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Sample records for biogas reactor performance

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

    DEFF Research Database (Denmark)

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

    2009-01-01

    The effect of post-digestion temperature on a lab-scale serial continuous-flow stirred tank reactor (CSTR) system performance was investigated. The system consisted of a main reactor operated at 55 degrees C with hydraulic retention time (HRT) of 15 days followed by post-digestion reactors with HRT...... of 5.3 days. Three post-digestion temperatures (55 degrees C, 37 degrees C and 15 degrees C) were compared in terms of biogas production, process stability, microbial community and methanogenic activity, The results showed that the post-digesters operated at 55 degrees C, 37 degrees C and 15 degrees C...... gave extra biogas production of 11.7%, 8.4% and 1.2%, respectively. The post-digester operated at 55 degrees C had the highest biogas production and was the most stable in terms of low VFA concentrations. The specific methanogenic activity tests revealed that the main reactor and the post...

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    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 run...... to examine the role of stochastic factors and disturbance in shaping microbial communities. In the triplicate biogas reactors with the same inoculum and operational conditions, similar process performances and microbial community profiles were observed under steady-state conditions. This indicated...

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

    Science.gov (United States)

    Boe, Kanokwan; Karakashev, Dimitar; Trably, Eric; Angelidaki, Irini

    2009-02-01

    The effect of post-digestion temperature on a lab-scale serial continuous-flow stirred tank reactor (CSTR) system performance was investigated. The system consisted of a main reactor operated at 55 degrees C with hydraulic retention time (HRT) of 15 days followed by post-digestion reactors with HRT of 5.3 days. Three post-digestion temperatures (55 degrees C, 37 degrees C and 15 degrees C) were compared in terms of biogas production, process stability, microbial community and methanogenic activity. The results showed that the post-digesters operated at 55 degrees C, 37 degrees C and 15 degrees C gave extra biogas production of 11.7%, 8.4% and 1.2%, respectively. The post-digester operated at 55 degrees C had the highest biogas production and was the most stable in terms of low VFA concentrations. The specific methanogenic activity tests revealed that the main reactor and the post-digester operated at 55 degrees C and 37 degrees C had very active acidogens and methanogens. In contrast, very low methanogenic activity was observed at 15 degrees C.

  4. Methanogenesis in Thermophilic Biogas Reactors

    DEFF Research Database (Denmark)

    Ahring, Birgitte Kiær

    1995-01-01

    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...... microorganism into methane. In thermophilic biogas reactors,, acetate oxidizing cultures occupied the niche of Methanothrix species, aceticlastic methanogens which dominate at low acetate concentrations in mesophilic systems. Normally, thermophilic biogas reactors are operated at temperatures from 52 to 560 C....... Experiments using biogas reactors fed with cow manure showed that the same biogas yield found at 550 C could be obtained at 610 C after a long adaptation period. However, propionate degradation was inhibited by increasing the temperature....

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

    DEFF Research Database (Denmark)

    Wang, Wen; Xie, Li; Luo, Gang;

    2013-01-01

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

  6. Impact of the substrate loading regime and phosphoric acid supplementation on performance of biogas reactors and microbial community dynamics during anaerobic digestion of chicken wastes.

    Science.gov (United States)

    Belostotskiy, Dmitry E; Ziganshina, Elvira E; Siniagina, Maria; Boulygina, Eugenia A; Miluykov, Vasili A; Ziganshin, Ayrat M

    2015-10-01

    This study evaluates the effects of increasing organic loading rate (OLR) and decreasing hydraulic retention time (HRT) as well as phosphoric acid addition on mesophilic reactors' performance and biogas production from chicken wastes. Furthermore, microbial community composition in reactors was characterized by a 16S rRNA gene-based pyrosequencing analysis. Each step of increasing OLR impacted on the activity of microorganisms what caused a temporary decrease in biogas production. The addition of phosphoric acid resulted in the increased biogas production with values between 361 and 447 mL g(VS)(-1) from day 61 to day 74 compared to control reactor (309-350 mL g(VS)(-1)). With reactors' operation, Bacteroidetes phylotypes were noticeably replaced with Firmicutes representatives, and significant increase of Clostridium sp. was identified. Within Euryarchaeota, Methanosarcina sp. dominated in all analyzed samples, in which high ammonium levels were detected (3.4-4.9 NH4(+)-N g L(-1)). These results can help in better understanding the anaerobic digestion process of simultaneously ammonium/phosphate-rich substrates.

