency of biogas plants. The foam can block gas pipes and cause severe damage to the bioreactor equipment, ranging from a failure of the feeders to a damage of the roof of the biogas plant. The most common foam removal methods - stirring in the foam, adding anti-foaming agents, diminishing substrate feeding, and altering the biogas reactor management - are not always successful. However, the reasons for the excessive foam formation during the biogas production process have not yet been elucidated in detail. In contrast, foam building in the rumen of ruminants as a cause for bloat has been studied thoroughly. In general, the interaction between proteins, polysaccharides (mucilage), and small plant particles is assumed to be the crucial factor. As the fermentation process in the rumen has many similarities with the biogas production process, the current research results on bloat in ruminants are summarized and compared with the process of foaming in biogas plants. (orig.)

  20. 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.

  1. Environmental systems analysis of biogas systems; Miljoeanalys av biogassystem

    Energy Technology Data Exchange (ETDEWEB)

    Boerjesson, Paal; Berglund, Maria

    2003-05-01

    the fields, from manure when handling and storing it in conventional ways, and from organic waste from municipalities and food industries when composting the organic wastes. The size of the reduction of emission of ammonia and leakage of nitrate could, however, vary due to local conditions. Losses of methane would only have minor impact on eutrophication and acidification through somewhat higher emissions from fossil fuels which are assumed to be used to compensate for the energy losses that methane leakage leads to. Biogas as transportation fuel leads to reduced emissions of compounds that can create photochemical oxidants, especially when gasoline is replaced. The same situation occurs when biogas is used for heat production, with a few exceptions, where the largest reduction is achieved when biogas from straw replaces combustion of straw in smallscale boilers. Biogas-based combined heat and power production in gas turbines may, however, result in an increased contribution when natural gas is replaced. When indirect environmental effects are considered, biogas from manure will give significant benefits, while losses of methane will give significant negative effects. Emissions of particles will be reduced in all analysed cases when biogas is used for heat production. Biogas for combined heat and power production may, however, result in both reduced and increased emissions. When biogas is utilised as transportation fuel, a reduction of emission of particles is almost always achieved, especially when diesel in trucks is replaced. The results from this study clearly show the importance of optimising both the performance and localisation of biogas systems in order to maximise the significant potential environmental benefits they can generate and to minimise the potential negative effects.

  2. Probabilistic assessment of light water reactor fuel performance

    International Nuclear Information System (INIS)

    Misfeldt, I.

    1978-10-01

    A computer system for the statistical evaluation of LWR fuel performance has been developed. The computer code FRP, Fuel Reliability Predictor, calculates the distributions for parameters characterizing the fuel performance and failure probability. The statistical methods employed are either Monte Carlo simulations or low order Taylor approximation. Included in the computer system is a deterministic fuel performance code, which has been verified by comparison with data from irradiation experiments. The distributions for all material data utilized in the fuel simulations are estimations from the best available information in the literature. For the failure prediction, a stress corrosion failure criterion has been derived. The failure criterion is based on data from out-of-reactor stress corrosion experiments performed on unirradiated and irradiated zircaloy with iodine present. By means of an example the typical distributions of the variables characterizing the fuel performance and the accuracy of the methods themselves have been investigated. The application of the computer system is illustrated by a number of examples, these include the evaluation of irradiation experiments, design comparisons, and analyses of minor accidents. (author)

  3. 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.

  4. Effects of chlortetracycline amended feed on anaerobic sequencing batch reactor performance of swine manure digestion.

    Science.gov (United States)

    Dreher, Teal M; Mott, Henry V; Lupo, Christopher D; Oswald, Aaron S; Clay, Sharon A; Stone, James J

    2012-12-01

    The effects of antimicrobial chlortetracycline (CTC) on the anaerobic digestion (AD) of swine manure slurry using anaerobic sequencing batch reactors (ASBRs) was investigated. Reactors were loaded with manure collected from pigs receiving CTC and no-antimicrobial amended diets at 2.5 g/L/d. The slurry was intermittently fed to four 9.5L lab-scale anaerobic sequencing batch reactors, two with no-antimicrobial manure, and two with CTC-amended manure, and four 28 day ASBR cycles were completed. The CTC concentration within the manure was 2 8 mg/L immediately after collection and 1.02 mg/L after dilution and 250 days of storage. CTC did not inhibit ASBR biogas production extent, however the volumetric composition of methane was significantly less (approximately 13% and 15% for cycles 1 and 2, respectively) than the no-antimicrobial through 56 d. CTC decreased soluble chemical oxygen demand and acetic acid utilization through 56 d, after which acclimation to CTC was apparent for the duration of the experiment. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. 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.

  6. Implementation of online volatile fatty acids sensor for control and optimization of anaerobic process for low cost biogas production from manure. Project report

    Energy Technology Data Exchange (ETDEWEB)

    Boe, K.; Angelidaki, I.

    2010-10-15

    Proper monitoring and control can improve process stability and enhance process performance for better economy of the biogas plants. Volatile fatty acid (VFA) is the most widely recognized as a direct, relevant measure of stability. Classic on-line measurement of individual VFA is based on filtration, which suffers from fouling when applied with manure slurries. A VFA sensor developed at DTU Environment, based on headspace chromatography technique could avoid the problems from particulate matters. In this work, the sensor had been implemented for online monitoring of the lab-scale and the pilot-scale manure digester. The industrial prototype of the VFA sensor and sample acquisition system has been constructed and implemented at a pilot scale biogas plant, located at Lundtofte, DTU. The VFA sensor has shown very satisfying results in terms of sensitivity and reliability for monitoring the biogas process. Moreover, the online VFA and biogas registration data were used as process indicators for automatic control of the biogas reactor. The results from control experiments confirmed that the combination of biogas production, total VFA concentration and propionate concentration could effectively reflect the dynamic state of the process which was very crucial for automatic control. Due to the standardized analyzing condition (pH<2, temperature>70 deg. C), the sensor responses were not affected by the manure composition (TS, VS or the addition of extra organics), which made these results representative for implementing in the full-scale biogas plant where some industrial organic wastes were added to increase the biogas production. During the project period, the sensor design and construction had been modified and tested several times to improve the robustness. However, the implementation of the sensor in full-scale biogas plant would need some further development such as improvement of mechanical design and further up-scaling depending on the dry solid content in the

  7. Use of biogas in PEM fuel cells; Einsatz von Biogas in PEM-Brennstoffzellen

    Energy Technology Data Exchange (ETDEWEB)

    Scholz, Volkhard; Schmersahl, Ralf; Ellner, Janine (comps.)

    2009-06-15

    This research project was dedicated to two problems: 1. What demands must biogas meet in order to conform to the specifications of PEM fuel cell systems and permit safe operation? 2. How must a fuel cell system be designed and operated in order to be well-adapted to the special features of biogas as opposed to natural gas? For this purpose biogas samples were taken from laboratory-scale and commercial plants and analysed by gas chromatography using various substrates and methods. By combining this with the use of a mass spectroscopy detector (GC-MS system) it was possible to perform a qualitative and quantitative analysis of sulphurious trace gases in the biogas which might cause damage to the fuel cell system. Investigations were performed on an experimental reformer using either modelled or native biogas of different compositions, the intent being to obtain information for the design of the individual process stages. The two operating parameters steam-methane ratio (or S/C ratio) and reforming temperature were varied to optimise parameter settings in terms of energy efficiency. By linking the reformer to a 500 W fuel cell it was possible confirm the suitability of the reformed biogas for use in fuel cells. [German] In diesm Forschungsvorhaben werden zwei Fragestellungen bearbeitet: 1. Welche Anforderungen ergeben sich an das Biogas, um den Spezifikationen von PEM-Brennstoffzellensystemen zu genuegen und eine sicheren Betrieb zu ermoeglichen? 2. Wie muss das Brennstoffzellensystem ausgelegt und gefuehrt werden, um den Besonderheiten von Biogas im Vergleich zu Erdgas Rechnung zu tragen? Dazu wurden Biogasproben aus Labor- und Praxisanlagen unter Beruecksichtigung unterschiedlicher Substrate und Verfahren gaschromatisch analysiert. Die Kopplung mit einem massenspektroskopischen Detektor (GC-MS System) ermoeglicht dabei die Qualifizierung und Quantifizierung der vorhandenen schwefelhaltigen Spurengase, die eine Schaedigung von Brennstoffzellenanlagen verursachen. Die

  8. Micro-scale H2-CO2 dynamics in a hydrogenotrophic methanogenic membrane reactor

    DEFF Research Database (Denmark)

    Garcia-Robledo, Emilio; Ottosen, Lars Ditlev Mørck; Voigt, Niels Vinther

    2016-01-01

    Biogas production is a key factor in a sustainable energy supply. It is possible to get biogas with very high methane content if the biogas reactors are supplied with exogenous hydrogen, and one of the technologies for supplying hydrogen is through gas permeable membranes. In this study the activ......Biogas production is a key factor in a sustainable energy supply. It is possible to get biogas with very high methane content if the biogas reactors are supplied with exogenous hydrogen, and one of the technologies for supplying hydrogen is through gas permeable membranes. In this study...

  9. Enrichment and cultivation of a sulfide-oxidizing bacteria consortium for its deploying in full-scale biogas desulfurization

    International Nuclear Information System (INIS)

    González Sánchez, Armando; Flores Márquez, Trinidad Eliseo; Revah, Sergio; Morgan Sagastume, Juan Manuel

    2014-01-01

    Operational experiences and strategies to get suitable chemolithoautotrophic sulfide-oxidizing biomass from activated sludge wastewater treatment plant for its deploying in a full-scale biogas desulfurization plant are described. An economic nutrient source was applied to foster microbial selection and rapid growth. Respirometry was implemented on full-scale installations to monitor the ability of the specialized bacteria consortium to oxidize reduced sulfur i.e. H 2 S. During the deployment in the full-scale desulfurization reactor, intermittent sulfide feed from biogas scrubbing was performed to accelerate the startup the desulfurization process. - Highlights: • A simple method for reaching high amounts of specialized sulfide-oxidizing bacterial consortium from activated sludge was developed. • The full-scale desulfurization process can be continuously monitored by respirometry allowing fast decision making if problems arise. • The dissolved sulfide concentration was estimated with an empirical correlation between measurements of ORP, dissolved oxygen and pH

  10. Fort St. Vrain reactor performance and operation to full power

    International Nuclear Information System (INIS)

    Simon, W.A.; Bramblett, G.C.

    1982-01-01

    The Fort St. Vrain Nuclear Generating Station, powered by a high-temperature gas-cooled reactor (HTGR), has now been tested to full thermal power. Testing was conducted for the dual purposes of demonstrating component and system capability as a part of the rise-to-power program and determining core fluctuation/redistribution behavior under full power conditions. Both objectives were met. Full power performance of all major components and the achievement of nearly all design objectives has been verified. In addition, the tests showed that the fluctuation phenomenon has been corrected. Core region outlet temperature redistributions have been characterized, related to a physical mechanism, and shown to be inconsequential for overall plant operation

  11. Increased performance of continuous stirred tank reactor with calcium supplementation

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Zhuliang; Yang, Haijun; Zhi, Xiaohua; Shen, Jianquan [Beijing National Laboratory for Molecular Sciences (BNLMS), New Materials Laboratory, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)

    2010-04-15

    Continuous biohydrogen production with calcium supplementation at low hydraulic retention time (HRT) in a continuous stirred tank reactor (CSTR) was studied to maximize the hydrogen productivity of anaerobic mixed cultures. After stable operations at HRT of 8-4 h, the bioreactor became unstable when the HRT was lowered to 2 h. Supplementation of 100 mg/L calcium at HRT 2 h improved the operation stability through enhancement of cell retention with almost two-fold increase in cell density than that without calcium addition. Hydrogen production rate and hydrogen yield reached 24.5 L/d/L and 3.74 mol H{sub 2}/mol sucrose, respectively, both of which were the highest values our group have ever achieved. The results showed that calcium supplementation can be an effective way to improve the performance of CSTR at low HRT. (author)

  12. Performance of Fragema fuel in pressurized water reactors

    International Nuclear Information System (INIS)

    Dumont, A.; Ravier, G.; Ballot, B.

