WorldWideScience

Sample records for biogas reactor performance

  1. 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

    . 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......Background The microbial community in a biogas reactor greatly influences the process performance. However, only the effects of deterministic factors (such as temperature and hydraulic retention time (HRT)) on the microbial community and performance have been investigated in biogas reactors. Little...... is known about the manner in which stochastic factors (for example, stochastic birth, death, colonization, and extinction) and disturbance affect the stable-state microbial community and reactor performances. Results In the present study, three replicate biogas reactors treating cattle manure were...

  2. 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 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...... against Methanothrix soehngenii or Methanothrix CALS-I in any of the thermophilic biogas reactors examined. Studies using 2-14C-labeled acetate showed that at high concentrations (more than approx. 1 mM) acetate was metabolized via the aceticlastic pathway, transforming the methyl-group of acetate...

  3. Multifeed biogas reactor for coffee waste water and biomass wastes : performance under highly fluctuating operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Chanakya, H.N.; Deepa, G.B.; Vinutha, D. [Indian Inst. of Science, Bangalore (India). Centre for Sustainable Technologies; Modak, J.M. [Indian Inst. of Science, Bangalore (India). Dept. of Chemical Engineering

    2004-07-01

    This study compared different operating conditions used in anaerobic digestion processes that convert coffee effluents into biogas. The effluent from wet coffee processing is rich in saccharide. In India, coffee processing is carried out at small to medium sized plantations which do not have the adequate facilities to treat the effluent for biogas recovery. Rather, the wastewater is treated in anaerobic-aerobic lagoons, but this process releases large quantities of methane to the atmosphere. More efficient alternatives are needed to stabilize the operating conditions, concentrations of wastewater and ambient operating temperatures. This study tested a newly developed multi-feed anaerobic reactor that can covert herbaceous biomass and coffee effluent to biogas and compost. The reactor is fed herbaceous biomass feedstock during the 8 month period when there is no coffee processing. Coffee effluent is fed to the reactor during the 4 month coffee processing season. The effluent flows through partially decomposed biomass beds where methanogenic activities yield a biofilm to facilitate conversion to biogas. The seasonal operation can be transformed into a year round advantage. The method can be applied to similar agro-processing units. 6 refs., 3 tabs., 5 figs.

  4. 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

    A new method for simultaneous coke oven gas (COG) biomethanation and in situ biogas upgrading in anaerobic reactor was developed in this study. The simulated coke oven gas (SCOG) (92% H2 and 8% CO) was injected directly into the anaerobic reactor treating sewage sludge through hollow fiber membrane...... (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...

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

    Science.gov (United States)

    Wang, Wen; Xie, Li; Luo, Gang; Zhou, Qi; Angelidaki, Irini

    2013-10-01

    A new method for simultaneous coke oven gas (COG) biomethanation and in situ biogas upgrading in anaerobic reactor was developed in this study. The simulated coke oven gas (SCOG) (92% H2 and 8% CO) was injected directly into the anaerobic reactor treating sewage sludge through hollow fiber membrane (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 and hydrogenotrophic genus Methanoculleus in the liquid, which indicated that H2 were converted to methane by both direct (hydrogenotrophic methanogenesis) and indirect (homoacetogenesis+aceticlastic methanogenesis) pathways in the liquid. However, the aceticlasitic genus Methanosaeta was dominant for archaea in the biofilm on the HFM, which indicated indirect (homoacetogenesis+aceticlastic methanogenesis) H2 conversion pathway on the biofilm. PMID:23941705

  6. 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

  7. Experimental Investigation of Biogas Reforming in Gliding Arc Plasma Reactors

    Directory of Open Access Journals (Sweden)

    P. Thanompongchart

    2014-01-01

    Full Text Available Biogas is an important renewable energy source. Its utilization is restricted to vicinity of farm areas, unless pipeline networks or compression facilities are established. Alternatively, biogas may be upgraded into synthetic gas via reforming reaction. In this work, plasma assisted reforming of biogas was investigated. A laboratory gliding arc plasma setup was developed. Effects of CH4/CO2 ratio (1, 2.33, 9, feed flow rate (16.67–83.33 cm3/s, power input (100–600 W, number of reactor, and air addition (0–60% v/v on process performances in terms of yield, selectivity, conversion, and energy consumption were investigated. High power inputs and long reaction time from low flow rates, or use of two cascade reactors were found to promote dry reforming of biogas. High H2 and CO yields can be obtained at low energy consumption. Presence of air enabled partial oxidation reforming that produced higher CH4 conversion, compared to purely dry CO2 reforming process.

  8. 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...

  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)

    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)

  10. 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.; Sales-Cruz, Alfonso Mauricio; Gani, Rafiqul; Ahring, Birgitte Kiær

    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 an...... improved removal of the volatile solids (VS). The properties of microbial communities of both reactors were analysed. The specific methanogenic activity (SMA) test showed that both biomasses had significant activity towards hydrogen and formate, while the activity with the VFA - acetate, propionate and...

  11. 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;

    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......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...

  12. Microbial analysis in biogas reactors suffering by foaming incidents

    DEFF Research Database (Denmark)

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

    2014-01-01

    Foam formation can lead to total failure of digestion process in biogas plants. In the present study, possible correlation between foaming and the presence of specific microorganisms in biogas reactors was elucidated. The microbial ecology of continuous fed digesters overloaded with proteins......, or decrease the surface tension of the media, increased their relative abundance after foam formation. Finally, a microorganism similar to widely known foaming bacteria (Nocardia and Desulfotomaculum) was found to increase its relative abundance in all reactors once foam was observed, regardless of the used...

  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

    and lipids. Spatial microbial distribution and activity was studied in digested materials fractionated into size of particles > 200 mum, 50-200 mum and 0.45-50 mum. With manure, the main pool of methanogenic activity from propionate, butyrate and hydrogen was associated with the particles > 200 mum......, while the activity of acetotrophic methanogens was uniformly distributed in all fractions. When digesting manure and lipids, an enhanced methanogenesis was detected both for particles > 200 mum and the 50-200 mum fraction. The molecular methods -temperature gradient gel electrophoresis (TGGE), cloning...... library and sequencing of 16S rDNA - showed presence of a restricted number of archaeal species in both reactors. The vast majority of clones was phylogenetically most closely related to Methanosarcina siciliae....

  14. 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...... more efficient in reducing foam when added directly into the liquid phase rather than added in the headspace of the reactor....

  15. Performance evaluation and effect of biogas circulation rate of a bubble column for biological desulfurization.

    Science.gov (United States)

    Kobayashi, Takuro; Xu, Kai-Qin; Li, Yu-You; Inamori, Yuhei

    2012-01-01

    Biological desulfurization using a bubble column reactor was investigated in a continuous biogas treatment. Rapid biogas circulation between the digester and the bubble column for biological desulfurization was used to stimulate the gas-liquid mass transfer of H(2)S. A positive correlation between the biogas circulation rate and H(2)S removal rate was observed. Moreover, the increase in the circulation rate stimulated the O(2) mass transfer, eventually translating into an increase in sulfate production from the oxidation of H(2)S. Throughout the continuous experiment, the reactor retained sufficient levels of sulfide-oxidizing bacteria. A comparison of the results of the continuous biogas treatment and batch tests suggests that the gas-liquid mass transfer rate of H(2)S was the rate-limiting step in the biological desulfurization in the reactor, indicating that the mass transfer efficiency of H(2)S needs to be improved to enhance the desulfurization performance. PMID:22925864

  16. 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

    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 PCR–DGGE. Nonetheless, they all belonged to the order Methanobacteriales, which can mediate hydrogenotrophic methanogenesis. Biogas upgrading was then tested in a thermophilic anaerobic reactor under various operation conditions. By continuous addition of hydrogen in the biogas reactor, high degree......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...

  17. 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.

  18. Performance optimization of the Växtkraft biogas production plant

    International Nuclear Information System (INIS)

    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 N2O from the fertilized soil is dependent on the soil type and spreading technology.

  19. 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....

  20. 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.

  1. 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 methanogenic spp. and their activity. In biofilm systems, such as the UASB reactors the presence of the two aceticlastic methanogens could be correlated to the difference in the kinetic properties of the two species. In biogas reactors treating solid wastes, such as manure or mixture of manure and organic...... industrial waste, only Methanosarcina spp. were identified.Methanosarcina spp. isolated from different plants had different kinetics depending on their origin. Relating the reactor performance data to measurement of the activity by conventional microbiological methods gave a good indication of the microbial...

  2. 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...... plants face an increasing necessity in finding efficient and cost-effective antifoaming solutions to avoid the dramatic consequences of foaming incidents. One of the most common solutions to suppress foaming is the use of chemical defoamers. The present work is a mini-review summarizing the aggregated...... 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...

  3. Influence of the biogas reburning for reducing nitric oxide emissions in an alundum-tube reactor

    Science.gov (United States)

    Zhao, Jie; Wang, Qingcheng; Yu, Lihui; Wu, Liyan

    2016-05-01

    The experimental study on reburning reduction reaction between biogas and NO is very important in de-NOx technology. The reburning experiments by the simulated biogas with different operation variables have been performed in an alundum-tube reactor. Results showed that the uppermost constituent in NO-reduction was CH4, H2 second, and NO-reduction by CO in biogas reburning was negligible at the same conditions. In the condition of oxygen-poor, H2 could promote CH4 oxidation and enhance the concentration of CH3 radicals, thereby increasing the reduction efficiency of NO accordingly. At the same temperature, with the increase of stoichiometric ratio, it would increase O radicals and decrease NO reduction efficiency. With the increase of reaction temperature, the reduction efficiency behaved a trend of first increased then decreased at the same stoichiometric ratio, and obtained the maximum value 51.38% at the condition of 1200 °C and λ = 0.6. Additionally, increasing the NO input concentration also could improve the reduction efficiency under the condition of fuel-rich.

  4. Influence of the biogas reburning for reducing nitric oxide emissions in an alundum-tube reactor

    Science.gov (United States)

    Zhao, Jie; Wang, Qingcheng; Yu, Lihui; Wu, Liyan

    2016-05-01

    The experimental study on reburning reduction reaction between biogas and NO is very important in de-NOx technology. The reburning experiments by the simulated biogas with different operation variables have been performed in an alundum-tube reactor. Results showed that the uppermost constituent in NO-reduction was CH4, H2 second, and NO-reduction by CO in biogas reburning was negligible at the same conditions. In the condition of oxygen-poor, H2 could promote CH4 oxidation and enhance the concentration of CH3 radicals, thereby increasing the reduction efficiency of NO accordingly. At the same temperature, with the increase of stoichiometric ratio, it would increase O radicals and decrease NO reduction efficiency. With the increase of reaction temperature, the reduction efficiency behaved a trend of first increased then decreased at the same stoichiometric ratio, and obtained the maximum value 51.38% at the condition of 1200 °C and λ = 0.6. Additionally, increasing the NO input concentration also could improve the reduction efficiency under the condition of fuel-rich.

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

    DEFF Research Database (Denmark)

    Luo, Gang; Johansson, Sara; Boe, Kanokwan;

    2011-01-01

    mixing intensity (shaking speed 300 rpm). Continuous addition of hydrogen (flow rate of 28.6 mL/(L/h)) to an anaerobic reactor fed with manure, showed that more than 80% of the hydrogen was utilized. The propionate and butyrate level in the reactor was not significantly affected by the hydrogen addition......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....... 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...

  6. 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. PMID:25978353

  7. 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...... 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...

  8. Start-up of semi-continously operated and completely stirred dry fermentation pilot-scale biogas reactor

    OpenAIRE

    Virkkunen, Elina

    2009-01-01

    In the year 2008, MTT Agrifood Research Finland built a pilot scale biogas reactor of 4.5 cubic meters situated in Sotkamo research station. The aim is to develop a completely stirred and semi-continuously operated biogas reactor that handles solid biomass.

  9. Comparative microbial analysis before and after foaming incidents in biogas reactors

    DEFF Research Database (Denmark)

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

    2014-01-01

    /or in the pre-storage feeding tank, resulting in 30-50% biogas production loss (Kougias et al., 2014). In activated sludge systems and in wastewater treatment plants the major causes of foaming are organic overload, the presence of surface active agents, operational parameters (e.g. digester’s shape......Foaming is one of the major problems that occasionally occurring in biogas plants affecting negatively the overall anaerobic digestion (AD) process. According to a recent survey, 15 out of 16 full-scale biogas plants, which were surveyed in Denmark, faced foaming incidents in the main reactor and...... extraction and metagenomic analysis. After sampling, the feedstock composition of each reactor was changed by the addition of gelatine or Na-Oleate or glucose (second experimental period). As a consequence, foam formation was observed in all reactors approximately after one HRT period. Once the daily volume...

  10. 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...... that barley contributes in stabilization of beer foam due to the activity of one of its proteins (Brey et al., 2003). For that reason, it could be hypothesised that the existence of barley particles in our reactors could contribute in foaming although their presence was also prior to the foaming...

  11. 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......%). Bacteroides, Acetobacterium and Pseudomonas genera had difficulties in the assignment, gathering medium-low probability as well (1 to 50%). On the contrary several other genera were assigned with high probability and no multiple matches. Some of them including only one species uniquely identified, some other...

  12. Start-up and Performance of a Novel Reactor-Jet Biogas Inter-loop Anaerobic Fluidized Bed%一种新型反应器——生物气射流循环厌氧流化床的启动与运行特性

    Institute of Scientific and Technical Information of China (English)

    邓志毅; 韦朝海; 周秀峰

    2008-01-01

    A novel anaerobic reactor, jet biogas inter-loop anaerobic fluidized bed (JBILAFB), was designed and constructed. The start-up and performance of the reactor was investigated in the process of artificial glucose waste-water treatment. With the wastewater recycle ratio of 2.5:1, the recycled wastewater with biogas could mix sludge and wastewater in the JBILAFB reactor completely. The start-up of the JBILAFB reactor could be completed in less than 70 d through maintenance of hydraulic retention time (HRT) and stepwise increase of feed total organic carbon (TOC) concentration. After the start-up, with the volumetric TOC loadings of 14.3 kg·m-3·d-1 the TOC removal ra-tio, the effluent pH, and the volatile fatty acids (VFA)/alkalinity of the JBILAFB reactor were more than 80%, close to 7.0 and less than 0.4, respectively. Moreover, CH4 was produced at more than 70% of the theoretical value. The reactor exhibited high stability under the condition of high volumetric TOC loading. Sludge granules in the JBI-LAFB reactor were developed during the start-up and their sizes were enlarged with the stepwise increase of volu-metric TOC loadings from 0.8 kg·m-3·d-1 to 14.3 kg·m-3·d-1. Granules, an offwhite color and a similar spherical shape, were mainly comprised of global-like bacteria. These had good methanogenic activity and settleability,which were formed probably through adhesion of the bacteria. Some inorganic metal compounds such as Fe, Ca,Mg, Al, etc. were advantageous to the formation of the granules.

  13. Contribution to valuation and dimensioning of biogas reactors which use substratum-biofilm systems

    International Nuclear Information System (INIS)

    The study develops an algorithm for valuating static substratum - biofilm systems used in biogas reactors. This valuation method permits coupling the service value of static substratum - biofilm systems as derived from individual quality factors with the costs of the substratum. Beyond this the cost-related value thus obtained is of principle value for comparing different variants. (orig.)

  14. Start-up strategies in manure-fed biogas reactors: Process parameters and methanogenic communities

    International Nuclear Information System (INIS)

    Four start-up strategies were assayed in 75 dm3 continuous stirred-tank reactors to select the optimal conditions for the start-up of the demonstration BIO4GAS® plant. Two reactors were completely filled with manure and their temperature increased from 20 to 37 °C at either a slow or fast rate. The other two reactors were started at 37 °C with a seed sludge from a stably operating plant and their load (cattle manure) increased at a low or high rate. Reactor performance was monitored for 35 days. The composition and abundance of the methanogenic communities was determined using a phylogenetic microarray and quantitative PCR. All reactors performed successfully in terms of biogas production and experienced a steady start-up, with pH values above 7.3 and VFA/alkalinity ratios below 0.3, denoting stability. Similar methanogenic loads (averaging 5 × 107 g-1 of 16S rRNA gene copies) were detected in the cattle manure and seed sludge, however the methanogenic diversity was higher in the manure with dominance of Methanosarcina and subdominance of Methanocorpusculum and Methanobrevibacter. Starting-up the reactors with an initial full load of manure and progressively increasing the temperature entailed less changes in the sludge chemical environment and in the dynamics of the dominant methanogens. Using a rate of temperature increase of 0.61 K d−1 proved better than1.21 K d−1 with a methane yield of 103.8 dm3 kg−1 VS and a COD mass removal efficiency of 28.3%. The diverse methanogenic community in the manure easily adapted to reactor upsets due to forced overload conditions. - Highlights: • Cattle manure holds abundant and diverse methanogenic communities. • CSTRs can be started up without seed, but manure and a slow temperature rise. • This warrants a smooth start-up in terms of performance and community dynamics. • Methanogenic communities in such reactors withstand upsets due to overload conditions

  15. 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)

  16. 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.

  17. 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.)

  18. 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; Campanaro, Stefano; Angelidaki, Irini

    2015-01-01

    The anaerobic digestion process is often inhibited by alteration of substrates and/or organic overload. This study aimed to elucidate changes of microbial ecology in biogas reactors upon radical changes of substrates and to determine their importance to process imbalance. For this reason......, continuously fed reactors were disturbed with pulses of proteins, lipids and carbohydrates and the microbial ecology of the reactors were characterized by 16S rRNA gene sequencing before and after the imposed changes. The microbial composition of the three reactors, initially similar, diverged greatly after...... 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. The...

  19. Modeling and simulation of a biogas reactor; Modellierung und Simulation eines Biogasreaktors

    Energy Technology Data Exchange (ETDEWEB)

    Muha, Ivo

    2012-11-22

    The anaerobic fermentation describes the decomposition of organic material in the absence of oxygen and consists four phases of the process (hydrolysis, acidogenesis, acetogenesis and methanogenesis). In this work, the distribution of these four phases of the process could be determined exactly on both stages of a two-stage two-phase biogas reactor. The distribution is of crucial importance for future work, as this can be determined exactly which substances must be taken into account in the measurements and in the modeling. In 2002, the IWA Task Group published the ADM1 model, which takes into account all four process stages of anaerobic fermentation. In the present work, a spatially resolved model for the anaerobic fermentation is developed, in which the ADM1 model is coupled with a flow model. Subsequently, a reduced simulation model for acetoclastic methanogenesis in a two-stage two-phase biogas reactor is created. Based on measurement data the decomposition of methane to acetic acid in the reactor by the simulation model can be reproduced well. Subsequently, the validated model is used to affiliate rules for optimal control of the reactor and furthermore, the efficiency of the reactor is determined by the local production of methane. The information obtained can be used to optimize the biogas reactor. [German] Die anaerobe Fermentation beschreibt den Abbau organischen Materials unter Ausschluss von Sauerstoff und setzt sich aus vier Prozessphasen (Hydrolyse, Acidogenese, Acetogenese und Methanogenese) zusammen. Im Rahmen dieser Arbeit konnte die Aufteilung dieser vier Prozessphasen auf die beiden Stufen eines zweistufigen zweiphasigen Biogas-Reaktors genau bestimmt werden. Die Aufteilung ist von entscheidender Bedeutung fuer zukuenftige Arbeiten, da dadurch genau festgelegt werden kann, welche Stoffe bei den Messungen und bei der Modellierung beruecksichtigt werden muessen. Im Jahre 2002 wurde von der IWA Taskgroup das ADM1-Modell, welches alle vier

  20. Biogas-utilizing nitrogen removal with a semi-partitioned reactor

    Energy Technology Data Exchange (ETDEWEB)

    Waki, M.; Suzuki, K.; Tanaka, Y. [National Inst. of Livestock and Grassland Science, Tsukuba, Ibaraki (Japan). Dept. of Livestock Industry Environment; Osada, T. [National Agricultural Research Center for Hokkaido Region, Sapporo, Hokkaido (Japan). Research Team for Harmony with Environment; Ike, M.; Fujita, M. [Osaka Univ., Osaka (Japan). Dept. of Environmental Engineering

    2004-07-01

    This paper presents a newly developed reactor to remove nitrogen using methane. This pilot study examined the feasibility of using such a reactor with swine wastewater. Denitrification of methane requires methane (CH{sub 4}) and oxygen (O{sub 2}). The problem is that the reactor off-gases contains both these gases in mixture, therefore, they are not usable as energy sources. A semi-partitioned reactor (SPR) was designed to discharge off-gases containing a high-concentration methane that can be used as energy. The partitioned headspace in the SPR extended partly into the liquid layer. The methane and oxygen were supplied separately to the liquid layer on the other side of the partition. The in flowing fluid was swine wastewater, the methane source was the biogas produced in the reactor and air was the oxygen source. During the 6 month pilot study, nitrogen was removed at an average rate of 0.11 kg N/m{sup 3} of wastewater. The methane concentration in off-gas was high enough to generate electricity. Adsorption removed hydrogen sulfide from the biogas. Nitrogen oxides were contained in off-gas from the reactor. 5 refs., 6 figs.

  1. Characteristics and biogas production potential of municipal solid wastes pretreated with a rotary drum reactor.

    Science.gov (United States)

    Zhu, Baoning; Gikas, Petros; Zhang, Ruihong; Lord, James; Jenkins, Bryan; Li, Xiujin

    2009-02-01

    This study was conducted to determine the characteristics and biogas production potential of organic materials separated from municipal solid wastes using a rotary drum reactor (RDR) process. Four different types of wastes were first pretreated with a commercial RDR system at different retention times (1, 2 and 3 d) and the organic fractions were tested with batch anaerobic digesters with 2.6 g VS L(-1) initial loading. The four types of waste were: municipal solid waste (MSW), a mixture of MSW and paper waste, a mixture of MSW and biosolids, and a mixture of paper and biosolids. After 20 d of thermophilic digestion (50+/-1 degrees C), it was found that the biogas yields of the above materials were in the range of 457-557 mL g VS(-1) and the biogas contained 57.3-60.6% methane. The total solid and volatile solid reductions ranged from 50.2% to 65.0% and 51.8% to 66.8%, respectively. For each material, the change of retention time in the RDR from 1 to 3d did not show significant (alpha=0.05) influence on the biogas yields of the recovered organic materials. Further studies are needed to determine the minimum retention time requirements in the RDR system to achieve effective separation of organic from inorganic materials and produce suitable feedstock for anaerobic digesters. PMID:18849162

  2. Identical full-scale biogas-lift reactors (Blrs) with anaerobic granular sludge and residual activated sludge for brewery wastewater treatment and kinetic modeling.

    Science.gov (United States)

    Xu, Fu; Huang, Zhenxing; Miao, Hengfeng; Ren, Hongyan; Zhao, Mingxing; Ruan, Wenquan

    2013-10-01

    Two identical full-scale biogas-lift reactors treating brewery wastewater were inoculated with different types of sludge to compare their operational conditions, sludge characteristics, and kinetic models at a mesophilic temperature. One reactor (R1) started up with anaerobic granular sludge in 12 weeks and obtained a continuously average organic loading rate (OLR) of 7.4 kg chemical oxygen demand (COD)/(m3 x day), COD removal efficiency of 80%, and effluent COD of 450 mg/L. The other reactor (R2) started up with residual activated sludge in 30 weeks and granulation accomplished when the reactor reached an average OLR of 8.3 kg COD/(m3 x day), COD removal efficiency of 90%, and effluent COD of 240 mg/L. Differences in sludge characteristics, biogas compositions, and biogas-lift processes may be accounted for the superior efficiency of the treatment performance of R2 over R1. Grau second-order and modified StoverKincannon models based on influent and effluent concentrations as well as hydraulic retention time were successfully used to develop kinetic parameters of the experimental data with high correlation coefficients (R2 > 0.95), which further showed that R2 had higher treatment performance than R1. These results demonstrated that residual activated sludge could be used effectively instead of anaerobic granular sludge despite the need for a longer time. PMID:24494489

  3. Biogas quality upgrade by simultaneous removal of CO2 and H2S in a packed column reactor

    International Nuclear Information System (INIS)

    Biogas from anaerobic digestion of biological wastes is a renewable energy resource. It has been used to provide heat, shaft power and electricity. Typical biogas contains 50-65% methane (CH4), 30-45% carbon dioxide (CO2), moisture and traces of hydrogen sulphide (H2S). Presence of CO2 and H2S in biogas affects engine performance adversely. Reducing CO2 and H2S content will significantly improve quality of biogas. In this work, a method for biogas scrubbing and CH4 enrichment is presented. Chemical absorption of CO2 and H2S by aqueous solutions in a packed column was experimentally investigated. The aqueous solutions employed were sodium hydroxide (NaOH), calcium hydroxide (Ca(OH)2) and mono-ethanolamine (MEA). Liquid solvents were circulated through the column, contacting the biogas in countercurrent flow. Absorption characteristics were examined. Test results revealed that the aqueous solutions used were effective in reacting with CO2 in biogas (over 90% removal efficiency), creating CH4 enriched fuel. H2S was removed to below the detection limit. Absorption capability was transient in nature. Saturation was reached in about 50 min for Ca(OH)2, and 100 min for NaOH and MEA, respectively. With regular replacement or regeneration of used solutions, upgraded biogas can be maintained. This technique proved to be promising in upgrading biogas quality.

  4. 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)

    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 m3/d to 3284 m3/d) depending on site factors such as pond efficiency, pond configuration and operational practices

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

    Science.gov (United States)

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

    2016-06-01

    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. PMID:26585859

  6. RESEARCHES ON THE DIGESTERS AND REACTORS WHICH CAN BE USED IN A FARM SCALE BIOGAS PLANT

    Directory of Open Access Journals (Sweden)

    Mariana DUMITRU

    2014-10-01

    Full Text Available In the general context of searching integrated system of renewable energy production, this paper present some researches on the reactors and the digesters, as a main part of a biogas plant at a farm scale. After we present the most used types of digesters, we also concentrated over the processes which take place into a digester, one of them being the removal of H2S from biogas (desulphurisation, which can be made by various methods, either biological or chemical, taking place inside or outside the digester. In the case of biological desulphurization outside the digester, we concentrate on the types of reactors which can be used in this case. Beside the well known types of reactors, we present the possibility of using an original self pressure membrane bioreactor. In this type of bioreactor, the metabolic activity of gas producing microorganisms, especially yeast, could obtain high pressure from gas produced in closed medium on the one hand, and separation of other products of metabolism through membrane on the other hand, using gas pressure as driving force. It is known that several strains of yeast resist on very high hydrostatic pressure heaving good activity. This fact give the possibility to use their energy for other purposes, such as producing mechanical work. Combination of both, gas pressure and alchool burning, increase the process efficiency.

  7. The Temperature Influence to Biogas Production on Anaerobic Reactor at Ponggol Singapore

    International Nuclear Information System (INIS)

    Temperature is one of the important factor which is influence the fermentation process, but in tropical country like Singapore or Indonesia heating process is not necessary, so it is needed to observe the benefit of heater installation. The observation of temperature influence to biogas production of 1500 m3, Totally mix anaerobic reactor with hydraulic retention time 10 days with and without heating process is 13% higher than without heating process. Gas quality is not influence the process during the observation time, while the degradation of total volatile solid with heating process is 75.8% and without heating process is 57.3%. (author)

  8. Thermodynamic modeling of iron and trace metal solubility and speciation under sulfidic and ferruginous conditions in full scale continuous stirred tank biogas reactors

    International Nuclear Information System (INIS)

    (II) and Pb(II) under sulfidic conditions. Under ferruginous conditions thiol complexes were still important, but carbonate and phosphate complexes in particular dominated the aqueous phase speciation of Co(II) and Ni(II). The aqueous phase speciation of Zn and Cu was dominated by Zn(II)-sulfide and Cu(I)-polysulfide complexes, respectively. The results highlights the importance of S:Fe molar ratio as a regulating factor for the chemical speciation of metals in biogas reactors which in turn is important for microbial trace metal uptake and growth as well as potential metal toxicity. Both these aspects are critical for a successful performance of biogas production process

  9. Performance optimization of the Växtkraft biogas production plant

    OpenAIRE

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

    2012-01-01

    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 graze land. The a...

  10. Biogas processing

    OpenAIRE

    Kudláč, Adam

    2010-01-01

    The diploma thesis includes proposals suitable for usage of the technologies for clearing the biogas into a quality of substitute natural gas (SNG). The most suitable technology is chosen for the clearing the biogas out of the septic tanks of the laboratory for biologically decomposable waste treatment at Institute of process and environmental engineering. There is a calculation , a proposal and a realisation of the experimental unit for clearing the biogas performed.

  11. Final report on household and institutional biogas : technical performance & economic potential

    NARCIS (Netherlands)

    Anonymous,

    2010-01-01

    This report gives an overview of the technical performance for the ARTI compact biogas system in Nairobi and of the potential economic savings therein, and provides a preliminary analysis of the “gas for cash” business concept in Kenya.

  12. 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.)

  13. 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

    Long chain fatty acids (LCFA) concentrations over 1.0 g L1 were inhibiting manure thermophilic digestion, in batch and semi-continuous experiments, resulting in a temporary cease of the biogas production. The aim of the work was to test and evaluate several recovery actions, such as reactor feeding...... 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...... and reducing the bioavailable LCFA concentration, were found to be the best recovery strategies, improving the recovery time from 10 to 2 days, in semi-continuously fed systems. Moreover, acclimatization was introduced by repeated inhibition and process recovery. The subsequent exposure of the anaerobic...

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

    International Nuclear Information System (INIS)

    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

  15. Wood ash amendment to biogas reactors as an alternative to landfilling? A preliminary study on changes in process chemistry and biology.

    Science.gov (United States)

    Podmirseg, Sabine M; Seewald, Martin S A; Knapp, Brigitte A; Bouzid, Ourdia; Biderre-Petit, Corinne; Peyret, Pierre; Insam, Heribert

    2013-08-01

    Wood ash addition to biogas plants represents an alternative to commonly used landfilling by improving the reactor performance, raising the pH and alleviating potential limits of trace elements. This study is the first on the effects of wood ash on reactor conditions and microbial communities in cattle slurry-based biogas reactors. General process parameters [temperature, pH, electrical conductivity, ammonia, volatile fatty acids, carbon/nitrogen (C/N), total solids (TS), volatile solids, and gas quantity and quality] were monitored along with molecular analyses of methanogens by polymerase chain reaction- denaturing gradient gel electrophoresis and modern microarrays (archaea and bacteria). A prompt pH rise was observed, as was an increase in C/N ratio and volatile fatty acids. Biogas production was inhibited, but recovered to even higher production rates and methane concentration after single amendment. High sulphur levels in the wood ash generated hydrogen sulphide and potentially hampered methanogenesis. Methanosarcina was the most dominant methanogen in all reactors; however, diversity was higher in ash-amended reactors. Bacterial groups like Firmicutes, Proteobacteria and Acidobacteria were favoured, which could improve the hydrolytic efficiency of the reactors. We recommend constant monitoring of the chemical composition of the used wood ash and suggest that ash amendment is adequate if added to the substrate at a rate low enough to allow adaptation of the microbiota (e.g. 0.25 g g(-1) TS). It could further help to enrich digestate with important nutrients, for example phosphorus, calcium and magnesium, but further experiments are required for the evaluation of wood ash concentrations that are tolerable for anaerobic digestion. PMID:23831776

  16. 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

    2015-09-01

    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

  17. 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

    the biogas 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...

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

    International Nuclear Information System (INIS)

    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.

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

    DEFF Research Database (Denmark)

    Luo, Gang; Fotidis, Ioannis; Angelidaki, Irini

    2016-01-01

    Background 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...

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

    International Nuclear Information System (INIS)

    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 m3 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 hm3 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.

  1. Dynamic functional characterization and phylogenetic changes due to Long Chain Fatty Acids pulses in biogas reactors.

    Science.gov (United States)

    Kougias, Panagiotis G; Treu, Laura; Campanaro, Stefano; Zhu, Xinyu; Angelidaki, Irini

    2016-01-01

    The process stability of biogas plants is often deteriorated by the accumulation of Long Chain Fatty Acids (LCFA). The microbial community shifts due to LCFA disturbances have been poorly understood as the molecular techniques used were not able to identify the genome characteristics of uncultured microorganisms, and additionally, the presence of limited number of reference genomes in public databases prevented the comprehension of specific functional roles characterizing these microorganisms. The present study is the first research which deciphers by means of high throughput shotgun sequencing the dynamics of the microbial community during an inhibitory shock load induced by single pulses of unsaturated LCFA at two different concentrations (i.e. 2 g/L-reactor and 3 g/L-reactor). The metagenomic analysis showed that only the microbes associated with LCFA degradation could encode proteins related to "chemotaxis" and "flagellar assembly", which promoted the ability to move towards the LCFA sources so as to degrade them. Moreover, the syntrophic interactions found between Syntrophomonas sp. together with Methanosarcina sp. were possibly assigned to the menaquinone-electron transfer. Finally, it was proven that a previously exposed to LCFA inoculum is more efficient in the degradation process of LCFA due to the specialization of the microbial consortium. PMID:27353502

  2. Modeling the performance of an anaerobic baffled reactor with the variation of hydraulic retention time.

    Science.gov (United States)

    Li, Jianzheng; Shi, En; Antwi, Philip; Leu, Shao-Yuan

    2016-08-01

    Anaerobic baffled reactors (ABRs) have been widely used in engineering but very few models have been developed to simulate its performance. Based on the integration of biomass retention and liquid-gas mass transfer of biogas into the biochemical process derived in the International Water Association (IWA) Anaerobic Digestion Model No.1 (ADM1), a mathematical model was developed to predict volatile fatty acids (VFAs), chemical oxygen demand (CODCr) and biogas in a 4-compartment ABR operated with variable hydraulic retention time (HRT). The model was calibrated and validated with the experimental data obtained from the reactor when the HRT decreased from 2.0 to 1.0d by stages. It was found that the predicted VFAs, CODCr and biogas agreed well with the experimental data. Consequently, the developed model was a reliable tool to enhance the understanding among the mechanisms of the anaerobic digestion in ABRs, as well as to reactor's designing and operation. PMID:27174615

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

    International Nuclear Information System (INIS)

    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

  4. 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)

  5. 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. PMID:27054741

  6. 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)

    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 (RV), 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 TCODremoved/m3-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.