  7. 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

  8. Realtime control of biogas reactors. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    Poulsen, Allan K.

    2010-12-15

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

  9. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  11. 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...

  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...

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

    DEFF Research Database (Denmark)

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

    2006-01-01

    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 butyrate - was low. The kinetic parameters of the VFA conversion revealed a reduced affinity of the microbial community from the CSTR fed with thermally pre-treated manure for acetate, propionate and butyrate. The bacterial and archaeal populations identified by t-RLFP analysis of 16S rRNA genes were found...

  14. biogas

    DEFF Research Database (Denmark)

    2015-01-01

    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...... number of reactors. With cumulative methane production data and data on reactor contents, biochemical methane potential (BMP) can be calculated and summarized, including subtraction of the inoculum contribution and normalization by substrate mass. Cumulative production and production rates can...... 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....

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

    DEFF Research Database (Denmark)

    Bassani, Ilaria; Kougias, Panagiotis; Treu, Laura;

    An innovative method for biogas upgrading (i.e. CH4 content more than 90%) combines the coupling of H2, which could be produced by water electrolysis using surplus renewable electricity produced from wind mills, with the CO2 of the biogas. CO2 is biologically converted to CH4 by hydrogenotrophic...... 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...

  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

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

  17. Effect of reactor configuration on biogas production from wheat straw hydrolysate.

    Science.gov (United States)

    Kaparaju, Prasad; Serrano, María; Angelidaki, Irini

    2009-12-01

    The potential of wheat straw hydrolysate for biogas production was investigated in continuous stirred tank reactor (CSTR) and up-flow anaerobic sludge bed (UASB) reactors. The hydrolysate originated as a side stream from a pilot plant pretreating wheat straw hydrothermally (195 degrees C for 10-12 min) for producing 2nd generation bioethanol [Kaparaju, P., Serrano, M., Thomsen, A.B., Kongjan, P., Angelidaki, I., 2009. Bioethanol, biohydrogen and biogas production from wheat straw in a biorefinery concept. Bioresource Technology 100 (9), 2562-2568]. Results from batch assays showed that hydrolysate had a methane potential of 384 ml/g-volatile solids (VS)(added). Process performance in CTSR and UASB reactors was investigated by varying hydrolysate concentration and/or organic loading rate (OLR). In CSTR, methane yields increased with increase in hydrolysate concentration and maximum yield of 297 ml/g-COD was obtained at an OLR of 1.9 g-COD/l d and 100% (v/v) hydrolysate. On the other hand, process performance and methane yields in UASB were affected by OLR and/or substrate concentration. Maximum methane yields of 267 ml/g-COD (COD removal of 72%) was obtained in UASB reactor when operated at an OLR of 2.8 g-COD/l d but with only 10% (v/v) hydrolysate. However, co-digestion of hydrolysate with pig manure (1:3 v/v ratio) improved the process performance and resulted in methane yield of 219 ml/g-COD (COD removal of 72%). Thus, anaerobic digestion of hydrolysate for biogas production was feasible in both CSTR and UASB reactor types. However, biogas process was affected by the reactor type and operating conditions.