    1986-06-01

    FRAGEMA fuel operating experience in power reactors is very extensive. Performance over a range of power and burnup levels for various operating conditions is quite satisfactory. However significant development programs are presently in progress to further extend our knowledge under increasingly severe operating conditions. In particular, upcoming data acquisition programs (1985-1988) will cover site and hot cell measurements on Gd poison rods, 4.5 % overenriched fuel rods over four operating cycles, 17 x 17 AFA fuel assemblies. For these products the same surveillance strategy as the one used for the standard assembly has been adopted, in order to continuously provide more data which can be used to upgrade design models and pave the way for the development of future products

  13. 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.

  14. Microbial community dynamics and biogas production from manure fractions in sludge bed anaerobic digestion.

    Science.gov (United States)

    Nordgård, A S R; Bergland, W H; Bakke, R; Vadstein, O; Østgaard, K; Bakke, I

    2015-12-01

    To elucidate how granular sludge inoculum and particle-rich organic loading affect the structure of the microbial communities and process performance in upflow anaerobic sludge bed (UASB) reactors. We investigated four reactors run on dairy manure filtrate and four on pig manure supernatant for three months achieving similar methane yields. The reactors fed with less particle rich pig manure stabilized faster and had highest capacity. Microbial community dynamics analysed by a PCR/denaturing gradient gel electrophoresis approach showed that influent was a major determinant for the composition of the reactor communities. Comparisons of pre- and non-adapted inoculum in the reactors run on pig manure supernatant showed that the community structure of the nonadapted inoculum adapted in approximately two months. Microbiota variance partitioning analysis revealed that running time, organic loading rate and inoculum together explained 26 and 31% of the variance in bacterial and archaeal communities respectively. The microbial communities of UASBs adapted to the reactor conditions in treatment of particle rich manure fractions, obtaining high capacity, especially on pig manure supernatant. These findings provide relevant insight into the microbial community dynamics in startup and operation of sludge bed reactors for methane production from slurry fractions, a major potential source of biogas. © 2015 The Society for Applied Microbiology.

  15. Evaluation of fuel performance for fresh and aged CANDU reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jong Yeob; Bae, Jun Ho; Park, Joo Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-10-15

    Like all other industrial plants, nuclear power plants also undergo degradations, so called ageing, with their operation time. Accordingly, in the recent safety analysis for a refurbished Wolsong 1 NPP, various ageing effects were incorporated into the hydraulic models of a number of the components in the primary heat transport system for conservatism. The ageing data of thermal-hydraulic components for 11 EFPY of Wolsong 1 were derived by using NUCIRC code based on the site operation data and they were modified to the appropriate input data for CATHENA code which is a thermal hydraulic code for a postulated accident analysis. This paper deals with the ageing effect of the PHTS (primary heat transport system) of CANDU reactor on the fuel performance during the normal operation. Initial conditions for fuel performance analysis were derived from the thermal-hydraulic analysis for both fresh and aged core models. Here, fresh core means a core state just right after the refurbishment and the aged core is 11 EFPY state after the refurbishment of Wolsong 1. The fuel performance was analyzed by using ELESTRES code for both fresh and aged core state and the results were compared in order to verify the ageing effect of CANDU HTS on the fuel performance.

  16. Reflector Performance Study in Ultra-long Cycle Fast Reactor

    International Nuclear Information System (INIS)

    Tak, Taewoo; Kong, Chidong; Choe, Jiwon; Lee, Deokjung

    2013-01-01

    There are reflector assemblies outside the fuel region, surrounding the fuel assemblies and axial reflector is located at the bottom of the core to control the neutron leakage fraction which is an important factor in fast reactor system. HT-9 was used as a reflector material as well as a structure material. In this study, alternative reflector materials were proposed and their reflection performance was tested and studied focused on its physics. ODS-MA957 and SiC were chosen from iron based alloy and ceramic respectively. The two materials were tested and compared with HT-9 in UCFR-1000 as a radial and an axial reflector and it was evaluated from the neutronics point of view with comparing the core life and the coolant void reactivity. The calculation and evaluation were performed by McCARD Monte Carlo code. The reflector materials for UCFR-1000 have been investigated in the aspect of neutronics. The reflection effect shows different performance corresponding to reflector material used. Also, the neutron energy spectrum is affected by changing materials which causes spectrum softening but it is not enough to influence the core life. With more reflector material candidates such as lead-based liquid metal, reflection performance and core parameter study will be investigated for next step

  17. 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

  18. Bio-Propane from glycerol for biogas addition

    Energy Technology Data Exchange (ETDEWEB)

    Brandin, Jan; Hulteberg, Christian; Liljegren Nilsson, Andreas (Biofuel-Solution AB, Malmoe (Sweden))

    2008-11-15

    In this report, the technical and economical feasibility to produce higher alkanes from bioglycerol has been investigated. The main purpose of producing this kind of chemicals would be to replace the fossil LPG used in upgraded biogas production. When producing biogas and exporting it to the natural gas grid, the Wobbe index and heating value does not match the existing natural gas. Therefore, the upgraded biogas that is put into the natural gas grid in Sweden today contains 8-10 vol-% of LPG. The experimental work performed in association to this report has shown that it is possible to produce propane from glycerol. However, the production of ethane from glycerol may be even more advantageous. The experimental work has included developing and testing catalysts for several intermediate reactions. The work was performed using different micro-scale reactors with a liquid feed rate of 18 g/h. The first reaction, independent on if propane or ethane is to be produced, is dehydration of glycerol to acrolein. This was showed during 60 h on an acidic catalyst with a yield of 90%. The production of propanol, the second intermediate to producing propane, was shown as well. Propanol was produced both using acrolein as the starting material as well as glycerol (combining the first and second step) with yields of 70-80% in the first case and 65-70% in the second case. The propanol produced was investigated for its dehydration to propene, with a yield of 70-75%. By using a proprietary, purposely developed catalyst the propene was hydrogenated to propane, with a yield of 85% from propanol. The formation of propane from glycerol was finally investigated, with an overall yield of 55%. The second part of the experimental work performed investigated the possibilities of decarbonylating acrolein to form ethane. This was made possible by the development of a proprietary catalyst which combines decarbonylation and water-gas shift functionality. By combining these two functionalities, no

  19. Exogenous addition of H2 for an in situ biogas upgrading through biological reduction of carbon dioxide into methane.

    Science.gov (United States)

    Mulat, Daniel Girma; Mosbæk, Freya; Ward, Alastair James; Polag, Daniela; Greule, Markus; Keppler, Frank; Nielsen, Jeppe Lund; Feilberg, Anders

    2017-10-01

    Biological reduction of CO 2 into CH 4 by exogenous addition of H 2 is a promising technology for upgrading biogas into higher CH 4 content. The aim of this work was to study the feasibility of exogenous H 2 addition for an in situ biogas upgrading through biological conversion of the biogas CO 2 into CH 4. Moreover, this study employed systematic study with isotope analysis for providing comprehensive evidence on the underlying pathways of CH 4 production and upstream processes. Batch reactors were inoculated with digestate originating from a full-scale biogas plant and fed once with maize leaf substrate. Periodic addition of H 2 into the headspace resulted in a completely consumption of CO 2 and a concomitant increase in CH 4 content up to 89%. The microbial community and isotope analysis shows an enrichment of hydrogenotrophic Methanobacterium and the key role of hydrogenotrophic methanogenesis for biogas upgrading to higher CH 4 content. Excess H 2 was also supplied to evaluate its effect on overall process performance. The results show that excess H 2 addition resulted in accumulation of H 2 , depletion of CO 2 and inhibition of the degradation of acetate and other volatile fatty acids (VFA). A systematic isotope analysis revealed that excess H 2 supply led to an increase in dissolved H 2 to the level that thermodynamically inhibit the degradation of VFA and stimulate homo-acetogens for production of acetate from CO 2 and H 2 . The inhibition was a temporary effect and acetate degradation resumed when the excess H 2 was removed as well as in the presence of stoichiometric amount of H 2 and CO 2 . This inhibition mechanism underlines the importance of carefully regulating the H 2 addition rate and gas retention time to the CO 2 production rate, H 2 -uptake rate and growth of hydrogenotrophic methanogens in order to achieve higher CH 4 content without the accumulation of acetate and other VFA. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Research about reactor operator's personability characteristics and performance

    Energy Technology Data Exchange (ETDEWEB)

    Wei Li; He Xuhong; Zhao Bingquan [Tsinghua Univ., Institute of Nuclear Energy Technology, Beijing (China)

    2003-03-01

    To predict and evaluate the reactor operator's performance by personality characteristics is an important part of reactor operator safety assessment. Using related psychological theory combined with the Chinese operator's fact and considering the effect of environmental factors to personality analysis, paper does the research about the about the relationships between reactor operator's performance and personality characteristics, and offers the reference for operator's selection, using and performance in the future. (author)

  1. 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...

  2. State Equation Determination of Cow Dung Biogas

    Science.gov (United States)

    Marzuki, A.; Wicaksono, L. B.

    2017-08-01

    A state function is a thermodynamic function which relates various macroscopically measurable properties of a system (state variable) describing the state of matter under a given set of physical conditions. A good understanding of a biogas state function plays a very important role in an effort to maximize biogas processes and to help predicting combation performance. This paper presents a step by step process of an experimental study aimed at determining the equation of state of cow dung biogas. The equation was derived from the data obtained from the experimental results of compressibility (κ) and expansivity (β) following the general form of gas state equation dV = βdT + κdP. In this equation, dV is gas volume variation, dT is temperature variation, and dP is pressure variation. From these results, we formulated a unique state equation from which the biogas critical temperature (Tc) and critical pressure were then determined (Tc = 266.7 K, Pc = 5096647.5 Pa).

  3. 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

  4. Biogas: fuel of the future

    Energy Technology Data Exchange (ETDEWEB)

    Da Silva, E J

    1980-01-01

    As the energy crisis worsens, bioconversion of organic residue has become increasingly attractive in recent years. There are thousands of biogas plants in developing countries (not including China) and more programs are being launched. Because biogas is conveniently renewable, the author argues that it has a vital role to play, especially as a future source of energy for both developed and developing countries. The operation of a typical biogas plant is described.

  5. Advanced Conversion of Organic Waste into Biogas

    Energy Technology Data Exchange (ETDEWEB)

    Offenbacher, Elmar [BDI-BioEnergy International AG, Grambach/Graz (Austria)

    2012-11-01

    Day by day, every human generates significant amounts of organic waste that most of the time ends on landfills. Disposing of organic residues is not just a waste of energy resources but also a burden to the environment as anthropogenic emissions of greenhouse gases are produced. In contrast to waste combustion that can't generate any energy out of organic waste but the contrary, anaerobic digestion is the most suitable technology for the sustainable and efficient conversion of all kind of organic waste into valuable biogas. Biogas generated from organic waste typically consists of 55-60% methane (CH{sub 4}) and provides an energy content of more than 20 MJ/Nm{sup 3}. The average biogas yield is around 150 Nm{sup 3} per ton of organic waste that can be converted into 350 kW of electricity plus the same amount of process heat. In other words a typical household could recover about one twentieth of its power consumption just out of the organic waste it is producing. Anaerobic digestion significantly reduces the amount of waste going to landfill as well as the uncontrolled emissions of methane. The BDI High Load Hybrid Reactor merges the core concepts of CSTR and UASB fermenters while providing a two phase anaerobic digestion system. The first process step accommodates hydrolysis and acidification to break down the complex organic molecules into simple sugars, amino acids, and fatty acids under acid conditions. In the second stage acetic acids are finally converted into methane (CH{sub 4}), carbon dioxide (CO{sub 2}) and water. This two-phase concept ensures maximum yield of biogas generated, paired with high loading rates and feedstock flexibility.