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

    Science.gov (United States)

    Turkdogan-Aydinol, F Ilter; Yetilmezsoy, Kaan

    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(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. PMID:20609515

  8. 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)], e-mail: ssouza@unioeste.br; 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)

  9. Model biogas steam reforming in a thin Pd-supported membrane reactor to generate clean hydrogen for fuel cells

    Science.gov (United States)

    Iulianelli, A.; Liguori, S.; Huang, Y.; Basile, A.

    2015-01-01

    Steam reforming of a model biogas mixture is studied for generating clean hydrogen by using an inorganic membrane reactor, in which a composite Pd/Al2O3 membrane separates part of the produced hydrogen through its selective permeation. The characteristics of H2 perm-selectivity of the fresh membrane is expressed in terms of H2/N2 ideal selectivity, in this case equal to 4300. Concerning biogas steam reforming reaction, at 380 °C, 2.0 bar H2O:CH4 = 3:1, GHSV = 9000 h-1 the permeate purity of the recovered hydrogen is around 96%, although the conversion (15%) and hydrogen recovery (>20%) are relatively low; on the contrary, at 450 °C, 3.5 bar H2O:CH4 = 4:1, GHSV = 11000 h-1 the conversion is increased up to more than 30% and the recovery of hydrogen to about 70%. This novel work constitutes a reference study for new developments on biogas steam reforming reaction in membrane reactors.

  10. Reactor performance calculations for water reactors

    International Nuclear Information System (INIS)

    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.

  11. 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

  12. 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)

  13. Performance assessment of natural gas and biogas fueled molten carbonate fuel cells in carbon capture configuration

    Science.gov (United States)

    Barelli, Linda; Bidini, Gianni; Campanari, Stefano; Discepoli, Gabriele; Spinelli, Maurizio

    2016-07-01

    The ability of MCFCs as carbon dioxide concentrator is an alternative solution among the carbon capture and storage (CCS) technologies to reduce the CO2 emission of an existing plant, providing energy instead of implying penalties. Moreover, the fuel flexibility exhibited by MCFCs increases the interest on such a solution. This paper provides the performance characterization of MCFCs operated in CCS configuration and fed with either natural gas or biogas. Experimental results are referred to a base CCS unit constituted by a MCFC stack fed from a reformer and integrated with an oxycombustor. A comparative analysis is carried out to evaluate the effect of fuel composition on energy efficiency and CO2 capture performance. A higher CO2 removal ability is revealed for the natural feeding case, bringing to a significant reduction in MCFC total area (-11.5%) and to an increase in produced net power (+13%). Moreover, the separated CO2 results in 89% (natural gas) and 86.5% (biogas) of the CO2 globally delivered by the CCS base unit. Further investigation will be carried out to provide a comprehensive assessment of the different solutions eco-efficiency considering also the biogas source and availability.

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

    Science.gov (United States)

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

    2014-09-15

    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 H2S 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 130s, H2S loading rate of 52gS-H2Sm(-3)h(-1) and pH 2.50-2.75. The EBRT reduction showed that the critical EBRT was 75s and the maximum EC 100gS-H2Sm(-3)h(-1). Stepwise increases of the inlet H2S concentration up to 10,000 ppmv lead to a maximum EC of 220gS-H2Sm(-3)h(-1). The H2S removal profile along the filter bed indicated that the first third of the filter bed was responsible for 70-80% of the total H2S removal. The oxidation rate of solid sulfur accumulated inside the bioreactor during periodical H2S starvation episodes was verified under acidic operating conditions. The performance under acidic pH was comparable to that under neutral pH in terms of H2S removal capacity. However, bioleaching of the metallic packing used as support and chemical precipitation of sulfide/sulfur salts occurred. PMID:25151242

  15. 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

    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...... 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....

  16. 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...... of bicarbonate concentration were related with the increase of the H2 flow rate. The CH4 content increased from 78.4 % to 90.2 % with the increase of the H2 flow rate from 930 to 1,440 ml/(l  day), while the pH in the reactor remained below 8.0. An even higher CH4 content (96.1 %) was achieved when the H2 flow...... rate was increased to 1,760 ml/(l  day); however, the pH increased to around 8.3 due to bicarbonate consumption which hampered the anaerobic process. The biofilm formed on the HFM was found not to be beneficial for the process since it increased the resistance of H2 diffusion to the liquid. The study...

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

    International Nuclear Information System (INIS)

    Highlights: • Desulfurization of high loads of H2S is feasible by acidic biotrickling filtration. • Robustness of the process is demonstrated in the long-term (550 d). • Biosulfur to sulfate oxidation under H2S 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 H2S 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, H2S loading rate of 52 g S–H2S 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–H2S m−3 h−1. Stepwise increases of the inlet H2S concentration up to 10,000 ppmv lead to a maximum EC of 220 g S–H2S m−3 h−1. The H2S removal profile along the filter bed indicated that the first third of the filter bed was responsible for 70–80% of the total H2S removal. The oxidation rate of solid sulfur accumulated inside the bioreactor during periodical H2S starvation episodes was verified under acidic operating conditions. The performance under acidic pH was comparable to that under neutral pH in terms of H2S removal capacity. However, bioleaching of the metallic packing used as support and chemical precipitation of sulfide/sulfur salts occurred

  18. Ultrasound assisted biogas production from landfill leachate

    International Nuclear Information System (INIS)

    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

  19. 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

  20. Biogas quality upgrade by simultaneous removal of CO{sub 2} and H{sub 2}S in a packed column reactor

    Energy Technology Data Exchange (ETDEWEB)

    Tippayawong, N.; Thanompongchart, P. [Department of Mechanical Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2010-12-15

    Biogas from anaerobic digestion of biological wastes is a renewable energy resource. It has been used to provide heat, shaft power and electricity. Typical biogas contains 50-65% methane (CH{sub 4}), 30-45% carbon dioxide (CO{sub 2}), moisture and traces of hydrogen sulphide (H{sub 2}S). Presence of CO{sub 2} and H{sub 2}S in biogas affects engine performance adversely. Reducing CO{sub 2} and H{sub 2}S content will significantly improve quality of biogas. In this work, a method for biogas scrubbing and CH{sub 4} enrichment is presented. Chemical absorption of CO{sub 2} and H{sub 2}S by aqueous solutions in a packed column was experimentally investigated. The aqueous solutions employed were sodium hydroxide (NaOH), calcium hydroxide (Ca(OH){sub 2}) and mono-ethanolamine (MEA). Liquid solvents were circulated through the column, contacting the biogas in countercurrent flow. Absorption characteristics were examined. Test results revealed that the aqueous solutions used were effective in reacting with CO{sub 2} in biogas (over 90% removal efficiency), creating CH{sub 4} enriched fuel. H{sub 2}S was removed to below the detection limit. Absorption capability was transient in nature. Saturation was reached in about 50 min for Ca(OH){sub 2}, and 100 min for NaOH and MEA, respectively. With regular replacement or regeneration of used solutions, upgraded biogas can be maintained. This technique proved to be promising in upgrading biogas quality. (author)

  1. 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.

  2. 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...... was higher than approx. 4 g-N/l the degradation efficiency of the plant decreased and as a consequence, the residual methane potential was high. Decrease of the residual methane potential with increasing hydraulic retention time was found. Digestion temperature was very important for effective post...

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

    DEFF Research Database (Denmark)

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

    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...... was higher than approx. 4 g-N/l the degradation efficiency of the plant decreased and as a consequence, the residual methane potential was high. Decrease of the residual methane potential with increasing hydraulic retention time was found. Digestion temperature was very important for effective post...

  4. 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.

  5. 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)

  6. 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)

  7. Performance analysis of upflow anaerobic sludge blanket reactors in the treatment of swine wastewater

    Directory of Open Access Journals (Sweden)

    Luiz A. V. Sarmento

    2007-07-01

    Full Text Available The adoption of confined systems for swine production have been increased the use of water in these installations and, consequently, an each time greater production of wastewater. Diagnostics have been showed a high level of water pollution due the waste material release on lands without criterions and in waters without previous treatment. The utilization of anaerobic process to reduce the liquid residues pollutant power has been detaching because beyond reducing the environmental pollution they allow to recover the energetic potential as fertilizer and biogas. In this work the performance of two real scale upflow anaerobic sludge blanket reactors treating swine wastewater were evaluated through operational system analysis, physical-chemical parameters of pollution and biogas production measurement. The results permitted to verify upflow rate speeds above of the value for which these reactors were designed and hydraulic residence times under of the design value. These factors affected negatively the treatment and had reflected on the law removal of the physical-chemical parameters and biogas production. The maximum removal efficiencies reached for TSS, BOD and COD were 72,5%, 34,7% and 40,0%, respectively. The mean rate of biogas liberation was 0,011 m-³ m-².h-1.

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

    International Nuclear Information System (INIS)

    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

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

    OpenAIRE

    Li, Jeremy (Zheng)

    2015-01-01

    International audience 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 gre...

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

    OpenAIRE

    Montebello, Andrea M.; Mora Garrido, Mabel; López de León, Luís Rafael; Bezerra, Tercia; Gamisans Noguera, Javier; Lafuente Sancho, Francisco Javier; Baeza Labat, Mireia; Gabriel Buguña, David

    2014-01-01

    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 H2S 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 130s, H2S loading rate of 52gS-H2Sm-3h-1 and pH 2.50-2.75. The EBRT reduction showed that the critical EBRT...

  11. 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

    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...... in the effluent was reduced by directly pumping the reactor effluent through the DU. In this way, the dissolved CH4 concentration in the effluent decreased from higher than 0.94mM to around 0.13mM, and thus efficient recovery of CH4 from the anaerobic effluent was achieved. In the whole operational period......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...

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

    International Nuclear Information System (INIS)

    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) VSadded 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 oC 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 CH4/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.

  13. Performance of Thorium ORGEL Reactor

    International Nuclear Information System (INIS)

    The aim of this paper is to show the general characteristics of a thorium ORGEL reactor. Reference is deliberately made to existing technology or techniques that are easily developable, avoiding any advanced solutions; in particular, the general design of the reactor is entirely similar to one operating on uranium, and includes an organic coolant, a gas-insulation and SAP pressure tube channel, and a continuous fuel cycle with one zone and one type of fuel. The criteria governing the choice of fuel element are reviewed, and an element consisting of a cluster of 37 SAP-clad thorium oxide rods is chosen. The technical and economic performance of the fuel cycle - investment in fissionable material, specific consumption, cost of the cycle - is analysed as a function of various parameters such as lattice pitch, power density and burn-up. For every case considered the uranium is entirely recycled; the supplementary fissionable material is uranium-235. Finally, the performance is compared with that obtained in a uranium reactor, and an analysis is made of the economic conditions under which the thorium cycle would become more advantageous than the uranium. (author)

  14. Anaerobic co-digestion of biodiesel waste glycerin with municipal wastewater sludge: microbial community structure dynamics and reactor performance.

    Science.gov (United States)

    Razaviarani, Vahid; Buchanan, Ian D

    2015-04-01

    Two 10 L completely mixed reactors operating at 37°C and 20 days SRT were used to evaluate the relationships between reactor performance and microbial community dynamics during anaerobic co-digestion of biodiesel waste glycerin (BWG) with municipal wastewater sludge (MWS). The addition of up to 1.35% (v/v) BWG to reactor feeds yielded increased VS and COD removal together with enhanced the biogas production and methane yield. This represented 50% of the MWS feed COD. Pyrosequencing analysis showed Methanosaeta (acetoclastic) and Methanomicrobium (hydrogenotrophic) to be the methanogenic genera present in greatest diversity during stable reactor operation. Methanosaeta sequences predominated at the lowest BWG loading while those of Methanomicrobium were present in greatest abundance at the higher BWG loadings. Genus Candidatus cloacamonas was present in the greatest number of bacterial sequences at all loadings. Alkalinity, pH, biogas production and methane yield declined and VFA concentrations (especially propionate) increased during the highest BWG loading. PMID:25678409

  15. Performance indicators for power reactors

    International Nuclear Information System (INIS)

    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

  16. 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)

    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

  17. Co-digestion Of Olive Mill Wastewater and Swine Manure Using Up-Flow Anaerobic Sludge Blanket Reactor for Biogas Production

    OpenAIRE

    Hassan Azaizeh; Jeries Jadoun

    2010-01-01

    Swine wastewater (SW) and olive mill wastewater (OMW) are two problematic wastes that have become major causes of health and environmental concerns. The main objective of the current work was to evaluate the efficiency of the co-digestion strategy for treatment of SW and OMW mixtures. Mesophilic batch reac-tors fed with mixtures of SW and OMW showed that the two adapted sludges Gadot and Prigat exhibited the best COD removal capacity and biogas production; therefore both were selected to seed...

  18. Qualitative and quantitative product analysis of the catalytic conversion of biogas in plasma-assisted flow tube reactors; Qualitative und quantitative Produktanalyse der katalytischen Konvertierung von Biogas in plasmagestuetzten Rohrstroemungsreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Kroker, Thorsten

    2011-05-31

    A cost effective method has been found to produce hydrogen and carbon monoxide from biogas by plasma enhanced flow tube. The presented method can be operated continuously (the starting material is continuously fed and the product is removed to parallel). The hydrogen and carbon monoxide are used in industry on a large scale as a synthesis gas. Synthesis gas can be e.g. refined by the Fischer-Tropsch synthesis to synthetic gasoline. In general, a synthesis gas composition of H2/CO with the ratio of 1.7 is used. Therefore a way was needed to maintain the composition of the synthesis gas, despite of the fluctuations in the CH4/CO2-composition of biogas. Due to the high flexibility of a DBE-assisted flow tube reactor, this problem could be solved (DBE = dielectric barrier discharge). [German] Es wurde ein kostenguenstiges Verfahren gefunden, das aus dem klimaunfreundlichen Biogas mit Hilfe eines plasmagestuetzten Stroemungsrohrs Wasserstoff und Kohlenmonoxid erzeugt. Das vorgestellte Verfahren kann kontinuierlich betrieben werden (das Edukt wird kontinuierlich zugefuehrt und das Produkt parallel dazu entnommen). Der Wasserstoff und das Kohlenmonoxid werden in der Industrie in grossem Massstab als Synthesegas eingesetzt. Synthesegas kann z.B. durch die Fischer-Tropsch-Synthese zu synthetischen Benzin veredelt werden. In der Regel wird dafuer eine Synthesegaszusammensetzung von H2/CO das Verhaeltnis von 1.7 eingesetzt. Deshalb musste noch ein Weg gefunden werden, um die Zusammensetzung des Synthesegases aufrechtzuerhalten, trotz Schwankungen der CH4/CO2-Zusammensetzung im Biogas. Durch die hohe Flexibilitaet eines DBE gestuetzten Stroemungsrohrreaktors konnte dieses Problem geloest werden (DBE = Dielektrische Barriere-Entladung).

  19. 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

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

    International Nuclear Information System (INIS)

    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

  1. BIOGAS PROCTION FROM ANAEROBIC CO-DIGESTION OF COW DUNG AND ORGANIC WASTES (NAPIER PAK CHONG I AND FOOD WASTE IN THAILAND: TEMPERATURE EFFECT ON BIOGAS PRODUCT

    Directory of Open Access Journals (Sweden)

    Lertluck Saitawee

    2014-01-01

    Full Text Available Biogas production has been attracting increasing attention as a biofuel of the future because biogas technology not only constitutes a biofuel source, but also can be applied in the various environmental pollutants. Anaerobic digestion of high solid slurries (such as food waste and cow dung is typically performed in continuously reactor (by force substrate flow to avoid problems with a thick floating layer or large amounts of sediments. Temperature also seems to have profound influence on the biogas production. The objective of the study was to identify the optimum biogas production for anaerobic co-digestion of cow dung and organic wastes (napierpakchong I and food waste. Influence of temperature (psyhrophilic temperature 25°C and thermoplilic temperature 45°C and active biogas process on single substrate (food waste feed and co-digestion of cow dung and organic wastes (napierpakchong I and food waste was used, within the reactor was studies in 1.80 cm high over a 45 day. Results showed that best digestion was achieved when digested of cow dung, napierpakchong I and food waste on 1:1:1 and thermoplilic temperature. Maximum biogas production (R4, biogas yield, methane content and %VS reduction was found that 70 L/day, 70 L/VS feed, 65 and 80%, respectively. The result showed that the biogas production increased progressively withhigher temperature.The increased in biogas production in thermophilic temperature and psyhrophilic temperature could be up 28.01 and 26%, respectively. The biogas yield increased 12.5% of co-digestion system, which compared to thermophilic temperature and psyhrophilic temperature (R4 and R2. This behavior might be due to the higher degradability. Therefore, temperature of digester can be used effectively as an operating strategy to optimize biogas production.

  2. 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)

    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.

  3. DEVELOPMENT TRENDS OF BIOGAS

    Directory of Open Access Journals (Sweden)

    Mariana DUMITRU

    2015-04-01

    Full Text Available All over the world, researches are made in order to improve the technologies, the operational and process stability and performance of biogas plants, because the world markets for biogas increased considerably in Europe and all over the world. In this paper we studied the most important parameters related to a biogas plant, starting from the ecologic landfill of Cristian, Sibiu, a landfill which storages industrial and household waste. In this respect, we studied operational parameters, such as organic load and hydraulic retention time, and parameters for evaluation of a biogas plant. Also, we made a case study concerning the evaluation of used waters in the landfill described above under the aspect of pollution sources, way of treatment and evacuation mode of used waters. The existing biomass resources everywhere in the world can give us an idea of the global potential of biogas production, which is not exploited to its capacity, especially in our country.

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

    International Nuclear Information System (INIS)

    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 NOx levels. The NOx 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 NOx pollution

  5. 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)

    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 CH4 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 CO2 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

  6. 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)

  7. High performance light water reactor

    International Nuclear Information System (INIS)

    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

  8. Complete genome analysis of Clostridium bornimense strain M2/40(T): A new acidogenic Clostridium species isolated from a mesophilic two-phase laboratory-scale biogas reactor.

    Science.gov (United States)

    Tomazetto, Geizecler; Hahnke, Sarah; Koeck, Daniela E; Wibberg, Daniel; Maus, Irena; Pühler, Alfred; Klocke, Michael; Schlüter, Andreas

    2016-08-20

    Taxonomic and functional profiling based on metagenome analyses frequently revealed that members of the class Clostridia dominate biogas reactor communities and perform different essential metabolic pathways in the biogas fermentation process. Clostridium bornimense strain M2/40(T) was recently isolated from a mesophilic two-phase lab-scale biogas reactor continuously fed with maize silage and wheat straw. The genome of the strain was completely sequenced and manually annotated to reconstruct its metabolic potential regarding carbohydrate active enzyme production and fermentation of organic compounds for consolidated biofuel production from biomass. The C. bornimense M2/40(T) genome consists of a chromosome (2,917,864bp in size) containing 2613 protein coding sequences, and a 699,161bp chromid (secondary replicon) harboring 680 coding sequences. Both replicons feature very similar GC-contents of approximately 29%. The complex genome comprises three prophage regions, two CRISPR-cas systems and a putative cellulosomal gene cluster that is located on the second replicon (chromid) of the strain. The overexpressed glycosyl hydrolases (GH) CelK (GH9) and CelA (GH48) encoded in the cellulosomal gene cluster were shown to be active on the substrates xylan and xyloglucan whereas XghA (GH74) is highly active on xyloglucan. Reconstruction of fermentation pathways from genome sequence data revealed that strain M2/40(T) encodes all enzymes for hydrogen, acetate, formate, lactate, butyrate, and ethanol production, leading to the classification of the isolate as acidogenic bacterium. Phylogenetic analyses uncovered that the closest characterized relative of C. bornimense is C. cellulovorans. Comparative analyses of the C. bornimense and C. cellulovorans genomes revealed considerable rearrangements within their chromosomes suggesting that both species evolved separately for a relatively long period of time and adapted to specific tasks within microbial consortia responsible for

  9. 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)

  10. Biogas desulfurization using autotrophic denitrification process.

    Science.gov (United States)

    Bayrakdar, Alper; Tilahun, Ebrahim; Calli, Baris

    2016-01-01

    The aim of this study was to evaluate the performance of an autotrophic denitrification process for desulfurization of biogas produced from a chicken manure digester. A laboratory scale upflow fixed bed reactor (UFBR) was operated for 105 days and fed with sodium sulfide or H2S scrubbed from the biogas and nitrate as electron donor and acceptor, respectively. The S/N ratio (2.5 mol/mol) of the feed solution was kept constant throughout the study. When the UFBR was fed with sodium sulfide solution with an influent pH of 7.7, about 95 % sulfide and 90 % nitrate removal efficiencies were achieved. However, the inlet of the UFBR was clogged several times due to the accumulation of biologically produced elemental sulfur particles and the clogging resulted in operational problems. When the UFBR was fed with the H2S absorbed from the biogas and operated with an influent pH of 8-9, around 98 % sulfide and 97 % nitrate removal efficiencies were obtained. In this way, above 95 % of the H2S in the biogas was removed as elemental sulfur and the reactor effluent was reused as scrubbing liquid without any clogging problem. PMID:26428238

  11. BIOGAS PROCTION FROM ANAEROBIC CO-DIGESTION OF COW DUNG AND ORGANIC WASTES (NAPIER PAK CHONG I AND FOOD WASTE) IN THAILAND: TEMPERATURE EFFECT ON BIOGAS PRODUCT

    OpenAIRE

    Lertluck Saitawee; KanokornHussaro; Sombat Teekasap; Noppadon Cheamsawat

    2014-01-01

    Biogas production has been attracting increasing attention as a biofuel of the future because biogas technology not only constitutes a biofuel source, but also can be applied in the various environmental pollutants. Anaerobic digestion of high solid slurries (such as food waste and cow dung) is typically performed in continuously reactor (by force substrate flow) to avoid problems with a thick floating layer or large amounts of sediments. Temperature also seems to have profound influence on t...

  12. 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

  13. 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

    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 and The...

  14. Biogas barometer

    International Nuclear Information System (INIS)

    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.)

  15. 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. PMID:23873639

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

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jianbin, E-mail: jianbinguo@gmail.com [Department of Environmental Engineering, Tsinghua University, Beijing 100084 (China); Dong, Renjie [College of Engineering, China Agricultural University, P.O. Box 184, Beijing 100083 (China); Clemens, Joachim [Institute of Crop Science and Resource Reservation (INRES), University of Bonn, Karlrobert-Kreiten-Strasse 13, 53115 Bonn (Germany); Wang, Wei [Department of Environmental Engineering, Tsinghua University, Beijing 100084 (China)

    2013-11-15

    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{sup −1} d{sup −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{sup −1} d{sup −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{sup −1} d{sup −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{sup −1} COD{sub removed,} which was higher than that at 38 °C (0.016 g VSS g{sup −1} COD{sub removed})

  17. 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.

  18. 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.

  19. Biogas Filter Based on Local Natural Zeolite Materials

    OpenAIRE

    Satriyo Krido Wahono; Wahyu Anggo Rizal

    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 ...

  20. 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/g......VS-added. Anaerobic digestion of potato-juice in an EGSB reactor could obtain a methane yield of 380mL-CH4/gVS-added at the organic loading rate of 3.2gCOD/(L-reactor.d). In a UASB reactor, higher organic loading rate of 5.1gCOD/(L-reactor.d) could be tolerated, however, it resulted in a lower methane yield of 240m......L-CH4/gVS-added. The treatment of reactor effluent was also investigated. By acidification with sulfuric acid to pH lower than 5, almost 100% of the ammonia content in the effluent could be retained during the successive up-concentration process step. The reactor effluent could be up...

  1. BiogasMotor; BiogasMotor

    Energy Technology Data Exchange (ETDEWEB)

    Roubaud, A.; Favrat, D.

    2002-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of tests made at the Swiss Federal Institute of Technology in Lausanne with an unscavenged prechamber ignition system on a 150 kW co-generation engine fuelled with biogas. The engine's performance in terms of fuel conversion efficiency was observed and the reduction potential for exhaust emissions to a level below the Swiss limits was verified. The tests made, which used natural gas mixed with CO{sub 2} as simulated biogas fuel, are described. The results of the tests, including figures on NO{sub x}, CO and HC emissions, are presented and discussed. The authors conclude that biogas engines with unscavenged prechamber ignition could provide a significant boost in energy conversion efficiency whilst keeping emissions within the tough Swiss limits.

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

    International Nuclear Information System (INIS)

    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

  3. Space reactor fuels performance and development issues

    International Nuclear Information System (INIS)

    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

  4. Space reactor fuels performance and development issues

    International Nuclear Information System (INIS)

    Three compact reactor concepts are now under consideration by the U.S. 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

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

    International Nuclear Information System (INIS)

    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, NOx and CO2 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 H2S 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

  6. Performance of Sand Channel as Pre-Treatment for Anaerobic Landfill Bioreactor Leachate and Biogas Generation

    OpenAIRE

    Emmanuel Olisa; Nasiman Sapari; Amirhossein Malakahmad; Ezerie Henry Ezechi; Ali Riahi; Kalu Uka Orji; Oseihioria Alex- Ohunyon; Salihi Umar Ibrahim

    2016-01-01

    The performance of a laboratory scale landfill bioreactor with two compartments (simulated landfill reactor and a sand channel) was investigated in this study. Solid waste components similar to the typical Malaysian waste were collected from the cafeterias in University Teknologi PETRONAS (UTP), Perak, Malaysia and used to generate leachate in the simulated landfill bioreactor. Leachate produced were slowly and systematically introduced into the bottom sand channel where methanogenesis rapidl...

  7. Influence of inoculum on performance of anaerobic reactors for treating municipal solid waste.

    Science.gov (United States)

    Lopes, Wilton Silva; Leite, Valderi Duarte; Prasad, Shiva

    2004-09-01

    The influence of bovine rumen fluid inoculum during anaerobic treatment of the organic fraction of municipal solid waste (MSW) was studied in this work. The parameters adopted for evaluation were the biostabilization constant of total volatile solids (TVS) and the biostabilization time of the chemical oxygen demand (COD) applied to the reactors. The work was realized in four anaerobic batch reactors of 20 l capacity each, during a period of 365 days. The proportions between MSW/inoculum loaded in the reactors were Reactor A (100%/0%), Reactor B (95%/5%), Reactor C (90%/10%) and Reactor D (85%/15%). The necessary time for biostabilization of half of the applied COD was 459, 347, 302 and 234 days and the average of methane concentration in the biogas produced was 3.6%, 13.0%, 25.0% and 42.6% for Reactors A, B, C and D, respectively. The data obtained affirm that the inoculum used substantially improved the performance of the process. PMID:15182832

  8. 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], e-mail: armin.feiden@creapr.org.br; 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)

  9. 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). PMID:26873284

  10. Biogas from anaerobic digestion of fruit and vegetable wastes: Experimental results on pilot-scale and preliminary performance evaluation of a full-scale power plant

    International Nuclear Information System (INIS)

    Highlights: • Biogas production from anaerobic digestion of fruit and vegetable wastes was studied. • A pilot scale tubular reactor fed by single waste substrates was used. • The optimum organic loading rate ranged from 2.5 to 3.0 kgVS/m3 d. • Biogas production was about 0.78 Nm3/kgVS, with a methane content of 55%. • Preliminary design of a full-scale anaerobic digestion system was carried out. - Abstract: This paper presents the experimental results obtained through an anaerobic digestion pilot plant by using fruit and vegetable wastes as single substrate. The substrate materials were sampled from the wastes produced by the Fruit and Vegetable Wholesale Market of Sardinia (Italy). The experimental study was carried out over a period of about 6 months to evaluate the most suitable operating parameters of the process depending on the availability of different kinds of fruit and vegetable wastes over the different periods of the year. Overall, the optimum daily loading rate of wastes was 35 kg/d, with a corresponding hydraulic residence time of 27 days. The optimum organic loading rate ranged from 2.5 to 3.0 kgVS/m3 d and the average specific biogas production was about 0.78 Nm3/kgVS, with a specific methane yield of about 0.43 Nm3/kgVS. The results of the experimental investigation were used for a preliminary performance evaluation of a full-scale anaerobic digestion power plant for treating all the fruit and vegetable wastes produced by the Wholesale Market of Sardinia (9 t/d). The estimate of daily methane production (290 Nm3/d) leads to a CHP unit with a power output of about 42 kW and an annual electrical production of about 300 MW h/year (about 25% of the wholesale market electrical consumption). The AD power plant also shows interesting economic features, since its energy production cost (about 150 €/MW h) is slightly lower than the energy purchase cost of the wholesale market (about 200 €/MW h) and a Pay-Back Time of about 7.25 years can be

  11. Biogas everywhere; Biogaz a tous les etages

    Energy Technology Data Exchange (ETDEWEB)

    Couturier, Ch. [SOLAGRO, 31 - Toulouse (France); Pegret-Rosa, A.S.; Leca, Ch. [CLERC, 93 - Montreuil (France); Adlec, E. [Club Biogaz, 94 - Arcueil (France)

    2009-01-15

    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.)

  12. Improvement of Biogas Production by Bioaugmentation

    OpenAIRE

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

    2012-01-01

    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, respective...

  13. 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...

  14. Performance and characterization of a newly developed self-agitated anaerobic reactor with biological desulfurization.

    Science.gov (United States)

    Kobayashi, Takuro; Li, Yu-You

    2011-05-01

    The continuous operation of a newly developed methane fermentation reactor, which requires no electricity for the agitation of the fermentation liquid was investigated, and the extent of the biological desulfurization was monitored. Inside the reactor, the continual change in the liquid level and the self-agitation, occurring between 5 and 16 times every day, distributed the organic load near the inlet port of the reactor, as well as providing a nutrient supply to the hydrogen sulfide oxidizing bacteria. At different COD(Cr) loading rates (5, 7, 10 kg m(3)d(-1)), the reactor achieved a biogas production yield of 0.72-0.82 m(3)g(-1)-TS, a COD(Cr) reduction of 79.4-85.5% and an average of 99% hydrogen sulfide removal. This investigation demonstrated that the self-agitated reactor is comparable in digestion performance to the completely stirred tank reactor (CSTR) investigated in a previous study, and that the desulfurization performance was significantly enhanced compared to the CSTR. PMID:21398119

  15. Study on the flow characteristics and the wastewater treatment performance in modified internal circulation reactor.

    Science.gov (United States)

    Wang, Jiade; Xu, Weijun; Yan, Jingjia; Yu, Jianming

    2014-12-01

    A modified internal circulation (MIC) reactor with an external circulation system was proposed and the performance of treating dyeing wastewater using both MIC and typical IC reactor were compared. Utilization of the external circulation system in the MIC reactor could dramatically improve the mixing intensity of the biomass with the wastewater and resulted in better performance. The COD removal efficiency, biogas production, volatile fatty acids and effluent color were approximately 87%, 98 L d−1, 180 mg L−1 and 100 times, respectively, in the MIC reactor with a hydraulic retention time of 5 h and organic loading rate of 15 kg COD m−3 d−1. The hydrodynamics of the MIC reactor under different flows rate of external circulation were also analyzed using computational fluid dynamics (CFD) method. The optimal flow rate of external circulation was 12 L min−1, which resulted in a corresponding up-flow velocity of 40 m h−1. The consistency of the result between experiment and simulation validated the scientificity of CFD technique applied to numerical simulation of the MIC reactor. PMID:25461928

  16. Harvesting biogas from wastewater sludge and food waste

    Science.gov (United States)

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

    2013-06-01

    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.

  17. Harvesting biogas from wastewater sludge and food waste

    International Nuclear Information System (INIS)

    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.

  18. Biogas building directions

    Energy Technology Data Exchange (ETDEWEB)

    Eggeling, G.; Guldager, R.; Hilliges, G.; Tietjen, C.; Werner, U.; Guldager, H.; Sasse, L.

    The purpose of this book is to approach the people living and working in the rural regions of developing countries with a technology enabling them to use their resources by their proper means in a way that they dispose of a cheap and inexhaustible source of energy and fertilizer. These building directives for biogas plants shall concretely give the fundamental information for the use of this technology and be a practical support in do-it-yourself construction of biogas plants by its intelligible way of description owing to designs and popular language. These directives are part of a work performed by German and Indian experts during two years working up the biogas technology in countries of the Third World and in industrial countries. The regulations have been discussed at an international workshop in Bremen with more than 60 experts from countries of all continents meeting to discuss the application of biogas plants. The result has been documented in the ''Report on the International Biogas-Workshop Bremen''.