  18. Antifoaming effect of chemical compounds in manure biogas reactors

    DEFF Research Database (Denmark)

    Kougias, Panagiotis; Tsapekos, Panagiotis; Boe, Kanokwan;

    2013-01-01

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

  19. 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...... promoted by the addition of protein, lipid, or carbohydrate co-substrates. However, in most cases, the defoaming efficiency of rapeseed oil was greater than that of oleic acid, and therefore, rapeseed oil is recommended to be used in biogas reactors to solve foaming problems....... 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...

  20. 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.

  1. Antifoaming effect of chemical compounds in manure biogas reactors.

    Science.gov (United States)

    Kougias, P G; Tsapekos, P; Boe, K; Angelidaki, I

    2013-10-15

    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 reduction was evaluated at concentration of 0.05%, 0.1% and 0.5% v/v(sample), in raw and digested manure. Moreover, two antifoam injection methods were compared for foam reduction efficiency. Natural oils (rapeseed and sunflower oil), fatty acids (oleic, octanoic and derivative of natural fatty acids), siloxanes (polydimethylsiloxane) and ester (tributylphosphate) were found to be the most efficient compounds to suppress foam. The efficiency of antifoamers was dependant on their physicochemical properties and greatly correlated to their chemical characteristics for dissolving foam. The antifoamers were more efficient in reducing foam when added directly into the liquid phase rather than added in the headspace of the reactor.

  2. 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

    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...... the existing natural gas grid. The current study presents a new biological method for biogas upgrading in a separate biogas reactor, containing enriched hydrogenotrophic methanogens and fed with biogas and hydrogen. Both mesophilic- and thermophilic anaerobic cultures were enriched to convert CO2 to CH4...... by addition of H2. Enrichment at thermophilic temperature (55°C) resulted in CO2 and H2 bioconversion rate of 320 mL CH4/(gVSS h), which was more than 60% higher than that under mesophilic temperature (37°C). Different dominant species were found at mesophilic- and thermophilic-enriched cultures, as revealed...

  3. 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.

  4. 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

    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......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...

  5. 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.

  6. 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.

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

    Science.gov (United States)

    Luo, Gang; Angelidaki, Irini

    2012-11-01

    Biogas produced by anaerobic digestion, is mainly used in a gas motor for heat and electricity production. However, after removal of CO(2) , biogas can be upgraded to natural gas quality, giving more utilization possibilities, such as utilization as autogas, or distant utilization by using the existing natural gas grid. The current study presents a new biological method for biogas upgrading in a separate biogas reactor, containing enriched hydrogenotrophic methanogens and fed with biogas and hydrogen. Both mesophilic- and thermophilic anaerobic cultures were enriched to convert CO(2) to CH(4) by addition of H(2) . Enrichment at thermophilic temperature (55°C) resulted in CO(2) and H(2) bioconversion rate of 320 mL CH(4) /(gVSS h), which was more than 60% higher than that under mesophilic temperature (37°C). Different dominant species were found at mesophilic- and thermophilic-enriched cultures, as revealed 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 of biogas upgrading was achieved. The produced biogas had a CH(4) content, around 95% at steady-state, at gas (mixture of biogas and hydrogen) injection rate of 6 L/(L day). The increase of gas injection rate to 12 L/(L day) resulted in the decrease of CH(4) content to around 90%. Further study showed that by decreasing the gas-liquid mass transfer by increasing the stirring speed of the mixture the CH(4) content was increased to around 95%. Finally, the CH(4) content around 90% was achieved in this study with the gas injection rate as high as 24 L/(L day).