  6. 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...

  7. Assessment of beam tube performance for the maple research reactor

    International Nuclear Information System (INIS)

    Lee, A.G.

    1986-06-01

    The MAPLE research reactor is a versatile new research facility that can be adapted to meet the requirements of a variety of reactor applications. A particular group of reactor applications involves the use of beams of radiation extracted from the reactor core via tubes that penetrate through the biological shield and terminate in the reflector surrounding the fuelled core. An assessment is given of the neutron and gamma radiation fields entering beam tubes that are located radially or tangentially with respect to the core

  8. THESEE-3, Orgel Reactor Performance and Statistic Hot Channel Factors

    International Nuclear Information System (INIS)

    Chambaud, B.

    1974-01-01

    1 - Nature of physical problem solved: The code applies to a heavy-water moderated organic-cooled reactor channel. Different fuel cluster models can be used (circular or hexagonal patterns). The code gives coolant temperatures and velocities and cladding temperatures throughout the channel and also channel performances, such as power, outlet temperature, boiling and burn-out safety margins (see THESEE-1). In a further step, calculations are performed with statistical values obtained by random retrieval of geometrical in- put data and taking into account construction tolerances, vibrations, etc. The code evaluates the mean value and standard deviation for the more important thermal and hydraulic parameters. 2 - Method of solution: First step calculations are performed for nominal values of parameters by solving iteratively the non-linear system of equations which give the pressure drops in subchannels of the current zone (see THESEE-1). Then a Gaussian probability distribution of possible statistical values of the geometrical input data is assumed. A random number generation routine determines the statistical case. Calculations are performed in the same way as for the nominal case. In the case of several channels, statistical performances must be adjusted to equalize the normal pressure drop. A special subroutine (AVERAGE) then determines the mean value and standard deviation, and thus probability functions of the most significant thermal and hydraulic results. 3 - Restrictions on the complexity of the problem: Maximum 7 fuel clusters, each divided into 10 axial zones. Fuel bundle geometries are restricted to the following models - circular pattern 6/7, 18/19, 36/67 rods, with or without fillers. The fuel temperature distribution is not studied. The probability distribution of the statistical input is assumed to be a Gaussian function. The principle of random retrieval of statistical values is correct, but some additional correlations could be found from a more

  9. Profile and Perceptions of Biogas as Automobile Fuel : A Study of Svensk Biogas

    OpenAIRE

    Larsson, Anneli

    2008-01-01

    From an environmental- and health perspective, biogas and other biomass-based fuels have several advantages; nevertheless the majority of motorists fill their cars with petroleum-based fuels. This thesis is designed to explore the profile of biogas in relation to its perceptions. It is a study concerning the communication between the biogas producing company Svensk Biogas and their biogas users and non biogas users. To obtain a thorough understanding of the profile and perceptions of biogas a...

  10. Biogas Opportunities Roadmap Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2015-12-01

    In support of the Obama Administration's Climate Action Plan, the U.S. Department of Energy, the U.S. Environmental Protection Agency, and U.S. Department of Agriculture jointly released the Biogas Opportunities Roadmap Progress Report, updating the federal government's progress to reduce methane emissions through biogas systems since the Biogas Opportunities Roadmap was completed by the three agencies in July 2014. The report highlights actions taken, outlines challenges and opportunities, and identifies next steps to the growth of a robust biogas industry.

  11. Biogas plants; Biogasanlagen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Within the KRdL expert meeting at 30th October, 2012 in Bonn (Federal Republic of Germany), the following lectures were held: (1) New requirements on biomass conversion plants based on the Federal Nuisance Control Ordinance (Hans-Peter Ewens); (2) State of the art of the operation of biomass conversion plants (Christina Dornack); (3) Implementation of the regulation VDI 3475 sheet 4 (Markus Helm); (4) Handling of constraints of residents in the licensing procedure as well as during operation (Helmar Hentschke); (5) Explosion protection for biomass conversion plants considering the matters of immission control (Michael Faber); (6) Microbiological and epidemic-hygienic aspects of agricultural biomass conversion plants and their fermentation residues (Werner Philipp); (7) Emissions of climatic relevant gases at the biogas production (Jacqueline Daniel-Gromke); (8) State of the art in the biogas processing (Joachim Krassowski).

  12. Operating performance of the prototype heavy water reactor Fugen

    International Nuclear Information System (INIS)

    1984-01-01

    Since the full scale operation was started in March, 1979, the ATR Fugen power station has been verifying the performance and reliability of the machinery and equipment, uranium-plutonium mixed oxide fuel and so on, and obtaining the technical prospect for putting ATRs in practical use by accumulating operation and maintenance techniques, through about five years of operation. In this report, the operational results of the Fugen power station are described. Fugen is a heavy water-moderated, boiling light water-cooled, pressure tube type reactor with 165 MWe output. As of the end of March, 1984, the total generated electric power was about 4.3 billion kWh, and the operation time was about 27,000 hours. The mean capacity ratio reached 58.8%. During the operation period, troubles including plant shutdown occurred eight times, but generally the performance and reliability of the machinery and equipment have been good. 580 fuels including 284 MOX fuels have been charged, but fuel breaking did not occur at all. The consumption of heavy water and the leak of tritium did not cause problem. The management of the core and fuel, the management of maintenance, the quality control of cooling water and heavy water, radiation control and the management of wastes are reported. (Kako, I.)

  13. Light water reactor pressure isolation valve performance testing

    International Nuclear Information System (INIS)

    Neely, H.H.; Jeanmougin, N.M.; Corugedo, J.J.

    1990-07-01

    The Light Water Reactor Valve Performance Testing Program was initiated by the NRC to evaluate leakage as an indication of valve condition, provide input to Section XI of the ASME Code, evaluate emission monitoring for condition and degradation and in-service inspection techniques. Six typical check and gate valves were purchased for testing at typical plant conditions (550F at 2250 psig) for an assumed number of cycles for a 40-year plant lifetime. Tests revealed that there were variances between the test results and the present statement of the Code; however, the testing was not conclusive. The life cycle tests showed that high tech acoustic emission can be utilized to trend small leaks, that specific motor signature measurement on gate valves can trend and indicate potential failure, and that in-service inspection techniques for check valves was shown to be both feasible and an excellent preventive maintenance indicator. Life cycle testing performed here did not cause large valve leakage typical of some plant operation. Other testing is required to fully understand the implication of these results and the required program to fully implement them. (author)

  14. Reactor performance and energy analysis of solid state anaerobic co-digestion of dairy manure with corn stover and tomato residues.

    Science.gov (United States)

    Li, Yangyang; Xu, Fuqing; Li, Yu; Lu, Jiaxin; Li, Shuyan; Shah, Ajay; Zhang, Xuehua; Zhang, Hongyu; Gong, Xiaoyan; Li, Guoxue

    2018-03-01

    Anaerobic co-digestion is commonly believed to be benefical for biogas production. However, additional of co-substrates may require additional energy inputs and thus affect the overall energy efficiency of the system. In this study, reactor performance and energy analysis of solid state anaerobic digestion (SS-AD) of tomato residues with dairy manure and corn stover were investigated. Different fractions of tomato residues (0, 20, 40, 60, 80 and 100%, based on volatile solid weight (VS)) were co-digested with dairy manure and corn stover at 15% total solids. Energy analysis based on experimental data was conducted for three scenarios: SS-AD of 100% dairy manure, SS-AD of binary mixture (60% dairy manure and 40% corn stover, VS based), and SS-AD of ternary mixture (36% dairy manure, 24% corn stover, and 40% tomato residues, VS based). For each scenario, the energy requirements for individual process components, including feedstock collection and transportation, feedstock pretreatment, biogas plant operation, digestate processing and handling, and the energy production were examined. Results showed that the addition of 20 and 40% tomato residues increased methane yield compared to that of the dairy manure and corn stover mixture, indicating that the co-digestion could balance nutrients and improve the performance of solid-state anaerobic digestion. The energy required for heating substrates had the dominant effect on the total energy consumption. The highest volatile solids (VS) reduction (57.0%), methane yield (379.1 L/kg VS feed ), and net energy production were achieved with the mixture of 24% corn stover, 36% dairy manure, and 40% tomato residues. Thus, the extra energy input for adding tomato residues for co-digestion could be compensated by the increase of methane yield. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. 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.

  16. Biogas of sanitary fillers

    International Nuclear Information System (INIS)

    Serrano Camacho, Ciro

    2007-01-01

    The author proposes a methodology for the preliminary estimation of the energetic potential and environmental improvement derivates of the implementation of these technologies that allows to make the first estimative of biogas generation of sanitary fillers with base in the results of the simulation of three predictive model: One Mexican, other denominated Scholl-Canyon of North American origin and the designed by the EPA. The three models use different versions and constants for a differential equation of degradation of first degree

  17. Bioelectrochemical removal of carbon dioxide (CO2): an innovative method for biogas upgrading.

    Science.gov (United States)

    Xu, Heng; Wang, Kaijun; Holmes, Dawn E

    2014-12-01

    Innovative methods for biogas upgrading based on biological/in-situ concepts have started to arouse considerable interest. Bioelectrochemical removal of CO2 for biogas upgrading was proposed here and demonstrated in both batch and continuous experiments. The in-situ biogas upgrading system seemed to perform better than the ex-situ one, but CO2 content was kept below 10% in both systems. The in-situ system's performance was further enhanced under continuous operation. Hydrogenotrophic methanogenesis and alkali production with CO2 absorption could be major contributors to biogas upgrading. Molecular studies showed that all the biocathodes associated with biogas upgrading were dominated by sequences most similar to the same hydrogenotrophic methanogen species, Methanobacterium petrolearium (97-99% sequence identity). Conclusively, bioelectrochemical removal of CO2 showed great potential for biogas upgrading. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Proceedings of the 1. annual Canadian farm and food biogas conference and exhibition

    International Nuclear Information System (INIS)

    2009-01-01

    This conference provided a forum for researchers, farmers, and electric utility operators to discuss issues related to the growth of Canada's biogas industry. Many farmers are now exploring methods of producing biogas from agricultural wastes using anaerobic digestion technologies. However, regulatory problems continue to stall the growth of the fledgling biogas industry. In addition, many biogas plants face challenges related to ensuring reliable grid connections. European and American perspectives on biogas development were presented at the conference along with issues related to provincial and federal regulations and policies. Technologies and strategies for connecting biogas systems with other power systems were presented. The conference was divided into 11 sessions and 2 plenary sessions: (1) B1 grid connection solutions; (2) B2D energy crops and other plant-based co-substrates; (3) B2E Ontario biogas today; (4) B3D mixed materials; (5) B3E siting, odour and safety; (6) B4D economics and policy issues; (7) B4E genset performance and efficiency panel; (8) B5D case studies of food or farm biogas systems; (9) B5E case studies of farm-based systems; (10) B6D biogas next steps; and (11) B6E biogas in an urban setting. The conference featured 42 presentations, of which 5 have been catalogued separately for inclusion in this database. A set of 12 poster presentations were also presented, as well as several networking forums. tabs., figs