  19. Biogas technology in Pakistan

    International Nuclear Information System (INIS)

    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)

  20. Assessment criteria for TRIGA reactors performances

    International Nuclear Information System (INIS)

    Full text: The international statistic data show that a number of 325 research reactors are now in operation. Their constructional and functional diversity is very large, a great share being represented by the TRIGA family reactors. Such reactors are now operating at: Tucson, Arizona - USA (1958); Austin, Texas - USA (1963); Belo Horizonte - Brazil (1960); Mainz - Germany (1975); Omaha - Veterans (1959); Heidelberg - Germany (1966); Bandung - Indonesia (1964/1971); Dalat - Vietnam (1963); Pavia - Italy (1965);, Rikkyo, Yokosuka - Japan (1961); Rome, Casaccia - Italy (1960); Seoul - Rep. of Korea (1962); Wien - Austria (1962); Dasa Bethesda, MD - USA (1962); Pitesti, Arges - Romania (1979), etc. In the proposed paper, the author sets the evaluation criteria for the TRIGA-type reactors performances. The treated phenomena can be described through functions of the type φ(N1,N2,N3,...) = constant, where for example, N1 FAα1Bβ1Cγ1Eδ1. (author)

  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. 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. PMID:25311769

  3. GlidArc-assisted production of synthesis gas from biogas

    International Nuclear Information System (INIS)

    We present an emerging biogas reformer based on a direct use of high-voltage discharges (called GlidArc) that strike in the flow of such widely available and renewable feedstock without any gas separation or purification. A poor biogas (containing only 35 - 50 vol.% of methane) is partially converted into hydrogen and carbon monoxide (SynGas). Such enhanced biogas can, for example, be used as gaseous fuel in Internal Combustion Engines, be considered as source of Hydrogen for PEM fuel cells or be directly consumed in some specific Fuel Cells. Any level of impurities is accepted for our reformer where the discharges provide all energy and catalytic assistance for endothermic process of so-called 'dry' reforming of CH4 + CO2 into H2 + CO. Our tests with simulated biogas are performed in a 1.4-L reactor working at atmospheric pressure at up to 0.6 kW electric power. Such input is fully sufficient to process a flow of a poor biogas carrying up to 7 kW of thermal power. (author)

  4. 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. PMID:25310868

  5. 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

  6. 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. PMID:25265327

  7. 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

  8. BIOGAS TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    D.B. SALUNKHE

    2012-12-01

    Full Text Available Due to scarcity of petroleum and coal it threatens supply of fuel throughout the world also problem of their combustion leads to research in different corners to get access the new sources of energy, like renewable energy resources. Solar energy, wind energy, different thermal and hydro sources of energy, biogas are all renewable energy resources. But, biogas is distinct from other renewable energies because of its characteristics of using, controlling and collecting organic wastes and at the same time producing fertilizer and water for use in agricultural irrigation. Biogas does not have any geographical limitations nor does it require advanced technology for producing energy, also it is very simple to use and apply. Anaerobic digestion is controlled biological degradation process which allows efficient capturing & utilization of biogas (approximately 60% methane and 40% carbon dioxide for energy generation. Anaerobic digestion of food waste is achievable but different types, composition of food waste results in varying degrees of methane yields, and thus the effects of mixing various types of food waste and their proportions should be determined on case by case basis.

  9. 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.)

  10. 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. PMID:24045173

  11. EU Agro Biogas Project

    OpenAIRE

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

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

    International Nuclear Information System (INIS)

    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 H2/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, CH4/CO2 = 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

  13. 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. PMID:27038432

  14. 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.

  15. Mitigation performance indicator for boiling water reactors

    International Nuclear Information System (INIS)

    All U.S. boiling water reactors (BWRs) inject hydrogen for mitigation of intergranular stress corrosion cracking (IGSCC), and most currently use or plan to use noble metals technology. The EPRI Boiling Water Reactor Vessels and Internals Project (BWRVIP) developed a Mitigation Performance Indicator (MPI) in 2006 to accurately depict to management the status of mitigation equipment and as a standardized way to show the overall health of reactor vessel internals from a chemistry perspective. It is a 'Needed' requirement in the EPRI BWR Water Chemistry Guidelines that plants have an MPI, and use of the BWRVIP MPI is a 'Good Practice'. The MPI is aligned with inspection relief criteria for reactor piping and internal components for U.S. BWRs. This paper discusses the history of the MPI, from its first use for plants operating with moderate hydrogen water chemistry (HWC-M) or Noble Metal Chemical Application (NMCA) + HWC to its more recent use for plants operating with On-Line NobleChem™ (OLNC) + HWC. Key mitigation parameters are discussed along with the technical bases for the indicators associated with the parameters. (author)

  16. 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

    had been exposed to oleate both reactors showed a lower VFA concentration along with a higher methane production than before the pulses. This indicates that oleate had a stimulating effect on the overall process. The improved acetogenic and methanogenic activity in the reactors was confirmed in batch......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 of...... oleate. Following pulses of 0.5 and 1.0 g oleate/L, the most distinct increase in volatile fatty acid (VFA) concentrations were observed in the reactor with the lowest TS/VS content. This suggests a higher adsorption of oleate on the surfaces of biofibers in the reactor with the highest TS/VS and a less...

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

    Science.gov (United States)

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

    2013-11-01

    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 4.3g ODML(-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 (1.3g ODML(-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 0.065g VSSg(-1) CODremoved, which was higher than that at 38°C (0.016g VSSg(-1) CODremoved). PMID:23842452

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

    OpenAIRE

    Gómez Montoya Juan Pablo; Amell Arrieta Andrés A.; Zapata Lopez Jaime F.

    2015-01-01

    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...

  19. Decentralized power generation from biogas

    International Nuclear Information System (INIS)

    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

  20. Thermal Simulation of Biogas Plants Using Mat Lab

    Directory of Open Access Journals (Sweden)

    Shaheen.M.Sain

    2014-10-01

    Full Text Available The major prerequisite for the optimum production of methane from a biogas plant is the sustenance of digester temperature within the narrow limits (300C-350C. It is experimentally investigated that, the MIT biogas plant is not maintaining optimum temperature, this decreases the efficiency and increases the detention time for charge. To maintain the plant in optimum temperature, it is necessary to find out the heat losses from the biogas plant and the external energy inputs need to operate the plant. Rate of gas yield, and the detention time (time necessary to anaerobically digest organic wastes in a biogas reactor, are favorable functions of the temperature in the digester. A thermal simulation for MIT biogas plant has developed using matlab in order to understand the heat transfer from the slurry and the gas holder to the surrounding earth and air respectively. The computation has been performed when the slurry is maintained at 200C and 300C, optimum temperature of anaerobic fermentation. If the slurry is considered to be at 350C, the optimum temperature of anaerobic fermentation, the total heat loss from the plant is higher than the heat loss when the slurry is maintained at 200C. The heat calculations provide an appraisal for the heat which has to be supplied by external means to compensate for the net heat losses which occur if the slurry is to be maintained at 350C. A solar system with auxiliary electric heater is designed for maintaining the slurry at 350C.In conclusion; the results of thermal analysis are used to define a strategy for operating biogas plant at optimum temperatures. .

  1. Effect of tryptone and ammonia on the biogas process in continuously stirred tank reactors treating cattle manure

    DEFF Research Database (Denmark)

    Nielsen, Hanne Bjerg; Ahring, Birgitte Kiær

    2007-01-01

    Two themophilic continuously stirred tank reactors, R1 and Two thermophilic continuously stirred tank reactors, R1 and R2, were subject to pulses of tryptone and ammonia. R1 was operated at an ammonia-N concentration of 3.0 g l(-1) and R2 was operated at an ammonia-N concentration of 1.7 g l(-1)....

  2. 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 of...

  3. Technical improvements with biogas plants

    Energy Technology Data Exchange (ETDEWEB)

    Perwanger, A.

    In theory and practice, science aims at smooth operation of biogas plants at a good cost/benefit ratio by improving plant design and introducing more effective process techniques. For several years now, experience gained with the construction and operation of over 40 biogas plants are evaluated at the Landtechnik Weihenstephan in co-operation with manufacturing companies and committed farmers. By means of elementary drawings, 10 differently designed biogas plants are explained in greater detail concerning their technical features (structure, efficiency, function) which comprise, too, a through-flow facility, separate gasometer, mechanical stirrer, construction and refitting of such plants by the user, a rotary reactor floating in a water tank, a small-sized gas cupola and a flexible foil hood. With optimum process technology, there are still some issues left unanswered like e.g. suitable process temperature and intensity of stirrer.

  4. Sustainability objects as performative definitions of sustainability: The case of food waste-based biogas and biofertilizers

    OpenAIRE

    Corvellec, Hervé

    2015-01-01

    This article introduces the notion of sustainability objects to label objects that come with a claim to promote a more sustainable mode of living. The purpose is to show that organizations that develop such objects contribute to defining sustainability. A case study of the development of a food waste-based biogas and biofertilizers production facility serves as empirical example of sustainability objects development. The analysis demonstrates that this development has involved situating bioga...

  5. 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.

  6. Hybridizing concentrated solar power (CSP) with biogas and biomethane as an alternative to natural gas: Analysis of environmental performance using LCA

    OpenAIRE

    San Miguel Alfaro, Guillermo; Corona Bellostas, Blanca

    2014-01-01

    Concentrating Solar Power (CSP) plants typically incorporate one or various auxiliary boilers operating in parallel to the solar field to facilitate start up operations, provide system stability, avoid freezing of heat transfer fluid (HTF) and increase generation capacity. The environmental performance of these plants is highly influenced by the energy input and the type of auxiliary fuel, which in most cases is natural gas (NG). Replacing the NG with biogas or biomethane (BM) in commercial C...

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

    OpenAIRE

    Pål Börjesson; Thomas Prade; Mikael Lantz; Lovisa Björnsson

    2015-01-01

    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 include...

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

    OpenAIRE

    Pål Börjesson; Thomas Prade; Mikael Lantz; Lovisa Björnsson

    2015-01-01

    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 include...

  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. Method of evaluating the reactor core performance

    International Nuclear Information System (INIS)

    Purpose: To enable exact evaluation for the core performance in a short period. Constitution: A reactor core is equally divided into 2, 4 or 8 sections considering the structure of the symmetricalness and calculation for the evaluation the core performance is carried out to at least one region of the divided core. However, the reactor core can not be said to be completely symmetrical and there is a difference more or less, because if identical type fuels are loaded the way of burning is different depending on the positions, thereby causing difference in the total heat calorie generated. Accordingly, the performance evaluation is conducted for the entire core at a predetermined time interval, the compensation value for each of the fuels is calculated based on the result of the calculation for the entire core and the corresponding result of the calculation in each of the divided cores and the compensated values are added to the calculation result for the divided cores to compensate the calculated evaluation value. This enables to shorten the calculation time and improve the calculation accuracy. (Yoshino, Y.)

  11. Performance tests for integral reactor nuclear fuel

    International Nuclear Information System (INIS)

    An integral type reactor SMART plans to utilize metallic Zr-U fuel which is Zr-based alloy with 34∼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

  12. 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)

    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

  13. Reactor fuel performance data file, 1985 edition

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)Cl3, allowed stable process conditions for an organic loading rate (OLR) up to 2.5 gVS L−1 d−1. Additional supplement of trace elements was necessary for process operation at OLRs above 2.5 gVS L−1 d−1

  15. Significance of fuel performance during reactor operation

    International Nuclear Information System (INIS)

    Since the start-up of the first light-water-reactor power stations the operational fuel performance became a matter of increasing importance. The todays requirements with regard to fuel operational behaviour are discussed with emphasis on the following items: - load following flexibility, - activity release, - fuel handling, - fuel cycle costs, - reduction of personal radiation exposure, - fuel behaviour during plant transients. The status of fuel performance and operational measures for the detection of failed fuel are presented. The fuel vendors recommendations with regard to the avoidance of PCI-failures are a further topic of consideration. Finally it will be pointed out that there is need for an improved fuel design which fullfills the discussed requirements as well as it minimizes the susceptibility to pellet clad interaction

  16. 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. PMID:27003270

  17. Effect of tryptone and ammonia on the biogas process in continuously stirred tank reactors treating cattle manure

    DEFF Research Database (Denmark)

    Nielsen, Hanne Bjerg; Ahring, Birgitte Kiær

    2007-01-01

    ). Shock loads of tryptone (10 g l(-1),10 g l(-1), 15 g l(-1)) had an immediate stimulating effect on methanogenesis for both reactors illustrated by significant peaks in methane production but also led to an organic overloading illustrated by a steep increase in volatile fatty acids (VFA) concentration...

  18. Assessment of The Performance of a Small Capacity SI Engine Fuelled with Model Lean Mixture of Biogas

    OpenAIRE

    Przybyla, Grzegorz Kazimierz; Szlek, Andrzej; Ziolkowski, Lukasz

    2013-01-01

    In this paper the results of the experimental study on the SI engine using biogas will be presented. The experiments were carried out on a petrol engine with a low engine displacement. Typical SI engine was selected in order to evaluate the potential application of gaseous fuel (i.e. biogas). These types of engines are available on a wide scale and commonly used in automotive sector because of the low purchase price and operating costs. It is expected that after minor modifications, the engin...

  19. 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.

  20. 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

  1. 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.

  2. Optimization of biogas production from manure

    DEFF Research Database (Denmark)

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

    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...... biogas production. At 13/87 ratio, no significant increase in biogas production was noticed. Both single and serial CSTR processes were stable when operated 90/10, 80/20, 70/30 or 50/50% volume distributions and also during an organic pulse load (19.6 to 65.3 g/l reactor volume). Results from pilot...

  3. 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.

  4. Performance of up flow anaerobic sludge fixed film bioreactor for the treatment of high organic load and biogas production of cheese whey wastewater

    Directory of Open Access Journals (Sweden)

    Tehrani Nazila Samimi

    2015-01-01

    Full Text Available Among various wastewater treatment technologies, biological wastewater treatment appears to be the most promising method. A pilot scale of hybrid anaerobic bioreactor was fabricated and used for the whey wastewater treatment. The top and bottom of the hybrid bioreactor known as up flow anaerobic sludge fixed film (UASFF; was a combination of up flow anaerobic sludge blanket (UASB and up flow anaerobic fixed film reactor (UAFF, respectively. The effects of operating parameters such as temperature and hydraulic retention time (HRT on chemical oxygen demand (COD removal and biogas production in the hybrid bioreactor were investigated. Treatability of the samples at various HRTs of 12, 24, 36 and 48 hours was evaluated in the fabricated bioreactor. The desired conditions for COD removal such as HRT of 48 hours and operation temperature of 40 °C were obtained. The maximum COD removal and biogas production were 80% and 2.40 (L/d, respectively. Kinetic models of Riccati, Monod and Verhalst were also evaluated for the living microorganisms in the treatment process. Among the above models, Riccati model was the best growth model fitted with the experimental data with R2 of about 0.99.

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

    International Nuclear Information System (INIS)

    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)

  6. Performance of a multipurpose research electrochemical reactor

    Energy Technology Data Exchange (ETDEWEB)

    Henquin, E.R. [Programa de Electroquimica Aplicada e Ingenieria Electroquimica (PRELINE), Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santiago del Estero 2829, S3000AOM Santa Fe (Argentina); Bisang, J.M., E-mail: jbisang@fiq.unl.edu.ar [Programa de Electroquimica Aplicada e Ingenieria Electroquimica (PRELINE), Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santiago del Estero 2829, S3000AOM Santa Fe (Argentina)

    2011-07-01

    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.

  7. High Performance Photocatalytic Oxidation Reactor System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Pioneer Astronautics proposes a technology program for the development of an innovative photocatalytic oxidation reactor for the removal and mineralization of...

  8. Sulphur K-edge XANES and acid volatile sulphide analyses of changes in chemical speciation of S and Fe during sequential extraction of trace metals in anoxic sludge from biogas reactors

    OpenAIRE

    Shakeri Yekta, Sepehr; Gustavsson, Jenny; Svensson, Bo H.; Skyllberg, Ulf

    2012-01-01

    The effect of sequential extraction of trace metals on sulphur (S) speciation in anoxic sludge samples from two lab-scale biogas reactors augmented with Fe was investigated. Analyses of sulphur K-edge X-ray absorption near edge structure (S XANES) spectroscopy and acid volatile sulphide (AVS) were conducted on the residues from each step of the sequential extraction. The S speciation in sludge samples after AVS analysis was also determined by S XANES. Sulphur was mainly present as FeS (~60% o...

  9. Process optimization of biogas production at Nemščak biogas plant by pre-treatment of the substrate and combining with waste sludge

    OpenAIRE

    Žitek, Filip

    2015-01-01

    The purpose of this thesis is to increase the amount of biogas produced by pre-treatment of the substrate and combining with waste sludge. For anaerobic digestion of different substrates, we used a pilot reactor to determine the biogas potential at Nemščak biogas plant. The pilot reactor was built in 2009 for the purpose of testing new substrates in the process of biogas production. The pilot reactor has a working volume of 2000 litres; there is a gas tank above it with the volume of 500 litr...

  10. Biogas from ley crops

    International Nuclear Information System (INIS)

    This report describes the cost of producing biogas from energy crops. Five process systems, sized 0.25-8 MW are studied. The cultivation of biogas-crops is made in three regions in Sweden. Also valued are the positive cultivation effects obtained when cereal dominated crop rotation is broken by biogas crops. 8 refs, 40 figs, 10 tabs

  11. New Networks for Biogas

    Energy Technology Data Exchange (ETDEWEB)

    Eekelen, R. van [Kiwa Gas Technology B. V., Apeldoorn (Netherlands)

    2012-06-15

    The study of 'New Networks for Biogas' main goal is to reduce the uncertainties associated with the design choices for biogas network configurations. Supplementary to the objective an overview of the state-of-the-art on the design, operations and maintenance of biogas networks in Europe is given.

  12. BIOGAS UPGRADING PROCESSES FOR THE PRODUCTION OF NATURAL GAS SUBSTITUTE

    OpenAIRE

    Čekanova, Patricia; Jasminska, Natalia; Brestovič, Tomaš; Schvarzbacherova, Eva

    2011-01-01

    Biogas from anaerobic digestion of biological wastes is a renewable energy resource. It has been used to provide heat, shaft power and electricity. Typical biogas contains 50-65% methane (CH4), 30-45% carbon dioxide (CO2), moisture and traces of hydrogen sulphide (H2S). Presence of CO2 and H2S in biogas affects engine performance adversely. Reducing CO2 and H2S content will significantly improve quality of biogas. In this work, a method for biogas scrubbing and CH4 enrichment is presented. Ch...

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

    Directory of Open Access Journals (Sweden)

    Leandro Janke

    2015-08-01

    Full Text Available 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.

  14. 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

  15. 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.

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

    International Nuclear Information System (INIS)

    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

  17. Special file: biogas

    International Nuclear Information System (INIS)

    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

  18. Reactor coolant pump seals: improving their performance

    International Nuclear Information System (INIS)

    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

  19. Performance of a multipurpose research electrochemical reactor

    International Nuclear Information System (INIS)

    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.

  20. Numerical investigation of biogas flameless combustion

    International Nuclear Information System (INIS)

    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 O2 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, NOx 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

  1. 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

  2. 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.

  3. Biogas generation in anaerobic wastewater treatment under tetracycline antibiotic pressure

    OpenAIRE

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

    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...

  4. Biogas Production on Demand Regulated by Butyric Acid Addition

    Science.gov (United States)

    Kasper, K.; Schiffels, J.; Krafft, S.; Kuperjans, I.; Elbers, G.; Selmer, T.

    2016-03-01

    Investigating effects of volatile fatty acids on the biogas process it was observed that butyric acid can be used for transient stimulation of the methane production in biogas plants operating with low energy substrates like cattle manure. Upon addition of butyrate the methane output of the reactors doubled within 24 h and reached almost 3-times higher methane yields within 3-4 days. Butyrate was quantitatively eliminated and the reactors returned to the original productivity state within 3 days when application of butyrate was stopped. The opportunity to use butyrate feeding for increased biogas production on demand is discussed.

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

    International Nuclear Information System (INIS)

    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.)

  6. Manure energy exploitation : the use of biogas to secure water supply in developing countries

    OpenAIRE

    Arntzen, Jarl Ove

    2013-01-01

    This thesis has investigated the feasibility to produce electricity for water pumping in developing countries by using a simple biogas reactor system with an internal combustion. This was done by visiting Katulani Secondary School (SS) in Kitui, Kenya. Here a biogas reactor fed with pig manure produces biogas currently used for cooking. A grid connected water pump owned by the school is also located here. Data collection through measurements and interviews was done during 8 days. 10 tests gav...

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

    International Nuclear Information System (INIS)

    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 CO2 emissions

  8. Research and development into power reactor fuel performance

    International Nuclear Information System (INIS)

    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 UO2 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

  9. 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.)

  10. Neutronic Core Performance of CAREM-25 Reactor

    International Nuclear Information System (INIS)

    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

  11. A new high performance research reactor

    International Nuclear Information System (INIS)

    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 4th 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)

  12. Australia's new high performance research reactor

    International Nuclear Information System (INIS)

    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)

  13. Biogas and biofuels barometer

    International Nuclear Information System (INIS)

    European union countries are becoming more and more interested by the characteristics of biogas in terms of environment and energy production and are developing their proper channels of valorization according to their potential. In this way, biogas production reached nearly 5,3 million tons oil equivalent in 2006, representing a 13,6% increase with respect to 2005. Statistical data are provided on the primary energy production of biogas, the electricity production from biogas, gross heat production from biogas, and the representative firms of the biogas sector. In a second part the biofuels barometer is presented. The agricultural environment and landscape of the European Union countries is redefined a little more each year by energy crops for biofuel production. According to the first estimates for 2006, biofuel consumption reached 5,38 Mtoe last year in the EU, corresponding to a 1,8% share of the total consumption of fuels devoted to transport. (A.L.B.)

  14. Testing and optimising biogas plants

    Energy Technology Data Exchange (ETDEWEB)

    Perwanger, A.

    1984-01-01

    The long-term output of biogas systems studied in practice of an average just under 1 cbm gross of biogas per GV and day is below the forecast levels. Only very few plants showed higher output in the long term. This makes it even more important to show ways of improving process control and reducing building costs for the system. As a result of comparative practical studies in connection with corresponding experiments in the laboratory, it has already been possible to find a number of proposals for improvements. For instance, raising substrate performance with substrate dilution, cost-reducing and functionally safe construction of systems with a gas-dome mounted on top and the possibility of simple biogas production in the final storage unit with low-cost voluminous gas storage at the same time. The latter solution has the advantage of allowing the fermentation substrate to be anaerobically treated all year round, the N-losses would be lower by contrast with open slurry storage, and that any ecologically relevant regulations about odeur control and slurry storage at the farm could be complied with absolutely safely and with the additional use of biogas.

  15. Enhancing Safety Performance of Research Reactors at Trombay

    International Nuclear Information System (INIS)

    Based on various national requirements of basic research, material testing, isotope production, criticality experiments and research related to future power reactor program, Indian research reactor program encompasses a variety of reactors from simple pool type reactor Apsara to complex 100 MW reactor like Dhruva. To meet the varied and complex safety requirements of research reactors, a strong safety management system has also been evolved and nurtured. With over 150 reactor years of operating feedback, wealth of experience has been gained and safety enhancement has been kept as a continuously evolving process at Trombay. The 100 MWth research reactor Dhruva has now completed more than two and half decades of operation. Based on a systematic In-Service Inspection (ISI) program, structured system performance monitoring and review and Periodic Safety Review (PSR) certain incipient failures in the system could be noted and corrected in time. Based on these reviews, certain mid-term safety upgrades in various systems of Dhruva were carried out. This paper will provide an overview of overall safety enhancement of research reactors, through refurbishment, and engineering changes. (author)

  16. Energy recovering and biogas

    International Nuclear Information System (INIS)

    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 CO2 emissions. (A.L.B.)

  17. Dynamic biogas upgrading based on the Sabatier process

    DEFF Research Database (Denmark)

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

    2015-01-01

    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...

  18. Integrated biogas systems

    Science.gov (United States)

    Amaratunga, M.

    1980-01-01

    Integrated biogas systems as alternatives to fossil fuels in Sri Lanka are considered from standpoints of population growth, land availability, and employment opportunities. Agricultural practices would be improved by use of chemical fertilizers, and health/nutrition problems be alleviated by using biogas systems. Fuel for cooking and rural industries will become more easily available; water weeds, such as water hyacinth and salvinia which pose a threat to waterways and rice paddy lands could be used for the production of biogas and fertilizers. A concept of an integrated biogas system comprising photosynthesis and anaerobic degradation processes to produce food and energy is presented.

  19. 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.

  20. Energy Efficiency Evaluation of two Biogas Plants

    OpenAIRE

    Nordlander, Eva; Holgersson, Jenny; Thorin, Eva; Thomassen, Martin; Yan, Jinyue

    2011-01-01

    Anaerobic digestion for biogas production is a promising renewable energy technology whichcan be used to achieve environmental goals set in the European Union and other regions. Thereare however many improvements that can still be made to the process. Furthermore, there arealternative energy conversion processes that compete for some of the substrates used inanaerobic digestion. Energy efficiency could therefore be a tool for measuring and comparingthe performance of biogas plants. This study...

  1. Produção específica de biogás a partir de manipueira em reator de fase única Specific biogas production from manipueira at one-phase reactor

    Directory of Open Access Journals (Sweden)

    Osvaldo Kuczman

    2011-02-01

    Full Text Available O presente artigo mostra um estudo sobre a produção de biogás a partir de manipueira, considerando o volume de um reator de fluxo tubular horizontal de fase única. O objetivo do trabalho foi avaliar a produção de biogás aumentando-se as cargas orgânicas e os volumes de alimentação, o que resultou em redução do tempo de retenção hidráulica (TRH. O reator foi alimentado continuamente, com cargas orgânicas de 1,18; 1,28; 1,57 e 2,68 g DQO L-1rd-1 (gramas de demanda química de oxigênio por litro de reator por dia em TRHs de 15; 13,0; 8,3; 6,6 dias, respectivamente. As produções de biogás foram de 0,52; 0,41; 0,65 e 0,63 L L-1rd-1, destacando-se que o primeiro TRH avaliado foi o de 13 dias, seguido de 8,3; 6,6 e 15 dias. Do estudo, concluiu-se que, com a diminuição do TRH, ocorre maior produção de biogás por volume de reator. Consequentemente, através da utilização do TRH adequado, pode-se aproveitar melhor o volume do reator, fato que resultará em economia na implantação da tecnologia em indústrias processadoras de mandioca.This article presents a study on biogas production from wastewater cassava considering the volume of a one-phase horizontal tubular flow reactor. The objective was to evaluate the biogas production, enlarging the organic loadings and feeding volums, resulting in minor hydraulic retention times (HRT. The reactor was continuously fed with organic charges corresponding to 1.18; 1.28; 1.57 and 2.68 g COD L-1r d-1 (grams of oxygen chemical demand per liter of reactor per day, resulting in hydraulic retention times 15; 13; 8.3 and 6.6 days. The correspondent specific biogas productions were, respectively, 0.52; 0.41; 0.65 and 0.63 L L-1rd-1 , emphasizing that the 13-day was the first HRT rated, followed by 8.3, 6.6 and 15 days. It was concluded that with the HRT decrease occurred larger biogas production per reactor volume. Therefore, with the correct selection for HRT, it is possible to make the best

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

    International Nuclear Information System (INIS)

    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

  3. Study on biogas premixed charge diesel dual fuelled engine

    International Nuclear Information System (INIS)

    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

  4. Complete Genome Sequence of Herbinix luporum SD1D, a New Cellulose-Degrading Bacterium Isolated from a Thermophilic Biogas Reactor

    Science.gov (United States)

    Koeck, Daniela E.; Maus, Irena; Wibberg, Daniel; Winkler, Anika; Zverlov, Vladimir V.; Liebl, Wolfgang; Pühler, Alfred; Schwarz, Wolfgang H.

    2016-01-01

    A novel cellulolytic bacterial strain was isolated from an industrial-scale biogas plant. The 16S rRNA gene sequence of the strain SD1D showed 96.4% similarity to Herbinix hemicellulosilytica T3/55T, indicating a novel species within the genus Herbinix (family Lachnospiraceae). Here, the complete genome sequence of Herbinix luporum SD1D is reported. PMID:27445379

  5. Complete Genome Sequence of Herbinix luporum SD1D, a New Cellulose-Degrading Bacterium Isolated from a Thermophilic Biogas Reactor.

    Science.gov (United States)

    Koeck, Daniela E; Maus, Irena; Wibberg, Daniel; Winkler, Anika; Zverlov, Vladimir V; Liebl, Wolfgang; Pühler, Alfred; Schwarz, Wolfgang H; Schlüter, Andreas

    2016-01-01

    A novel cellulolytic bacterial strain was isolated from an industrial-scale biogas plant. The 16S rRNA gene sequence of the strain SD1D showed 96.4% similarity to Herbinix hemicellulosilytica T3/55(T), indicating a novel species within the genus Herbinix (family Lachnospiraceae). Here, the complete genome sequence of Herbinix luporum SD1D is reported. PMID:27445379

  6. 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

  7. Effect of pressure on biogas production

    Directory of Open Access Journals (Sweden)

    Ahmet ERYAŞAR

    2009-02-01

    Full Text Available In facilities in which biogas systems are installed biogas is not produced and consumed simultaneously. Therefore, biogas produced when there is no consumption should be stored. Low pressure gasometers with 1- 1,5 kPa value are preferred in the rural area and when needed pressurizer is added to the system. When the pressure which gas production and usage require is provided by natural ways without usage of an added pressurizer, a respectively high pressure atmosphere can be seen. In this study, the effects of different low pressures on anaerobic fermentation of cattle manure were experimentally analyzed. Fermentation experiment which was carried out with 9 reactors with fed-batch type, 3 parallels in pressures of 19.6 kPa, 9.5 kPa and 1.5 kPa continued 60 days at 35 ºC. The acquired experimental data was subjected to LSD test in P

  8. 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

  9. Biogas Production through the Syntrophic Acetate-Oxidising Pathway. Characterisation and Detection of Syntrophic Acetate- Oxidising Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Westerholm, Maria [Faculty of Natural Resources and Agricultural Sciences, Dept. of Microbiology, Swedish Univ. of Agricultural Sciences, Uppsala (Sweden)

    2012-11-01

    Biogas produced from wastes, residues and energy crops has promising potential to reduce greenhouse gas emissions and to secure future energy supply. Methane is the energy-rich component of biogas, and is formed as the end product during degradation of organic material without oxygen (anaerobic). Acetate is an important intermediate in anaerobic degradation and can be converted to methane through two pathways: aceticlastic methanogenesis and syntrophic acetate oxidation (SAO). SAO is a two-step reaction, consisting of acetate oxidation to hydrogen and carbon dioxide by syntrophic acetate-oxidising bacteria (SAOB), followed by conversion of these products to methane by hydrogenotrophic methanogens. Ammonia and acetate concentration, hydraulic retention time, temperature and methanogenic population structure are operational parameters considered to influence the acetate conversion pathway. This thesis sought to increase understanding of SAO by examining syntrophic acetate oxidisers in pure culture, co-culture and methanogenic reactors. Two novel species of SAOB, Syntrophaceticus schinkii and Tepidanaerobacter acetatoxydans, were isolated and their phenotypic and phylogenetic traits were characterised. Quantitative molecular approaches were developed and applied to determine structural dynamics in the methane-producing population in a mesophilic biogas reactor during an ammonia-induced shift from aceticlastic to syntrophic acetate degradation. The abundance of SAOB increased, with a simultaneous decrease in aceticlastic methanogens. The majority of known SAOB are considered acetogens, and gradually increased ammonia concentration was shown to cause distinct shifts in the putative acetogenic population structure in mesophilic biogas reactors. However, the acetogenic bacterial abundance remained relatively stable. Bioaugmentation of syntrophic acetate-oxidising cultures did not improve process performance or support establishment of SAO as the dominant acetate

  10. 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. PMID:27209038

  11. Titer-plate formatted continuous flow thermal reactors: Design and performance of a nanoliter reactor

    OpenAIRE

    Chen, Pin-Chuan; Park, Daniel S.; You, Byoung-Hee; Kim, Namwon; Park, Taehyun; Steven A Soper; Nikitopoulos, Dimitris E.; Murphy, Michael C.

    2010-01-01

    Arrays of continuous flow thermal reactors were designed, configured, and fabricated in a 96-device (12 × 8) titer-plate format with overall dimensions of 120 mm × 96 mm, with each reactor confined to a 8 mm × 8 mm footprint. To demonstrate the potential, individual 20-cycle (740 nL) and 25-cycle (990 nL) reactors were used to perform the continuous flow polymerase chain reaction (CFPCR) for amplification of DNA fragments of different lengths. Since thermal isolation of the required temperatu...

  12. Reactor and turbine building layout of the high performance light water reactor

    International Nuclear Information System (INIS)

    Based on the information generated within the European funded project ''High Per-formance Light Water Reactor Phase 2'', a general plant layout has been developed. The central building is the reactor building, in which the containment and safety sys-tems are located. The reactor building is with app. 90.000 m3 considerably smaller compared to other BWR buildings, thus providing a huge potential for cost savings. The turbine building with app 250,000 m3 is of approximately the same size like for existing BWRs. (orig.)