  8. Anaerobic Digestion and Biogas Production: Combine Effluent Treatment with Energy Generation in UASB Reactor as Biorefinery Annex

    Directory of Open Access Journals (Sweden)

    Mauro Berni

    2014-01-01

    Full Text Available The issue of residues and industrial effluents represents an unprecedented environmental challenge in terms of recovery, storage, and treatment. This work discusses the perspectives of treating effluents through anaerobic digestion as well as reporting the experience of using an upflow anaerobic sludge blanket (UASB reactor as biorefinery annex in a pulp and paper industrial plant to be burned in the boilers. The performance of the reactors has shown to be stable under considerable variations in load and showed a significant potential in terms of biogas production. The reactors UASB treated 3600.00 m3 of effluent daily from a production of 150.00 tons. The biogas generation was 234.000 kg/year/mill, equivalent in combustible oil. The results of methane gas generated by the anaerobic system UASB (8846.00 kcal/m3 dislocate the equivalent of 650.0 kg of combustible oil (10000.00 kcal/kg per day (or 234.000 kg/year. The production of 8846.00 Kcal/m3 of energy from biogas can make a run at industrial plant for 2 hours. This substitution can save US$ 128.700 annually (or US$ 550.0 of fuel oil/tons. The companies are invested in the use of the biogas in diesel stationary motors cycle that feed the boilers with water in case of storage electricity.

  9. 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.

  10. Effect of organic loading rate and feedstock composition on foaming in manure-based biogas reactors

    DEFF Research Database (Denmark)

    Kougias, Panagiotis; Boe, Kanokwan; Angelidaki, Irini

    2013-01-01

    Foaming is one of the major problems that occasionally occur in biogas plants, affecting negatively the overall digestion process. In the present study, the effect of organic loading rate (OLR) and feedstock composition on foaming was elucidated in continuous reactor experiments. By stepwise...... increasing the OLR and the concentration of proteins or lipids in the substrate, foaming in biogas reactors was investigated. No foam formation was observed at the OLR of 3.5. g volatile solids/(L-reactor·day). Organic loading was the main factor affecting foam formation in manure digester, while the organic...

  11. 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

    reactor was continuously stirred using a magnetic stirrer. The operating temperature was maintained at 54 ± 1 °C using thermal jackets. Each reactor was fed with a different mixed substrate, which was found to have an influence on foam formation in our previous study (Kougias et al., 2013). The hydraulic......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...... system etc) and filamentous microorganisms (e.g. Gordonia species, Microthrix parvicella) (Ganidi et al., 2009). However, the contribution of specific microorganisms on foam generation in biogas reactors fed with agro-industrial wastes has not been previously investigated. The aim of the present study...

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

    Science.gov (United States)

    Deepanraj, B; Sivasubramanian, V; Jayaraj, S

    2015-11-01

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

  13. 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 efficiency of CH4...

  14. 养猪废水厌氧产沼反应器产气性能的研究%Research on the Performance of the Piggery Water Anaerobic Biogas-producing Reactor

    Institute of Scientific and Technical Information of China (English)

    肖磊; 万艳雷; 邹俊波; 魏元芹

    2014-01-01

    The anaerobic biogas-producing reactor with seeding efficient anaerobic granular sludge and kept running smoothly.During the operation, the impact of load, pH, ammonia nitrogen on gas production performance was studied . The research showed that gas production to a certain extent associated with the water load , the higher the water load and the greater the gas production .Gas production increased steadily in the optimum pH range for Methanogens .The ammonia nitrogen density elevates caused waste water pH to change , destructing the anaerobic microorganism 's best living environment .Ammonia nitrogen concentrations below 1 500 mg/L, no apparent adverse effects to Methanogens , but above 1 500 mg/L the activity of methane -producing bacteria inhibited and lower the gas production , and the reactor performance declined .%厌氧反应器中接种高效厌氧颗粒污泥并保持启动后平稳运行。在运行过程中对负荷、 pH、氨氮对产气性能的影响进行研究。研究表明气体产量在一定范围内与进水负荷相关,进水负荷越高,产气量越大;在产甲烷菌的最适pH范围内产气量稳定上升;氨氮浓度升高使废水pH发生变化,破坏厌氧微生物的最佳生存环境,氨氮浓度在1500 mg/L以下时对产甲烷菌没有明显不利影响;氨氮浓度超过1500 mg/L时抑制产甲烷菌的活性,产气量降低,反应器性能下降。

  15. 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.