  19. Life cycle assessment of coupling household biogas production to agricultural industry: A case study of biogas-linked persimmon cultivation and processing system

    International Nuclear Information System (INIS)

    Chen, Bin; Chen, Shaoqing

    2013-01-01

    Biogas plant construction has been boosted in rural China not only due to the immediate merit from biogas production but also the succeeding benefit from by-product utilization in agro-industry, both of which are significant strategies to address energy shortage and global warming issues. However, little work has been done to evaluate the coupling of biogas projects to traditional agrosystems from a life-cycle perspective, which is most important in process and system optimization in different senses. By taking persimmon cultivation and processing with supports from a household biogas plant as a case study, this study conducts a life cycle assessment of coupling biogas production to agro-industry in terms of energy, environmental and economic performance. The results suggest that each production stage following the biogas/digestate utilization chain (biogas operation-persimmon cultivation-product processing) is beneficial across all three aspects. However, a tradeoff only exists in utilizing digestate as top-dressing and employing biogas utilization as engine fuel, while biogas application in fresh-keeping and digestate reuse as base fertilizer fails to increase either energy production or greenhouse gas mitigation. The coupled system can be hopefully optimized through increasing fermentation efficiency and joint operation of biogas digesters. -- Highlights: •Biogas/digestate utilization is overall beneficial in all production stages. •Each bioresource application may not be profitable in all respects. •Tradeoffs in using biogas and digestate vary among different utilization ways. •Multi-user operation and fermentation efficiency elevation optimize system

  20. Continuous dry fermentation of swine manure for biogas production.

    Science.gov (United States)

    Chen, Chuang; Zheng, Dan; Liu, Gang-Jin; Deng, Liang-Wei; Long, Yan; Fan, Zhan-Hui

    2015-04-01

    A down plug-flow anaerobic reactor (DPAR) was designed for the feasibility study on continuous dry fermentation of swine manure without any additional stirring. Using fresh swine manure as the feedstock with TS concentration (w/w) of 20%, 25%, 30%, and 35%, stable volumetric biogas production rates of 2.40, 1.92, 0.911, and 0.644L · (Ld)(-1) and biogas yields of 0.665, 0.532, 0.252, and 0.178 L g(-)(1)VS were obtained respectively, and the TS degradation rates were 46.5%, 45.4%, 53.2%, and 55.6%, respectively. With the increase of feedstock TS concentration, the concentration of ammonia nitrogen grew up to the maximum value of 3500 mg L(-1). Biogas production was obviously inhibited when the concentration of ammonia nitrogen was above 3000 mg L(-1). The maximal volumetric biogas production rate of 2.34 L ·(Ld)(-1) and biogas yield of 0.649 L g(-1)VS were obtained with TS concentration of 25% at 25°C without inhibition. Liquidity experiments showed that TS concentration of digestate could be less than 15.8%, and the flow rate of digestate more than 0.98 m s(-1) when the feedstock TS concentration was less than 35%, which indicated the digestate could be easily discharged from a DPAR. Therefore, it is feasible to conduct a continuous dry fermentation in a DPAR using fresh swine manure as the feedstock with TS concentration less than 35%, whereas the feedstock TS concentration should not exceed 30% to achieve the maximal biogas production rate and biogas yield. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. CO2/CH4 Separation Performance of Ionic-Liquid-Based Epoxy-Amine Ion Gel Membranes under Mixed Feed Conditions Relevant to Biogas Processing.

    Czech Academy of Sciences Publication Activity Database

    Friess, K.; Lanč, M.; Pilnáček, Kryštof; Fíla, V.; Vopička, O.; Sedláková, Zuzana; Cowan, M.G.; McDaniel, W.M.; Noble, R.D.; Gin, D.L.; Izák, Pavel

    2017-01-01

    Roč. 528, APRIL (2017), s. 64-71 ISSN 0376-7388 R&D Projects: GA ČR GA14-12695S; GA MŠk LH14006; GA TA ČR TE01020080 Institutional support: RVO:67985858 Keywords : epoxy-amine-based ion gel membranes * biogas processing * humid mixed-gas permeation Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 6.035, year: 2016

  2. Rancang Bangun Konverter Biogas Untuk Motor Bensin Silinder Tunggal

    Directory of Open Access Journals (Sweden)

    Desrial

    2014-02-01

    Full Text Available The need for energy continues to increase along with the increase of population in Indonesia . This is in contrast with the fact that the main oil energy source is reducing day by. To overcome this problem renewable energy sources such as biogas becomes very important. Methane content in the biogas ranged between 60-65 % , where the value is large enough to be used as an energy source replacement of gasoline. The purpose of this study is to design a converter that is capable to perform biogas and air mixing for optimum use of biogas in gasoline engine. The main parts of biogas converter are the venturi, choke valves , throttle valves, as well as the coupler to the engine. Testing was done by applying converter on a gasoline engine with biogas fuel. Engine performance was tested using a dynamometer and the results are compared with the performance of the motor using gasoline fuel . Test results show that the optimal power is achieved at 0979 kW at 3146 rpm and a torque of 4.3 Nm, while the motor power with gasoline kW and a torque of 1.86 Nm at 6:21.

  3. Performance of nuclear fuel in the Krsko reactor; Spremljanje delovanja jedrskega goriva v reaktorju NE Krsko

    Energy Technology Data Exchange (ETDEWEB)

    Jurcevic, M; Kurincic, B; Levstek, M F; Sambo, B; Vrcko, P [Nuklearna elektrana Krsko, Krsko (Yugoslavia)

    1987-07-01

    In this paper activities to follow performance of the nuclear fuel and operational status of the reactor of Nuclear Power Plant Krsko are presented. Short descriptions of the methods as well as nuclear and process instrumentation used for surveillance of the reactor performance are given. The purpose of the subject activities is to assure safe operation of the reactor in accordance with the Final safety Analysis Report of NPP Krsko. (author)

  4. International experience and status of fuel element performance and modelling for water reactors

    International Nuclear Information System (INIS)

    Gittus, J.H.

    1982-04-01

    Current knowledge concerning water reactor fuel performance and technology is reviewed (212 references). The emphasis is on aspects of in-reactor performance including behaviour in accidents. Computer models for predicting fuel behaviour during the ordinary running of the reactor and during accidents are described. These codes include COMETHE, HOTROD, SLEUTH-SEER and FRAPCON. Their agreement with experimental data is examined. (U.K.)

  5. Effects of the reduction of the hydraulic retention time to 1.5 days at constant organic loading in CSTR, ASBR, and fixed-bed reactorsPerformance and methanogenic community composition

    International Nuclear Information System (INIS)

    Schmidt, Thomas; Ziganshin, Ayrat M.; Nikolausz, Marcell; Scholwin, Frank; Nelles, Michael; Kleinsteuber, Sabine; Pröter, Jürgen

    2014-01-01

    The hydraulic retention time (HRT) is one of the key parameters in biogas processes and often it is postulated that a minimum HRT of 10–25 days is obligatory in continuous stirred tank reactors (CSTR) to prevent a washout of slow growing methanogens. In this study the effects of the reduction of the HRT from 6 to 1.5 days on performance and methanogenic community composition in different systems with and without immobilization operated with simulated thin stillage (STS) at mesophilic conditions and constant organic loading rates (OLR) of 10 g L −1 d −1 of volatile solids were investigated. With the reduction of the HRT process instability was first observed in the anaerobic sequencing batch reactor (ASBR) (at HRT of 3 days) followed by the CSTR (at HRT of 2 days). The fixed bed reactor (FBR) was stable until the end of the experiment, but the reduction of the HRT to 1.5 days caused a decrease of the specific biogas production to about 450 L kg −1 of VS compared to about 600 L kg −1 of VS at HRTs of 4–5 days. Methanoculleus and Methanosarcina were the dominant genera under stable process conditions in the CSTR and the ASBR and members of Methanosaeta and Methanospirillum were only present at HRT of 4 days and lower. In the effluent of the FBR Methanosarcina spp. were not detected and Methanosaeta spp. were more abundant then in the other reactors. - Highlights: • A CSTR was operated at high OLR of 10 (g L −1  d −1  VS) and low HRT of 3 days. • Exceeding washout of methanogenic archaea did not take place. • pH and nutrient concentrations influenced the reproduction rate more than HRT. • Methanoculleus and Methanosarcina were the dominant genera in the CSTR

  6. A regional biogas infrastructure, prospects for the biogas grid

    NARCIS (Netherlands)

    Hengeveld, Evert Jan; van Gemert, Wim; Bekkering, Jan; Broekhuis, A.A.

    2014-01-01

    A model to describe biogas transport costs in a regional grid is presented. In the model biogas is collected to a central location by transport through dedicated pipelines. Costs have been calculated for two different lay-outs of the grid i.e. star and fishbone lay-out. The costs depend on the

  7. Performance Monitoring for Nuclear Safety Related Instrumentation at PUSPATI TRIGA Reactor (RTP)

    International Nuclear Information System (INIS)

    Zareen Khan Abdul Jalil Khan; Ridzuan Abdul Mutalib; Mohd Sabri Minhat

    2015-01-01

    The Reactor TRIGA PUSPATI (RTP) at Malaysia Nuclear Agency is a TRIGA Mark II type reactor and pool type cooled by natural circulation of light water. This paper describe on performance monitoring for nuclear safety related instrumentation in TRIGA PUSPATI Reactor (RTP) of based on various parameter of reactor safety instrument channel such as log power, linear power, Fuel temperature, coolant temperature will take into consideration. Methodology of performance on estimation and monitoring is to evaluate and analysis of reactor parameters which is important of reactor safety and control. And also to estimate power measurement, differential of log and linear power and fuel temperature during reactor start-up, operation and shutdown .This study also focus on neutron power fluctuation from fission chamber during reactor start-up and operation. This work will present result of performance monitoring from RTP which indicated the safety parameter identification and initiate safety action on crossing the threshold set point trip. Conclude that performance of nuclear safety related instrumentation will improved the reactor control and safety parameter during reactor start-up, operation and shutdown. (author)

  8. Microbial electrochemical separation of CO2 for biogas upgrading.

    Science.gov (United States)

    Kokkoli, Argyro; Zhang, Yifeng; Angelidaki, Irini

    2018-01-01

    Biogas upgrading to natural gas quality has been under focus the recent years for increasing the utilization potential of biogas. Conventional methods for CO 2 removal are expensive and have environmental challenges, such as increased emissions of methane in the atmosphere with serious greenhouse impact. In this study, an innovative microbial electrochemical separation cell (MESC) was developed to in-situ separate and regenerate CO 2 via alkali and acid regeneration. The MESC was tested under different applied voltages, inlet biogas rates and electrolyte concentrations. Pure biomethane was obtained at 1.2V, inlet biogas rate of 0.088mL/h/mL reactor and NaCl concentration of 100mM at a 5-day operation. Meanwhile, the organic matter of the domestic wastewater in the anode was almost completely removed at the end. The study demonstrated a new sustainable way to simultaneously upgrade biogas and treat wastewater which can be used as proof of concept for further investigation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. PLUS7TM In-Reactor Operating Performance and Economics

    International Nuclear Information System (INIS)

    Kim, Kyutae; Jang, Youngki; Choi, Joonhyung; Lee, Jinseok; Kim, Yoonho; Suh, Jungmin