  13. 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

    Ammonia (NH4+/NH3) inhibition during anaerobic digestion process is one of the most frequent problems existing in biogas plants, resulting in unstable process and reduced biogas production. In this study, we developed a novel hybrid system, consisted of a submersed microbial resource recovery cell...

  14. Electricity from biogas

    International Nuclear Information System (INIS)

    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 CO2 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

  15. LVR-15 reactor performance and transformation to low enriched fuel

    International Nuclear Information System (INIS)

    Experimental research reactor LVR-15 situated in Nuclear Research Institute Rez, plc. has been utilized since 1957. The present reactor nominal power is 10 MW. Standard reactor cycle is 21 days and the reactor operates 8 - 10 cycles per year. The State Office for Nuclear Safety newly licensed the reactor till 2014. The reactor is of multi-purpose use. The basic research is carried out using horizontal neutron beams and one of them is used for development and application of the boron neutron captures therapy for brain tumors. Mostly material testing of PWR and BWR specimens is performed in high-pressure loops and irradiation rigs operated in the reactor. Several vertical channels serve for production of neutron transmutation doped silicon and isotopes production for medical purposes. Reactor was originally designed with EK-10 fuel type and consequently reconstructed for HEU with the 80% 235U enrichment in 1987-89. In period 1987-1989 the reactor undertook the second reconstruction to enhance its experimental and commercial utilizing. Later, the fuel enrichment was changed to 36 % with the use of the IRT-2M fuel type. The neutron-physical characteristics of the reactor core and fuel cycle design and analyses are carried out using the WIMS-D4m, NODER and OMEGA programs. The codes were used for a preliminary evaluation of essential changes of main neutronic characteristics of the LVR-15 core with the prospective conversion to low enriched fuel (LEU). Three types of FA-s has been assessed: 1) currently used IRT-2M(36%), 2) IRT-3M(20%), 3) IRT-4M(20%) and results are presented in the article. (author)

  16. Performance and dynamic characteristics of microbial communities in an internal circulation reactor for treating brewery wastewater.

    Science.gov (United States)

    Xu, Fu; Miao, Heng-Feng; Huang, Zhen-Xing; Ren, Hong-Yan; Zhao, Ming-Xing; Ruan, Wen-Quan

    2013-01-01

    A laboratory-scale internal circulation (IC) anaerobic reactor fed with brewery wastewater was operated at 35 degrees C + 1 degrees C. The influent was pumped into the bottom of the IC reactor by a pulse pump, whereas the effluent was drawn from the upper outlet and allowed to flow into the effluent tank. The biogas volume was recorded using a gas container connected to a biogas metre. The results indicated that the maximum organic loading rate (OLR) of the IC reactor was 19.5 kg chemical oxygen demand (COD)/m3/day; at which point, the dominant archaeal populations found in the sludge using the polymerase chain reaction with denaturing gradient gel electrophoresis were Methanosaeta species. The COD removal efficiencies of the reactor exceeded 85%, with a maximum specific methane production rate of 210 mL CH4/g volatile suspended solids (VSS)/day and a coenzyme F420 content of 0.16 micromol/g VSS, respectively. The main archaeal species in the sludge samples at different OLRs varied greatly, as compared with the organisms in the inoculated sludge. The dominant archaeal species in the treated sludge at low OLRs were Methanosarcina species, whereas those at high OLRs were Methanosaeta species. PMID:24527653

  17. Environmental perspectives on using cast seaweed for biogas production

    DEFF Research Database (Denmark)

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

    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......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...

  18. Mini digester and biogas production from plant biomass

    Directory of Open Access Journals (Sweden)

    P. Vindis

    2009-08-01

    Full Text Available Purpose: The aim of the paper is to present the construction of a mini digester for biogas production from different agriculture plant biomass and other organic wastes. The amount of biogas production (methane is observed by the mini digester.Design/methodology/approach: The mini digester consisting of twelve units was built and some measurements with agriculture plant biomass were performed according to DIN 38414 part 8. Four tests simultaneously with three repetitions can be performed.Findings: With the mini digester the amount of biogas production is observed. The parameters such as biogas production and biogas composition from maize and sugar beet silage in certain ratio were measured and calculated. The highest biogas and methane yield was 493 NI kg VS-1 or 289 NI CH4 kg VS-1.Research limitations/implications: The scope of substrates for the anaerobic digestion process is on the increase so the interest in the use of the biogas as a source of a renewable energy is very high. With mini digester it is possible to observe the amount of biogas (methane production and so the most suitable plant giving the maximum methane yield, can be determined.Practical implications: The aim of biogas as renewable source of energy is to replace fossil fuels with sustainable energy production systems and to fulfil the requirements of the Kyoto Protocol. On big farms the liquid manure and different energy crops can be used for biogas production. That can improve the economical efficiency of the farm and reduce the CO2 emissions.Originality/value: Mini digester for biogas production was built as special equipment. The quality of produced biogas is determined with a gas analyser GA 45.

  19. Performance of a Novel Decentralised Sewage Treatment Reactor

    Directory of Open Access Journals (Sweden)

    Dong Sheng Shen

    2013-01-01

    Full Text Available A novel decentralised sewage treatment reactor (DSTR for treating domestic sewage in rural areas was designed and investigated. The reactor was started aerobically after inoculation with biomass; the amount of initial mixed liquid suspended solids was 1.5 g/L. Oxygen was supplied to the reactor and the dissolved oxygen concentration was maintained at 1.3 ± 0.2 mg/L. The pollutant removal performance was investigated, and the average removal efficiencies of total chemical oxygen demand (TCOD, NH4+-N, suspended solids, and turbidity were 76%, 77.15%, 84.17%, and 83.93%, respectively. The DSTR exhibited good performance compared with the traditional activated sludge (AS reactor. The resistance to impact load of the DSTR was superior to that of the AS reactor during surface load experiments. During the 120 days of operation, no sludge bulking was observed. The DSTR effluent NH4+-N and TCOD levels were a little higher than those for the AS reactor, but the disparity was not major.

  20. Use of biogas in agriculture

    OpenAIRE

    Hejný, František

    2012-01-01

    Biogas results from anaerobic fermentation of organic substances either in oxygen atmosphere or non-oxygen atmosphere, depending on decomposition stage. Composition of Biogas is different, depends mainly on development of fermentation and additional important factors. The most important for Biogas is the maximum contents of methane. Biogas stations exploit Biogas for production of electric energy and heat energy by means of congregational units and there is also possibility to generate c...

  1. 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.

  2. Biologische Entschwefelung von Biogas

    OpenAIRE

    Schneider, Ralf

    2009-01-01

    Ziel dieser Arbeit ist die Erhöhung von Abbauleistung und Stabilität des biologischen Abbaus von Schwefelwasserstoff (H2S) in Biotropfkörpern zur Entschwefelung von Biogas. Für die Nutzung von Biogas ist häufig eine Reduktion des H2S-Gehalts erforderlich. Üblicherweise wird H2S von aeroben Mikroorganismen bei Zugabe von Luft zum Biogas entweder direkt im Biogasreaktor oder in nachgeschalteten Biotropfkörpern zu Schwefel und Schwefelsäure oxidiert. In der Praxis auftretende Schwankungen der H2...

  3. The impact of mesophilic and thermophilic anaerobic digestion on biogas production

    OpenAIRE

    P. Vindis; B. Mursec; M. Janzekovic; F. Cus

    2009-01-01

    Purpose: of this paper is to compare mesophilic and thermophilic anaerobic digestion of three maize varieties. Parameters such as biogas production and biogas composition from maize silage were measured and calculated. The amount of biogas production (methane) was observed by the mini digester.Design/methodology/approach: Biogas production and composition in mesophilic (35 degrees C) and thermophilic (55 degrees C) conditions were measured and compared. The measurements were performed with mi...

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

    International Nuclear Information System (INIS)

    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

  5. An implicit solution framework for reactor fuel performance simulation

    International Nuclear Information System (INIS)

    The simulation of nuclear reactor fuel performance involves complex thermomechanical processes between fuel pellets, made of fissile material, and the protective cladding that surrounds the pellets. An important design goal for a fuel is to maximize the life of the cladding thereby allowing the fuel to remain in the reactor for a longer period of time to achieve higher degrees of burnup. This presentation examines various mathematical and computational issues that impact the modeling of the thermomechanical response of reactor fuel, and are thus important to the development of INL's fuel performance analysis code, BISON. The code employs advanced methods for solving coupled partial differential equation systems that describe multidimensional fuel thermomechanics, heat generation, and transport within the fuel

  6. Mitigating reactor incidents through performance-based training

    International Nuclear Information System (INIS)

    The Advanced Test Reactor (ATR), located at the Idaho National Engineering Laboratory, is operated for the Department of Energy by EG and G Idaho, Inc. The ATR is a 250 MW research reactor. Its primary mission is to support DOE research on fuel and material irradiation. In addition, limited space at the ATR is available to industry for materials irradiation and radioactive isotopes production. The training of operating personnel is as important as any other component of reactor safety. The question of what exactly these operators need to know in order to accurately and quickly recognize and respond to system malfunctions is extremely important and sometimes difficult to specifically identify. The use of a performance based training system combined with learning from the past experiences are currently the best tools available. The purpose of this paper is to present ATR's approach to performance based training

  7. Modern control technology for improved nuclear reactor performance

    International Nuclear Information System (INIS)

    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

  8. Decision Support for the Construction of Farm-Scale Biogas Digesters in Developing Countries with Cold Seasons

    OpenAIRE

    Sven Gjedde Sommer; Charlotte Rennuit

    2013-01-01

    Biogas production is a clean renewable energy source that can improve lives in developing countries. However, winter temperatures in some areas are too low to enable enough biogas production in small unheated digesters to meet the energy requirements of households. Low-cost, high yield reactors adapted to the local climate are needed in those situations. A decision-support model was developed to assist in the design of biogas reactors capable of meeting households’ year-round energy needs. Mo...

  9. Influence of different practices on biogas sustainability

    International Nuclear Information System (INIS)

    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

  10. Practices for Neutronic Design of Research Reactors: Safety and Performances

    International Nuclear Information System (INIS)

    In brief, the design aims to have a facility which is quickly operational and profitable, safe and able to evolve over 40 or 60 years, taking into account both the evolution of the requirements for experiments or production yet to be realized and the safety practices. This paper presents the AREVA current design and safety practices (both cannot be realized without the other) for the neutronic design of the research reactor (RR) cores. It completes the paper and presents the general methodology of neutronic design studies for the safety and performance aspects and only slightly focuses on the reactivity shutdown systems and the neutronic calculation schemes. The main points are illustrated with examples of the Jules Horowitz Reactor (core designer point of view). On this basis of our general methodology, certain problems are separated in order to permit rapid reiteration at an individual level before the final synthesis. For example: to carry out generic studies of fuel management strategies and core reactivity control in order to manage the power peak (need core depletion calculation) and to be able to reason step 0 for certain optimizations of the core geometry and characteristics. For the neutronic calculation scheme, our current practice is to combine the use of the deterministic and stochastic codes. The strong points of each type of code are used to reinforce the safety and the performance of our cores. In this field, AREVA has a R and D framework involving and coordinating the participants from the various sectors (power reactors, research reactor etc) in the development of the general calculation methods and associated tools, in particular for Monte Carlo core depletion calculations. The CEA (along with APOLLO, CRONOS and TRIPOLI codes) largely supports us in this field. Comparisons between MCNP and TRIPOLI and between the various libraries (ENDF, JEF, etc.) are also performed. That includes the recalculation of existing reactors (OSIRIS, ORPHEE, AZUR

  11. 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 packi

  12. The performance of structured packings in trickle-bed reactors.

    NARCIS (Netherlands)

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

    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 packi

  13. Research performed at the ETRR-1 reactor using TOF technique

    International Nuclear Information System (INIS)

    This paper represents the results of studies of neutron transmission at several single crystals, performed at ETRR-1 reactor horizontal channels. The results of these studies starting in 1984 and continuing to date are discussed; the use of large single crystals as a band pass filter is also assessed

  14. Fuel element situation and performance data TRIGA Mark II reactor

    International Nuclear Information System (INIS)

    Electronic data acquisition of the position and movement of Triga fuel elements (FE) in the TRIGA II Vienna reactor was the objective of this project. Using one month power data and the Fuel element position in core it is possible to calculate their burnup. Fuel element performance data during 1962 to 2003 are provided. (nevyjel)

  15. Biphasic mini-reactor for characterization of biocatalyst performance

    OpenAIRE

    Van Den Wittenboer, Anne; Schmidt, Thomas; Müller, Pia; Ansorge-Schumacher, Marion Bettina; Greiner, Lasse

    2009-01-01

    Abstract Biphasic reaction media are extending the scope of technical biocatalysis. Thorough investigation of the factors affecting catalyst performance under these conditions is of key importance for the successful implementation of catalytic processes. Here, we present a reactor setup suitable for comprehensive systematic characterization and optimization of biocatalyzed reactions in biphasic systems with distinct phases. It is distinguished by small volumes allowing reproducible...

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

    International Nuclear Information System (INIS)

    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.)

  17. 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

  18. Biogas barometer 2011

    International Nuclear Information System (INIS)

    Biogas energy recovery for both electricity and heat application has increased in the European Union in 2011 (compared to 2010): +18% for gross electricity production from biogas and +16% for the gross heat production from biogas. The magnitude of the reduction (-7%) in the primary energy figures between 2010 and 2011 can be played down as it can be explained by a change in reporting method of the main producer country, Germany. Germany has taken the lead by far in the E.U. for the production of primary energy of biogas and its uses for heat or electricity production. Among the 13 most representative firms in the anaerobic digestion (methanization) sector in Europe, 8 are German. New markets are starting to emerge but the economic crisis and regulatory restrictions do not augur well of their expansion

  19. Energy crops for biogas

    International Nuclear Information System (INIS)

    This investigation aims at describing the effects on cropping systems, containing a.o. leguminosae plant leys for biogas production. Problems treated are effects on soil physics, circulation of crop nutrients, use of chemical pesticides, preceding crop effects, and the possibility of utilizing catch crops for methane production. It is observed that the studied biogas-crop sequences gives positive effects on soil structure, reduced need for artificial fertilizers and chemical pesticides. 26 refs, 28 tabs

  20. Density dependence of reactor performance with thermal confinement scalings

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Performance of fast reactor irradiated fueled emitters at goal burnup

    International Nuclear Information System (INIS)

    UO2-fueled W emitters were examined that had been irradiated to goal burnups of approximately 4 at.% at emitter surface temperatures to 1820 K in a fast reactor to establish their performance for use in thermionic reactors with power levels from tens of kilowatts to multimegawatts. The examinations provided first-time data on structural integrity, dimensional stability, component compatibility, and fuel and fission product behavior. The data are consistent with similar measurements at approximately 2 at.% burnup with the exception of one emitter which breached the W during irradiation

  2. 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.

  3. BISON and MARMOT Development for Modeling Fast Reactor Fuel Performance

    International Nuclear Information System (INIS)

    BISON and MARMOT are two codes under development at the Idaho National Laboratory for engineering scale and lower length scale fuel performance modeling. It is desired to add capabilities for fast reactor applications to these codes. The fast reactor fuel types under consideration are metal (U-Pu-Zr) and oxide (MOX). The cladding types of interest include 316SS, D9, and HT9. The purpose of this report is to outline the proposed plans for code development and provide an overview of the models added to the BISON and MARMOT codes for fast reactor fuel behavior. A brief overview of preliminary discussions on the formation of a bilateral agreement between the Idaho National Laboratory and the National Nuclear Laboratory in the United Kingdom is presented.

  4. BISON and MARMOT Development for Modeling Fast Reactor Fuel Performance

    Energy Technology Data Exchange (ETDEWEB)

    Gamble, Kyle Allan Lawrence [Idaho National Lab. (INL), Idaho Falls, ID (United States); Williamson, Richard L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schwen, Daniel [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Yongfeng [Idaho National Lab. (INL), Idaho Falls, ID (United States); Novascone, Stephen Rhead [Idaho National Lab. (INL), Idaho Falls, ID (United States); Medvedev, Pavel G. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    BISON and MARMOT are two codes under development at the Idaho National Laboratory for engineering scale and lower length scale fuel performance modeling. It is desired to add capabilities for fast reactor applications to these codes. The fast reactor fuel types under consideration are metal (U-Pu-Zr) and oxide (MOX). The cladding types of interest include 316SS, D9, and HT9. The purpose of this report is to outline the proposed plans for code development and provide an overview of the models added to the BISON and MARMOT codes for fast reactor fuel behavior. A brief overview of preliminary discussions on the formation of a bilateral agreement between the Idaho National Laboratory and the National Nuclear Laboratory in the United Kingdom is presented.

  5. EFFECT OF DYE CONCENTRATION ON SEQUENCING BATCH REACTOR PERFORMANCE

    Directory of Open Access Journals (Sweden)

    A. A. Vaigan ، M. R. Alavi Moghaddam ، H. Hashemi

    2009-01-01

    Full Text Available Reactive dyes have been identified as problematic compounds in textile industries wastewater as they are water soluble and cannot be easily removed by conventional aerobic biological treatment systems. The treatability of a reactive dye (Brill Blue KN-R by sequencing batch reactor and the influence of the dye concentration on system performance were investigated in this study. Brill Blue KN-R is one of the main dyes that are used in textile industries in Iran. Four cylindrical Plexiglas reactors were run for 36 days (5 days for acclimatization of sludge and 31 days for normal operation at different initial dye concentrations. The dye concentrations were adjusted to be 20, 25, 30 and 40 mg/L in the reactors R1, R2, R3 and R4, respectively. In all reactors, effective volume, influent wastewater flowrate and sludge retention time were 5.5 L, 3.0 L/d and 10 d, respectively. According to the obtained data, average dye removal efficiencies of R1, R2, R3 and R4 were 57% ± 2, 50.18% ± 3, 44.97% ± 3 and 30.98% ± 3, respectively. The average COD removal efficiencies of all reactors were 97% ± 1, 97.12% ± 1, 96.93% ± 1 and 97.22% ± 1, respectively. The dye removal efficiency was decreased by increasing the dye concentration with the correlation coefficient of 0.997.

  6. Horse dung waste utilization as a household energy resource and estimation of biogas production

    Science.gov (United States)

    Umbara, Rian F.; Sumaryatie, Erni D.; Kirom, M. R.; Iskandar, Reza F.

    2013-09-01

    Horses are still used as traditional transportation in Soreang, West Java. About 6-7 horses can produce 25-30 kg of dung every day. Horse dung can produce biogas that can be used as an energy resource. A biogas reactor with capacity of 4 m3 has been built in Soreang. The reactor is filled with a mixture of 50 kg of horse dung and 100 liters of water every two days. This research was conducted to observe the quality of biogas produced from the reactor and to estimate the volume of biogas produced per day. The observation of daily biogas production conducted in 22 days. Laboratory tests showed that the composition of gases contained in the produced biogas consists of 56.53% of CH4, 26.98% of CO2, 12.35% of N2, 4.13% of O2, and 0.007% of H2. Daily biogas production data indicate a stationary trend. A moving average time series model is used to model the data. Using the model, it is estimated that the reactor can produce 0.240112 m3 of biogas per day, which is sufficient to meet the energy needs of a household.

  7. 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

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    Sunarso

    2009-12-01

    Full Text Available 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 (R and tap water (W in several ratio resulting six different M:W:R ratio contents i.e. 1:1:0; 1:0.75:0.25; 1:0.5:0.5; 1:0.25:0.75; and 1:0:1 (correspond to 0; 12.5; 25, 37.5; 50, and 100 % rumen, respectively. The research showed that, either in room temperature as well as in 38.5 C, the best performance of biogas production was obtained with rumen fluid in the range of 25-50 %. Increasing rumen content will also increase biogas production. This is suggest that, due to the optimum total solid (TS content for biogas production between 7-9 % (or correspond to more and less manure and total liquid 1:1, the rumen fluid content of 50 % will give the best performance for biogas production. However, intensively research need to be carried in further research to study interaction effect of TS and rumen content to biogas production.

  10. 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. PMID:26718471

  11. Energy from Biomass - Comparision of biogas production at ambient temperature and at mesophilic temperature in semicontenous anaerobic digester using vegetable market waste

    Directory of Open Access Journals (Sweden)

    Dhanalakshmi Sridevi V.

    2014-03-01

    Full Text Available Studies are conducted in semicontinuous anaerobic reactors of 2 L Capacity with effective volume of 1.5 L. Experiments were carried out in the mesophilic temperature range maintained at 35°C in a thermostat, and parallel experiments were performed at ambient temperature on biogas production from the month of Februray to August. The reactors were operated with an organic loading rate of 0.5 gVS/L/d with 25 days HRT. The feed stock used for the study was vegetable market waste obtained from Koyambedu vegetable market. The specific biogas production was found to be 0.530 L gVS add-1 for the reactor operated at mesophilic temperature and in the range of 0.431 to 0.732 L gVSadd -1 for the reactor operated in the ambient temperature condition from the month of February to August. The daily biogas production was found to be similar (approximately 350 mL/d when reactors were operated at mesophilic and ambient temperature except for the period of May and June wherein higher amount of daily biogas production (472 and 529 mL/d was observed in the reactor operated at ambient temperature. The ratio of total VFA and alkalinity and propionic acid to acetic acid (PA/AA was found to be in the range of 0.25 – 0.4 and 0.34 - 1.38 during the operation of the reactor for the entire period, which was within the range reported for digester stability.

  12. 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

  13. 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

  14. Experiences with biogas in Denmark

    OpenAIRE

    Bundgaard, Sirid Sif; Kofoed-Wiuff, Anders

    2014-01-01

    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 taskforce 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 relationshi...

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  17. Fuel performance at high burnup for water reactors

    International Nuclear Information System (INIS)

    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

  18. Experimental Facilities for Performance Evaluation of Fast Reactor Components

    International Nuclear Information System (INIS)

    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

  19. EFFECT OF DYE CONCENTRATION ON SEQUENCING BATCH REACTOR PERFORMANCE

    OpenAIRE

    A. A. Vaigan ، M. R. Alavi Moghaddam ، H. Hashemi

    2009-01-01

    Reactive dyes have been identified as problematic compounds in textile industries wastewater as they are water soluble and cannot be easily removed by conventional aerobic biological treatment systems. The treatability of a reactive dye (Brill Blue KN-R) by sequencing batch reactor and the influence of the dye concentration on system performance were investigated in this study. Brill Blue KN-R is one of the main dyes that are used in textile industries in Iran. Four cylindrical Plexiglas reac...

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

    International Nuclear Information System (INIS)

    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

  1. 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.

  2. The effect of storage conditions on microbial community composition and biomethane potential in a biogas starter culture.

    Science.gov (United States)

    Hagen, Live Heldal; Vivekanand, Vivekanand; Pope, Phillip B; Eijsink, Vincent G H; Horn, Svein J

    2015-07-01

    A new biogas process is initiated by adding a microbial community, typically in the form of a sample collected from a functional biogas plant. This inoculum has considerable impact on the initial performance of a biogas reactor, affecting parameters such as stability, biogas production yields and the overall efficiency of the anaerobic digestion process. In this study, we have analyzed changes in the microbial composition and performance of an inoculum during storage using barcoded pyrosequencing of bacterial and archaeal 16S ribosomal RNA (rRNA) genes, and determination of the biomethane potential, respectively. The inoculum was stored at room temperature, 4 and -20 °C for up to 11 months and cellulose was used as a standard substrate to test the biomethane potential. Storage up to 1 month resulted in similar final methane yields, but the rate of methane production was reduced by storage at -20 °C. Longer storage times resulted in reduced methane yields and slower production kinetics for all storage conditions, with room temperature and frozen samples consistently giving the best and worst performance, respectively. Both storage time and temperature affected the microbial community composition and methanogenic activity. In particular, fluctuations in the relative abundance of Bacteroidetes were observed. Interestingly, a shift from hydrogenotrophic methanogens to methanogens with the capacity to perform acetoclastic methanogensis was observed upon prolonged storage. In conclusion, this study suggests that biogas inocula may be stored up to 1 month with low loss of methanogenic activity, and identifies bacterial and archaeal species that are affected by the storage. PMID:25947246

  3. 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.

  4. 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.

  5. 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. PMID:25176305

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

    International Nuclear Information System (INIS)

    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

  7. Reliable reactor coolant pump seal performance - the station's role

    International Nuclear Information System (INIS)

    During the early days of the Canada deuterium uranium (CANDU) power reactor program, operators and designers learned that close attention to reactor coolant pump (RCP) seals was imperative for achieving high-capacity factors. This lesson was driven home by unpredictable and frequent seal failures in the following early CANDU plants. Those seal failures caused forced outages, maintenance/dose burdens, and heavy-water losses. Because then-available industrial seal technology proved inadequate in providing satisfactory fixes, Atomic Energy of Canada Limited (AECL) began a major effort to understand seal performance, develop improved designs, and evolve the station technology needed to attain the RCP seal reliable lifetime requirement of 4 yr. The payback has been huge: Fixes have been successfully implemented and excellent performance is now being achieved with AECL improved RCP seals. In this paper, the CANDU RCP seal experience, the methodology (with emphasis on the station's role) for attaining reliable long RCP seal life, and the adaptability of this technology to US light water reactors (LWRs) are discussed

  8. 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.

  9. 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 %.

  10. Biogas Plant in MUAS

    OpenAIRE

    Varapnickaite, Ernesta

    2015-01-01

    The first and the most important aim is to find out if it is profitable to build a biogas plant in MUAS. Biogas plant has already proved that it is efficient way to use waste and make additional energy for heating and electricity. However in MUAS we have limited amount of biowaste so I will investigate how much energy would ir be possible to get. The second aim is to learn what is the best way to use the energy from the plant – if it should be used in all buildings for electricity and heating...

  11. Biogas: quo vadis?

    International Nuclear Information System (INIS)

    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

  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. PMID:27367811

  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. Performance targets for fusion-fission (hybrid) reactors

    International Nuclear Information System (INIS)

    The potential roles for various performance levels of hybrid power plants in the United States have been estimated for various scenarios which describe the systems with which the hybrid plants must compete. Due to the uncertainty in estimating the costs of hybrid power plants, a parametric approach was chosen to identify acceptable characteristics and associated tradeoffs. Because hybrid power plants produce substantial quantities of both plutonium and electricity, a simulation model is necessary which appropriately values each of these products. This would permit design tradeoffs and realistic interactions with other generating plants, such as Liquid Metal Fast Breeder Reactors (LMFBRs) and Light Water Reactors (LWRs), to be estimated. A linear programming model nearly identical to that used for the recent LMFBR cost-benefit analysis was utilized for this purpose

  15. Overcoming the effects of stress on reactor operator performance

    International Nuclear Information System (INIS)

    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)

  16. Verification tests performed for development of an integral type reactor

    International Nuclear Information System (INIS)

    SMART is an integral type reactor with innovative design features aimed at achieving a highly enhanced safety and improved economics. The SMART design is based on proven reactor design technologies with the use of new advanced design features. Most of the design features implemented into the SMART have been proven, however the advanced design features implemented into the SMART should be proven by testing. Various thermal hydraulic experiments have been carried out and also planned to assure the fundamental behavior of major concepts of the SMART and to prove the performance of the systems with new innovative technologies. This paper describes the thermal hydraulic test program for the SMART development and briefly discusses the typical test results. (author)

  17. Impact of reactor water chemistry on cladding performance

    International Nuclear Information System (INIS)

    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)

  18. Evaluation of performance of select fusion experiments and projected reactors

    Science.gov (United States)

    Miley, G. H.

    1978-01-01

    The performance of NASA Lewis fusion experiments (SUMMA and Bumpy Torus) is compared with other experiments and that necessary for a power reactor. Key parameters cited are gain (fusion power/input power) and the time average fusion power, both of which may be more significant for real fusion reactors than the commonly used Lawson parameter. The NASA devices are over 10 orders of magnitude below the required powerplant values in both gain and time average power. The best experiments elsewhere are also as much as 4 to 5 orders of magnitude low. However, the NASA experiments compare favorably with other alternate approaches that have received less funding than the mainline experiments. The steady-state character and efficiency of plasma heating are strong advantages of the NASA approach. The problem, though, is to move ahead to experiments of sufficient size to advance in gain and average power parameters.

  19. 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....

  20. Microbial community structure and dynamics during co-digestion of whey permeate and cow manure in continuous stirred tank reactor systems.

    Science.gov (United States)

    Hagen, Live Heldal; Vivekanand, Vivekanand; Linjordet, Roar; Pope, Phillip B; Eijsink, Vincent G H; Horn, Svein J

    2014-11-01

    Microbial community profiles in two parallel CSTR biogas reactors fed with whey permeate and cow manure were investigated. The operating conditions for these two reactors were identical, yet only one of them (R1) showed stable performance, whereas the other (R2) showed a decrease in methane production accompanied by accumulation of propionic acid and, later, acetic acid. This gave a unique opportunity to study the dynamics of the microbial communities in two biogas reactors apparently operating close to the edge of stability. The microbial community was dominated by Bacteroidetes and Firmicutes, and the methanogens Methanobacteriales and Methanomicrobiales in both reactors, but with larger fluctuations in R2. Correlation analyses showed that the depletion of propionic acid in R1 and the late increase of acetic acid in R2 was related to several bacterial groups. The biogas production in R1 shows that stable co-digestion of manure and whey can be achieved with reasonable yields. PMID:25222739

  1. 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)

    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 m3 biogas production from ∼3.2 t sewage sludge AD can save 0.92 m3 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 m3 biogas can save 0.92 m3 natural gas. An average UK household (with a demand of 2 kWe) requires 180,000 MJ or 5000 Nm3 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 generations

  2. Liquid membrane purification of biogas

    Energy Technology Data Exchange (ETDEWEB)

    Majumdar, S.; Guha, A.K.; Lee, Y.T.; Papadopoulos, T.; Khare, S. (Stevens Inst. of Tech., Hoboken, NJ (United States). Dept. of Chemistry and Chemical Engineering)

    1991-03-01

    Conventional gas purification technologies are highly energy intensive. They are not suitable for economic removal of CO{sub 2} from methane obtained in biogas due to the small scale of gas production. Membrane separation techniques on the other hand are ideally suited for low gas production rate applications due to their modular nature. Although liquid membranes possess a high species permeability and selectivity, they have not been used for industrial applications due to the problems of membrane stability, membrane flooding and poor operational flexibility, etc. A new hollow-fiber-contained liquid membrane (HFCLM) technique has been developed recently. This technique overcomes the shortcomings of the traditional immobilized liquid membrane technology. A new technique uses two sets of hydrophobic, microporous hollow fine fibers, packed tightly in a permeator shell. The inter-fiber space is filled with an aqueous liquid acting as the membrane. The feed gas mixture is separated by selective permeation of a species through the liquid from one fiber set to the other. The second fiber set carries a sweep stream, gas or liquid, or simply the permeated gas stream. The objectives (which were met) of the present investigation were as follows. To study the selective removal of CO{sub 2} from a model biogas mixture containing 40% CO{sub 2} (the rest being N{sub 2} or CH{sub 4}) using a HFCLM permeator under various operating modes that include sweep gas, sweep liquid, vacuum and conventional permeation; to develop a mathematical model for each mode of operation; to build a large-scale purification loop and large-scale permeators for model biogas separation and to show stable performance over a period of one month.

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

    International Nuclear Information System (INIS)

    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 (CO2) equivalent dioxide. (full text)

  4. Simulation of Plasma Performance of the Tokamak DEMO Nuclear Fusion Reactors Design

    International Nuclear Information System (INIS)

    The DEMOnstration Power Plant is intended to be the first fusion reactor to generate electrical power. It is designed to produce up to 500 megawatts of electricity which will require a thermal output of around 1500 megawatts. If DEMO is built at roughly the same size as ITER, it will require much higher heat flux through the reactor walls and improved plasma performance. As a reference design, DEMO reactor was designed with reference to the SSTR (steady-state tokamak reactor) using the BALDUR code. Plasma evaluation analysis of the fusion reactor DEMO using BALDUR code is performed to predict the performance of fusion power for the DEMO reactor.

  5. 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. PMID:25864735

  6. Biogas document; Dossier Biogaz

    Energy Technology Data Exchange (ETDEWEB)

    Verchin, J.C.; Servais, C. [Club BIOGAZ, 94 - Arcueil (France)

    2002-06-01

    In this document concerning the biogas, the author presents this renewable energy situation in 2001-2002, the concerned actors, the accounting of the industrial methanization installations in France, the three main chains of process for industrial wastes and two examples of methanization implementation in a paper industry and in a dairy. (A.L.B.)

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

    International Nuclear Information System (INIS)

    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 CH4-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 CH4-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

  8. Jet mixing improving biogas production performance of mesophilic anaerobic fermentation with cow manure%射流搅拌提高牛粪中温厌氧发酵产沼气性能

    Institute of Scientific and Technical Information of China (English)

    熊向峰; 贾丽娟; 宁平; 瞿广飞; 周成

    2015-01-01

    th day. The methane content variation was less than 10% in approximately 20 days. Carbon dioxide in biogas could be absorbed by the jet mixing, and therefore it was reused to generate methane with hydrogen as an electron donor. Moreover, the acetate could be formed from hydrogen and carbon dioxide by hydrogen-oxidizing acetogenic bacteria. These reactions should improve the performance of methanogenesis process. To sum up, the jet mixing method had a higher methane content and lower carbon dioxide content. Based on the results presented in this article, the jet mixing system shows a higher efficiency than the mechanical mixer and single slurry recirculation.