  16. 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.

  17. 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.)

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

    Science.gov (United States)

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

    2015-09-01

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

  19. Where does the removal of H₂S from biogas occur in microaerobic reactors?

    Science.gov (United States)

    Ramos, I; Peña, M; Fdz-Polanco, M

    2014-08-01

    In order to maximise the efficiency of biogas desulphurisation and reduce the oxygen cost during microaerobic digestion, it is essential to know how the process occurs. For this purpose, a reactor with a total volume of 266 L, treating 10 L/d of sewage sludge, was operated with 25.0 L and without headspace. Under anaerobic conditions, the H2S concentration in the biogas varied between 0.21 and 0.38%v/v. Next, O2 was supplied from the bottom of the reactor. At 0.25-0.30 NLO₂/Lfed, the biogas was entirely desulphurised, and its O₂ content remained below 1.03%v/v, when the digester had 25.0 L of gas space. However, with almost no headspace, the H2S content in the biogas fluctuated from 0.08 to 0.21%v/v, while the average O2 concentration was 1.66%v/v. The removed H2S accumulated in the outlet pipe of the biogas in the form of S(0) due to the insufficient headspace.

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

    Science.gov (United States)

    Luo, Gang; Johansson, Sara; Boe, Kanokwan; Xie, Li; Zhou, Qi; Angelidaki, Irini

    2012-04-01

    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 methanogenesis with conversion of more than 90% of the consumed hydrogen to methane. The hydrogen consumption rates were affected by both P(H₂) (hydrogen partial pressure) and mixing intensity. Inhibition of propionate and butyrate degradation by hydrogen (1 atm) was only observed under high 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 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 to the consumption of bicarbonate, which subsequently caused slight inhibition of methanogenesis.

  1. 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

    methanogenesis with conversion of more than 90% of the consumed hydrogen to methane. The hydrogen consumption rates were affected by both $P_{{\\rm H}_{{\\rm 2}} } $ (hydrogen partial pressure) and mixing intensity. Inhibition of propionate and butyrate degradation by hydrogen (1 atm) was only observed under high...... 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...

  2. 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.

  3. 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.)

  4. 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

  5. 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

  6. 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)

  7. 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

  8. 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.

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

    Science.gov (United States)

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

    2015-10-20

    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 efficiency of CH4 production and CO2 conversion was recorded. The consequent increase of pH did not inhibit the process indicating adaptation of microorganisms to higher pH levels. The effects of H2 on the microbial community were studied using high-throughput Illumina random sequences and full-length 16S rRNA genes extracted from the total sequences. The relative abundance of archaeal community markedly increased upon H2 addition with Methanoculleus as dominant genus. The increase of hydrogenotrophic methanogens and syntrophic Desulfovibrio and the decrease of aceticlastic methanogens indicate a H2-mediated shift toward the hydrogenotrophic pathway enhancing biogas upgrading. Moreover, Thermoanaerobacteraceae were likely involved in syntrophic acetate oxidation with hydrogenotrophic methanogens in absence of aceticlastic methanogenesis.

  10. 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

    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......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...

  11. 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.

  12. 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

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

    Science.gov (United States)

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

    2015-10-23

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

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

    Science.gov (United States)

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

    2015-01-01

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

  15. 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.

  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. 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.

  18. 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.

  19. 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

  20. 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

  1. 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)

  2. 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

  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. 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.

  5. 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.