    2006-01-01

    KNFC has developed an advanced fuel, PLUS7 TM , for the Korean Standard Nuclear Power Plants(KSNPs) through the joint development program with Westinghouse. With the help of various out-of-pile tests, it is found that the PLUS7 TM shows much better performance than the current fuel, GUARDIAN TM from the safety and economy points of view. Now four Lead Test Assembles(LTAs) of the PLUS7 TM are being irradiated for the 3 rd cycle after the successful completion of the 1 st and 2 nd irradiation cycles. During the 1 st and 2 nd irradiation cycles, no fuel failure was observed at LTAs and their nuclear-related parameters matched their design values well. During the overhaul period, on the other hand, pool side examinations were performed for four LTAs to generate key in-reactor fuel performance data such as fuel rod and assembly growths, fuel rod-to-top nozzle gap, fuel assembly bow and twist, fuel rod bow, spacer grid width, fuel rod diameter and fuel rod oxide layer thickness. It is found that all measured values are bounded by upper and lower predicted ones. The detailed economic analyses have shown that significant fuel cycle cost can be reduced by more than one million dollars per cycle of one KSNP with the introduction of the PLUS7 TM assembly. Furthermore, more than one hundred million dollars with power up-rating of 5% can be saved annually for currently operating eight KSNPs, which is easily and safety achievable with the PLUS7 TM assembly

  10. Biogas - the calculable energy

    Science.gov (United States)

    Kith, Károly; Nagy, Orsolya; Balla, Zoltán; Tamás, András

    2015-04-01

    EU actions against climate change are rising energy prices, both have emphasized the use of renewable energy,increase investments and energy efficiency. A number of objectives formulated in the EC decree no. 29/2009 by 2020. This document is based on the share of renewable energies in energy consumption should be increased to 20% (EC, 2009). The EU average is 20% but the share of renewables vary from one member state to another. In Hungary in 2020, 14.65% renewable energy share is planned to be achieved. According to the latest Eurostat data, the share of renewable energy in energy consumption of the EU average was 14.1%, while in Hungary, this share was 9.6% in 2012. (EUROSTAT, 2014). The use of renewable energy plant level is influenced by several factors. The most important of these is the cost savings and efficiency gains. Hungarian investments in renewable energy production usually have high associated costs and the payback period is substantially more than five years, depending on the support rate. For example, the payback period is also influenced by the green electricity generated feed prices, which is one of the lowest in Hungary compared the Member States of the European Union. Consequently, it is important to increase the production of green energy. Nowadays, predictable biogas energy is an outstanding type of decentralized energy production. It follows directly that agricultural by-products can be used to produce energy and they also create jobs by the construction of a biogas plant. It is important to dispose of and destroy hazardous and noxious substances in energy production. It follows from this that the construction of biogas plants have a positive impact, in addition to green energy which is prepared to reduce the load on the environment. The production of biogas and green electricity is one of the most environment friendly forms of energy production. Biogas production also has other important ecological effects, such as the substitution of

  11. A New and Sound Technology for Biogas from Solid Waste and Biomass

    International Nuclear Information System (INIS)

    Busch, G.; Grossmann, J.; Sieber, M.; Burkhardt, M.

    2009-01-01

    Organic waste, as a main constituent of municipal solid waste, has as well as solid biomass a high potential for biogas generation. Despite the importance of biogas generation from these materials, the availability of large-scale biogas processes lacks behind the demand. A newly developed double-stage solid-liquid biogas process, consisting of an open hydrolysis stage and a fixed-bed methane reactor, allows the biogas production from almost all biodegradable solid waste and renewable resources like maize, grass, sugar cane, etc. Furthermore, residues from industrial processes, like the glycerine waste water from biodiesel production, can also be converted into biogas successfully. Due to the strong separation of hydrolysis and methanation, the process is extremely stable. No malfunction has been detected so far. The open hydrolysis releases CO 2 and allows oxidation of sulfur. Consequently, the biogas has a high methane (>72%) and low H 2 S concentration (<100 ppm). Stirrers or other agitation equipment are not necessary; only liquids are pumped. The biogas generation becomes controllable for the first time; thus, the actual generation can be easily adapted to the consumption

  12. 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

  13. Mechanical Pretreatment to Increase the Bioenergy Yield for Full-scale Biogas Plants

    DEFF Research Database (Denmark)

    Tsapekos, Panagiotis; Kougias, Panagiotis; Angelidaki, Irini

    % compared to the untreated one. The digestion of meadow grass as an alternative co-substrate had positive impact on the energy yield of full-scale biogas reactors operating with cattle manure, pig manure or mixture of both. A preliminary analysis showed that the addition of meadow grass in a manure based...... biogas reactor was possible with biomass share of 10%, leading to energy production of 280 GJ/day. The digestion of pretreated meadow grass as alternative co-substrate had clearly positive impact in all the examined scenarios, leading to increased biogas production in the range of 10%-20%.......This study investigated the efficiency of commercially available harvesting machines for mechanical pretreatment of meadow grass, in order to enhance the energy yield per hectare. Excoriator was shown to be the most efficient mechanical pretreatment increasing the biogas yield of grass by 16...

  14. Effect of temperature and active biogas process on passive separation of digested manure

    DEFF Research Database (Denmark)

    Kaparaju, Prasad Laxmi-Narasimha; Angelidaki, Irini

    2008-01-01

    The objective of the study was to identify the optimum time interval for effluent removal after temporarily stopping stirring in otherwise continuously stirred tank reactors. Influence of temperature (10 and 55 degrees C) and active biogas process on passive separation of digested manure, where...... no outside mechanical or chemical action was used, within the reactor was studied in three vertical settling columns (100 cm deep). Variations in solids and microbial distribution at top, middle and bottom layers of column were assessed over a 15 day settling period. Results showed that best solids...... separation was achieved when digested manure was allowed to settle at 55 degrees C with active biogas process (pre-incubated at 55 degrees C) compared to separation at 55 degrees C without active biogas process (autoclaved at 120 degrees C, for 20 min) or at 10 degrees C with active biogas process. Maximum...

  15. Analysis of bacterial communities and bacterial pathogens in a biogas plant by the combination of ethidium monoazide, PCR and Ion Torrent sequencing

    DEFF Research Database (Denmark)

    Luo, Gang; Angelidaki, Irini

    2014-01-01

    with time were also observed. This could be attributed to varying composition of the influent. Batch experiments showed that the methane recovery from the digested residues (obtained from biogas reactor) was mainly related with post-digestion temperature. However, post-digestion time rather than temperature......The present study investigated the changes of bacterial community composition including bacterial pathogens along a biogas plant, i.e. from the influent, to the biogas reactor and to the post-digester. The effects of post-digestion temperature and time on the changes of bacterial community...... showed that the bacterial community composition in the influent was changed after anaerobic digestion. Firmicutes were dominant in all the samples, while Proteobacteria decreased in the biogas reactor compared with the influent. Variations of bacterial community composition in the biogas reactor...

  16. Physics methods for calculating light water reactor increased performances

    International Nuclear Information System (INIS)

    Vandenberg, C.; Charlier, A.

    1988-01-01

    The intensive use of light water reactors (LWRs) has induced modification of their characteristics and performances in order to improve fissile material utilization and to increase their availability and flexibility under operation. From the conceptual point of view, adequate methods must be used to calculate core characteristics, taking into account present design requirements, e.g., use of burnable poison, plutonium recycling, etc. From the operational point of view, nuclear plants that have been producing a large percentage of electricity in some countries must adapt their planning to the need of the electrical network and operate on a load-follow basis. Consequently, plant behavior must be predicted and accurately followed in order to improve the plant's capability within safety limits. The Belgonucleaire code system has been developed and extensively validated. It is an accurate, flexible, easily usable, fast-running tool for solving the problems related to LWR technology development. The methods and validation of the two computer codes LWR-WIMS and MICROLUX, which are the main components of the physics calculation system, are explained

  17. Enhancement of Tokamak Fusion Test Reactor performance by lithium conditioning

    International Nuclear Information System (INIS)

    Mansfield, D.K.; Hill, K.W.; Strachan, J.D.; Bell, M.G.; Scott, S.D.; Budny, R.; Marmar, E.S.; Snipes, J.A.; Terry, J.L.; Batha, S.; Bell, R.E.; Bitter, M.; Bush, C.E.; Chang, Z.; Darrow, D.S.; Ernst, D.; Fredrickson, E.; Grek, B.; Herrmann, H.W.; Janos, A.; Jassby, D.L.; Jobes, F.C.; Johnson, D.W.; Johnson, L.C.; Levinton, F.M.; Mikkelsen, D.R.; Mueller, D.; Owens, D.K.; Park, H.; Ramsey, A.T.; Roquemore, A.L.; Skinner, C.H.; Stevenson, T.; Stratton, B.C.; Synakowski, E.; Taylor, G.; von Halle, A.; von Goeler, S.; Wong, K.L.; Zweben, S.J.

    1996-01-01

    Wall conditioning in the Tokamak Fusion Test Reactor (TFTR) [K. M. McGuire et al., Phys. Plasmas 2, 2176 (1995)] by injection of lithium pellets into the plasma has resulted in large improvements in deuterium endash tritium fusion power production (up to 10.7 MW), the Lawson triple product (up to 10 21 m -3 s keV), and energy confinement time (up to 330 ms). The maximum plasma current for access to high-performance supershots has been increased from 1.9 to 2.7 MA, leading to stable operation at plasma stored energy values greater than 5 MJ. The amount of lithium on the limiter and the effectiveness of its action are maximized through (1) distributing the Li over the limiter surface by injection of four Li pellets into Ohmic plasmas of increasing major and minor radius, and (2) injection of four Li pellets into the Ohmic phase of supershot discharges before neutral-beam heating is begun. copyright 1996 American Institute of Physics

  18. Reduced enrichment fuels for Canadian research reactors - Fabrication and performance

    Energy Technology Data Exchange (ETDEWEB)

    Wood, J C; Foo, M T; Berthiaume, L C; Herbert, L N; Schaefer, J D; Hawley, D [Atomic Energy of Canada Limited, Chalk River Nuclear Laboratories, Chalk River, ON KOJ 1JO (Canada)

    1985-07-01

    Our facilities have been upgraded to manufacture fuel rods comprising dispersions of U{sub 3}Si in aluminum, to complement the dispersions of U{sub 3}Si alloyed with 1.5 and 3.0 wt% Al fabricated and tested previously. Further advances have been made in process optimization particularly in core extrusion where production rate has been doubled while maintaining high quality standards. Our mini-element irradiations of Al-61.5 wt% (U,3.5 wt% Si, 1.5 wt% Al) and Al-62.4 wt% (U,3.2 wt% Si, 30 wt% Al) have been completed successfully up to the terminal burnup of 93 atomic percent. Fuel core swelling remained marginally below 1% per 10 atomic percent burnup over the whole irradiation. Also mini-elements containing Al-72.4 wt% USiAl and Al-73.4 wt% USi*Al have been irradiated to 82 atomic percent burnup, their swelling rate marginally exceeding 1% per 10 atomic percent burnup. Three full-size 12-element NRU assemblies containing Al-62.4 wt% USi*Al have been fabricated and installed in the NRU reactor where they have performed normally without problems. The cores for four more full-size 12-element NRU assemblies containing Al-61.0 wt% U{sub 3}Si have been manufactured. (author)

  19. Reduced enrichment fuels for Canadian research reactors - Fabrication and performance

    International Nuclear Information System (INIS)

    Wood, J.C.; Foo, M.T.; Berthiaume, L.C.; Herbert, L.N.; Schaefer, J.D.; Hawley, D.