  9. Mini digester and biogas production from plant biomass

    OpenAIRE

    P. Vindis; B. Mursec; C. Rozman; M. Janzekovic; F. Cus

    2009-01-01

    Purpose: The aim of the paper is to present the construction of a mini digester for biogas production from different agriculture plant biomass and other organic wastes. The amount of biogas production (methane) is observed by the mini digester.Design/methodology/approach: The mini digester consisting of twelve units was built and some measurements with agriculture plant biomass were performed according to DIN 38414 part 8. Four tests simultaneously with three repetitions can be performed.Find...

  10. Biogas production with the use of mini digester

    OpenAIRE

    P. Vindis; B. Mursec; C. Rozman; M. Janzekovic; F. Cus

    2008-01-01

    Purpose: of this paper is to present the construction of a mini digester for biogas production from different energy plants and organic wastes. With the mini digester the amount of biogas production (methane) is observed.Design/methodology/approach: Firstly, the mini digester consisting of twelve units was built and secondly some measurements with energy plants were performed. The measurements were performed with mini digester according to DIN 38414 part 8. Four tests simultaneously with...

  11. General performance and utilization plan of the Egyptian Second Research Reactor

    International Nuclear Information System (INIS)

    The Egyptian Second Research Reactor, ETRR-2, is a Multi-Purpose Reactor for material tests, radioisotopes production, neutron physics research, etc.. The reactor is an open pool type of 22 MWth light water cooled and moderated, with an average flux of 2x1014 n/cm2·s. Various experimental facilities are installed in the reactor to meet the requirements of the utilization group. Description of the reactor Performance and proposed utilization plan is presented. (author)

  12. Plasma performance study for the tandem mirror reactor

    International Nuclear Information System (INIS)

    A computer code was developed for assessing the performance of new variations on the thermal barrier idea for tandem mirror reactors (TMR's). The code solves the particle and energy balance equations simultaneously for each species of particles in each portion of the machine. The code is thus able to determine the neutral beam and ECRH injection powers that are required to sustain an equilibrium situation, and, from these, to determine the machine's Q value. This paper focuses on the methodology and numerical algorithms used in accomplishing this solution. We plan to use this code to compare the A-cell barrier TMR with axisymmetric TMR's

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

    International Nuclear Information System (INIS)

    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

  14. 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.

  15. Serial CSTR digester configuration for improving biogas production from manure

    DEFF Research Database (Denmark)

    Boe, Kanokwan; Angelidaki, Irini

    2009-01-01

    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 di...

  16. 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

    , while the activity of acetotrophic methanogens was uniformly distributed in all fractions. When digesting manure and lipids, an enhanced methanogenesis was detected both for particles > 200 mum and the 50-200 mum fraction. The molecular methods -temperature gradient gel electrophoresis (TGGE), cloning...

  17. Rancang Bangun Alat Penghasil Biogas dari Plastik Polietilen

    OpenAIRE

    Latif

    2011-01-01

    Biogas is a gas the can be produced from anaerobic fermentation of organic matters such as animal or human’s feces, agricultural wastes, or their combination in a digester. In this research the biogas was produced from mixture of cow dung and paddy hay. The aim of this research was to design of a drift biogas producer which was easy to be assembled, cheap, and had a best performance. The result of this experiment showed that the polyethylene digester had a: capacity of 0,25 m3, wet volume 0,2...

  18. Rancang Bangun Konverter Biogas untuk Motr Bensin Silinder Tunggal

    OpenAIRE

    Desrial; Dyah Wulandani

    2014-01-01

    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 a...

  19. 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

  20. 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.)

  1. A Critical Assessment of Microbiological Biogas to Biomethane Upgrading Systems.

    Science.gov (United States)

    Rittmann, Simon K-M R

    2015-01-01

    Microbiological biogas upgrading could become a promising technology for production of methane (CH(4)). This is, storage of irregular generated electricity results in a need to store electricity generated at peak times for use at non-peak times, which could be achieved in an intermediate step by electrolysis of water to molecular hydrogen (H(2)). Microbiological biogas upgrading can be performed by contacting carbon dioxide (CO(2)), H(2) and hydrogenotrophic methanogenic Archaea either in situ in an anaerobic digester, or ex situ in a separate bioreactor. In situ microbiological biogas upgrading is indicated to require thorough bioprocess development, because only low volumetric CH(4) production rates and low CH(4) fermentation offgas content have been achieved. Higher volumetric production rates are shown for the ex situ microbiological biogas upgrading compared to in situ microbiological biogas upgrading. However, the ex situ microbiological biogas upgrading currently suffers from H(2) gas liquid mass transfer limitation, which results in low volumetric CH(4) productivity compared to pure H(2)/CO(2) conversion to CH(4). If waste gas utilization from biological and industrial sources can be shown without reduction in volumetric CH(4) productivity, as well as if the aim of a single stage conversion to a CH(4) fermentation offgas content exceeding 95 vol% can be demonstrated, ex situ microbiological biogas upgrading with pure or enrichment cultures of methanogens could become a promising future technology for almost CO(2)-neutral biomethane production. PMID:26337846

  2. Biogas in Vietnam : a proposed business model in biogas sector

    OpenAIRE

    Phan, Thi Thanh Thao

    2011-01-01

    The purpose of this thesis was to discover a biogas opportunity in the Mekong Delta area in Vietnam. The discussed biogas production is derived from organic waste and targeted to fullfill the demand for gas for cooking in condition of non-pipeline system. However, different products from this production were introduced to maximize the technology profitability. Another aim was to propose a business model to foreign investors who own advanced technologies in biogas production. Qualitative r...

  3. Trace element and temperature effects on microbial communities and links to biogas digester performance at high ammonia levels

    OpenAIRE

    Westerholm, Maria; Müller, Bettina; Isaksson, Simon; Schnürer, Anna

    2015-01-01

    Background High levels of ammonia and the presence of sulphide have major impacts on microbial communities and are known to cause operating problems in anaerobic degradation of protein-rich material. Operating strategies that can improve process performance in such conditions have been reported. The microbiological impacts of these are not fully understood, but their determination could help identify important factors for balanced, efficient operation. This study investigated the correlations...

  4. Investigations on the efficiency of the Bavarian biogas pilot plants using Data Envelopment Analysis; Untersuchungen zur Effizienz der Bayerischen Biogas-Pilotanlagen mittels Data Envelopment Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Djatkov, D.; Effenberger, M.; Lehner, A.; Gronauer, A. [Bayerische Landesanstalt fuer Landwirtschaft (LfL), Freising (Germany). Inst. fuer Landtechnik und Tierhaltung

    2009-07-01

    In the course of the present study it was possible to show that Data Envelopment Analysis (DEA) is in principle a suitable means of assessing the relative efficiency of biogas plants. The results were plausible in most cases from an expert viewpoint. Efficiency indicators resulting from DEA can be used to create a ranking of the biogas plants under study. However, the absolute efficiency values are not directly comparable, i.e. they cannot be interpreted on a cardinal scale. In order to arrive at a comprehensive assessment of the energy efficiency and environmental effects of a biogas plant it is necessary to include one more important parameter, namely methane yield. However this would mean splitting the DEA procedure into at least two parts: an analysis of the processes of biogas production and an analysis of biogas utilisation. Performing a complete and comprehensive assessment of the efficiency of biogas plants on the basis of one single parameter is therefore not possible.

  5. 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.

  6. 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

  7. Verification Test of Hydraulic Performance for Reactor Coolant Pump

    International Nuclear Information System (INIS)

    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·m3/m·m), capacity; 3115m3/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·m3/m·m), capacity; 539.4m3/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 2000m3/h and design pressure 1.0MPaG. Auxiliary pump was designed with centrifugal pump having capacity; 1100m3/h, total head; 42.0m, motor output; 190kw

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

    International Nuclear Information System (INIS)

    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. H2S. 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

  9. Empirical Study on Factors Affecting Biogas Production

    OpenAIRE

    Prasad, Ravita D.

    2012-01-01

    In Fiji, biogas has a huge potential to be one of the energy providers for cooking in rural areas but currently its use is very minimal. Main component of biogas is methane which releases energy when combusted. This paper mainly presents the factors that affect biogas production using experimental study. The first section presents an overview on what is biogas, types of biogas digesters present, and some background on the current use of biogas in Fiji. The second section of the paper describe...

  10. Life cycle assessment of flexibly fed biogas processes for an improved demand-oriented biogas supply.

    Science.gov (United States)

    Ertem, Funda Cansu; Martínez-Blanco, Julia; Finkbeiner, Matthias; Neubauer, Peter; Junne, Stefan

    2016-11-01

    This paper analyses concepts to facilitate a demand oriented biogas supply at an agricultural biogas plant of a capacity of 500kWhel, operated with the co-digestion of maize, grass, rye silage and chicken manure. In contrast to previous studies, environmental impacts of flexible and the traditional baseload operation are compared. Life Cycle Assessment (LCA) was performed to detect the environmental impacts of: (i) variety of feedstock co-digestion scenarios by substitution of maize and (ii) loading rate scenarios with a focus on flexible feedstock utilization. Demand-driven biogas production is critical for an overall balanced power supply to the electrical grid. It results in lower amounts of emissions; feedstock loading rate scenarios resulted in 48%, 20%, 11% lower global warming (GWP), acidification (AP) and eutrophication potentials, and a 16% higher cumulative energy demand. Substitution of maize with biogenic-waste regarding to feedstock substitution scenarios could create 10% lower GWP and AP. PMID:27522120

  11. 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.

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

    Science.gov (United States)

    Lin, Chiu-Yue

    2014-01-01

    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. PMID:24672398

  13. Biogas energy development in Slovenia

    OpenAIRE

    Bojnec, Štefan; Papler, Drago

    2013-01-01

    This paper analyses the development of the biogas energy production and use in Slovenia. The major concern is given to ecological, economic and technical determinants in decision making process for selection among alternative biogas energy production plants and use of energy for heating and electricity. The investments into the biogas plants have reduced ecological problems from large environmental polluters in urban and rural areas. Among them are sewage systems, food wastes, wastes from lar...

  14. Thermodynamic performance of a gas-core fission reactor

    International Nuclear Information System (INIS)

    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 SiN2, SiC2 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

  15. A Monitoring System for the Assessment of Reactor Shield Performance

    International Nuclear Information System (INIS)

    This paper describes the objectives of a shield survey, presents the results of intercomparisons and makes recommendations on the selection of a monitoring system. The performance of a reactor shield must be assessed efficiently to enable immediate repairs to be made to defective shields. Correlation of survey results with shield designer's predictions has proved difficult and the factors contributing to the disagreement have been examined. The shield designer uses flux to dose conversion factors which neglect the radiation equilibrium situation at the shield-air interface and the effect of attenuation and scattering external to the shield. The presence of the operator can significantly influence a measurement. The use of the ''maximum exposure dose'' (MED) concept is recommended for gamma photon predictions and this is compared with absorbed dose measurements in phantoms. Shield survey instruments must have a flat response over a wide range of energies. For example, many gamma dosimeters are designed for use at energies up to about 2 MeV whereas around most reactors a proportion of dose is due to 6 MeV gamma photons, with some contribution from higher energies. Tests were carried out to select suitable detectors using actual reactor operating conditions and simulated conditions at specific energies, notably 6 MeV. In practice discrepancies exceeding a factor of 3 were frequently found. A comparison was made between thermoluminescent dosimeters and film badges for the purpose of fixed position integrating dosimeters. The film dosimeter (AERE/RPS) was found to over-estimate by a factor of 2 for 6 MeV gamma radiation and in practical situations over-estimated by 20 to 80%. Thermoluminescent dosimetry is recommended for shield surveys provided that a build-up cap is used to achieve charged particle equilibrium. (author)

  16. 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.

  17. 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)

  18. Use of biogas for cogeneration of heat and electricity for local application: performance evaluation of an engine power generator and a sludge thermal dryer.

    Science.gov (United States)

    Lobato, L C S; Chernicharo, C A L; Pujatti, F J P; Martins, O M; Melo, G C B; Recio, A A R

    2013-01-01

    A small unit of cogeneration of energy and heat was tested at the Centre for Research and Training on Sanitation UFMG/COPASA - CePTS, located at the Arrudas Sewage Treatment Plant, in Belo Horizonte, Minas Gerais, Brazil. The unit consisted of an engine power generator adapted to run on biogas, a thermal dryer prototype and other peripherals (compressor, biogas storage tank, air blower, etc.). The heat from engine power generator exhaust gases was directed towards the thermal dryer prototype to dry the sludge and disinfect it. The results showed that the experimental apparatus is self-sufficient in electricity, even producing a surplus, available for other uses. The tests of drying and disinfection of sludge lasted 7 h, leading to an increase in solids content from 4 to 8% (50% reduction in sludge volume). Although the drying of sludge was not possible (only thickening was achieved), the disinfection process proved very effective, enabling the complete inactivation of helminth eggs. PMID:23128634

  19. 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

  20. Biogas barometer; barometre biogaz

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-11-15

    The biogas sector has never before aroused so much attention as it does today. Elected officers and investors' interest has been fired by the gradual introduction of regulatory restrictions on the treatment of organic waste and the renewable energy commitments recently made by the European Union Member States. The biogas sector is gradually deserting its core activities of waste cleanup and treatment and getting involved in energy production, with so much enthusiasm that in some countries its scope of action has extended to using energy crops. Across the European Union, the sector's progress is as clear as daylight, as in 2009, primary energy growth leapt by a further 4.3 per cent. (author)

  1. 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.

  2. 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...

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

    International Nuclear Information System (INIS)

    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

  4. High performance light water reactor core design studies

    International Nuclear Information System (INIS)

    The High Performance Light Water Reactor (HPLWR) is the European version of the various supercritical water cooled reactor proposals. The paper presents the activity of KFKI-AEKI in the field of neutronic core design within the framework of the European funded project: 'HPLWR Phase 2'. As the coolant density along the axial direction shows remarkable change, coupled neutronic-thermohydraulic calculations are essential which take into account the heating of moderator in the special water rods of the assemblies. A parametrized diffusion cross section library was prepared for the HPLWR assembly with the MULTICELL neutronic transport code. The parametrized cross sections are used by the KARATE program system, which was verified by comparative Monte Carlo calculations. Methodical core calculations have been carried out. Without thermal insulation in the second superheater of the three pass core, the temperature of moderator water exceeds the pseudocritical temperature resulting in poor moderation. Applying heat insulators helps to avoid the extreme heat up of moderator, so it provides better moderation for neutrons. The increase of the local multiplication in the superheaters favorably affects the power distribution and keff of the core. Preliminary loadings of the HPLWR core were assessed, which contain insulated assemblies with Gd burnable absorbers. The initial reactivity excess was compensated by control rods. The reactivity coefficients of HPLWR with respect to temperatures show substantial negative feedback at normal operating conditions. (author)

  5. Bacterial Contamination of Biogas

    Czech Academy of Sciences Publication Activity Database

    Mrázek, Jakub; Čermáková, J.; Tenkrát, D.; Kopečný, Jan; Fliegerová, Kateřina

    Smolenice : IAP, Slovak Academy of Sciences, Košice, 2011. s. 11-11. ISBN 978-80-968618-6-6. [7th International Symposium on Anaerobic Microbiology. 15.6.2011-18.6.2011, Smolenice] R&D Projects: GA ČR GPP503/10/P394; GA MZe QI92A286 Institutional research plan: CEZ:AV0Z50450515 Keywords : biogas * bacterium Subject RIV: EE - Microbiology, Virology

  6. 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

    2016-06-01

    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.

  7. Rancang Bangun Konverter Biogas untuk Motr Bensin Silinder Tunggal

    Directory of Open Access Journals (Sweden)

    Desrial

    2014-04-01

    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.

  8. Proceedings of the 1. annual Canadian farm and food biogas conference and exhibition

    International Nuclear Information System (INIS)

    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

  9. 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)

    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

  10. PRELIMINARY STUDY ON BIOGAS PRODUCTION OF BIOGAS FROM MUNICIPAL SOLID WASTE (MSW LEACHATE

    Directory of Open Access Journals (Sweden)

    WAN AZLINA WAN AB KARIM GHANI

    2009-12-01

    Full Text Available Laboratory-scale digesters were operated to study the effect of leachate chemical oxygen demand strength on biogas (methane production. Three sets of experiment were performed using municipal solid waste leachate slurry with two different chemical oxygen demand strength strengths namely 3000 and 21000 mg/L (referred as low and high strength, respectively. The experiments were conducted at a controlled temperature of 35°C and pH ranging from 6.8 to 7.3 over 20 days period. The process performance was evaluated based on the biogas production and pollutants removal efficiencies. Results showed that the high and low strength samples performed quite similarly but with different biogas production rate observed. The biochemical oxygen demand in the effluent removed up to 80%, but the performance of other parameters such as chemical oxygen demand, total suspended solid and volatile suspended solid was slightly decreased which contributes 33 to 46%, 21 to 37% and 20 to 35%, respectively. From this study, it can be concluded that this method not only contributed to renewable biogas production but also improved the effluent quality.

  11. Cladding and wrapper development for fast breeder reactor high performance

    International Nuclear Information System (INIS)

    In order to ensure economic performance, of both the existing reactors and the future EFR, much recent research has been carried out within the framework of the European R and D agreement to examine the properties of various wrapper and cladding alloys. This paper reviews the status of the European research and development programmes on these steels and highlights the most striking results. For the cladding alloys, results on dimensional stability and tensile properties for fuel pin cladding irradiated in PFR or Phenix will be given. As for wrappers the presently available results of those wrappers irradiated in Phenix and PFR show that both ferritic steels are very good candidates and that on the basis of our present knowledge most of the properties are satisfactory for wrapper applications

  12. U.S. ALMR sodium cooled reactor design and performance

    International Nuclear Information System (INIS)

    The U.S. Advanced Liquid Metal Reactor (ALMR) has innovative features for reliable operation, accident prevention and severe accident accommodation. The relatively small size of the reactor allows factory fabrication. The reactor shutdown system, inherent reactivity control and the passive decay heat removal systems result in extremely high scram and shutdown reliability. The robust primary boundary and lower internal structures allow accommodation of a hypothetical core disruptive accident and retention of a whole core molten fuel-clad mixture within the reactor. The reactor's low operating temperatures and seismic isolation result in large structural margins and high seismic capabilities. (author)

  13. 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

  14. Sustainable energy management in industry of Republic of Serbia: Biogas power plants advantages

    OpenAIRE

    Golušin Mirjan; Dodić Siniša; Vučurović Damjan; Jovanović Larisa; Munitlak-Ivanović Olja

    2012-01-01

    This paper reviews the specifics of energy policy in Serbia on the example of designing a biogas power plant. The biogas power plant is designed in accordance with the existing energy policy that recognizes producers of energy from renewable sources as This paper reviews the previously performed analysis in the sphere of energy consumption, which served as the basis for creating a new corporate energy policy. The paper presents an analysis of biogas power plant output (electrical and thermal ...

  15. Integration of centralized biogas plant in cold-snowy region in Japan

    OpenAIRE

    Umetsu K.; Ying C.; Kikuchi S.; Iwasaki M.; Takeuchi Y.; Oi M.; Shiroishi K.; Uematsu T.; Yasui S.

    2011-01-01

    A centralized biogas plant was built in Shikaoi town, Hokkaido, Japan to treat manure from 1320 cattle heads. The biogas plant was designed to operate at a feeding amount of 85.8 t/day, a hydraulic retention time (HRT) of 37 days and at a digester temperature of 38 °C. In this study, the operational performance of biogas plant, utilization of digested slurry and economic balance were investigated. Since the working conditions of the plant became stable, the...

  16. Investigation of Phasic Process of Biogas Yield by Measuring pH, ORP and Electrical Power Changes

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Abdoli

    2016-04-01

    Full Text Available Background & Aims of the Study: Studying the phasic process of the biogas yieldis required to optimize the design and operations; it also helps to lower energy production costs by decreasing the capital investment and operational costs. Here we determine the biogas process by measuring pH, ORP, electrical power and make compatibility to the biogas production trend. Materials and Methods: In this research, one 1150 ml single chamber reactor is used. Biogas production trend was precisely followed by a probable compatibleness with pH, Oxidation Reduction Potential (ORP, electrical Power at a temperature of 37+ 0.5˚C with the substrate of cattle manure. The experiment was followed for 120 days approximately. Results: As a result, the phases of biogas yield could be determined by the measuring of pH, ORP and its compatibility to gas production. In the reactor, hydrolytic, acetogenic and methanogenic phases were occurred in the days 1-7, 8-16 and 17-104, respectively. Also the electrical power at first showed to be produced at high range but by increasing, the production of biogas decreased and then by decreasing the biogas production gradually, it increased slightly. Conclusion: Our results indicated that the phases of biogas production can be separated  completely and by diffracting the phases, the efficiency of biogas production could be increased.

  17. 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)

  18. Biogas: A renewable energy source

    International Nuclear Information System (INIS)

    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.

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

    International Nuclear Information System (INIS)

    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

  20. THESEE-3, Orgel Reactor Performance and Statistic Hot Channel Factors

    International Nuclear Information System (INIS)

    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

  1. Eliminating methanogenic activity in hydrogen reactor to improve biogas production in a two-stage anaerobic digestion process co-digesting municipal food waste and sewage sludge.

    Science.gov (United States)

    Zhu, Heguang; Parker, Wayne; Conidi, Daniela; Basnar, Robert; Seto, Peter

    2011-07-01

    Laboratory scale two-stage anaerobic digestion process model was operated for 280 days to investigate the feasibility to produce both hydrogen and methane from a mixture feedstock (1:1 (v/v)) of municipal food waste and sewage sludge. The maximum hydrogen and methane yields obtained in the two stages were 0.93 and 9.5 mL/mL feedstock. To eliminate methanogenic activity and obtain substantial hydrogen production in the hydrogen reactor, both feedstock and mixed liquor required treatment. The heat treatment (100°C, 10 min) for feedstock and a periodical treatment (every 2-5 weeks, either heating, removal of biomass particles or flushing with air) for mixed liquor were effective in different extent. The methane production in the second stage was significantly improved by the hydrogen production in the first stage. The maximum methane production obtained in the period of high hydrogen production was more than 2-fold of that observed in the low hydrogen production period. PMID:21592783

  2. Performance of primary shut down system of research reactor Dhruva

    International Nuclear Information System (INIS)

    The primary shut down system of Dhruva consists of nine shut off rods. Under reactor operating condition absorber section of the shut off rods are held at parking elevation by 48V DC electromagnetic clutch. Fast shut down of the reactor is achieved by gravity insertion of all the nine shut off rods into the core on a trip signal. Shut off rod mechanism consist of a headgear assembly, a shield assembly, a cadmium absorber assembly, an absorber guide tube assembly and a lattice guide tube assembly. The coolant channels have been suitably designed such that the shut off rod location can be interchanged with any other pile location in future if need arises. This provision of interchangeability, though providing flexibility for any future core design change, placed severe space constraints for accommodating the Headgear mechanism within the available headroom of 750 mm long and 120 mm diameter in the coolant channel. As certain components such as drum containing wire ropes, snubber arrangement etc could not be designed following standard design, the components had to be developed which could be accommodated within the drum for better space utilization. These arrangements resulted in a complicated and complex design of the shut off rod driving mechanism. The complex design of shut off rod driving mechanism had limited its in-pile service life. The experience gained over the years was utilized to evolve operation and maintenance checklist, design modifications and operating procedures for ensuring reliable in pile performance of shut off rod driving mechanism. This paper describes operating experience, modifications and operating practices adopted for optimization of service life of shut off rod driving mechanism. (author)

  3. The potential of biogas energy

    International Nuclear Information System (INIS)

    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)

  4. A New and Sound Technology for Biogas from Solid Waste and Biomass

    International Nuclear Information System (INIS)

    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 CO2 and allows oxidation of sulfur. Consequently, the biogas has a high methane (>72%) and low H2S 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

  5. 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.

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

    International Nuclear Information System (INIS)

    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

  7. Stirring and biomass starter influences the anaerobic digestion of different substrates for biogas production

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, Christian; Fang, Sheng; Uhlenhut, Frank; Borchert, Axel; Stein, Ingo; Schlaak, Michael [Institut fuer Umwelttechnik EUTEC, Fachbereich Technik, Fachhochschule Emden/Leer, Emden (Germany)

    2010-08-15

    Here, we present the results of lab-scale experiments conducted in a batch mode to determine the biogas yield of lipid-rich waste and corn silage under the effect of stirring. Further semi-continuous experiments were carried out for the lipid-rich waste with/without stirring. Additionally, it was analyzed how the starter used for the batch experiment influences the digestion process. The results showed a significant stirring effect on the anaerobic digestion only when seed sludge from a biogas plant was used as a starter. In this case, the experiments without stirring yielded only about 50% of the expected biogas for the investigated substrates. The addition of manure slurry to the batch reactor as part of the starter improved the biogas production. The more diluted media in the reactor allowed a better contact between the bacteria and the substrates making stirring not necessary. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  8. Light water reactor pressure isolation valve performance testing

    International Nuclear Information System (INIS)

    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)

  9. Evaluating the biogas potential of the dry fraction from pretreatment of food waste from households

    International Nuclear Information System (INIS)

    Highlights: ► A novel approach for biogas production from a waste fraction that today is incinerated. ► Biogas production is possible in spite of the impurities of the waste. ► Tracer studies are applied in a novel way. ► Structural material is needed to improve the flow pattern of the waste. ► We provide a solution to biological treatment for the complex waste fraction. - Abstract: At the waste handling company NSR, Helsingborg, Sweden, the food waste fraction of source separated municipal solid waste is pretreated to obtain a liquid fraction, which is used for biogas production, and a dry fraction, which is at present incinerated. This pretreatment and separation is performed to remove impurities, however also some of the organic material is removed. The possibility of realising the methane potential of the dry fraction through batch-wise dry anaerobic digestion was investigated. The anaerobic digestion technique used was a two-stage process consisting of a static leach bed reactor and a methane reactor. Treatment of the dry fraction alone and in a mixture with structural material was tested to investigate the effect on the porosity of the leach bed. A tracer experiment was carried out to investigate the liquid flow through the leach beds, and this method proved useful in demonstrating a more homogenous flow through the leach bed when structural material was added. Addition of structural material to the dry fraction was needed to achieve a functional digestion process. A methane yield of 98 m3/ton was obtained from the dry fraction mixed with structural material after 76 days of digestion. This was in the same range as obtained in the laboratory scale biochemical methane potential test, showing that it was possible to extract the organic content in the dry fraction in this type of dry digestion system for the production of methane

  10. Evaluating the biogas potential of the dry fraction from pretreatment of food waste from households

    Energy Technology Data Exchange (ETDEWEB)

    Murto, Marika, E-mail: marika.murto@biotek.lu.se [Department of Biotechnology, Lund University, P.O. Box 124, SE-221 00 Lund (Sweden); Björnsson, Lovisa, E-mail: lovisa.bjornsson@miljo.lth.se [Department of Biotechnology, Lund University, P.O. Box 124, SE-221 00 Lund (Sweden); Environmental and Energy Systems Studies, Lund University, P.O. Box 118, SE-221 00 Lund (Sweden); Rosqvist, Håkan, E-mail: hakan@rosqvist-resurs.se [Rosqvist Resurs, Gamla Malmövägen 25, SE-230 41 Klågerup (Sweden); Bohn, Irene, E-mail: irene.bohn@nsr.se [NSR AB, Hjortshögsvägen 1, SE-251 89 Helsingborg (Sweden)

    2013-05-15

    Highlights: ► A novel approach for biogas production from a waste fraction that today is incinerated. ► Biogas production is possible in spite of the impurities of the waste. ► Tracer studies are applied in a novel way. ► Structural material is needed to improve the flow pattern of the waste. ► We provide a solution to biological treatment for the complex waste fraction. - Abstract: At the waste handling company NSR, Helsingborg, Sweden, the food waste fraction of source separated municipal solid waste is pretreated to obtain a liquid fraction, which is used for biogas production, and a dry fraction, which is at present incinerated. This pretreatment and separation is performed to remove impurities, however also some of the organic material is removed. The possibility of realising the methane potential of the dry fraction through batch-wise dry anaerobic digestion was investigated. The anaerobic digestion technique used was a two-stage process consisting of a static leach bed reactor and a methane reactor. Treatment of the dry fraction alone and in a mixture with structural material was tested to investigate the effect on the porosity of the leach bed. A tracer experiment was carried out to investigate the liquid flow through the leach beds, and this method proved useful in demonstrating a more homogenous flow through the leach bed when structural material was added. Addition of structural material to the dry fraction was needed to achieve a functional digestion process. A methane yield of 98 m{sup 3}/ton was obtained from the dry fraction mixed with structural material after 76 days of digestion. This was in the same range as obtained in the laboratory scale biochemical methane potential test, showing that it was possible to extract the organic content in the dry fraction in this type of dry digestion system for the production of methane.

  11. Development of a complete bio-NGV production process based on agricultural biogas at farm scale

    OpenAIRE

    Sarperi, Laura

    2014-01-01

    Bio-NGV (bio- Natural Gas for Vehicles) is a bio-fuel based on the biogas in which components such as CO2and H2S are removed. But the economical feasibility of available and commercial technologies to perform these removals is limited to 80 Nm3/h of treated biogas. Regarding farm scale biogas plant, fuel needs of 1 fill-upper day would represent the treatment of only 1 Nm3/hof raw biogas. The aim of our work was to develop a solution economically adapted to farm scale to produce bio-NGV from ...

  12. 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.

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

    International Nuclear Information System (INIS)

    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*105 kWh to produce 1 m3 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 m3 of methane using brewers spent grins

  14. Two-phase anaerobic digestion of spent tea leaves for biogas and manure generation.

    Science.gov (United States)

    Goel, B; Pant, D C; Kishore, V V

    2001-11-01

    Anaerobic digestion of spent tea leaves from an instant tea manufacturing factory was studied in a two-phase digester. The hydrolysis and acidification phase resulted in the formation of high organic strength liquid called leachate, with a chemical oxygen demand (COD) of 12,880 mg/l, within the retention time of 10 days. The leachate was tested in a batch methanaogensis reactor for biogas production. An average biogas yield of 0.48 m3/kg of COD destroyed was obtained with an average COD reduction of 93%. The biogas was analyzed for 73% methane content. PMID:11563707

  15. Arsenic volatilization in model anaerobic biogas digesters

    International Nuclear Information System (INIS)

    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. Thermal core design of the high performance light water reactor

    International Nuclear Information System (INIS)

    The High Performance Light Water Reactor (HPLWR) is a SCWR concept, operated at an inlet pressure of 25 MPa with a core outlet temperature of 500 deg. C. A thermal core design for this reactor has been worked out by a consortium of Euratom member states within the 6th European Framework Program. Aiming at peak cladding temperatures of less than 630 deg. C, including uncertainties and allowances for operation, the coolant is heated up in three steps with intermediate coolant mixing to eliminate hot streaks. Each fuel assembly is built from 40 fuel pins with 8 mm diameter and a pitch of 9.4mm, housed in a thermally insulated assembly box. Additional moderator water is foreseen in water rods inside each assembly and in gaps between the assembly boxes. With a thermal power of 2300 MW, a net electric power of 1000 MW shall be achieved, resulting in a net efficiency of 43.5%. This concept has been studied with neutronic, thermal-hydraulic and structural analyses to assess its feasibility, which will be summarized in this paper. Coupled neutronic / thermal-hydraulic analyses by Maraczy et al. with the 2 group diffusion code KARATE and the one-dimensional code SPROD are defining an initial distribution of fuel enrichment, the positioning of the control rods, and the use of the burnable Gd absorbers to reach the envisaged power distribution. An equilibrium cycle analysis is showing radial form factors and the discharge burn-up. Different from conventional reactors, the radial power profile is intended to be non-uniform, with the highest power in the first heat up step in the core center and the lowest power in the second superheater step to result in the same peak cladding temperatures in each region. Sub-channel analyses by Himmel et al. performed for different radial power gradients demonstrate the excellent coolant mixing inside assemblies thanks to the wire wrap spacers used in this design. Coolant mixing above and underneath the core has been studied by Wank et al

  17. 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 .

  18. Developing a Comprehensive Software Suite for Advanced Reactor Performance and Safety Analysis

    International Nuclear Information System (INIS)

    This paper provides an introduction to the reactor analysis capabilities of the nuclear power reactor simulation tools that are being developed as part of the US Department of Energy’s Nuclear Energy Advanced Modeling and Simulation (NEAMS) Toolkit. The NEAMS Toolkit is an integrated suite of multiphysics simulation tools that leverage high performance computing to reduce uncertainty in the prediction of the performance and safety of advanced reactor and fuel designs. The toolkit effort is composed of two major components, the fuels product line, which provides tools for fuel performance analysis, and the reactor product line, which provides tools for reactor performance and safety analysis. This paper presents an overview of the NEAMS reactor product line development effort. (author)

  19. 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)

    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−1d−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

  20. Two-Stage Conversion of Land and Marine Biomass for Biogas and Biohydrogen Production

    OpenAIRE

    Nkemka, Valentine

    2012-01-01

    The replacement of fossil fuels by renewable fuels such as biogas and biohydrogen will require efficient and economically competitive process technologies together with new kinds of biomass. A two-stage system for biogas production has several advantages over the widely used one-stage continuous stirred tank reactor (CSTR). However, it has not yet been widely implemented on a large scale. Biohydrogen can be produced in the anaerobic two-stage system. It is considered to be a useful fuel for t...