  6. Clostridium bornimense sp. nov., isolated from a mesophilic, two-phase, laboratory-scale biogas reactor.

    Science.gov (United States)

    Hahnke, Sarah; Striesow, Jutta; Elvert, Marcus; Mollar, Xavier Prieto; Klocke, Michael

    2014-08-01

    A novel anaerobic, mesophilic, hydrogen-producing bacterium, designated strain M2/40(T), was isolated from a mesophilic, two-phase, laboratory-scale biogas reactor fed continuously with maize silage supplemented with 5% wheat straw. 16S rRNA gene sequence comparison revealed an affiliation to the genus Clostridium sensu stricto (cluster I of the clostridia), with Clostridium cellulovorans as the closest characterized species, showing 93.8% sequence similarity to the type strain. Cells of strain M2/40(T) were rods to elongated filamentous rods that showed variable Gram staining. Optimal growth occurred at 35 °C and at pH 7. Grown on glucose, the main fermentation products were H2, CO2, formate, lactate and propionate. The DNA G+C content was 29.6 mol%. The major fatty acids (>10 %) were C(16 : 0), summed feature 10 (C(18 : 1)ω11c/ω9t/ω6t and/or unknown ECL 17.834) and C(18 : 1)ω11c dimethylacetal. Based on phenotypic, chemotaxonomic and phylogenetic differences, strain M2/40(T) represents a novel species within the genus Clostridium, for which we propose the name Clostridium bornimense sp. nov. The type strain is M2/40(T) ( = DSM 25664(T) = CECT 8097(T)).

  7. 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.

  8. Performance of photoperiod and light intensity on biogas upgrade and biogas effluent nutrient reduction by the microalgae Chlorella sp.

    Science.gov (United States)

    Yan, Cheng; Zheng, Zheng

    2013-07-01

    Biogas is an environment-friendly fuel but that must be upgraded before being utilized. The method about removing CO2 from biogas by microalgal culturing using biogas effluent as nutrient medium in this study could effectively upgrade biogas and simultaneously reduce the biogas effluent nutrient. Results showed that the optimum parameters for microalgal growth and biogas effluent nutrient reduction was moderate light intensity with middle photoperiod. While low light intensity with long photoperiod and moderate light intensity with middle photoperiod obtained the best biogas CO2 removal and biogas upgrade effects. Therefore, the optimal parameters were moderate light intensity 350 μmol m(-2)s(-1) with middle photoperiod 14 h light:10h dark. Under this condition, the microalgal dry weight, CH4 concentration, reduction efficiency of chemical oxygen demand, total nitrogen, and total phosphorus was 615.84 ± 33.07 mg L(-1), 92.16 ± 2.83% (v/v), 88.74 ± 3.45%, 83.94 ± 3.51%, and 80.43 ± 4.17%, respectively.

  9. 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

  10. 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)

  11. COD removal and biogas production at the manipueira treatment in anaerobic one-stage reactor with different supporting media; Remocao de DQO e producao de biogas no tratamento de manipueira em reator anaerobico monofasico com diferentes meios de suporte

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Douglas Guedes Batista; Kunzler, Kathia Regina; Gomes, Simone Damasceno; Tavares, Maria Herminia Ferreira; Assis, Tatiane Martins de [Universidade Estadual do Oeste do Parana (UNIOESTE), PR (Brazil)], Emails: simoned@unioeste.br, mhstavar@certto.com.br

    2009-07-01

    This study aims at evaluating the efficiency for organic load removal and biogas production for the manipueira treatment in two anaerobic reactors using as supporting media bamboo rings and polyurethane. The manipueira loads added to the systems were 0.548, 1.156, 1.471 and 3.049 g COD/ L{sub reactorday}, gradually increased. With bamboo as supporting media, the load increasing carried the greatest biogas production, with 3.049 g COD/ L{sub reactorday}. Using polyurethane, the greatest production occurred with the 1.471 g CODL{sub reactorday} {sup -1}load. Therefore, it was shown that the supporting media use allowed greater loads and biogas productions, comparatively to the literature data. (author)

  12. Microbial community composition and dynamics in high-temperature biogas reactors using industrial bioethanol waste as substrate.