    1985-01-01

    Our facilities have been upgraded to manufacture fuel rods comprising dispersions of U 3 Si in aluminum, to complement the dispersions of U 3 Si alloyed with 1.5 and 3.0 wt% Al fabricated and tested previously. Further advances have been made in process optimization particularly in core extrusion where production rate has been doubled while maintaining high quality standards. Our mini-element irradiations of Al-61.5 wt% (U,3.5 wt% Si, 1.5 wt% Al) and Al-62.4 wt% (U,3.2 wt% Si, 30 wt% Al) have been completed successfully up to the terminal burnup of 93 atomic percent. Fuel core swelling remained marginally below 1% per 10 atomic percent burnup over the whole irradiation. Also mini-elements containing Al-72.4 wt% USiAl and Al-73.4 wt% USi*Al have been irradiated to 82 atomic percent burnup, their swelling rate marginally exceeding 1% per 10 atomic percent burnup. Three full-size 12-element NRU assemblies containing Al-62.4 wt% USi*Al have been fabricated and installed in the NRU reactor where they have performed normally without problems. The cores for four more full-size 12-element NRU assemblies containing Al-61.0 wt% U 3 Si have been manufactured. (author)

  20. Innovative test method for the estimation of the foaming tendency of substrates for biogas plants

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Lucie, E-mail: lucie.moeller@ufz.de [UFZ – Helmholtz Centre for Environmental Research, Centre for Environmental Biotechnology, Permoserstrasse 15, 04318 Leipzig (Germany); Eismann, Frank, E-mail: info@antoc.de [Eismann & Stöbe GbR, GeoPark, Geb. A12, Bautzner Strasse 67, 04347 Leipzig (Germany); Wißmann, Daniel, E-mail: d.s.wissmann@gmx.de [University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy (LA740), Garbenstrasse 9, 70599 Stuttgart (Germany); Nägele, Hans-Joachim, E-mail: hajo.naegele@uni-hohenheim.de [University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy (LA740), Garbenstrasse 9, 70599 Stuttgart (Germany); Zielonka, Simon, E-mail: simon.zielonka@uni-hohenheim.de [University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy (LA740), Garbenstrasse 9, 70599 Stuttgart (Germany); Müller, Roland A., E-mail: roland.mueller@ufz.de [UFZ – Helmholtz Centre for Environmental Research, Centre for Environmental Biotechnology, Permoserstrasse 15, 04318 Leipzig (Germany); Zehnsdorf, Andreas, E-mail: andreas.zehnsdorf@ufz.de [UFZ – Helmholtz Centre for Environmental Research, Centre for Environmental Biotechnology, Permoserstrasse 15, 04318 Leipzig (Germany)

    2015-07-15

    Graphical abstract: Display Omitted - Highlights: • Foaming in biogas plants depends on the interactions between substrate and digestate. • Foaming tests enable the evaluation of substrate foaming tendency in biogas plants. • Leipzig foam tester enables foaming tests of substrates prior to use. - Abstract: Excessive foaming in anaerobic digestion occurs at many biogas plants and can cause problems including plugged gas pipes. Unfortunately, the majority of biogas plant operators are unable to identify the causes of foaming in their biogas reactor. The occurrence of foaming is often related to the chemical composition of substrates fed to the reactor. The consistency of the digestate itself is also a crucial part of the foam formation process. Thus, no specific recommendations concerning substrates can be given in order to prevent foam formation in biogas plants. The safest way to avoid foaming is to test the foaming tendency of substrates on-site. A possible solution is offered by an innovative foaming test. With the help of this tool, biogas plant operators can evaluate the foaming disposition of new substrates prior to use in order to adjust the composition of substrate mixes.

  1. Biocatalysis conversion of methanol to methane in an upflow anaerobic sludge blanket (UASB) reactor: Long-term performance and inherent deficiencies.

    Science.gov (United States)

    Lu, Xueqin; Zhen, Guangyin; Chen, Mo; Kubota, Kengo; Li, Yu-You

    2015-12-01

    Long-term performance of methanol biocatalysis conversion in a lab-scale UASB reactor was evaluated. Properties of granules were traced to examine the impact of methanol on granulation. Methanolic wastewater could be stably treated during initial 240d with the highest biogas production rate of 18.6 ± 5.7 L/Ld at OLR 48 g-COD/Ld. However, the reactor subsequently showed severe granule disintegration, inducing granule washout and process upsets. Some steps (e.g. increasing influent Ca(2+) concentration, etc.) were taken to prevent rising dispersion, but no clear improvement was observed. Further characterizations in granules revealed that several biotic/abiotic factors all caused the dispersion: (1) depletion of extracellular polymeric substances (EPS) and imbalance of protein/polysaccharide ratio in EPS; (2) restricted formation of hard core and weak Ca-EPS bridge effect due to insufficient calcium supply; and (3) simplification of species with the methanol acclimation. More efforts are required to solve the technical deficiencies observed in methanolic wastewater treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. 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

  3. 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....

  4. Biogas in Austria and Switzerland

    Energy Technology Data Exchange (ETDEWEB)

    Urbanek, A.

    Several well-functioning biogas plants in Austria and in Switzerland are briefly described. The profitability of the combination of dairy farming and pig breeding is emphasized. The whey produced by the cheese-dairies is fed to the pigs and the pigs dung is fermented to biogas.

  5. Technological assumptions for biogas purification.

    Science.gov (United States)

    Makareviciene, Violeta; Sendzikiene, Egle

    2015-01-01

    Biogas can be used in the engines of transport vehicles and blended into natural gas networks, but it also requires the removal of carbon dioxide, hydrogen sulphide, and moisture. Biogas purification process flow diagrams have been developed for a process enabling the use of a dolomite suspension, as well as for solutions obtained by the filtration of the suspension, to obtain biogas free of hydrogen sulphide and with a carbon dioxide content that does not exceed 2%. The cost of biogas purification was evaluated on the basis of data on biogas production capacity and biogas production cost obtained from local water treatment facilities. It has been found that, with the use of dolomite suspension, the cost of biogas purification is approximately six times lower than that in the case of using a chemical sorbent such as monoethanolamine. The results showed travelling costs using biogas purified by dolomite suspension are nearly 1.5 time lower than travelling costs using gasoline and slightly lower than travelling costs using mineral diesel fuel.

  6. Biogas: A renewable energy source

    International Nuclear Information System (INIS)

    Imiere, E.E.; Ojih, V.B.; Esiekpe, L.E.; Okafor, M.C.; Attoh, V. A.

    2011-01-01

    Biogas refers to a gas produced by the biological breakdown of organic matter in the absence of oxygen. Biogas can be used as a fuel in any country for any heating purpose such as cooking. By means of digesters, the energy in the gas can be converted to electricity and heat. Biogas like natural gas can also be used to power motor vehicle. Biogas is a renewable fuel which qualifies it for a renewable energy subsidy. It is non-toxic, environment-friendly and serve as a means of combating global warming. Biogas is presently being used in U.S.A, U.K, China, Sweden, Brazil, and India amongst others for domestic purposes, transportation and power generation. In this regard, this paper discusses biogas production. It also presents a model design of domestic biogas plant suitable for Nigerian households. The paper recommends that Nigerian Government should intensify efforts in educating the masses on this novel technology for a sustainable global development. A biogas plant designed for Nigerian household discussed in this paper is also recommended.

  7. Code structure for U-Mo fuel performance analysis in high performance research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Gwan Yoon; Cho, Tae Won; Lee, Chul Min; Sohn, Dong Seong [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of); Lee, Kyu Hong; Park, Jong Man [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    A performance analysis modeling applicable to research reactor fuel is being developed with available models describing fuel performance phenomena observed from in-pile tests. We established the calculation algorithm and scheme to best predict fuel performance using radio-thermo-mechanically coupled system to consider fuel swelling, interaction layer growth, pore formation in the fuel meat, and creep fuel deformation and mass relocation, etc. In this paper, we present a general structure of the performance analysis code for typical research reactor fuel and advanced features such as a model to predict fuel failure induced by combination of breakaway swelling and pore growth in the fuel meat. Thermo-mechanical code dedicated to the modeling of U-Mo dispersion fuel plates is being under development in Korea to satisfy a demand for advanced performance analysis and safe assessment of the plates. The major physical phenomena during irradiation are considered in the code such that interaction layer formation by fuel-matrix interdiffusion, fission induced swelling of fuel particle, mass relocation by fission induced stress, and pore formation at the interface between the reaction product and Al matrix.

  8. ASSESSMENT OF THE BIODIVERSITY OF SAMPLES USED FOR ISOLATION OF MICROBIAL STRAINS CAPABLE OF CONVERTING STRAW DESTINED AS A SUBSTRATE FOR BIOGAS PLANT

    Directory of Open Access Journals (Sweden)

    Krystyna Cybulska

    2016-01-01

    Full Text Available In biogas plants, almost any type of organic matter can be used as a substrate to produce biogas. To make the process of methane fermentation more effective, these materials are pretreated. This applies in particular to a group of difficult substrates. Straw, due to its hemicellulose structure and saturation, is hardly fermented by biogas reactor microorganisms. The methods of post-harvest residue preparation for anaerobic digestion being applied so far are expensive, while their application has a negative effect on methanoegenic bacteria. Therefore, the microorganisms being able to degrade straw hemicellulose structure, utilisation of which could precede the proper fermentation process, have been searched for. This paper presents the results of microbial biodiversity analysis in the environmental samples being lupin, cereal, rape and maize straw as well as hay and haylage at different degradation stages. The analysis of biodiversity will help at a further stage of study to isolate active microbial strains showing cellulolytic, hemicellulolytic or ligninolytic activity which are desirable in the process of straw biodegradation. Analysis of the microbial count was performed by the method of deep inoculation on different microbiological culture media. The conducted tests include determination of the number of fungi, bacteria and actinomycetes. The results obtained confirm the usefulness of the analysed samples for isolation of microbial strains capable of converting straw preceding the biogas production.

  9. CONTROL PARAMETERS FOR UNDERSTANDING AND PREVENTING PROCESS IMBALANCES IN BIOGAS PLANTS. EMPHAS IS ON VFA DYNAMICS

    DEFF Research Database (Denmark)

    Bangsø Nielsen, Henrik

    environmental changes differ widely between the different groups. As a consequence of this, an unrestrained reactor operation can lead to disturbances in the balance between the different microbial groups, which might lead to reactor failure. Therefore, reliable parameters and tools for efficient process...... control and understanding are necessary. The work of present study was directed towards this challenge. Initially, the response of the anaerobic digestion process to various types of process imbalances was investigated with special focus on volatile fatty acid dynamics (VFA), methane production and pH...... of process imbalances in biogas plants. At Danish full-scale biogas plants the biogas production is normally the only continuously measured parameter. In order to examine the usability of propionate as control parameter a reactor experiment was constructed in which the reactor operation either was carried...

  10. Operation and Performance of the Supercritical Fluids Reactor (SFR)

    National Research Council Canada - National Science Library

    Hanush, R

    1996-01-01

    The Supercritical Fluids Reactor (SFR) at Sandia National Laboratories, CA has been developed to examine and solve engineering, process, and fundamental chemistry issues regarding the development of supercritical water oxidation (SCWO...

  11. The potential of biogas energy

    International Nuclear Information System (INIS)

    Acaroglu, M.; Hepbasli, A.; Kocar, G.

    2005-01-01

    Biogas technology has been known about for a long time, but in recent years the interest in it has significantly increased, especially due to the higher costs and the rapid depletion of fossil fuels as well as their environmental considerations. The main objective of the present study is to investigate the potential of biogas energy in the 15 European Union (EU) countries and in Turkey, which is seeking admission to the EU and is trying to meet EU environmental standards. Biogas energy potential of the 15 EU countries is estimated to be about 800 PJ. Besides this, Turkey's annual animal waste potential is obtained to be about 11.81 million tons with a biogas energy equivalent of 53.6 PJ. It is expected that this study will be helpful in developing highly applicable and productive planning for energy policies towards the optimum utilization of biogas energy. (author)

  12. Biogas production from solid pineapple waste

    Energy Technology Data Exchange (ETDEWEB)

    Tanticharoen, M.; Bhumiratana, S.; Tientanacom, S.; Pengsobha, L.