  1. Treatment of Biogas for Use as Energy

    OpenAIRE

    Koller, J.

    2010-01-01

    The biogas generated in biogas plants offers significant potential for the production of energy from renewable energy sources. The number biogas plants in the Czech Republic is expected to exceed one hundred in the near future. Substrates from agriculture, industry and municipal wastes are used for biogas production. Biogas plants usually use co-generation units to generate electricity and heat. Increased effectiveness can be achieved by using heat as a source of energy for producing renewabl...

  2. Natural attenuation of biogas in landfill covers

    International Nuclear Information System (INIS)

    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

  3. In-reactor performance of prototype SBR MOX fuel

    International Nuclear Information System (INIS)

    As part of the international Callisto experiment, BNFL have undertaken the base irradiation, ramp testing and post-irradiation examination of two fuel rods, manufactured by BNFL's Short Binderless Route (SBR) for MOX fuel. Although of only short (lm) length, the rods were in other respects of standard PWR geometry. Base irradiation was performed in the Callisto loop of the BR2 reactor and achieved burn-ups of 17 GWd/tM, 28 GWd/tM peak pellet, at moderate to high power levels. No problems were encountered during base irradiation, confirmed by intermediate examination. In a separate BR2 capsule, a ramp test was then performed on one of the two rods. Again, the rod showed no problems and was discharged intact. The ramp test conditions employed were somewhat more onerous than the level corresponding to the best-estimate failure level for standard UO2 fuel. The survival of the rod confirms the general observation that the PCI failure resistance of MOX fuel is superior to that of standard UO2. The irradiation has been followed by a detailed programme of non-destructive and destructive hot-cell examinations on both of the rods. Profilometry, ECT and gamma-scanning confirmed the overall satisfactory performance of the rods and the absence of incipient damage. Puncture testing and gas analysis showed the fission gas release levels in both the ramped and unramped rods to be in line with what would be expected for a UO2 rod. The satisfactory microstructure of the fuel was confirmed via optical ceramography and autoradiography. This paper will describe the fuel manufacture, base irradiation and ramp test conditions, and will provide a summary of the results of the PIE programme. (author)

  4. International experience and status of fuel element performance and modelling for water reactors

    International Nuclear Information System (INIS)

    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. Beets for biogas. News from the laboratory and practice; Rueben fuer Biogas. Neues aus Labor und Praxis

    Energy Technology Data Exchange (ETDEWEB)

    Jeche, Ulrike [KWS Saat AG, Einbeck (Germany). Vertrieb Zuckerruebe Deutschland und Oesterreich; Schaffner, Sebastian

    2011-07-01

    Being a multi-talented crop, sugar beets are increasingly convincing biogas plant owners with their positive properties. In a mixture of substrates, they are a perfect partner for biogas production as they can push gas yield. In breeding, the experts mainly focus on increasing dry matter yield. There is a close correlation with sugar yield. The market already offers a multitude of highly performing sugar beet varieties for most diverse cropping conditions. The beets are harvested and transported from the field to the biogas plant with harvesting and transport technology which has proved its efficiency for many years. Other than harvested for other purposes, sugar beet for biogas production are stripped of their leaves instead of being topped. Stocking sugar beet at the biogas plant is a quite demanding issue. Sugar beets may be stocked as ensiled, whole beet, as pulp, or as crushed beet in mixed silage. There is a whole range of most diverse storage and crushing concepts. When used as a substrate for biogas production, sugar beet mostly need to be cleaned and stones need to be discarded before feeding the beets into the digester. In the meanwhile, the market offers a large choice of cleaning technique to pave the ways for sugar beets as a substrate. (orig.)

  6. 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.

  7. Continuous dry fermentation of swine manure for biogas production

    International Nuclear Information System (INIS)

    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−1VS 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−1VS 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

  8. 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.

  9. Performance of high-temperature gas-cooled reactor as a tritium production device for fusion reactors

    International Nuclear Information System (INIS)

    Highlights: ► The performance of a gas-cooled reactor as a tritium production device was studied. ► Gas-cooled reactors with 3 GWt output can produce 5–8 kg of tritium in a year. ► Use of Li2O compound is efficient compared with Li4SiO4 or Li2TiO3 one. ► Amount of tritium produced can be increased by reducing the enrichment of 235U. - Abstract: The performance of a high-temperature gas-cooled reactor as a tritium production device is examined. A gas turbine high-temperature reactor of 300 MWe nominal capacity (GTHTR300) is assumed as the calculation target of a typical gas-cooled reactor, and using the continuous-energy Monte Carlo transport code MVP-BURN, burn-up simulations for the 3-dimensional entire-core region of GTHTR300 were carried out considering its unique double heterogeneity structure. It is shown that gas-cooled reactors with thermal output power of 3 GW in all can produce 5–8 kg of tritium in a year.

  10. 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. PMID:26441026

  11. Reduced enrichment fuels for Canadian research reactors - Fabrication and performance

    International Nuclear Information System (INIS)

    Our facilities have been upgraded to manufacture fuel rods comprising dispersions of U3Si in aluminum, to complement the dispersions of U3Si 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% U3Si have been manufactured. (author)

  12. Performance analysis of 233U for fixed bed nuclear reactors

    International Nuclear Information System (INIS)

    Criticality and burn up behavior of the Fixed Bed Nuclear Reactor (FBNR) are investigated for the mixed fuel 233UO2/ThO2 as an alternative to low enriched 235UO2 fuel. CERMET fuel with a zirconium matrix and cladding has been used throughout the study. The main results of the study can be summarized as follows: Reactor criticality is already achieved by ∝2% 233UO2 with the mixed 233UO2/ThO2 fuel. At higher 233U fractions, reactor criticality rises rapidly and exceeds keff > 1.5 already by 9% 233UO2. With 100% 233UO2, start up criticality can reach keff = 2.0975. Time dependent reactor criticality keff and fuel burn up have been investigated for two different mixed fuel 233UO2/ThO2 compositions, namely: 4% 233UO2 + 96% ThO2 for a reactor power of 40 MWel (120 MWth) and 9% 233UO2 + 91% ThO2 for a reactor power of 70 MWel (210 MWth). Sufficient reactor criticality (keff > 1.06) for continuous operation without fuel change can be sustained during ∝ 5 and 12 years with 4% and 9% 233UO2 fractions in the mixed fuel, leading to burn ups of ∝ 36000 and > 105000 MWD/t, respectively. Thorium based fuel produces no prolific uranium. Plutonium production remains negligible. (orig.)

  13. Biogas production from different grass

    OpenAIRE

    Liubarskij, Vladimir; Mahnert, Pia; Heiermann, Monika; Linke, Bernd

    2006-01-01

    The importance of forage as a feed supply for dairy and beef cattle stocks is decreasing. Therefore, interest is rising in alternative use of grasslands. An ecologically sound option is the anaerobic digestion of the biomass as co-substrates in biogas plants. Three fresh and ensiled grass species were investigated in lab-scale batch experiments at 35 °C to determine their maximum biogas production potential. The volatile solid-based biogas and methane yield were observed to be in the range...

  14. ASSESSMENT OF THE BIODIVERSITY OF SAMPLES USED FOR ISOLATION OF MICROBIAL STRAINS CAPABLE OF CONVERTING STRAW DESTINED AS A SUBSTRATE FOR BIOGAS PLANT

    OpenAIRE

    Krystyna Cybulska; Paweł Kołosowski; Ilona Wrońska; Tomasz Dobek

    2016-01-01

    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 ...

  15. Biogas production and biogas as vehicle fuel - Swedish experiences

    Energy Technology Data Exchange (ETDEWEB)

    Lindberg, A.E. [VBB Viak AB, Stockholm (Sweden)

    1997-08-01

    In Sweden there are totally about 220 biogas plants in operation. The major part of these plants (134) are represented by sewage sludge treatment facilities at waste water treatment plants. At 60 sites the biogas is generated from landfills or cell digesters at landfills. In 1996, the amount produced had a total energy content of about 1,35 TWh (or 4 900 PJ). (EG)

  16. Advanced-power-reactor design concepts and performance characteristics

    Science.gov (United States)

    Davison, H. W.; Kirchgessner, T. A.; Springborn, R. H.; Yacobucci, H. G.

    1974-01-01

    Five reactor cooling concepts which allow continued reactor operation following a single rupture of the coolant system are presented for application with the APR. These concepts incorporate convective cooling, double containment, or heat pipes to ensure operation after a coolant line rupture. Based on an evaluation of several control system concepts, a molybdenum clad, beryllium oxide sliding reflector located outside the pressure vessel is recommended.

  17. Biogas production and microbial community shift through neutral pH control during the anaerobic digestion of pig manure.

    Science.gov (United States)

    Zhou, Jun; Zhang, Rui; Liu, Fenwu; Yong, Xiaoyu; Wu, Xiayuan; Zheng, Tao; Jiang, Min; Jia, Honghua

    2016-10-01

    Laboratory-scale reactors, in which the pH could be auto-adjusted, were employed to investigate the mesophilic methane fermentation with pig manure (7.8% total solids) at pH 6.0, 7.0, and 8.0. Results showed that the performance of anaerobic digestion was strongly dependent on pH value. Biogas production and methane content at neutral pH 7.0 were significantly higher (16,607mL, 51.81%) than those at pH 6.0 (6916mL, 42.9%) and 8.0 (9739mL, 35.6%). Denaturing gradient gel electrophoresis fingerprinting and Shannon's index indicated that the samples contained highly diverse microbial communities. The major genus at pH 7.0 was Methanocorpusculum, compared with that was Methanosarcina at both pH 6.0 and 8.0. Our research revealed that cultures maintained at pH 7.0 could support increased biogas production, which has significant implications for the scale-up biogas engineering. PMID:26944458

  18. Economic analysis of anaerobic digestion - A case of Green power biogas plant in The Netherlands

    NARCIS (Netherlands)

    Gebrezgabher, S.A.; Meuwissen, M.P.M.; Prins, B.A.M.; Oude Lansink, A.G.J.M.

    2010-01-01

    One of the key concerns of biogas plants is the disposal of comparatively large amounts of digestates in an economically and environmentally sustainable manner. This paper analyses the economic performance of anaerobic digestion of a given biogas plant based on net present value (NPV) and internal r

  19. Evaluating the Air Quality, Climate Change, and Economic Impacts of Biogas Management Technologies

    Science.gov (United States)

    This is an abstract for a presentation that describes a project to evaluate economic and environmental performance of several biogas management technologies. It will analyze various criteria air pollutants, greenhouse gas emissions, and costs associated with the use of biogas. Th...

  20. Experimental and economical evaluation of a novel biogas digester

    International Nuclear Information System (INIS)

    Highlights: • Textile biogas digester was tested with synthetic nutrients and MSW. • Economical evaluation was made with replacement of LPG and kerosene. • The investment is positive until the price of fuel goes down. • Sensitivity analysis was performed to check the stability of the digester. - Abstract: Many developing countries face an energy demand to satisfy the daily needs of the people. Household biogas digesters are among the interesting solutions to meet the energy demands for cooking and lighting, and at the same time taking care of the kitchen wastes. In this study, a novel textile-based biogas digester was developed. The digester was evaluated for biogas production from a synthetic nutrient and an organic fraction of municipal solid waste (OFMSW) as substrates for more than a year. The obtained biogas productivity in both experiments was 570 L/kgVS/day, which indicates that the digester is as efficient in handling of OFMSW as the synthetic nutrients. Based on the obtained biogas production data, the techno-economic evaluation and sensitivity analysis for the process were performed, replacing LPG and kerosene consumption with biogas in households. A 2-m3 digester can supply the fuel needed for cooking for a family of 4–6 people. The sum of investment and 15-years operational costs of this digester was 656 USD, which can be compared with 1455 USD for subsidized-LPG and 975 USD for kerosene, respectively. The results from the sensitivity analysis show that it was a positive investment, unless the price of kerosene goes down to less than 0.18 USD/L

  1. BIOGAS PRODUCTION FROM WASTE TO ANIMAL

    Directory of Open Access Journals (Sweden)

    EDVAL LUIZ BATISTA DOS SANTOS

    2013-08-01

    Full Text Available Climate change is a current issue. Greenhouse gas emissions (GGEs are changing the atmosphere physio-chemical characteristics also affecting biosphere natural balance and life quality on Earth. The search for renewable and clean source is an alternative to reverse, control and attenuate the problems caused by greenhouse gases. Biomass is one of the major energy sources available in rural and agribusiness areas. Anaerobic biological degradation of organic material present in solid agricultural waste generates a gaseous mixture of methane (CH4 and carbon dioxide (CO2, called biogas. It is possible to use its energy potential through the burning and obtaining of thermal energy. Biogas generation offers producers a renewable energy source of optimum performance which supports external electric expenses and provides clean energy as well as adequate distribution of generated effluent. Biogas usage is a large energetic potential concerning small and medium-sized farms. This paper aims at observing how this kind of energy can help the control of GGE emissions, adequate animal waste disposal as well dumping and especially the generation of clean and renewable energy. It also intends to answer questions about this technology aiming to help producers to take advantages of such technique by decreasing electric energy costs providing an economical development as well as improvement on local and national energetic area.

  2. The Finnish biogas register no 15. Information compiled from 2011; Suomen biokaasulaitosrekisteri n:o 15. Tiedot vuodelta 2011

    Energy Technology Data Exchange (ETDEWEB)

    Huttunen, M.; Kuittinen, V.

    2012-11-01

    In Finland altogether 16 biogas reactor plants have been in operation at different municipal wastewater treatment plants by the end of 2011. Industrial wastewaters were treated anaerobically at three different plants. Farm-scale biogas plants were operating at 10 places. Municipal solid wastes were treated at eight biogas plants. In 2011, the amount of biogas produced by the reactor installations was 43.6 million m{sup 3} and the combustion of surplus biogas 6.3 million m{sup 3}. Production of thermal, electrical and mechanical energy was 203.4 GWh. As compared to the previous year, there was a fair increase in the total amount of the produced biogas and the energy. There were altogether 39 landfill gas recovery plants operating at the end of 2011. The amount of the recovered biogas was 102.0 million m{sup 3}. The amount of recovered biogas used for the production of electrical and thermal energy was 77.2 million m{sup 3} producing 314.5 GWh. (orig.)

  3. 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 biogas 6.1 million m{sup 3}. Production of thermal, electrical and mechanical energy was 256.2 GWh. As compared to the previous year, there was a notable increase in the total amount of the produced biogas and the energy. There were altogether 40 landfill gas recovery plants operating at the end of 2012. The amount of the recovered biogas was 94.5 million m{sup 3}. The amount of recovered biogas used for the production of electrical and thermal energy was 74.8 million m{sup 3}, producing 312.2 GWh. (orig.)

  4. Nitrogen availability of biogas residues

    Energy Technology Data Exchange (ETDEWEB)

    El-Sayed Fouda, Sara

    2011-09-07

    The objectives of this study were to characterize biogas residues either unseparated or separated into a liquid and a solid phase from the fermentation of different substrates with respect to their N and C content. In addition, short and long term effects of the application of these biogas residues on the N availability and N utilization by ryegrass was investigated. It is concluded that unseparated or liquid separated biogas residues provide N at least corresponding to their ammonium content and that after the first fertilizer application the C{sub org}:N{sub org} ratio of the biogas residues was a crucial factor for the N availability. After long term application, the organic N accumulated in the soil leads to an increased release of N.

  5. BIOGAS PRODUCTION FROM CATCH CROPS

    DEFF Research Database (Denmark)

    Molinuevo-Salces, Beatriz; Larsen, Søren U.; Ahring, Birgitte Kiær;

    2014-01-01

    Catch crop cultivation combined with its use for biogas production would increase renewable energy production in the form of methane, without interfering with the production of food and fodder crops. The low biomass yield of catch crops is the main limiting factor for using these crops as co......-substrate in manure-based biogas plants and the profit obtained from the sale of biogas barely compensates for the harvest costs. A new agricultural strategy to harvest catch crops together with the residual straw of the main crop was investigated to increase the biomass and thereby the methane yield per hectare...... biomass. Leaving the straw on the field until harvest of the catch crop in the autumn could benefit biogas production due to the organic matter degradation of the straw taking place on the field during the autumn months. This new agricultural strategy may be a good alternative to achieve economically...

  6. Monitoring of biogas test plants

    DEFF Research Database (Denmark)

    Holm-Nielsen, Jens Bo; Esbensen, Kim H.

    2011-01-01

    Most studies reported in the literature have investigated near infrared spectroscopy (NIR) in laboratory-scale or minor pilot biogas plants only; practically no other studies have examined the potential for meso-scale/full-scale on-line process monitoring. The focus of this study is on a meso......-scale biogas test plant implementation of process analytical technologies (PAT) to develop multivariate calibration/prediction models for anaerobic digestion (AD) processes. A 150 L bioreactor was fitted with a recurrent loop at which NIR spectroscopy and attendant reference sampling were carried out. In all...... realistic bioreactor scales, it is necessary to obtain a fairly constant level of volatile fatty acid (VFA) concentration, which furthers a stable biogas production. Uncontrolled VFA contents have a significant negative impact on biogas production; VFA concentrations should not exceed 5–6000 mg/L lest...

  7. 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.

  8. Scalable synthesis of ionic liquids: comparison of performances of microstructured and stirred batch reactors

    OpenAIRE

    Iken, Hicham; Guillen, Frédéric; Chaumat, Hélène; Mazières, Marie-Rose; Plaquevent, Jean-Christophe; Tzedakis, Théodore

    2012-01-01

    A range of alkylpyridinium bromide ionic liquids have been synthesized in a stirred reactor at multigram scale and characterized by physical methods (viscosity, conductivity, melting point, electrochemical window, and water content). One ionic liquid, octylpyridinium bromide, was chosen to be synthesized in both macro and reduced scale reactors, in order to compare its performance and to afford evidence of the advantages of a cross channel micro reactor (channel width = 1 mm) compared to a st...

  9. Biogas production from lignocellulosic materials

    OpenAIRE

    Li SUN

    2015-01-01

    Lignocellulosic materials such as agricultural plant residues are widely available in large amounts and can be used for production of biogas without the risk of competition for arable land. However, the intricate structure of lignocellulose, a major component of the plant cell wall, limits microbial degradation and consequently results in low degradation rate and low biogas yield. The aim of this thesis was to investigate microbial communities engaged in the degradation of lignocellulose and ...

  10. Collective biogas plants

    International Nuclear Information System (INIS)

    Papers contributed to the European seminar on collective biogas plants held at Herning, Denmark on October 22-23 under the auspices of the Commission of the European Communities, Directorate-General for Energy (DG XVII) are presented. Within the framework of the THERMIE programme, a network of OPETs (Organizations for the Promotion of Energy Technologies) was set up in order to disseminate information on new energy technologies throughout the European communities. The potential for further implementation of centralized capacity for the conversion of animal manures and other organic wastes to bio-fuels, not only in central and eastern Europe but also in the developing countries, is discussed in addition to the relevant technologies. Actual biomass conversion plants are described and details are given on operational experience and plant management. Agricultural, economic and policy aspects are also dealt with. (AB)

  11. Combined utilization of biogas and natural gas

    International Nuclear Information System (INIS)

    The Danish natural gas network has been established during the past 10 years. Running parallel with this a small but growing production of biogas from centralized biogas plants and landfills has been developed. The annual biogas production is expected to keep growing and increase tenfold in the next 25 year period with a reduction of green house gas emissions as one of the important incentives. The last years' development and expansion of the Danish biogas sector has shown a need for combined utilization of biogas and natural gas. If larger volumes of biogas are present, upgrading and distribution by the natural gas network may be an alternative to combined utilization. (au) 12 refs

  12. The commercialization of biogas production

    International Nuclear Information System (INIS)

    Currently there are ten large collective biogas plants and ten smaller farm plants operating in Denmark. During the last five years, biogas technology has undergone extensive technological development. The developmental process is supported by a public R and D programme and a follow-up programme for full-scale demonstration plants. Most plants still need considerable income increases before a final conclusion can be reached as to whether it is possible to achieve a profit from a corporate economic viewpoint. All plants have received investment grants. Gas production is in most cases reliable, especially due to the admixture of easily convertible organic waste as a supplement to the slurry supplies. Profitable collective biogas plants are within reach, even without investment grants. The total intake of biomass must be supplemented by 10 to 25 per cent easily convertible organic waste so that the minimum gas production reaches 30 to 35 m3 per m3 of biomass. Plants based solely on animal manure are not profitable. Energy from the biogas has to be sold at prices corresponding to consumer prices, which include Danish energy taxes. Collective biogas plants in Denmark appear to be approaching a commercial breakthrough. The concept of a collective biogas plant has been developed to address the energy-related, environmentally-related and agricultural problems. (AB)

  13. Biogas production from Jatropha curcas press-cake

    Energy Technology Data Exchange (ETDEWEB)

    Staubmann, R.; Guebitz, G.M.; Lafferty, R.M. [Graz Technical Univ. (Austria)] [and others

    1997-12-31

    Seeds of the tropical plant Jatropha curcas (purge nut, physic nut) are used for the production of oil. Several methods for oil extraction have been developed. In all processes, about 50% of the weight of the seeds remain as a press cake containing mainly protein and carbohydrates. Investigations have shown that this residue contains toxic compounds and cannot be used as animal feed without further processing. Preliminary experiments have shown that the residue is a good substrate for biogas production. Biogas formation was studied using a semicontinous upflow anaerobic sludge blanket (UASB) reactor; a contact-process and an anaerobic filter each reactor having a total volume of 110 L. A maximum production rate of 3.5 m{sup 3} m{sup -3} d{sup -1} was obtained in the anaerobic filter with a loading rate of 13 kg COD m{sup -3} d{sup -1}. However, the UAS reactor and the contact-process were not suitable for using this substrate. When using an anaerobic filter with Jatropha curcas seed cake as a substrate, 76% of the COD was degraded and 1 kg degraded COD yielded 355 L of biogas containing 70% methane. 28 refs., 3 figs., 4 tabs.

  14. A novel application of red mud-iron on granulation and treatment of palm oil mill effluent using upflow anaerobic sludge blanket reactor.

    Science.gov (United States)

    Ahmad, Anwar

    2014-01-01

    The performance of the upflow anaerobic sludge blanket reactor that used red mud-iron (RM-Fe) for methane production for the treatment of palm oil mill effluent (POME) at various hydraulic retention time (HRT) was determined. POME was used as the substrate carbon source. The biogas production rate was 1.7 l biogas/h with a methane yield of 0.78 l CH4/g CODremoved and chemical oxygen demand (COD) removal was 85% at POME concentration of 30 g COD/l at HRT 16 h. The reactor R2 showed average methane content of biogas and COD reduction of 78% and 85% at 400 mg/l RM-Fe. Significant increase in the granule diameter (up to 2900 μm) in R2 was compared to control R1 (up to 86 μm) at end of the experiment. PMID:25176306

  15. Investigation of Discharge Performance of SOFC Using Biogas and Its Off-gas%生物气及其电池尾气 SOFC 放电性能研究

    Institute of Scientific and Technical Information of China (English)

    王德震; 左薇; 张军; 吴晓燕; 孔晓伟

    2015-01-01

    To investigate the discharge performance of Ni-YSZ anode solid oxide fuel cell using various biogas and evaluate the valve of reusing its off-gas, electrochemical performance and gas properties were studied when two SOFC operated in tandem using diverse ratio of CH4/CO2 at 750 ℃. Compared with the cell performance using H2, two SOFC both operated at high power density with the first stage SOFC using various CH4/CO2 biogas and the second stage using the off-gas of the first stage. Both of two SOFC worked mostly steadily at constant current density for short time with little carbon deposition. The analysis of the gas properties at 566 mA•cm-2 indicated that the dry reforming rate was the highest when the ratio of CH4/CO2 was 2. The research results show that power generation of SOFC using biogas and its off-gas is feasible. This research can be useful for designing gas circuit of SOFC piles using biogas.%为探究以不同浓度生物气为燃料的固体氧化物燃料电池(SOFC)发电性能及该类电池尾气的再发电价值,通过模拟含不同比例甲烷和二氧化碳的生物气,在750℃下对气路串联 Ni/YSZ 阳极支撑 SOFC 进行放电性能测试和气体特性分析。放电结果显示燃料气经第一级 SOFC 利用后通入第二级 SOFC,同氢气经过两级 SOFC 相比,不同浓度下生物气均获得了较高的功率密度,且短时间恒流时,两级电池均能稳定运行;两级电池均以566 mA· cm-2电流密度恒流放电时的气体分析表明,当 CO2/CH4为2时,电池内甲烷的干重整率最高。研究结果表明两级 SOFC 使用生物气及其电池尾气发电是可行的,可为以生物气为燃料 SOFC 电堆气路设计提供依据。

  16. High-solid Anaerobic Co-digestion of Food Waste and Rice Straw for Biogas Production

    Institute of Scientific and Technical Information of China (English)

    Pei Zhan-jiang; Liu Jie; Shi Feng-mei; Wang Su; GaoYa-bing; Zhang Da-lei

    2014-01-01

    Anaerobic co-digestion of food waste (FW) and rice straw (RS) in continuously stirred tank reactor (CSTR) at high organic loading rate (OLR) was investigated. Co-digestion studies of FW and RS with six different mixing ratios were conducted at an initial volatile solid (VS) concentration of more than 3 gVS•L-1. The biogas production, methane contents, degradation efficiency of VS, chemical oxygen demand (COD) and volatile fatty acids (VFAs) were determined to evaluate the stability and performance of the system. The results showed that the co-digestion process had higher system stability and higher volumetric biogas production than mono-digestions. Increase in FW content in the feedstock could increase the methane yield and shorten retention time. The efficiency of co-digestion systems mainly relied on the mixing ratios of FW and RS to some extent. The highest methane yield was 60.55 mL•gV•S-1•d-1 at a mass ratio (FW/RS) of 3: 1, which was 178% and 70% higher than that of mono-digestions of FW and RS, respectively. Consequently, the anaerobic co-digestion of FW and RS could have superior stability and better performance than mono-digestions in higher organic loading system.

  17. Trends vs. reactor size of passive reactivity shutdown and control performance

    International Nuclear Information System (INIS)

    In LMR [liquid metal reactor] concepts, favorable passive reactivity shutdown performance in response to ATWS [anticipated transient without scram] events has been shown to be achievable when measurable, integral reactivity parameters satisfy certain requirements. The trends in the integral reactivity parameters with reactor size for both oxide and metal fuel have been developed based on a data base of about two dozen reactor designs in the range 400 to 3,600 MWth. The general conclusion is that the favorable passive reactivity control features which accrue to the metallic-fueled reactors in the modular size range can be achieved as well in the larger commercial sizes

  18. 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)

    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/m3 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/m3 day in the AMBR reactor. The COD removal efficiencies decreased from 91% to 85% at a NB loading rate of 66.67 g/m3 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/m3 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/m3 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/m3 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

  19. UTILIZATION OF POULTRY, COW AND KITCHEN WASTES FOR BIOGAS PRODUCTION: A COMPARATIVE ANALYSIS

    Directory of Open Access Journals (Sweden)

    K. Animasahun

    2007-09-01

    Full Text Available The amount of solid wastes generated in developing countries such as Nigeria has steadily increased over the last two decades as a result of population explosion and continuous growth of industries and agricultural practices. In agriculture, particularly cattle rearing, large quantities of cow wastes are generated, which could be used as biogas inputs to compliment the fuel usage alternative. In addition, a large number of families generate heavy wastes in the kitchen on a daily basis, which could be converted to economic benefits. In this work, a comparative study of biogas production from poultry droppings, cattle dung, and kitchen wastes was conducted under the same operating conditions. 3kg of each waste was mixed with 9L of water and loaded into the three waste reactors. Biogas production was measured for a period of 40 days and at an average temperature of 30.5oC. Biogas production started on the 7th day, and attained maximum value on the 14th days for reactor 1. Production reached its peak on the 14th day with 85´10-3dm3 of gas produced in reactor 2. For reactor 3, biogas production started on the 8th day and production reached a peak value on the 14th day. The average biogas production from poultry droppings, cow dung and kitchen waste was 0.0318dm3/day, 0.0230dm3/day and 0.0143dm3/day, respectively. It is concluded that the wastes can be managed through conversion into biogas, which is a source of income generation for the society.

  20. Modified-open fuel cycle performance with breed-and-burn advanced reactor concepts

    International Nuclear Information System (INIS)

    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)

  1. Economic performance of liquid-metal fast breeder reactor and gas-cooled fast reactor radial blankets

    International Nuclear Information System (INIS)

    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

  2. Production of biogas from municipal solid waste with domestic sewage.

    Science.gov (United States)

    Elango, D; Pulikesi, M; Baskaralingam, P; Ramamurthi, V; Sivanesan, S

    2007-03-01

    In this study, experiments were conducted to investigate the production of biogas from municipal solid waste (MSW) and domestic sewage by using anaerobic digestion process. The batch type of reactor was operated at room temperature varying from 26 to 36 degrees C with a fixed hydraulic retention time (HRT) of 25 days. The digester was operated at different organic feeding rates of 0.5, 1.0, 2.3, 2.9, 3.5 and 4.3kg of volatile solids (VS)/m(3) of digester slurry per day. Biogas generation was enhanced by the addition of domestic sewage to MSW. The maximum biogas production of 0.36m(3)/kg of VS added per day occurred at the optimum organic feeding rate of 2.9kg of VS/m(3)/day. The maximum reduction of total solids (TS) (87.6%), VS (88.1%) and chemical oxygen demand (COD) (89.3%) occurred at the optimum organic loading rate of 2.9kg of VS/m(3)/day. The quality of biogas produced during anaerobic digestion process was 68-72%. PMID:16914265

  3. 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.

  4. The analysis of physical performances of the reactor RBMK-1500

    International Nuclear Information System (INIS)

    Main direction of work is construction of mathematical models of severe accidents and models of different transient regimes in the reactor RBMK-1500 and in all complex of the NPP equipment as well. The analysis of serviceability of the important technological schemes in emergency operation also is carried out. (authors)

  5. The analyses of physical performances of the reactor RBMK-1500

    International Nuclear Information System (INIS)

    Main direction of work is construction of mathematical models of severe accidents and models of different transient regimes in the reactor RBMK-1500 and in all complex of the NPP equipment as well. The analysis of serviceability of the important technological schemes in emergency operation also is carried out. (authors)

  6. Power probability density function control and performance assessment of a nuclear research reactor

    International Nuclear Information System (INIS)

    Highlights: • In this paper, the performance assessment of static PDF control system is discussed. • The reactor PDF model is set up based on the B-spline functions. • Acquaints of Nu, and Th-h. equations solve concurrently by reformed Hansen’s method. • A principle of performance assessment is put forward for the PDF of the NR control. - Abstract: One of the main issues in controlling a system is to keep track of the conditions of the system function. The performance condition of the system should be inspected continuously, to keep the system in reliable working condition. In this study, the nuclear reactor is considered as a complicated system and a principle of performance assessment is used for analyzing the performance of the power probability density function (PDF) of the nuclear research reactor control. First, the model of the power PDF is set up, then the controller is designed to make the power PDF for tracing the given shape, that make the reactor to be a closed-loop system. The operating data of the closed-loop reactor are used to assess the control performance with the performance assessment criteria. The modeling, controller design and the performance assessment of the power PDF are all applied to the control of Tehran Research Reactor (TRR) power in a nuclear process. In this paper, the performance assessment of the static PDF control system is discussed, the efficacy and efficiency of the proposed method are investigated, and finally its reliability is proven

  7. Efficient Heat Use from Biogas CHP Plants. Case Studies from Biogas Plants in Latvia

    OpenAIRE

    Dzene, Ilze; Slotiņa, Lāsma

    2013-01-01

    This paper is focusing on efficient heat use from biogas plants. It gives an overview about various biogas heat use options and specifically addresses biogas heat use market in Latvia. In the end three examples from typical agricultural biogas plants in Latvia and their heat use plans are described.