    Science.gov (United States)

    Röske, Immo; Sabra, Wael; Nacke, Heiko; Daniel, Rolf; Zeng, An-Ping; Antranikian, Garabed; Sahm, Kerstin

    2014-11-01

    Stillage, which is generated during bioethanol production, constitutes a promising substrate for biogas production within the scope of an integrated biorefinery concept. In this study, a microbial community was grown on thin stillage as mono-substrate in a continuous stirred tank reactor (CSTR) at a constant temperature of 55 °C, at an organic loading rate of 1.5 goTS/L*d and a retention time of 25 days. Using an amplicon-based dataset of 17,400 high-quality sequences of 16S rRNA gene fragments (V2-V3 regions), predominance of Bacteria assigned to the families Thermotogaceae and Elusimicrobiaceae was detected. Dominant members of methane-producing Euryarchaeota within the CSTR belonged to obligate acetoclastic Methanosaetaceae and hydrogenotrophic Methanobacteriaceae. In order to investigate population dynamics during reactor acidification, the organic loading rate was increased abruptly, which resulted in an elevated concentration of volatile fatty acids. Acidification led to a decrease in relative abundance of Bacteria accompanied with stable numbers of Archaea. Nevertheless, the abundance of Methanosaetaceae increased while that of Methanobacteriales decreased successively. These findings demonstrate that a profound intervention to the biogas process may result in persistent community changes and reveals uncommon bacterial families as process-relevant microorganisms.

  13. 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...

  14. Effects of mixing system and pilot fuel quality on diesel-biogas dual fuel engine performance.

    Science.gov (United States)

    Bedoya, Iván Darío; Arrieta, Andrés Amell; Cadavid, Francisco Javier

    2009-12-01

    This paper describes results obtained from CI engine performance running on dual fuel mode at fixed engine speed and four loads, varying the mixing system and pilot fuel quality, associated with fuel composition and cetane number. The experiments were carried out on a power generation diesel engine at 1500 m above sea level, with simulated biogas (60% CH(4)-40% CO(2)) as primary fuel, and diesel and palm oil biodiesel as pilot fuels. Dual fuel engine performance using a naturally aspirated mixing system and diesel as pilot fuel was compared with engine performance attained with a supercharged mixing system and biodiesel as pilot fuel. For all loads evaluated, was possible to achieve full diesel substitution using biogas and biodiesel as power sources. Using the supercharged mixing system combined with biodiesel as pilot fuel, thermal efficiency and substitution of pilot fuel were increased, whereas methane and carbon monoxide emissions were reduced.

  15. 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. Results...... analysis showed higher relative abundance of hydrogenotrophic methanogens. Principal coordinates analysis showed the sludge-based samples were clearly distinct from the manure-based samples for both taxonomic and functional patterns, and canonical correspondence analysis showed that the both temperature...

  16. 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....

  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. 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.

  19. 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

  20. 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.

  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. 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)

  3. 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

  4. 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)

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  7. Computer model for performance prediction and optimization of unheated biogas plant

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Parm Pal; Ghuman, B.S. [Punjab Agricultural Univ., Mechanical Engineering Dept., Punjab (India); Grewal, N.S. [Punjab Agricultural Univ., Civil Engineering Dept., Punjab (India)

    1998-12-01

    A mathematical model of an unheated biogas plant described in this paper can be used to predict biogas generation at any given geographical location by using laboratory experimental data of methane gas generation at different values of temperature and retention time. So, this model obviates the need for repeating field experiments at different geographical locations. The introduction of new concepts of equivalent temperature and biogas coefficient help to convert laboratory data into field data and minimize the necessity of conducting field experiments. Further, retention time and size of the biogas plant for a given daily requirement of biogas are optimized through life cycle economic analysis. The model has been elaborated by calculating results for biogas generation with cattle dung in a fixed dome type biogas plant located at Ludhiana. Results are presented for various values of daily biogas requirement and cost of feedstock. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-10-15

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

  9. 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

    /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......-digestion. Post-digestion for recovering the residual methane potential at temperatures below 15 degrees C was very inefficient....

  10. 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...