    1984-01-01

    Solid pineapple waste composed of shell and core was used as substrate in anaerobic fermentation producing CH4. The experiments were carried out using four 30-L vessels and no mixing, a 200-L plug-flow reactor, and a 5-cubic m stirred tank. Because of high acidity of the substrate, the loading rate is as low as 2.5 g dry solid added/L-day. The average gas yield is 0.3-0.5 L/g dry substrate. A pretreatment of wet solid with sludge effluent prior loading to the digester resulted in better stability of the biodigester than without pretreatment. These studies showed that loading rate can be much higher than those previously used. The 2-stage process was tested to determine a conversion efficiency of high loading and at much shorter reactor retention times. The results of the entire program indicated that biogas production from cannery pineapple waste is technically feasible.

  13. Precision control of biogas plants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, H.B.; Nielsen, Anders M.; Ward, A.J.

    2009-10-15

    The objective of the project has been to improve design and process stability in biogas plants. The results can be divided within the following main categories: 1) Pre-treatment, serial coupling of digesters and post digestion 2) Process inhibition 3) Process control Ad 1) This work has shown that extreme thermophilic pre-treatment of cattle manure and pig manure mixed with silage has a considerable effect on methane yield in a subsequent methanogenic reactor. Ad 2) The effect of ammonia inhibition was studied in a series of continuously stirred tank reactors co-digesting pig manure (40%) with the addition of solid fractions (60%) and increasing concentrations of ammonia caused by addition of NH{sub 4}Cl pulses. Ad 3) Near infrared spectroscopy (NIRS) was used to predict liquid phase volatile fatty acid (VFA) concentrations in three experiments treating three different materials: pig slurry with maize silage, chicken manure and cattle slurry.

  14. Small Scale Regenerative Desulfurization of Biogas

    NARCIS (Netherlands)

    Linders, M.J.G.; Stille, L.C.; Miedema, M.C.; Groenestijn, J.W. van; Goetheer, E.L.V.

    2016-01-01

    The application of small scale biogas digesters to supply biogas to households in developing countries is well established. The biogas is used for different applications, amongst other cooking. Generally, no further treatment of the biogas is applied. Hydrogen Sulfide (H2S) is present in varying

  15. 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

  16. Reactor

    International Nuclear Information System (INIS)

    Toyama, Masahiro; Kasai, Shigeo.

    1978-01-01

    Purpose: To provide a lmfbr type reactor wherein effusion of coolants through a loop contact portion is reduced even when fuel assemblies float up, and misloading of reactor core constituting elements is prevented thereby improving the reactor safety. Constitution: The reactor core constituents are secured in the reactor by utilizing the differential pressure between the high-pressure cooling chamber and low-pressure cooling chamber. A resistance port is formed at the upper part of a connecting pipe, and which is connect the low-pressure cooling chamber and the lower surface of the reactor core constituent. This resistance part is formed such that the internal sectional area of the connecting pipe is made larger stepwise toward the upper part, and the cylinder is formed larger so that it profiles the inner surface of the connecting pipe. (Aizawa, K.)

  17. Reactor

    International Nuclear Information System (INIS)

    Ikeda, Masaomi; Kashimura, Kazuo; Inoue, Kazuyuki; Nishioka, Kazuya.

    1979-01-01

    Purpose: To facilitate the construction of a reactor containment building, whereby the inspections of the outer wall of a reactor container after the completion of the construction of the reactor building can be easily carried out. Constitution: In a reactor accommodated in a container encircled by a building wall, a space is provided between the container and the building wall encircling the container, and a metal wall is provided in the space so that it is fitted in the building wall in an attachable or detatchable manner. (Aizawa, K.)

  18. 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 .

  19. A study on the establishment of component/equipment performance criteria considering Heavy Water Reactor characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Keun Sun; Kwon, Young Chul; Lee, Min Kyu; Lee, Yun Soo [Sunmoon Univ., Asan (Korea, Republic of); Chang, Seong Hoong; Ryo, Chang Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of); Kim, Soong Pyung; Hwnag, Jung Rye; Chung, Chul Kee [Chosun Univ., Gwangju (Korea, Republic of)

    2002-03-15

    Foreign and domestic technology trends, regulatory requirements, design and researches for heavy water reactors are analyzed. Safety design guides of Canada industry and regulatory documents and consultative documents of Canada regulatory agency are reviewed. Applicability of MOST guidance 16 Revision 'guidance for technical criteria of nuclear reactor facility' is reviewed. Specific performance criteria are established for components and facilities for heavy water reactor.

  20. Closing CO2 Loop in Biogas Production: Recycling Ammonia As Fertilizer.

    Science.gov (United States)

    He, Qingyao; Yu, Ge; Tu, Te; Yan, Shuiping; Zhang, Yanlin; Zhao, Shuaifei

    2017-08-01

    We propose and demonstrate a novel system for simultaneous ammonia recovery, carbon capture, biogas upgrading, and fertilizer production in biogas production. Biogas slurry pretreatment (adjusting the solution pH, turbidity, and chemical oxygen demand) plays an important role in the system as it significantly affects the performance of ammonia recovery. Vacuum membrane distillation is used to recover ammonia from biogas slurry at various conditions. The ammonia removal efficiency in vacuum membrane distillation is around 75% regardless of the ammonia concentration of the biogas slurry. The recovered ammonia is used for CO 2 absorption to realize simultaneous biogas upgrading and fertilizer generation. CO 2 absorption performance of the recovered ammonia (absorption capacity and rate) is compared with a conventional model absorbent. Theoretical results on biogas upgrading are also provided. After ammonia recovery, the treated biogas slurry has significantly reduced phytotoxicity, improving the applicability for agricultural irrigation. The novel concept demonstrated in this study shows great potential in closing the CO 2 loop in biogas production by recycling ammonia as an absorbent for CO 2 absorption associated with producing fertilizers.

  1. Continuous dry fermentation of swine manure for biogas production

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chuang; Zheng, Dan [Biogas Institute of Ministry of Agriculture, Chengdu 610041 (China); Liu, Gang–Jin [Biogas Institute of Ministry of Agriculture, Chengdu 610041 (China); Bioprocess Control AB, Scheelevägen 22, 223 63 Lund (Sweden); Deng, Liang–Wei, E-mail: dengliangwei@caas.cn [Biogas Institute of Ministry of Agriculture, Chengdu 610041 (China); Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture, Chengdu 610041 (China); Southwest Collaborative Innovation Center of Swine for Quality & Safety, Chengdu 611130 (China); Long, Yan; Fan, Zhan–Hui [Biogas Institute of Ministry of Agriculture, Chengdu 610041 (China)

    2015-04-15

    Highlights: • Continuous dry fermentation of swine manure for biogas production is feasible. • The feedstock TS concentration exerted a significant impact on biogas production. • Influences of ammonia and digestate liquidity were investigated in this study. • The results showed that the feedstock TS of swine manure should not exceed 30%. - Abstract: A down plug-flow anaerobic reactor (DPAR) was designed for the feasibility study on continuous dry fermentation of swine manure without any additional stirring. Using fresh swine manure as the feedstock with TS concentration (w/w) of 20%, 25%, 30%, and 35%, stable volumetric biogas production rates of 2.40, 1.92, 0.911, and 0.644 L·(L d){sup −1} and biogas yields of 0.665, 0.532, 0.252, and 0.178 L g{sup −1}VS were obtained respectively, and the TS degradation rates were 46.5%, 45.4%, 53.2%, and 55.6%, respectively. With the increase of feedstock TS concentration, the concentration of ammonia nitrogen grew up to the maximum value of 3500 mg L{sup −1}. Biogas production was obviously inhibited when the concentration of ammonia nitrogen was above 3000 mg L{sup −1}. The maximal volumetric biogas production rate of 2.34 L·(L d){sup −1} and biogas yield of 0.649 L g{sup −1}VS were obtained with TS concentration of 25% at 25 °C without inhibition. Liquidity experiments showed that TS concentration of digestate could be less than 15.8%, and the flow rate of digestate more than 0.98 m s{sup −1} when the feedstock TS concentration was less than 35%, which indicated the digestate could be easily discharged from a DPAR. Therefore, it is feasible to conduct a continuous dry fermentation in a DPAR using fresh swine manure as the feedstock with TS concentration less than 35%, whereas the feedstock TS concentration should not exceed 30% to achieve the maximal biogas production rate and biogas yield.

  2. Continuous dry fermentation of swine manure for biogas production

    International Nuclear Information System (INIS)

    Chen, Chuang; Zheng, Dan; Liu, Gang–Jin; Deng, Liang–Wei; Long, Yan; Fan, Zhan–Hui

    2015-01-01

    Highlights: • Continuous dry fermentation of swine manure for biogas production is feasible. • The feedstock TS concentration exerted a significant impact on biogas production. • Influences of ammonia and digestate liquidity were investigated in this study. • The results showed that the feedstock TS of swine manure should not exceed 30%. - Abstract: A down plug-flow anaerobic reactor (DPAR) was designed for the feasibility study on continuous dry fermentation of swine manure without any additional stirring. Using fresh swine manure as the feedstock with TS concentration (w/w) of 20%, 25%, 30%, and 35%, stable volumetric biogas production rates of 2.40, 1.92, 0.911, and 0.644 L·(L d) −1 and biogas yields of 0.665, 0.532, 0.252, and 0.178 L g −1 VS were obtained respectively, and the TS degradation rates were 46.5%, 45.4%, 53.2%, and 55.6%, respectively. With the increase of feedstock TS concentration, the concentration of ammonia nitrogen grew up to the maximum value of 3500 mg L −1 . Biogas production was obviously inhibited when the concentration of ammonia nitrogen was above 3000 mg L −1 . The maximal volumetric biogas production rate of 2.34 L·(L d) −1 and biogas yield of 0.649 L g −1 VS were obtained with TS concentration of 25% at 25 °C without inhibition. Liquidity experiments showed that TS concentration of digestate could be less than 15.8%, and the flow rate of digestate more than 0.98 m s −1 when the feedstock TS concentration was less than 35%, which indicated the digestate could be easily discharged from a DPAR. Therefore, it is feasible to conduct a continuous dry fermentation in a DPAR using fresh swine manure as the feedstock with TS concentration less than 35%, whereas the feedstock TS concentration should not exceed 30% to achieve the maximal biogas production rate and biogas yield

  3. Natural attenuation of biogas in landfill covers

    International Nuclear Information System (INIS)

    Cossu, R.; Privato, A.; Raga, R.