  8. Development of system design and seismic performance evaluation for reactor pool working platform of a research reactor

    International Nuclear Information System (INIS)

    Highlights: • Design of reactor pool working platform (RPWP) is newly proposed for an open-tank-in-pool type research reactor. • Main concept of RPWP is to minimize the pool top radiation level. • Framework for seismic performance evaluation of nuclear SSCs in a deterministic and a probabilistic manner is proposed. • Structural integrity, serviceability, and seismic margin of the RPWP are evaluated during and after seismic events. -- Abstract: The reactor pool working platform (RPWP) has been newly designed for an open-tank-in-pool type research reactor, and its seismic response, structural integrity, serviceability, and seismic margin have been evaluated during and after seismic events in this paper. The main important concept of the RPWP is to minimize the pool top radiation level by physically covering the reactor pool of the open-tank-in-pool type research reactor and suppressing the rise of flow induced by the primary cooling system. It is also to provide easy handling of the irradiated objects under the pool water by providing guide tubes and refueling cover to make the radioisotopes irradiated and protect the reactor structure assembly. For this concept, the new three dimensional design model of the RPWP is established for manufacturing, installation and operation, and the analytical model is developed to analyze the seismic performance. Since it is submerged under and influenced by water, the hydrodynamic effect is taken into account by using the hydrodynamic added mass method. To investigate the dynamic characteristics of the RPWP, a modal analysis of the developed analytical model is performed. To evaluate the structural integrity and serviceability of the RPWP, the response spectrum analysis and response time history analysis have been performed under the static load and the seismic load of a safe shutdown earthquake (SSE). Their stresses are analyzed for the structural integrity. The possibility of an impact between the RPWP and the most

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

    Directory of Open Access Journals (Sweden)

    Vimac Nolla-Ardevol

    2015-06-01

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

  10. Biogas Koczala. Biogas project in Koczala. Feasibility study. Technical report

    International Nuclear Information System (INIS)

    The present production of district heating in Koczala is based on coal. The district heating system is worn out technically and economically and according to the 2001 Energy Plan of Koczala the district heating plant shall be converted to a combination of a biogas fired CHP and a wood chip boiler. The overall objective of this project is to access the feasibility and viability construction an operation of a biogas plant owned by the co-operative agricultural company, Poldanor S.A. The feasibility study includes: 1) Availability of organic waste in the Koczala area, 2) Possibilities of using energy crops in the biogas plant, 3) Possibilities of receiving grants from the Polish National Fund for Environmental Protection, the new EU regional funds and through the joint implementation market (CO2 quotas), 4) Alternative locations of the biogas plant and the CHP unit, 5) Alternative strategies for selling electricity and heat, 6) Organisational issues (ownership). This report concludes that implementing the biogas project is environmentally and financially feasible and viable. If organic waste and/or maize silage can be provided and gasified without problems, the plant can supply as well the Koczala farm as the fodder mill with steam and heat, and also supply Koczala district heating system with approx. 75% of yearly heat consumption. Furthermore, electricity is supplied to the fodder mill and the public grid. (BA)

  11. Environmental and economic analysis of application of water hyacinth for eutrophic water treatment coupled with biogas production.

    Science.gov (United States)

    Wang, Zanxin; Calderon, Margaret M

    2012-11-15

    The proliferation of water hyacinth is currently controlled by removing it from a water body and disposing it by landfill in China. Using water hyacinth to remove nutrients from water bodies and to produce biogas is another technically feasible option for the control of water hyacinth, but its environmental and economic performances are not well understood. This study collected data from an experimental biogas plant to develop a lifecycle analysis and a cost benefit analysis for the control of water hyacinth proliferation in a eutrophic lake in China. Comparison was made between the alternative option of using water hyacinth for biogas production and the current practice of disposing it in landfills. The results reveal that the biogas option is economically feasible with a positive energy balance. The removal of water hyacinth to produce biogas can contribute to water quality improvement and GHG emission reduction whose values, however, depend on the processing scale of the biogas plant. Since both the current approach and the biogas option can remove nutrients from water bodies, the additional value of water quality improvement resulting from the biogas option is only possible when the processing scale of the biogas plant is greater than the amount of water hyacinth disposed by landfill. The emission of methane deserves attention when water hyacinth is disposed by landfill. The biogas option can respond to China's policies on water pollution control, renewable energy development, and energy saving and emission reduction. PMID:22813757

  12. Deeper insight into the structure of the anaerobic digestion microbial community; the biogas microbiome database is expanded with 157 new genomes

    DEFF Research Database (Denmark)

    Treu, Laura; Kougias, Panagiotis; Campanaro, Stefano;

    2016-01-01

    This research aimed to better characterize the biogas microbiome by means of high throughput metagenomic sequencing and to elucidate the core microbial consortium existing in biogas reactors independently from the operational conditions. Assembly of shotgun reads followed by an established binning...... strategy resulted in the highest, up to now, extraction of microbial genomes involved in biogas producing systems. From the 236 extracted genome bins, it was remarkably found that the vast majority of them could only be characterized at high taxonomic levels. This result confirms that the biogas microbiome...

  13. Biogas production from communal grass cuttings. Final report. Biogaserzeugung aus kommunalen Grasabfaellen im Klaewerk. Endbericht

    Energy Technology Data Exchange (ETDEWEB)

    Perwanger, A.; Seifert, M.; Radeloff, D.

    1988-02-01

    An investigation was carried out in the sewage works of the town of Selb over a period of two years as to the possibility of adding grass to sewage sludge for biogas production. Communal grass cuttings were added to the large (2500 m{sup 3}) reactor tower of the sewage plant. Additionally the gas production rate from grass and sludge was determined using a continuous flow trial reactor of 1 m{sup 3} capacity run in parallel to the main reactor. The remaining grass was analysed for mineral and heavy metal content, and the vollumetric reduction measured. In accompanying laboratory investigations using 45 biogas reactors of 10 to 1000 litre capacity 29 specific trials were carried out. The principle factors determined were: 1. Optimum mixture of sewage sludge and grass, 2. Specific gas production from grass, silage and hay, 3. Comparative suitability of batch storage and flow biogas reactors. The results are evaluated in terms of substrate and reactor efficiency. Based on the insight gained, three proposals for the construction and operation of biogas plants for energy production from grass have been designed. (orig.) With 22 refs., 29 tabs., 98 figs.

  14. Biogas and methanation; Biogaz et methanisation

    Energy Technology Data Exchange (ETDEWEB)

    Vachey, C.

    2000-05-01

    This paper recalls the methanation principle, biochemical phenomenon which occurs in closed wall, where the organic matter is transformed in biogas. It presents the biogas valorization channels and their advantages. (A.L.B.)

  15. Commercial scale performance predictions for high-temperature electrolysis plants coupled to three advanced reactor types

    International Nuclear Information System (INIS)

    This paper presents results of system analyses that have been developed to assess the hydrogen-production performance of commercial-scale high-temperature electrolysis (HTE) plants driven by three different advanced reactor - power-cycle combinations: a high-temperature helium-cooled reactor coupled to a direct Brayton power cycle, a supercritical CO2-cooled reactor coupled to a direct recompression cycle, and a sodium-cooled fast reactor coupled to a Rankine cycle. The system analyses were performed using UniSim software. The work described in this report represents a refinement of previous analyses in that the process flow diagrams include realistic representations of the three advanced reactors directly coupled to the power cycles and integrated with the high-temperature electrolysis process loops. In addition, this report includes parametric studies in which the performance of each HTE concept is determined over a wide range of operating conditions. Results of the study indicate that overall thermal-to-hydrogen production efficiencies (based on the low heating value of the produced hydrogen) in the 45 - 50% range can be achieved at reasonable hydrogen production rates with the high-temperature helium-cooled reactor concept, 42 - 44% with the supercritical CO2-cooled reactor and about 33 - 34% with the sodium-cooled reactor. (authors)

  16. Neutronic performance of a 14 MW TRIGA reactor: LEU vs HEU fuel

    International Nuclear Information System (INIS)

    A primary objective of the US Reduced Enrichment Research and Test Reactor (RERTR) Program is to develop means for replacing, wherever possible, currently used highly-enriched uranium (HEU) fuel (235U enrichment > 90%) with low-enriched uranium (LEU) fuel (235U enrichment < 20%) without significantly degrading the performance of research and test reactors. The General Atomic Company has developed a low-enriched but high uranium content Er-U-ZrH/sub 1.6/ fuel to enable the conversion of TRIGA reactors (and others) from HEU to LEU. One possible application is to the water-moderated 14 MW TRIGA Steady State Reactor (SSR) at the Romanian Institute for Nuclear Power Reactors. The work reported here was undertaken for the purpose of comparing the neutronic performance of the SSR for HEU fuel with that for LEU fuel. In order to make these relative comparisons as valid as possible, identical methods and models were used for the neutronic calculations

  17. Bioenergy, protein and fibres from grass - biogas process monitoring; Bioenergie, Protein und Fasern aus Gras - Monitoring des Biogasprozesses

    Energy Technology Data Exchange (ETDEWEB)

    Baier, U.; Delavy, P.

    2003-07-01

    Starting in Summer 2001 the first full scale Swiss Bio-refinery for grass processing took up operation in Schaffhausen. Grass processing covers the production of technical fibres and protein concentrate as well as anaerobic digestion of residual slops for the production of biogas and 'green' electricity. The refinery is operated by the company Bioenergie Schaffhausen as a P+D (pilot + demonstration) project of the Swiss Federal Office of Energy. Under full load it will deliver 2,000 MWh of 'green' electricity (10% own needs) and 3,000 MWh heat (50% own needs). Prior to start up the Swiss technology holder 2B Biorefineries AG mandated the University of Applied Sciences HSW with lab scale testing of the mesophilic biogas potential and anaerobic degradability of residual grass processing slops. Nutrient limitations and possible inhibition risks were evaluated. During the initial 8 months of full scale operation of the refinery in Schaffhausen an intensive monitoring of the anaerobic digester's performance was carried out. Carbon and nitrogen mass balances have been set up and the development of the granular EGSB sludge was characterised. From operational data a set of performance values was elaborated. The first year of operation was characterised by only partial exploitation of the refinery's grass processing capacity. Furthermore the protein separation and production unit has not yet been incorporated. Consequently, the EGSB biogas reactor showed a significant hydraulic underload when compared to dimensioning basics. Raw residuals were characterised by a higher particulate protein fraction. Operational conditions for the EGSB reactor were worked out to allow stable operation at elevated load conditions and with protein separation in operation. (author)

  18. The biogas; Le biogaz se detend

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-05-15

    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.)

  19. Biogas production from a systems analytical perspective

    OpenAIRE

    Berglund, Maria

    2006-01-01

    Anaerobic digestion and the production of biogas can provide an efficient means of meeting several objectives concerning energy, environmental and waste management policy. Interest in biogas is increasing, and new facilities are being built. There is a wide range of potential raw material, and both the biogas and digestates produced can be used in many different applications. The variation in raw materials and digestion processes contributes to the flexibility of biogas production systems, bu...

  20. BIOGAS-ECONOMICAL SIGNIFICANCE AND GENERATION THEREOF

    OpenAIRE

    Kazimierz Brodowicz

    1983-01-01

    The paper presents a review of worldwide and domestic knowledge in the field of biogas generation techniques. To this there are discussed the basic fermentation processes being resonsible for biogas generation and actually used typical systems therefor presented.Particular attention has been paid to energetic aspects of the biogas. The generalization of biogas production would render possible large scale utilization of the biomass which is useless for other purposes but still renewable as a s...

  1. Avaliação do desempenho de um aquecedor para aves adaptado para utilizar biogás como combustível Birds heater adaptation and performance using biogas as fuel

    Directory of Open Access Journals (Sweden)

    Tânia M. B. Santos

    2007-12-01

    Full Text Available Desenvolveu-se ensaio para avaliar a adaptação (diâmetro do injetor e o desempenho (consumo e eficiência de aquecimento de um aquecedor tipo campânula, adaptado para queimar biogás. Foi testado um aquecedor comum que, queimando gás liquefeito de petróleo (GLP, opera à baixa pressão (28 cm.c.a., com capacidade calorífica de 5.024 kJ h-1 e recomendado para 500 aves. O aquecedor foi avaliado com o combustível original (GLP, sem qualquer modificação no injetor de gás, e após adaptação para o funcionamento a biogás. Na adaptação, foi mantida a mesma grelha do queimador principal, aumentando-se a perfuração do injetor para permitir o funcionamento e a avaliação. Foram avaliados cinco injetores com perfurações de 1,0053; 1,5080; 1,5708; 1,7672 e 1,980 mm². Também se variaram as pressões do biogás na entrada do aquecedor de 10; 12; 15; 17 e 20 cm de coluna d'água (cm.c.a.. Os resultados indicaram que as expressões de cálculo teórico e parâmetros propostos na bibliografia podem ser utilizados com segurança na adaptação de aquecedores do tipo campânula utilizados em aviários; que a adaptação é de simples execução, indicando a viabilidade da utilização dos aquecedores já existentes em granjas e no mercado, e que as temperaturas do ar foram semelhantes às obtidas com o combustível original (GLP.It was carried out a trial to evaluate the adaptation (injector diameter and performance (biogas consumption and heating efficiency of a heating adapted to burn biogas. It was tried a common heater, burning liquefied petroleum gas (LPG, operating with low gas pressure (28 cm water column, with calorific capacity of 5024 kJ/h and recommended for 500 birds. The heater was evaluated with the original fuel (LPG without any modification in the gas injector and after adapting to biogas burning. Five injectors were evaluated with drillings of 1,0053; 1,5080; 1,5708; 1,7672 and 1,980 mm2. It also was varied the biogas

  2. Evaluation of biogas quality from home biogas pits installed in central Vietnam

    OpenAIRE

    Štěpánek, Pavel

    2013-01-01

    Abstract Biomass or biogas, they are an essential component of the energy sources used in the conditions of the Vietnamese countryside due to its availability and relatively low investment costs. This thesis is focused on the quality and quantity of biogas produced from home biogas plants installed in Central Vietnam. In this thesis is shown the description of the fermentation process, its final product is biogas. The thesis describes the types of home biogas digesters, which are used ...

  3. Performance of piezoresistive and piezoelectric sensors in pulsed reactor experiments

    International Nuclear Information System (INIS)

    Pulsed reactor-based experiments require radiation tolerant sensors that do not perturb the device under test, or allow a radiation-induced signal to mask the true sensor output. Several commercial off-the-shelf accelerometers, pressure transducers, and acoustic emission sensors were subjected to multiple high-power reactor pulses. A piezoresistive accelerometer capable of operation to at least 44 kGy and 8.7 x 1015 n/cm2 is identified, and a piezoresistive pressure transducer that is resistant to about half that radiation level is selected. Further, two piezoelectric acoustic emission sensors employing lead metaniobate are also found to function to 55 kGy and 1.1 x 1016 n/cm2.

  4. Transient performance during stopping the research reactor primary loop pump

    Energy Technology Data Exchange (ETDEWEB)

    Akbarian Shourkaei, Hossein [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of). Plasma Physics Research Group

    2015-03-15

    In this work an attempt is made to achieve characteristics curves for the Tehran Research Reactor (TRR) during stopping. The TRR pump speed during the event is time dependent. This is done for the TRR first quadrant operating characteristics. The obtained results indicate that the time needed for the coolant flow rate to reach zero is greater than the time necessary for the pump to come to complete stoppage.

  5. Improved performance of parallel surface/packed-bed discharge reactor for indoor VOCs decomposition: optimization of the reactor structure

    Science.gov (United States)

    Jiang, Nan; Hui, Chun-Xue; Li, Jie; Lu, Na; Shang, Ke-Feng; Wu, Yan; Mizuno, Akira

    2015-10-01

    The purpose of this paper is to develop a high-efficiency air-cleaning system for volatile organic compounds (VOCs) existing in the workshop of a chemical factory. A novel parallel surface/packed-bed discharge (PSPBD) reactor, which utilized a combination of surface discharge (SD) plasma with packed-bed discharge (PBD) plasma, was designed and employed for VOCs removal in a closed vessel. In order to optimize the structure of the PSPBD reactor, the discharge characteristic, benzene removal efficiency, and energy yield were compared for different discharge lengths, quartz tube diameters, shapes of external high-voltage electrode, packed-bed discharge gaps, and packing pellet sizes, respectively. In the circulation test, 52.8% of benzene was removed and the energy yield achieved 0.79 mg kJ-1 after a 210 min discharge treatment in the PSPBD reactor, which was 10.3% and 0.18 mg kJ-1 higher, respectively, than in the SD reactor, 21.8% and 0.34 mg kJ-1 higher, respectively, than in the PBD reactor at 53 J l-1. The improved performance in benzene removal and energy yield can be attributed to the plasma chemistry effect of the sequential processing in the PSPBD reactor. The VOCs mineralization and organic intermediates generated during discharge treatment were followed by CO x selectivity and FT-IR analyses. The experimental results indicate that the PSPBD plasma process is an effective and energy-efficient approach for VOCs removal in an indoor environment.

  6. Economic and ecological evaluation of biogas plant configurations for a demand oriented biogas supply for flexible power generation

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, Henning

    2015-07-01

    The transformation of the power supply towards renewable energy (RE) sources will depend on a large scale of fluctuating RE sources, primarily of wind energy and photovoltaics. However, the variable power generation of these renewable sources will lead to an increased need of flexible power producers in order to balance differences between energy generation and consumption. Among the different types of RE sources, biogas plants have the advantage that their input biomass and the produced biogas can be stored and electricity can consequently be generated on demand. Since electricity from biogas has not been used to balance fluctuations of intermittent RE in the past, new concepts are required. These concepts should be able to meet the requirements of highly renewable electricity systems and to supply biogas according to the varying demand for long-and short-term balance power generation. In this regard, this thesis focused on the identification of biogas plant concepts for flexible power generation, as well as on ranking them regarding their economic and life cycle performance.

  7. Economic and ecological evaluation of biogas plant configurations for a demand oriented biogas supply for flexible power generation

    International Nuclear Information System (INIS)

    The transformation of the power supply towards renewable energy (RE) sources will depend on a large scale of fluctuating RE sources, primarily of wind energy and photovoltaics. However, the variable power generation of these renewable sources will lead to an increased need of flexible power producers in order to balance differences between energy generation and consumption. Among the different types of RE sources, biogas plants have the advantage that their input biomass and the produced biogas can be stored and electricity can consequently be generated on demand. Since electricity from biogas has not been used to balance fluctuations of intermittent RE in the past, new concepts are required. These concepts should be able to meet the requirements of highly renewable electricity systems and to supply biogas according to the varying demand for long-and short-term balance power generation. In this regard, this thesis focused on the identification of biogas plant concepts for flexible power generation, as well as on ranking them regarding their economic and life cycle performance.

  8. Performance of anaerobic sequencing batch reactors (pilot-scale in domestic sewage treatment

    Directory of Open Access Journals (Sweden)

    Eugenio Foresti

    2005-02-01

    Full Text Available This study shows the results obtained during 70 days using four pilot scale anaerobic sequencing batch reactors, for sewage system treatment of the campus of the University of São Paulo in São Carlos – SP. Each reactor system with 1.2 m³ of total volume, was designed for the treatment of 1.95 m³d³ of domestic sewage, with geometrical conceptions (ratio H-height/D-diameter, mechanical conceptions (mechanical mixing or liquid re-circulation and different biomass retention type. Three of them were ASBR (AnaerobicSequencing Batch Reactor with granular biomass and another one was an ASBBR (Anaerobic Sequencing Batch Biofilm Reactor with biomass consisting of cubic matrices of polyurethane foam. The reactors were inoculated and operated within an 8-hour batch cycle. The reactors monitoring included the oxygen chemical demand (OCD, pH, total suspended solids (TSS and volatile suspended solids, volatile fatty acids, alkalinity to bicarbonate and methane concentration. Both ASBR reactors with liquid re-circulation did not show a satisfactory performance. The average values of OCD and TSS removal were close to 40% and 60% respectively. In the ASBR reactors with mechanical mixing and ASBBR with immobilized biomass, showed better results. The ASBBR reactor reached average efficiency of 61% and 75% in OCD and TSS removal, while in the ASBR with mechanical mixing, it reached 60% and 79%, respectively.

  9. The influence of leachates on the extraction of biogas in solid refuse tips; Lixiviados en los vertederos de residuos solidos, su incidencia en la extraccion de biogas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-08-01

    The presence of leachates not far below the surface in solid refuse tips interferes with biogas generation irrespective of the recovery system employed (vertical or horizontal collectors). Biogas management can be optimised by monitoring the level of leachates, which tem have to be eliminated. The results are given of analytical tests on leachates in urban, urban/industrial and industrial waste dumps. Finally, the system used at the Can Mata dump, in which the leachate is pumped out, is described, Controlling the amount extracted has made it possible to optimise the biogas recovery facility and obtain the best energy performance. (Author)

  10. Biogas and Hydrogen Systems Market Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Milbrandt, Anelia [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bush, Brian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Melaina, Marc [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-03-31

    This analysis provides an overview of the market for biogas-derived hydrogen and its use in transportation applications. It examines the current hydrogen production technologies from biogas, capacity and production, infrastructure, potential and demand, as well as key market areas. It also estimates the production cost of hydrogen from biogas and provides supply curves at a national level and at point source.

  11. Biogas production from the aquatic weed Pistia (Pistia stratiotes)

    Energy Technology Data Exchange (ETDEWEB)

    Abbasi, S.A.; Nipaney, P.C. (Pondicherry (Central) Univ. (IN). Salim Ali School of Ecology); Panholzer, M.B. (Institute for Environmental Research, Graz (AT))

    1991-01-01

    Pistia stratiotes, an aquatic weed, was investigated as a substrate for biogas production in batch digestion. An inoculum was necessary to obtain biogas production form the weed. With Pistia,only production of carbon dioxide alone was high during the first five days of digestion but began to level off thereafter. With inoculated Pistia, a high rate of biogas production was sustained for nearly 10 days and the average methane content was 58%-68%. The digesters charged with Pistia alone had significant concentrations of propionic, butyric, isobutyric, valeric, and isovaleric acids. These acids were not present in detectable concentrations, in the digesters running with inoculated Pistia, except during the first 4 days of the digestion when propionic acid was formed. When an inoculum was added to a 'soured' digester the performance of the latter improved dramatically. (author).

  12. Biogas plasticization coupled anaerobic digestion: batch test results.

    Science.gov (United States)

    Schimel, Keith A

    2007-06-01

    Biogas has unique properties for improving the biodegradability of biomass solids during anaerobic digestion (AD). This report presents batch test results of the first investigation into utilizing biogas plasticization to "condition" organic polymers during active digestion of waste activated sludge (WAS). Preliminary design calculations based on polymer diffusion rate limitation are presented. Analysis of the 20 degrees C batch test data determined the first order (k(1)) COD conversion coefficient to be 0.167 day(-1) with a maximum COD utilization rate of 11.25 g L(-1) day(-1). Comparison of these batch test results to typical conventional AD performance parameters showed orders of magnitude improvement. These results show that biogas plasticization during active AD could greatly improve renewable energy yields from biomass waste materials such as MSW RDF, STP sludges, food wastes, animal manure, green wastes, and agricultural crop residuals. PMID:17054122

  13. Performance evaluation on reactor power control by H{sup {infinity}} controller with gain scaling

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Nobuyuki; Suzuki, Katsuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-05-01

    A `gain scaling method` is proposed to improve the performance of reactor power control by the controller based on linear control theory. The method is derived from the simple nonlinearity of the neutron kinetics of reactor that is caused by the cross term of input reactivity and neutronic output. It is the main idea to scale down the control input generated by the linear controller with respect to the reactor power level. The evaluation of the performance of H{sup {infinity}} control system with the gain scaling in time and frequency domains indicates the effectiveness of the proposed method. (author)

  14. The influence on biogas production of three slurry-handling systems in dairy farms

    Directory of Open Access Journals (Sweden)

    Damiano Coppolecchia

    2015-04-01

    Full Text Available Handling systems can influence the production of biogas and methane from dairy farm manures. A comparative work performed in three different Italian dairy farms showed how the most common techniques (scraper, slatted floor, flushing can change the characteristics of collected manure. Scraper appears to be the most neutral choice, as it does not significantly affect the original characteristics of manure. Slatted floor produces a manure that has a lower methane potential in comparison with scraper, due to: a lower content of volatile solids caused by the biodegradation occurring in the deep pit, and a lower specific biogas production caused by the change in the characteristics of organic matter. Flushing can produce three different fluxes: diluted flushed manure, solid separated manure and liquid separated manure. The diluted fraction appears to be unsuitable for conventional anaerobic digestion in completely stirred reactors (CSTR, since its content of organic matter is too low to be worthwhile. The liquid separated fraction could represent an interesting material, as it appears to accumulate the most biodegradable organic fraction, but not as primary substrate in CSTR as the organic matter concentration is too low. Finally, the solid-liquid separation process tends to accumulate inert matter in the solid separated fraction and, therefore, its specific methane production is low.

  15. Biogas from by-products; Biogas aus Nebenprodukten

    Energy Technology Data Exchange (ETDEWEB)

    Mack, Andreas [Eisenmann Anlagenbau GmbH und Co. KG, Boeblingen (Germany)

    2013-01-15

    The Italian sugar producer Co.Pro.B. (Minerbio, Italy) looked for an industrially experienced plant engineer for the biogas process in order to utilize energetically the by-products from the processing of sugar beets. Co.Pro.B. found the German environmental technology specialist Eisenmann Anlagenbau GmbH and Co. KG (Boeblingen, Federal Republic of Germany). After a planning and building period of only six months, even three biogas plants with plug-flow fermentation were brought on line in the provinces Bologna and Padua in autumn 2012.

  16. Formation and suppression of foam in biogas plants; Bildung von Schaum in Biogasanlagen und seine Bekaempfung

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Lucie [Helmholtz-Zentrum fuer Umweltforschung, Leipzig (Germany); Goersch, Kati; Zehnsdorf, Andreas

    2012-07-01

    Excessive foaming in the process of anaerobic digestion is one of the most common disorders of the biological stage of the biogas production process. Especially biogas plants treating biogenic residues and waste materials are affected. A survey of fifteen operators of waste-utilizing biogas plants in Saxony, Saxony-Anhalt and Thuringia showed that 80 % of the operators have already had problems with excessive foam formation in their biogas reactor. More than half of them complained about regular foam events. The consequences of excessive foam formation may vary depending on the extent of foaming. They range from extra costs for anti-foaming agents to cleaning and repair costs in case of construction defects. Foam in the reactor may have many causes. They involve the careless application of risk substrates, inadequate plant management or technical errors and accidents. Mostly, the direct cause of foaming remains unclear. Although foam formation in the biogas reactor is a very common phenomenon, only little research has been done in this field until now. (orig.)

  17. Integrated rural industrialization through biogas

    International Nuclear Information System (INIS)

    Role of biogas in rural industrialization in India is explained. The Khadi and Village Industries Commission has installed over 2 lakhs (0.2 million) biogas plants during the last 30 years. A 15 cu.m. capacity plant costs Rs. 35,000/-. It produces 65 tons bio-manure worth Rs. 13,000/- in a year and fuel gas equivalent to 3,285 litres of kerosene worth Rs. 9855/-. It provides employment to 300 man days. In addition to serving as a source of energy and manure, it reduces deforestation, solves rural sanitation problem and maintain environmental equilibrium. Industrial activities suitable for rural areas and which can use biogas as a source of power are indicated. (M.G.B.)

  18. Biogas production from catch crops

    DEFF Research Database (Denmark)

    Molinuevo-Salces, Beatriz; Larsen, Søren U.; Ahring, Birgitte Kiær;

    2013-01-01

    Manure-based biogas plants in Denmark are dependent on high yielding biomass feedstock in order to secure economically feasible operation. The aim of this study was to investigate the potential of ten different catch crop species or mixtures as feedstock for biogas production in co......, being in the ranges of 1.4–3.0 t ha−1 and 0.3–1.7 t ha−1 for Holstebro and Aabenraa, respectively. Specific methane yields were in the range of 229–450 m3 t−1 of VS. Methane yields per hectare of up to 800 m3 ha−1 were obtained, making catch crops a promising source of feedstock for manure-based biogas...

  19. Biogas Production from Citrus Waste by Membrane Bioreactor

    Directory of Open Access Journals (Sweden)

    Rachma Wikandari

    2014-08-01

    Full Text Available Rapid acidification and inhibition by d-limonene are major challenges of biogas production from citrus waste. As limonene is a hydrophobic chemical, this challenge was encountered using hydrophilic polyvinylidine difluoride (PVDF membranes in a biogas reactor. The more sensitive methane-producing archaea were encapsulated in the membranes, while freely suspended digesting bacteria were present in the culture as well. In this membrane bioreactor (MBR, the free digesting bacteria digested the citrus wastes and produced soluble compounds, which could pass through the membrane and converted to biogas by the encapsulated cell. As a control experiment, similar digestions were carried out in bioreactors containing the identical amount of just free cells. The experiments were carried out in thermophilic conditions at 55 °C, and hydraulic retention time of 30 days. The organic loading rate (OLR was started with 0.3 kg VS/m3/day and gradually increased to 3 kg VS/m3/day. The results show that at the highest OLR, MBR was successful to produce methane at 0.33 Nm3/kg VS, while the traditional free cell reactor reduced its methane production to 0.05 Nm3/kg VS. Approximately 73% of the theoretical methane yield was achieved using the membrane bioreactor.

  20. Report on LVR-15 reactor performance in 1998

    International Nuclear Information System (INIS)

    The following tasks were implemented on the reactor in 1998: experiments in the horizontal channels, irradiation of samples in the vertical channels, preparation of neutron-alloyed silicon single crystals in the DONA facility; VGB Experiment - VGB-1CT and VGB-2CT probes, BWR-2 loop; RVS-3 loop for the IASCC and FRAMATOME experiments; active operation of the 'zinc' loop; preparation and tests of BWR-1 loop for the ANERI experiment; assembling and inactive testing of the new RVS-4 loop; mockup experiments 1 and 2 with an 1CT probe dummy; and beam measurements. (P.A.)

  1. Assets and irradiation performance of the silene reactor

    International Nuclear Information System (INIS)

    The need to study the behavior and the consequences of a criticality accident led the Nuclear Protection and Safety Institute in 1974 to design and build an experimental facility called Silene at the site of Valduc, France. The reactor is in the form of a small annular vessel in which a fissile solution of uranyl nitrate is designed to open-quotes divergeclose quotes by withdrawing a control rod. This intense source of neutron and gamma radiation soon proved to be an exceptional research tool, whose scope largely exceeded that of criticality. The reasons for this success and SILENE's extended polyvalence result from its main assets, which are presented here

  2. Outage performance improvement by state of the art reactor stud tensioning

    International Nuclear Information System (INIS)

    Actual methods of reactor closing, i.e. cover to vessel sealing, is based on the creation of an equal load to the sealing circumference by tensioning all reactor studs with an equal force. This method ensures leak tightness through equal compression of the reactor seal in normal circumstances and is largely applied for all types of reactors throughout many generations and designs of nuclear power stations. The tension generated in each reactor stud is controlled indirectly by measuring the reactor stud elongation while under stress. Most studs are designed to measure this elongation easily by conventional or more advanced systems (from individual clock gauge to integrated digital transmission to a computer screen). It is this elongation value, prescribed by the reactor vessel/cover manufacturer which must be respected and demonstrated during all reactor closing operations, weather they take place for initial hydro testing, refuelling operations or periodical hydraulic tests of the primary circuit. Closing (and re-opening) of reactor vessels has become a routine operation as it is required for fuel reloading of the reactor core. This operation is performed on all PWR and BWR type of reactors with a large variety of tooling. As most of the utilities have implemented maintenance optimisation programs, the refuelling outage is reduced to a sequence of activities that allow quick and efficient refuelling of the core. The performance and efficiency of instrumentation and tooling deployed during these essential activities are of the utmost importance to minimise the critical path of the refuelling outage. Today, in support of outage performance, many utilities have invested in new and refurbished tooling to allow quick and efficient opening and closing of the reactor vessel. The features and properties of the most performing multi stud tensioning machines currently in service in nuclear power stations world wide (Africa, Europe, Asia and USA) are presented in the paper

  3. Outage performance improvement by state of the art reactor stud tensioning

    Energy Technology Data Exchange (ETDEWEB)

    Oehler, Horst Werner [Wenutec GmbH, Industriestrasse 1, D-44534 Luenen (Germany); Vervliet, Herman [Wenutec Sarl, 2, Parc des Fontenelles, F-78870 Bailly (France)

    2006-07-01

    Actual methods of reactor closing, i.e. cover to vessel sealing, is based on the creation of an equal load to the sealing circumference by tensioning all reactor studs with an equal force. This method ensures leak tightness through equal compression of the reactor seal in normal circumstances and is largely applied for all types of reactors throughout many generations and designs of nuclear power stations. The tension generated in each reactor stud is controlled indirectly by measuring the reactor stud elongation while under stress. Most studs are designed to measure this elongation easily by conventional or more advanced systems (from individual clock gauge to integrated digital transmission to a computer screen). It is this elongation value, prescribed by the reactor vessel/cover manufacturer which must be respected and demonstrated during all reactor closing operations, weather they take place for initial hydro testing, refuelling operations or periodical hydraulic tests of the primary circuit. Closing (and re-opening) of reactor vessels has become a routine operation as it is required for fuel reloading of the reactor core. This operation is performed on all PWR and BWR type of reactors with a large variety of tooling. As most of the utilities have implemented maintenance optimisation programs, the refuelling outage is reduced to a sequence of activities that allow quick and efficient refuelling of the core. The performance and efficiency of instrumentation and tooling deployed during these essential activities are of the utmost importance to minimise the critical path of the refuelling outage. Today, in support of outage performance, many utilities have invested in new and refurbished tooling to allow quick and efficient opening and closing of the reactor vessel. The features and properties of the most performing multi stud tensioning machines currently in service in nuclear power stations world wide (Africa, Europe, Asia and USA) are presented in the paper

  4. Testing the effect of different enzyme blends on increasing the biogas yield of straw and digested manure fibers

    DEFF Research Database (Denmark)

    Njoku, Stephen Ikechukwu; Jurado, Esperanza; Malmgren-Hansen, Bjørn;

    In this study, enzymatic treatment was tested to increase the biogas yield of wheat straw (WS) and digested manure fibers (DMF) in the Re-Injection Loop Concept, which combines anaerobic digestion with solid separation to enhance the biogas yield per ton of manure by: 1. Digestion of the easily...... degradable fraction of manure in the biogas process. 2. Separation of the residual recalcitrant digested fiber fraction project. 3. Ultrasound and/or enzymatic treatment of the digested fiber fraction. 4. Recirculation of the treated fiber fraction into the reactor....