    2005-01-01

    In the risk evaluation of uncontrolled biogas emissions from landfills, the process of natural attenuation in landfill covers assumes a very important role. The capacity of biogas oxidation in the cover soils seems to be the most important control to mitigate the biogas emission during the aftercare period when the biogas collection system might fail. In the present paper laboratory experiences on lab columns to study the biogas oxidation are discussed [it

  4. Effect of increasing nitrobenzene loading rates on the performance of anaerobic migrating blanket reactor and sequential anaerobic migrating blanket reactor/completely stirred tank reactor system

    International Nuclear Information System (INIS)

    Kuscu, Ozlem Selcuk; Sponza, Delia Teresa

    2009-01-01

    A laboratory scale anaerobic migrating blanket reactor (AMBR) reactor was operated at nitrobenzene (NB) loading rates increasing from 3.33 to 66.67 g NB/m 3 day and at a constant hydraulic retention time (HRT) of 6 days to observe the effects of increasing NB concentrations on chemical oxygen demand (COD), NB removal efficiencies, bicarbonate alkalinity, volatile fatty acid (VFA) accumulation and methane gas percentage. Moreover, the effect of an aerobic completely stirred tank reactor (CSTR) reactor, following the anaerobic reactor, on treatment efficiencies was also investigated. Approximately 91-94% COD removal efficiencies were observed up to a NB loading rate of 30.00 g/m 3 day in the AMBR reactor. The COD removal efficiencies decreased from 91% to 85% at a NB loading rate of 66.67 g/m 3 day. NB removal efficiencies were approximately 100% at all NB loading rates. The maximum total gas, methane gas productions and methane percentage were found to be 4.1, 2.6 l/day and 59%, respectively, at a NB loading rate of 30.00 g/m 3 day. The optimum pH values were found to be between 7.2 and 8.4 for maximum methanogenesis. The total volatile fatty acid (TVFA) concentrations in the effluent were 110 and 70 mg/l in the first and second compartments at NB loading rates as high as 66.67 and 6.67 g/m 3 day, respectively, while they were measured as zero in the effluent of the AMBR reactor. In this study, from 180 mg/l NB 66 mg/l aniline was produced in the anaerobic reactor while aniline was completely removed and transformed to 2 mg/l of cathechol in the aerobic CSTR reactor. Overall COD removal efficiencies were found to be 95% and 99% for NB loading rates of 3.33 and 66.67 g/m 3 day in the sequential anaerobic AMBR/aerobic CSTR reactor system, respectively. The toxicity tests performed with Photobacterium phosphoreum (LCK 480, LUMIStox) and Daphnia magna showed that the toxicity decreased with anaerobic/aerobic sequential reactor system from the influent, anaerobic and to

  5. Optimization of Methane Gas Formation Rate with The Addition of EM4 Starter-made from Tofu Liquid Waste and Husk Rice Waste Using Biogas Reactor-Fixed Dome in Langensari West Ungaran

    Directory of Open Access Journals (Sweden)

    Arifan Fahmi

    2018-01-01

    Full Text Available Indonesia is a country that has abundant energy resources, namely oil, gas, coal, geothermal, and so forth. Biogas is an alternative fuel that can be used as a substitute for primary fuel. The term biogas is already familiar to the people, it is because biogas has usefulness as a vehicle fuel, domestic (cooking, and generate electricity. Cow dung has a value of C / N ratio is large enough that 18. Rice husk has a C / N ratio is sufficient High temperatures of 38.9. EM-4 (effective microorganism is a bacterial culture which is usually used as an activator. In the manufacture of biogas from waste fluids out and chaff has the advantage because the content of the C / N is high enough. The composition of the raw materials used are liquid wastes out of 5 kg and 1 kg of husk-em with the addition of 4500 ml and the resulting calorific value of 1047.9 A fermentation time for 9 days. Ph maintained in neutral or alkaline conditions, namely 7-7.5, because the effectiveness of the methane formation is highly dependent on pH wherein the microorganism will grow and thrive in neutral. The test results has been done is the color of the flame and the time at yield is good enough where the color of the flame produced at day to9 blue with time for 40 seconds.

  6. Optimization of Methane Gas Formation Rate with The Addition of EM4 Starter-made from Tofu Liquid Waste and Husk Rice Waste Using Biogas Reactor-Fixed Dome in Langensari West Ungaran

    Science.gov (United States)

    Arifan, Fahmi; Muhammad, Fuad; Winarni, Sri; Rama Devara, Hafizh; Hanum, Latifah

    2018-02-01

    Indonesia is a country that has abundant energy resources, namely oil, gas, coal, geothermal, and so forth. Biogas is an alternative fuel that can be used as a substitute for primary fuel. The term biogas is already familiar to the people, it is because biogas has usefulness as a vehicle fuel, domestic (cooking), and generate electricity. Cow dung has a value of C / N ratio is large enough that 18. Rice husk has a C / N ratio is sufficient High temperatures of 38.9. EM-4 (effective microorganism) is a bacterial culture which is usually used as an activator. In the manufacture of biogas from waste fluids out and chaff has the advantage because the content of the C / N is high enough. The composition of the raw materials used are liquid wastes out of 5 kg and 1 kg of husk-em with the addition of 4500 ml and the resulting calorific value of 1047.9 A fermentation time for 9 days. Ph maintained in neutral or alkaline conditions, namely 7-7.5, because the effectiveness of the methane formation is highly dependent on pH wherein the microorganism will grow and thrive in neutral. The test results has been done is the color of the flame and the time at yield is good enough where the color of the flame produced at day to9 blue with time for 40 seconds.

  7. Modified-open fuel cycle performance with breed-and-burn advanced reactor concepts

    International Nuclear Information System (INIS)

    Heidet, Florent; Kim, Taek K.; Taiwo, Temitope A.

    2011-01-01

    Recent advances in fast reactor designs enable significant increase in the uranium utilization in an advanced fuel cycle. The category of fast reactors, collectively termed breed-and-burn reactor concepts, can use a large amount of depleted uranium as fuel without requiring enrichment with the exception of the initial core critical loading. Among those advanced concepts, some are foreseen to operate within a once-through fuel cycle such as the Traveling Wave Reactor, CANDLE reactor or Ultra-Long Life Fast Reactor, while others are intended to operate within a modified-open fuel cycle, such as the Breed-and-Burn reactor and the Energy Multiplier Module. This study assesses and compares the performance of the latter category of breed-and-burn reactors at equilibrium state. It is found that the two reactor concepts operating within a modified-open fuel cycle can significantly improve the sustainability and security of the nuclear fuel cycle by decreasing the uranium resources and enrichment requirements even further than the breed-and-burn core concepts operating within the once-through fuel cycle. Their waste characteristics per unit of energy are also found to be favorable, compared to that of currently operating PWRs. However, a number of feasibility issues need to be addressed in order to enable deployment of these breed-and-burn reactor concepts. (author)

  8. 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.)

  9. Economic performance of liquid-metal fast breeder reactor and gas-cooled fast reactor radial blankets

    International Nuclear Information System (INIS)

    Tsoulfanidis, N.; Jankhah, M.H.

    1979-01-01

    The economic performance of the radial blanket of a liquid-metal fast breeder reactor (LMFBR) and a gas-cooled fast reactor (GCFR) has been studied based on the calculation of the net financial gain as well as the value of the levelized fuel cost. The necessary reactor physics calculations have been performed using the code CITATION, and the economic analysis has been carried out with the code ECOBLAN, which has been written for that purpose. The residence time of fuel in the blanket is the main variable of the economic analysis. Other parameters that affect the results and that have been considered are the value of plutonium, the price of heat, the effective cost of money, and the holdup time of the spent fuel before reprocessing. The results show that the radial blanket of both reactors is a producer of net positive income for a broad range of values of the parameters mentioned above. The position of the fuel in the blanket and the fuel management scheme applied affect the monetary gain. There is no significant difference between the economic performance of the blanket of an LMFBR and a GCFR

  10. 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

  11. Recent performance experience with US light water reactor self-actuating safety and relief valves

    Energy Technology Data Exchange (ETDEWEB)

    Hammer, C.G.

    1996-12-01

    Over the past several years, there have been a number of operating reactor events involving performance of primary and secondary safety and relief valves in U.S. Light Water Reactors. There are several different types of safety and relief valves installed for overpressure protection of various safety systems throughout a typical nuclear power plant. The following discussion is limited to those valves in the reactor coolant systems (RCS) and main steam systems of pressurized water reactors (PWR) and in the RCS of boiling water reactors (BWR), all of which are self-actuating having a setpoint controlled by a spring-loaded disk acting against system fluid pressure. The following discussion relates some of the significant recent experience involving operating reactor events or various testing data. Some of the more unusual and interesting operating events or test data involving some of these designs are included, in addition to some involving a number of similar events and those which have generic applicability.

  12. Performance Testing of Hydrodesulfurization Catalysts Using a Single-Pellet-String Reactor

    NARCIS (Netherlands)

    Moonen, Roel; Ras, Erik Jan; Harvey, Clare; Alles, Jeroen; Moulijn, J.A.

    2017-01-01

    Small-scale parallel trickle-bed reactors were used to evaluate the performance of a commercial hydrodesulfurization catalyst under industrially relevant conditions. Catalyst extrudates were loaded as a single string in reactor tubes. It is demonstrated that product sulfur levels and densities

  13. Internalizing the external costs of biogas supply chains in the Italian energy sector

    International Nuclear Information System (INIS)

    Patrizio, P.; Leduc, S.; Chinese, D.; Kraxner, F.

    2017-01-01

    In Italy biogas support schemes are being revised to include subsidies for the production of biomethane. Energy policies should foster environmentally optimal solutions, especially because social acceptance issues often arise in the case of biogas. In this paper we use the external cost methodology to quantify the environmental impact of airborne emissions associated with biogas-based energy vectors and their corresponding fossil substitutes These are evaluated at supply chain level and incorporated in a spatially explicit optimization model. The method is applied to northern Italy to compare the potential impact of alternative policy options. It is found that, while the external costs of biogas-based pathways are always lower than corresponding fossil fuel based pathways, the differences are generally so small that policies based on internalization of external costs alone would not lead to further development of biogas-based technologies. For all utilization pathways, consideration of local externalities leads to a less favourable evaluation of biogas-based technologies, which results in external costs even higher than the substituted fossil fuel if biogas is allocated to local heating. - Highlights: • A MILP model has been developed to optimize the economic and environmental performance of the biogas supply chain. • The external costs methodology has been included in the optimization process. • The emissions of the most relevant pollutants generated along the supply chain have been included in the assessment. • Different biogas utilization pathways have been considered.

  14. Estimation of biogas and methane yields in an UASB treating potato starch processing wastewater with backpropagation artificial neural network.

    Science.gov (United States)

    Antwi, Philip; Li, Jianzheng; Boadi, Portia Opoku; Meng, Jia; Shi, En; Deng, Kaiwen; Bondinuba, Francis Kwesi

    2017-03-01

    Three-layered feedforward backpropagation (BP) artificial neural networks (ANN) and multiple nonlinear regression (MnLR) models were developed to estimate biogas and methane yield in an upflow anaerobic sludge blanket (UASB) reactor treating potato starch processing wastewater (PSPW). Anaerobic process parameters were optimized to identify their importance on methanation. pH, total chemical oxygen demand, ammonium, alkalinity, total Kjeldahl nitrogen, total phosphorus, volatile fatty acids and hydraulic retention time selected based on principal component analysis were used as input variables, whiles biogas and methane yield were employed as target variables. Quasi-Newton method and conjugate gradient backpropagation algorithms were best among eleven training algorithms. Coefficient of determination (R 2 ) of the BP-ANN reached 98.72% and 97.93% whiles MnLR model attained 93.9% and 91.08% for biogas and methane yield, respectively. Compared with the MnLR model, BP-ANN model demonstrated significant performance, suggesting possible control of the anaerobic digestion process with the BP-ANN model. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. The Finnish biogas register no 16. Information compiled from 2012; Suomen biokaasulaitosrekisteri n:o 16. Tiedot vuodelta 2012

    Energy Technology Data Exchange (ETDEWEB)

    Huttunen, M.; Kuittinen, V.

    2013-11-01

    In Finland altogether 16 biogas reactor plants have been in operation at different municipal wastewater treatment plants by the end of 2012. Industrial wastewaters were treated anaerobically at three different plants. Farm-scale biogas plants were operating at 10 places. Municipal solid wastes were treated at 10 biogas plants. In 2012, the amount of biogas produced by the reactor installations was 55.9 million m{sup 3} and the combustion of surplus