  5. Moving bed biofilm reactor technology: process applications, design, and performance.

    Science.gov (United States)

    McQuarrie, James P; Boltz, Joshua P

    2011-06-01

    The moving bed biofilm reactor (MBBR) can operate as a 2- (anoxic) or 3-(aerobic) phase system with buoyant free-moving plastic biofilm carriers. These systems can be used for municipal and industrial wastewater treatment, aquaculture, potable water denitrification, and, in roughing, secondary, tertiary, and sidestream applications. The system includes a submerged biofilm reactor and liquid-solids separation unit. The MBBR process benefits include the following: (1) capacity to meet treatment objectives similar to activated sludge systems with respect to carbon-oxidation and nitrogen removal, but requires a smaller tank volume than a clarifier-coupled activated sludge system; (2) biomass retention is clarifier-independent and solids loading to the liquid-solids separation unit is reduced significantly when compared with activated sludge systems; (3) the MBBR is a continuous-flow process that does not require a special operational cycle for biofilm thickness, L(F), control (e.g., biologically active filter backwashing); and (4) liquid-solids separation can be achieved with a variety of processes, including conventional and compact high-rate processes. Information related to system design is fragmented and poorly documented. This paper seeks to address this issue by summarizing state-of-the art MBBR design procedures and providing the reader with an overview of some commercially available systems and their components. PMID:21751715

  6. Membrane Separation for Biogas Purification

    Czech Academy of Sciences Publication Activity Database

    Morávková, Lenka; Kárászová, Magda; Sedláková, Zuzana; Šimčík, Miroslav; Vejražka, Jiří; Izák, Pavel

    Praha : Česká společnost průmyslové chemie, 2015, s. 28 /p65./. ISBN 978-80-86238-73-9. [mezinárodní chemicko-technologická konference (ICCT 2015) /3./. Mikulov (CZ), 13.04.2015-15.04.2015] R&D Projects: GA TA ČR TE01020080; GA MŠk(CZ) LD13018 Institutional support: RVO:67985858 Keywords : membrane separation * biogas purification * biogas purification Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  7. Ecological analysis of a typical farm-scale biogas plant in China

    Science.gov (United States)

    Duan, Na; Lin, Cong; Wang, Pingzhi; Meng, Jing; Chen, Hui; Li, Xue

    2014-09-01

    The aim of this work was to present the common anaerobic digestion technologies in a typical farm-scale biogas plant in China. The comprehensive benefits of most biogas plants in China have not been fully assessed in past decades due to the limited information of the anaerobic digestion processes in biogas plants. This paper analyzed four key aspects (i.e., operational performance, nonrenewable energy (NE) savings, CO2 emission reduction (CER) and economic benefits (EBs)) of a typical farm-scale biogas plant, where beef cattle manure was used as feedstock. Owing to the monitoring system, stable operation was achieved with a hydraulic retention time of 18-22 days and a production of 876,000 m3 of biogas and 37,960 t of digestate fertilizer annually. This could substantially substitute for the nonrenewable energy and chemical fertilizer. The total amount of NE savings and CER derived from biogas and digestate fertilizer was 2.10×107 MJ (equivalent to 749.7 tce) and 9.71×105 kg, respectively. The EBs of the biogas plant was 6.84×105 CNY·yr-1 with an outputs-to-inputs ratio of 2.37. As a result, the monitoring system was proved to contribute significantly to the sound management and quantitative assessment of the biogas plant. Biogas plants could produce biogas which could be used to substitute fossil fuels and reduce the emissions of greenhouse gases, and digestate fertilizer is also an important bio-product.

  8. Integration of biogas in the natural gas grid: Thermodynamic characterization of a biogas-like mixture

    International Nuclear Information System (INIS)

    Highlights: • Accurate density data of a 4 components synthetic biogas-like mixture are presented. • Experimental data are compared with the densities calculated from the GERG-2008 equation of state. • Relative deviations in density were within a 0.2% band at temperatures above 300 K. • Densities at T = 275 K and pressures around 10 MPa showed higher deviations. - Abstract: The composition of biogas may vary significantly due to the diversity of production sources, making it essential to have a detailed knowledge of their thermophysical properties in order to develop and validate methods for the estimation of density, heat capacity and calorific value of biogas and biomethane. In this work the thermodynamic behavior of a synthetic biogas-like mixture, composed of methane (50%), carbon dioxide (35%), nitrogen (10%) and carbon monoxide (5%), is studied through accurate (p, ρ, T) experimental data obtained by using a single sinker densimeter with magnetic suspension coupling. The mixture was prepared by the gravimetric method at the Spanish National Metrology Institute (Centro Español de Metrología, CEM) and the accurate density measurements have been performed in the temperature range from (275 to 400) K and pressures up to 20 MPa. This work is part of the research project ‘Metrology for Biogas’ supported by the European Metrology Research Program. Experimental data are compared with the densities calculated with the GERG-2008 equation of state. The deviation between experimental and estimated densities is within a ±0.2% band at all temperatures, except at the lower temperature, 275 K, and pressures from (6 to 15) MPa, which shows a higher deviation

  9. Improving biogas yields using an innovative pretreatment concept for conversion of the fiber fraction of manure

    DEFF Research Database (Denmark)

    Biswas, Rajib; Uellendahl, Hinrich; Ahring, Birgitte Kiær

    % increase in methane yield compared to the untreated digested manure fibers in batch experiments. In a continuous mesophilic reactor process the addition of WEx treated digested fibers in co-digestion with filtered manure did not show any signs of process inhibition and the overall methane yield was in......A new concept to enable economically feasible operation of manure based biogas plants was tested in lab-scale. Wet explosion (WEx) was implemented as treatment of the residual manure fibers separated after the anaerobic digestion process for enhancing the biogas production before reintroducing into...... the biogas reactor. The increase in methane yield of the digested manure fibers was investigated by applying the WEx treatment under 5 different process conditions. The WEx treatment at 180 ºC and a retention time of 10 minutes without addition of oxygen was found to be optimal, resulting in 136...

  10. CONTROL PARAMETERS FOR UNDERSTANDING AND PREVENTING PROCESS IMBALANCES IN BIOGAS PLANTS. EMPHAS IS ON VFA DYNAMICS

    DEFF Research Database (Denmark)

    Bangsø Nielsen, Henrik

    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 p...... indication 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 out on the basis of the methane production or on the basis of fluctuations in the concentration of propionate. The experiment confirmed that propionate is a useful parameter for (1) indication of process imbalances and (2) for regulation and optimization of the anaerobic digestion process in CSTRs...

  11. Coupling safety methods in the determination of the operational safety performance indicators for a research reactor

    International Nuclear Information System (INIS)

    In analyzing performance indicators of a nuclear research reactor, the first step is to verify if this installation operates in a regular regime. If this condition is not verified, a special technique should be used to adapt the performance indicators established for a normal situation. The paper will present the method used in the implementation of operational safety performance indicators in a research reactor in accordance with its activities and operational mode. The method will adapt the performance indicators of nuclear power plants. It is based on coupling some safety techniques, especially, operational experience feedback and the events during the life cycle of the installation. (author)

  12. The Jules Horowitz Reactor - A new High Performance European Material Testing Reactor open to International Users Present Status and Objectives

    International Nuclear Information System (INIS)

    The development of sustainable nuclear energy requires R and D on fuel and material behaviour under irradiation with a high level of performance in order to meet the needs and challenges for the benefit of industry, research and public bodies. These stakes require a sustainable and secured access to an up-to-date high performance Material Testing Reactor. Following a broad survey within the European Research Area, the international community agreed that the need for Material Test Reactors in support of nuclear power plant safety and operation will continue in the context of sustainable nuclear energy. The Jules Horowitz Reactor project (JHR) copes with this context. JHR is designed as a user facility addressing the needs of the international community. This means: - flexibility with irradiation loops able to reproduce a large variation in operation conditions of different power reactor technologies, - high flux capacity to address Generations II, III, and IV needs. JHR is designed, built and operated as an international user facility because: - Given the maturity and globalization of the industry, domestic tools have no more the required level of economic and technical efficiency. Meanwhile, countries with nuclear energy need an access to high performance irradiation experimental capabilities to support technical skill and guarantee the competitiveness and safety of nuclear energy. - Many research items related to safety or public policy (waste management, etc.) require international cooperation to share costs and benefits of resulting consensus. JHR design is optimised for offering high performance material and fuel irradiation capability for the coming decades. This project is driven and funded by an international consortium gathering vendors, utilities and public stakeholders. This consortium has been set up in March 2007 when the construction began. The construction is in progress and the start of operation is scheduled for 2014. The JHR is a research

  13. Economic analysis and energy balance of biogas at swine farms; Analise economica e balanco energetico do biogas em granja de suinos

    Energy Technology Data Exchange (ETDEWEB)

    Lira, Joao Carlos U.; Marra, Enes G. [Universidade Federal de Goias (UFG), Goiania, GO (Brazil); Domingues, Elder G. [Instituto Federal de Educacao, Ciencia e Tecnologia de Goias (IFG), Goiania, GO (Brazil)

    2010-06-15

    This paper presents the analyse of a case taking advantage of biogas generated from the swine dejects. Performed in a farm at southeast of the state of Goias, Brazil, it evaluates the viability of utilization of biogas for generation of electric energy, for heating, or both. The process presents environmental and economic benefits as the carbon emissions are reduced and their credits can be negotiated. (author)

  14. Steam generator tube performance. Experience with water-cooled nuclear power reactors during 1985

    International Nuclear Information System (INIS)

    The performance of steam generator tubes at water-cooled reactors during 1985 has been reviewed. Seventy-three of 168 reactors in the survey experienced tube degradation sufficient for the tubes to be plugged. The number of tubes plugged was 6837 or 0.28% of those in service. The leading cause of tube failure was stress corrosion cracking from the primary side. Stress corrosion cracking or intergranular attack from the secondary side and pitting were also major causes of tube failure. Unlike most previous years, fretting was a substantial problem at some reactors. Overall, corrosion continued to account for more than 80% of the defects. 20 refs

  15. The kinetics of Scenedesmus obliquus microalgae growth utilizing carbon dioxide gas from biogas

    International Nuclear Information System (INIS)

    Microalgae Scenedesmus obliquus was cultured in a laboratory photobioreactor to determine the efficacy of using biogas as a carbon source for the microalgae's growth. The biogas contained ∼60% CH4 and ∼40% CO2, and was derived from an anaerobic digester operating from animal wastes, and an anaerobic reactor utilizing high strength wastewater. The results showed that biogas is a viable carbon source for microalgae growth and that significant portions of the biogas' CO2 can be utilized for algae growth, resulting in a biogas having a high concentration of methane. This paper develops the kinetic expressions for the algae's growth by assuming an autocatalytic reaction between carbon substrate and microalgae. The maximum specific growth rate and biomass productivity of S. obliquus were 0.56 d−1 and 0.145 g L−1d−1 respectively. The biomass contained 51.8% carbon and higher heating value (HHV) was 22.9 MJ kg−1. - Highlights: • Biogas is a viable carbon source for microalgae growth. • Biomass production rate and characteristics were assessed. • Scenedesmus obliquus can adjust to grow with high concentration of CO2 in the carbon source

  16. A Framework for Human Performance Criteria for Advanced Reactor Operational Concepts

    Energy Technology Data Exchange (ETDEWEB)

    Jacques V Hugo; David I Gertman; Jeffrey C Joe

    2014-08-01

    This report supports the determination of new Operational Concept models needed in support of the operational design of new reactors. The objective of this research is to establish the technical bases for human performance and human performance criteria frameworks, models, and guidance for operational concepts for advanced reactor designs. The report includes a discussion of operating principles for advanced reactors, the human performance issues and requirements for human performance based upon work domain analysis and current regulatory requirements, and a description of general human performance criteria. The major findings and key observations to date are that there is some operating experience that informs operational concepts for baseline designs for SFR and HGTRs, with the Experimental Breeder Reactor-II (EBR-II) as a best-case predecessor design. This report summarizes the theoretical and operational foundations for the development of a framework and model for human performance criteria that will influence the development of future Operational Concepts. The report also highlights issues associated with advanced reactor design and clarifies and codifies the identified aspects of technology and operating scenarios.

  17. Description of the french graphite reactor and of the experiments performed in 1956

    International Nuclear Information System (INIS)

    This paper is an introduction to the experiments performed on the G1 reactor, experiments fully described in the papers following (670 'B to P'). The main results are given together with some comments. The neutronic parameters of the core, a description of the most important structures, and a few words of the tests leading to normal operation of the reactor under load complete our survey. (author)

  18. Microbiology and performance of a methanogenic biofilm reactor during the start-up period

    OpenAIRE

    Cresson, R.; Dabert, P.; Bernet, N.

    2009-01-01

    Aims: To understand the interactions between anaerobic biofilm development and process performances during the start-up period of methanogenic biofilm reactor. Methods and Results: Two methanogenic inverse turbulent bed reactors have been started and monitored for 81 days. Biofilm development (adhesion, growth, population dynamic) and characteristics (biodiversity, structure) were investigated using molecular tools (PCRSSCP, FISH-CSLM). Identification of the dominant populations, in relati...

  19. Microbiology and performance of a methanogenic biofilm reactor during the start-up period

    OpenAIRE

    Cresson, R.; Dabert, P.; Bernet, N.

    2009-01-01

    Aims: To understand the interactions between anaerobic biofilm development and process performances during the start-up period of methanogenic biofilm reactor. Methods and Results: Two methanogenic inverse turbulent bed reactors have been started and monitored for 81 days. Biofilm development (adhesion, growth, population dynamic) and characteristics (biodiversity, structure) were investigated using molecular tools (PCRSSCP, FISH-CSLM). Identification of the dominant populations, in relation ...

  20. Fuel performance under transients, and accident management using Geno-Fuzzy concept for nuclear reactors

    International Nuclear Information System (INIS)

    Simulation of Pressurized Water Reactor Power Plant (PWR) has been investigated by simulating all components installed in the power plant namely: the reactor core, steam generator, pressurizer, reactor coolant pumps, and turbine. All plant components have been introduced. This simulator is useful for transient analysis studies, engineering designs, safety analysis, and accident management. Accidents in Pressurized Water Reactor Nuclear Power Plant (PWR NPP) may be occurred either due to component failures or human error during maintenance or operation. The main target of accident management is to mitigate accidents if it occurs. The Geno-Fuzzy concept is the way to select some important plant state variables as a gene for the overall plant state chromosome. The selected genes are: reactor power, primary coolant pressure, steam generator water level, and onset boiling on clad surface which has direct impact on fuel behavior. Each of these genes has associated fuzzy level. The main objective of Geno-Fuzzy is turning the plant gene from abnormal states to the normal state by associated control variable using the inference wise fuzzy technique. The Pressurized Water Reactor Nuclear Power Plant simulator has been tested for a typical PWR, for normal transients, Anticipated Transient Without Scram (ATWS), and using the proposed Geno-Fuzzy concept for accident management, which gives very good results in reactor accident mitigation. Some of these tested accidents are; reactor control rod ejection, change in turbine steam load, and loss of coolant flow, which have direct effects on fuel safety and performance. The parameters affecting the behavior of the reactor fuel integrity are analyzed to be considered in future reactor designs. (author)

  1. Biogas reforming process investigation for SOFC application

    International Nuclear Information System (INIS)

    Highlights: • Mathematical model of fuel processor and experimental validation was made. • Simulations made to find syngas composition varying fuel processor operating conditions. • Experimental tests were carried out on SOFC mono-cell to obtain polarization curves. • The best conditions for SOFC/fuel processor integrated systems were defined. - Abstract: In recent years, research efforts on fuel cells have been addressed on the development of multifuel reformers with particular emphasis toward the potential use of non-traditional fuels. Among these, biogas is considered very promising to be used as syngas source for fuel cell system applications. The interest on this hydrogen source is focused mainly to supply high temperature fuel cells (HTFC). This paper reports a wide experimental research investigation on SOFC device supplied by syngas produced with different biogas reforming processes (steam reforming, autothermal reforming and partial oxidation). Thermodynamic simulations have been performed to determine the reformed gas composition varying process, reaction temperature and steam to carbon – oxygen to carbon ratios. Syngas mixtures obtained were experimentally tested in order to evaluate the performance of a SOFC mono-cell. Furthermore, an analysis of the combination: fuel processor with a SOFC stack has been determined in order to assess the total energy efficiency

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

    International Nuclear Information System (INIS)

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

  3. Liquid Membranes for Biogas Upgrading

    Czech Academy of Sciences Publication Activity Database

    Poloncarzová, Magda; Vejražka, Jiří; Izák, Pavel

    Toruň: Nicolaus Copernicus University, 2010 - (Kujawski, W.), s. 78 ISBN N. [International Scientific Conference on Pervaporation and Vapor Permeation. Toruň (PL), 18.04.2010-21.04.2010] Institutional research plan: CEZ:AV0Z40720504 Keywords : biogas * biomass * ecological fuel Subject RIV: CC - Organic Chemistry http://www.pv.chem.umk.pl

  4. Technical improvements of biogas plants

    Energy Technology Data Exchange (ETDEWEB)

    Perwanger, A.

    1983-01-01

    Experience in the construction and operation of more than 40 new biogas plants in Bavaria has shown that gas-tightness, corrosion resistance and prevention of obstruction are the most important points. Gas-tightness was a problem especially in brick or concrete fermenters.

  5. Simplified analysis of PRISM RVACS [Reactor Vessel Auxiliary Cooling System] performance without liner spill-over

    International Nuclear Information System (INIS)

    Simplified analysis of the performance of the PRISM RVACS decay heat removal system under off-normal conditions, i.e., without the liner spill-over, is described. Without the spilling of hot-pool sodium over the liner and the resultant down-flow along the inside of the reactor vessel wall, the RVACS system performance becomes dominated by the radial heat condition and radiation. Simple estimates of the resulting heat conduction and radiation processes support GE's contention that the RVACS performance is not severely impacted by the absence of spillover, and can improve significantly if sodium has leaked into the region between the reactor and containment vessels. 7 refs

  6. Performance of TOF powder diffractometers on reactor sources

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Judith [Hahn-Meitner-Institut Berlin, Glienicker Str. 100, D-14109 Berlin (Germany)]. E-mail: peters@hmi.de; Bleif, Hans-Juergen [Hahn-Meitner-Institut Berlin, Glienicker Str. 100, D-14109 Berlin (Germany); Kali, Gyoergy [Budapest Research Reactor, 1121 Budapest, Konkoly Thege ut 29-33 (Hungary); Rosta, Laszlo [Research Institute for Solid State Physics and Optics, 1525 Budapest, P.O.B. 49 (Hungary); Mezei, Ferenc [Hahn-Meitner-Institut Berlin, Glienicker Str. 100, D-14109 Berlin (Germany): LANSCE, Los Alamos National Laboratory, Los Alamos, NM 87544 (United States)

    2006-11-15

    In 1998, a prototype of a time-of-flight (TOF) powder diffractometer was built at KFKI in Budapest in collaboration with the Hahn-Meitner-Institut (HMI) in Berlin. At a reactor source the neutron pulses are produced by a chopper system, which allows for shorter pulses than those obtained at pulsed spallation sources in the wavelength range most relevant for diffraction work, i.e. {lambda}{>=}0.7 A. Furthermore, the chopper system provides an ideal symmetric line shape. First results proved the high potential of the approach, namely an excellent resolution of 1-5x10{sup -3} for {delta}d/d was achieved. The prototype is presently rebuilt as a user instrument at the Budapest Neutron Centre. At HMI Berlin a new much more complex TOF powder diffractometer (EXED=extreme environment diffractometer) with higher resolution is under construction. It will benefit from variable resolution to achieve either ultrahigh resolution or very high intensities at conventional resolutions. EXED is devoted to studies under extreme sample conditions, for instance the TOF technique permits the access of a broad range of Q-values or d-spacing domains under scattering angle access strongly restricted by the use of highest field magnets. The whole instrument was simulated by Monte Carlo (MC) technique, and the simulations yield promising results.

  7. Performance of TOF powder diffractometers on reactor sources

    International Nuclear Information System (INIS)

    In 1998, a prototype of a time-of-flight (TOF) powder diffractometer was built at KFKI in Budapest in collaboration with the Hahn-Meitner-Institut (HMI) in Berlin. At a reactor source the neutron pulses are produced by a chopper system, which allows for shorter pulses than those obtained at pulsed spallation sources in the wavelength range most relevant for diffraction work, i.e. λ≥0.7 A. Furthermore, the chopper system provides an ideal symmetric line shape. First results proved the high potential of the approach, namely an excellent resolution of 1-5x10-3 for Δd/d was achieved. The prototype is presently rebuilt as a user instrument at the Budapest Neutron Centre. At HMI Berlin a new much more complex TOF powder diffractometer (EXED=extreme environment diffractometer) with higher resolution is under construction. It will benefit from variable resolution to achieve either ultrahigh resolution or very high intensities at conventional resolutions. EXED is devoted to studies under extreme sample conditions, for instance the TOF technique permits the access of a broad range of Q-values or d-spacing domains under scattering angle access strongly restricted by the use of highest field magnets. The whole instrument was simulated by Monte Carlo (MC) technique, and the simulations yield promising results

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

    DEFF Research Database (Denmark)

    Boe, Kanokwan; Steyer, J.P.; 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...... stress under gradual overload and thus recommended as an alarm in the control algorithm....

  9. A Comparative Study of Swedish and Chinese Biogas Production with a Brief Economical Feasibility Analysis

    OpenAIRE

    Olsson, Alexander

    2012-01-01

    This Master of Science and Engineering thesis in Chemical Engineering treats biogas production in China. The thesis is divided into two parts. The first part contains an energy potential and situation analysis of biogas in China and a comparison with the situation in Sweden. The biogas potential in China is 950-2180 TWh depending on source. Specially, the potential from fish waste is 11 TWh. Part 1 also includes batch experiments where co-digestion of corn straw and swine manure is performed ...

  10. Energy from whey - comparison of the biogas and bioethanol processes; Energie a partir de petit-lait : comparaison des filieres biogaz et bioethanol

    Energy Technology Data Exchange (ETDEWEB)

    Fruteau de Laclos, H.; Membrez, Y. [Erep SA, Aclens (Switzerland)

    2004-07-01

    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{sub 2} emissions.

  11. Hot channel factors determination and evaluation for water-cooled nuclear research reactors performance

    International Nuclear Information System (INIS)

    This paper presents the general outlines of the evaluation, selecting, determination, and applying peaking hot channel factors for nuclear research reactors. As an example, the uncertainty in the heat transfer coefficient is a major contributor to the reduction in nuclear research reactor performances and thermal hydraulic safety margins, where the uncertainties are due to the reactor fuel coolant channel design fabrication defects (fuel meat and clad thickness uncertainties), and the fuel element's heterogeneity. Both the uncertainties are important contributors and an area where more information may be useful in reducing this uncertainty. In this case we take the WWR-M2 nuclear reactor (Russian type) fuel coolant channel (fuel Assembly) as sample problem for applying and determination the peaking factors, and understanding this method. (author)

  12. Performance and testing of refractory alloy clad fuel elements for space reactors

    International Nuclear Information System (INIS)

    Two fast reactor irradiation tests, SP-1 and SP-2, provide a unique and self-consistent data set with which to evaluate the technical feasibility of potential fuel systems for the SP-100 space reactor. Fuel pins fabricated with leading cladding candidates (Nb-1Zr, PWC-11, and Mo-13Re) and fuel forms (UN and UO2) are operated at temperatures typical of those expected in the SP-100 design. The first US fast reactor irradiated, refractory alloy clad fuel pins, from the SP-1 test, reached 1 at .% burnup in EBR-II in March 1985. At that time selected pins were discharged for interim examination. These examinations confirmed the excellent performance of the Nb-1Zr clad uranium oxide and uranium nitride fuel elements, which are the baseline fuel systems for two SP-100 reactor concepts

  13. Investigation of fuel lattice pitch changes influence on reactor performance through evaluate the neutronic parameters

    International Nuclear Information System (INIS)

    Highlights: • One of the most complex issues that Nu-engineers deal with is the design of NR core. • Numerous factors in nuclear core design depend on Fuel-to-Moderator volume ratio. • Aim of this research is to investigate RX performance for different lattice pitches. - Abstract: Nuclear reactor core design is one of the most complex issues that nuclear engineers deal with. The number and complexity of effective parameters and their impact on reactor design, which makes the problem difficult to solve, require precise knowledge of these parameters and their influence on the reactor operation. Numerous factors in a nuclear reactor core design depend on the Fuel-to-Moderator volume ratio, VF/VM, in a fuel cell. This ratio can be modified by changing the lattice pitch which is the thickness of water channels between fuels plates while keeping fuel slab dimensions fixed. Cooling and moderating properties of water are affected by such a change in a reactor core, and hence some parameters related to these properties might be changed. The aim of this research is to provide the suitable knowledge for nuclear core designing. To reach this goal, the first operating core of Tehran Research Reactor (TRR) with different lattice pitches is simulated, and the effect of different lattice pitches on some parameters such as effective multiplication factor (Keff), reactor life time, distribution of neutron flux and power density in the core, as well as moderator temperature and density coefficient of reactivity are evaluated. The nuclear reactor analysis code, MTR-PC package is employed to carry out the considered calculation. Finally, the results are presented in some tables and graphs that provide useful information for nuclear engineers in the nuclear reactor core design

  14. Burnup performance of OTTO cycle pebble bed reactors with ROX fuel

    International Nuclear Information System (INIS)

    Highlights: • A 300 MWt Small Pebble Bed Reactor with Rock-like oxide fuel is proposed. • Using ROX fuel can achieve high discharged burnup of spent fuel. • High geological stability can be expected in direct disposal of the spent ROX fuel. • The Pebble Bed Reactor with ROX fuel can be critical at steady state operation. • All the reactor designs have a negative temperature coefficient. - Abstract: A pebble bed high-temperature gas-cooled reactor (PBR) with rock-like oxide (ROX) fuel was designed to achieve high discharged burnup and improve the integrity of the spent fuel in geological disposal. The MCPBR code with a JENDL-4.0 library, which developed the analysis of the Once-Through-Then-Out (OTTO) cycle in PBR, was used to perform the criticality and burnup analysis. Burnup calculations for eight cases were carried out for both ROX fuel and a UO2 fuel reactor with different heavy-metal loading conditions. The effective multiplication factor of all cases approximately equalled unity in the equilibrium condition. The ROX fuel reactor showed lower FIFA than the UO2 fuel reactor at the same heavy-metal loading, about 5–15%. However, the power peaking factor and maximum power per fuel ball in the ROX fuel core were lower than that of UO2 fuel core. This effect makes it possible to compensate for the lower-FIFA disadvantage in a ROX fuel core. All reactor designs had a negative temperature coefficient that is needed for the passive safety features of a pebble bed reactor

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

    Directory of Open Access Journals (Sweden)

    Zilin Song,

    2012-06-01

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

  16. An integrated metagenome and -proteome analysis of the microbial community residing in a biogas production plant.

    Science.gov (United States)

    Ortseifen, Vera; Stolze, Yvonne; Maus, Irena; Sczyrba, Alexander; Bremges, Andreas; Albaum, Stefan P; Jaenicke, Sebastian; Fracowiak, Jochen; Pühler, Alfred; Schlüter, Andreas

    2016-08-10

    To study the metaproteome of a biogas-producing microbial community, fermentation samples were taken from an agricultural biogas plant for microbial cell and protein extraction and corresponding metagenome analyses. Based on metagenome sequence data, taxonomic community profiling was performed to elucidate the composition of bacterial and archaeal sub-communities. The community's cytosolic metaproteome was represented in a 2D-PAGE approach. Metaproteome databases for protein identification were compiled based on the assembled metagenome sequence dataset for the biogas plant analyzed and non-corresponding biogas metagenomes. Protein identification results revealed that the corresponding biogas protein database facilitated the highest identification rate followed by other biogas-specific databases, whereas common public databases yielded insufficient identification rates. Proteins of the biogas microbiome identified as highly abundant were assigned to the pathways involved in methanogenesis, transport and carbon metabolism. Moreover, the integrated metagenome/-proteome approach enabled the examination of genetic-context information for genes encoding identified proteins by studying neighboring genes on the corresponding contig. Exemplarily, this approach led to the identification of a Methanoculleus sp. contig encoding 16 methanogenesis-related gene products, three of which were also detected as abundant proteins within the community's metaproteome. Thus, metagenome contigs provide additional information on the genetic environment of identified abundant proteins. PMID:27312700

  17. Influence of Maintenance Intervals on Performance and Emissions of a 192 kWel Biogas Gas Otto CHP Unit and Results of Lubricating Oil Quality Tests—Outcome from a Continuous Two-Year Measuring Campaign

    Directory of Open Access Journals (Sweden)

    Thomas Jungbluth

    2013-06-01

    Full Text Available In the present work, we focus on long-term and permanent measurements of approximately two years on a 192 kWel Gas Otto CHP (combined heat and power unit at a full-scale research biogas plant. In detail the influence of 600 h and 1800 h maintenance intervals on electrical efficiency consumption and exhaust gas emissions such as NOx and CO have been studied under real life conditions. Lubricating oil quality analyses throughout the CHP operation time are presented to show the destructive changes in property and its influence on condition based maintenance. The results confirm the well-known fact that after readjustment of the air-fuel ratio after 1800 h maintenance the emission values for NOx decline while CO increases. The emission-optimized operation mode leads to lower engine efficiency. The maintenance tasks carried out at 600 h intervals lead to lower NOx emissions in nine cases while in 14 cases the emissions remained unchanged. The permanent measurements proved their legitimacy showing various emission deviations from the limiting values prior and post maintenance. The results show that by monitoring the lubricating oil quality, the oil change intervals can be maximized while ensuring that engine performance is not endangered, and a longer engine lifespan can be expected. The oil analyses allow the operator to reduce maintenance expenditures while minimizing wear.

  18. Shut-off rod performance study for the Point Lepreau reactor

    International Nuclear Information System (INIS)

    Shut-Off Rods (SORs) are strong neutron absorbing reactivity devices which are inserted into the Pt. Lepreau reactor core to terminate the nuclear chain reaction. SORs are inserted automatically by Shut-Down System One (SDS-1), in the event any of its trip parameters reach the trip set point on 2 out of the 3 electronic trip channels. SOR performance requirements for the Pt. Lepreau reactor have recently been reviewed and are reported here. In addition, the impact of rod unavailability and slow insertion characteristics on overall SDS-1 capability have been assessed. The shut-off rod system for the Pt. Lepreau reactor consists of 28 vertical rods which re suspended normally by an electromagnetic clutch assembly at the top fo the reactor just outside the core. Upon receipt of a trip signal, on two out of three SDS-1 trip channels, the electromagnetic clutches de-energize and allow the SORs to fall (spring assisted) into the core. In assessing the operational performance of the SOR system the two key parameters are the number of SORs available for insertion at any given time and the rate at which the rods are inserted when they fall. During the operation of the plant the number of rods available to be inserted may change due to routine maintenance and testing or due to system impairments. The rate at which the rods drop may also change due to mechanical wear or malfunction of the clutch or suspension assembly. The purpose of this study was to define the operational performance envelope which clearly identifies the SOR performance required to ensure a safe reactor shut down for all anticipated reactivity transients. Thus the main impetus of the study was to provide a clear technical basis for establishing operating performance requirements from which operating impairment guidelines could be derived. These guidelines are necessary to provide instructions for appropriate and timely action to the reactor operator in the event of SOR performance degradation

  19. Biogas infrastructures from farm to regional scale, prospects of biogas transport grids

    OpenAIRE

    Hengeveld, E.J.; Bekkering, J.; Gemert, W.J.T. van; Broekhuis, A.A.

    2016-01-01

    The volume of biogas produced in agricultural areas is expected to increase in coming years. An increasing number of local and regional initiatives show a growing interest in decentralized energy production, wherein biogas can play a role. Biogas transport from production sites to user, i.e. a CHP, boiler or an upgrading installation, induces a scale advantage and an efficiency increase. Therefore the exploration of the costs and energy use of biogas transport using a dedicated infrastructure...

  20. Processing biogas; Biogas-Aufbereitung. Methanverlust von 1%: technisch moeglich

    Energy Technology Data Exchange (ETDEWEB)

    Judex, J.

    2009-07-01

    This article takes a look at the results of a study made at the Institute of Bio-technology at the Zurich University of Applied Sciences and the Paul Scherrer Institute PSI. The study was made at the wastewater treatment plant in Emmen, Switzerland, on methane losses in the processing of biogas to give it natural gas quality. The avoidance of methane losses - methane is a greenhouse gas - is discussed and various technologies used in the processing of biogas generated from organic waste digestion are examined. The installations at the wastewater treatment plant in Emmen are commented on and the measurement concept and equipment used are described. The results and observations made are also presented in graphical form.