  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

    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...... 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...

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

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Angelidaki, Irini

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

  13. Ultrasound assisted biogas production from landfill leachate.

    Science.gov (United States)

    Oz, Nilgün Ayman; Yarimtepe, Canan Can

    2014-07-01

    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 (pbiogas and methane production rate. In anaerobic batch reactor feed with ultrasonically pretreated leachate, 40% more biogas was obtained compared to the control reactor. For statistical analysis, Mann-Whitney U test was performed to compare biogas and methane production rates for raw and pretreated leachate samples and it has been found that ultrasonic pretreatment significantly enhanced biogas and methane production rates from leachate (p<0.05) in anaerobic batch reactors. The overall results showed that low frequency ultrasound pretreatment can be potentially used for wastewater management especially with integration of anaerobic processes.

  14. 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

  15. 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

    stirred tank reactors (CSTR) fed with manure and supplemental amounts of lipids, proteins and carbohydrates. Once foaming was formed in the reactors, samples from the liquid and foaming layer were obtained and screened using 16S rDNA sequencing. The results of these analyses revealed that there are indeed...

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Berglund, Maria; Boerjesson, Paal [Environmental and Energy Systems Studies LTH, Lund University, Gerdagatan 13, SE-223 62 Lund (Sweden)

    2006-03-15

    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 200km (manure), or up to 700km (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. (author)

  18. 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

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

  19. 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

  20. 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...

  1. 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})

  2. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-06-15

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

  4. 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

  5. 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.

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

    Science.gov (United States)

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

    2006-10-01

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

  7. MODIFIKASI KARBON AKTIF SEBAGAI ADSORBEN UNTUK PEMURNIAN BIOGAS

    Directory of Open Access Journals (Sweden)

    Heru Susanto

    2012-08-01

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

  8. 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)

  9. The kinetics of nitrogen removal and biogas production in an anammox non-woven membrane reactor.

    Science.gov (United States)

    Ni, Shou-Qing; Lee, Po-Heng; Sung, Shihwu

    2010-08-01

    The anammox non-woven membrane reactor (ANMR) is a novel reactor configuration to culture the slowly growing anammox bacteria. Different mathematical models were used to study the process kinetics of the nitrogen removal in the ANMR. The kinetics of nitrogen gas production of anammox process was first evaluated in this paper. For substrate removal kinetics, the modified Stover-Kincannon model and the Grau second-order model were more applicable to the ANMR than the first-order model and the Monod model. For nitrogen gas production kinetics, the Van der Meer and Heertjes model was more appropriate than the modified Stover-Kincannon model. Model evaluation was carried out by comparing experimental data with predicted values calculated from suitable models. Both model kinetics study and model testing showed that the Grau second-order model and the Van der Meer and Heertjes model seemed to be the best models to describe the nitrogen removal and nitrogen gas production in the ANMR, respectively.

  10. 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...

  11. Optimization of biogas production from manure

    DEFF Research Database (Denmark)

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

    posttreatments to improve the degradability of the undegraded material. Both lab-scale and pilot-scale experiments were carried out at the Institute of Environment & Resources, Technical University of Denmark. In the first experiment, the effect of serial digestion on process performance and methane production...... 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...

  12. Co-digestion of manure and whey for in situ biogas upgrading by the addition of H(2): process performance and microbial insights.

    Science.gov (United States)

    Luo, Gang; Angelidaki, Irini

    2013-02-01

    In situ biogas upgrading was conducted by introducing H(2) directly to the anaerobic reactor. As H(2) addition is associated with consumption of the CO(2) in the biogas reactor, pH increased to higher than 8.0 when manure alone was used as substrate. By co-digestion of manure with acidic whey, the pH in the anaerobic reactor with the addition of hydrogen could be maintained below 8.0, which did not have inhibition to the anaerobic process. The H(2) distribution systems (diffusers with different pore sizes) and liquid mixing intensities were demonstrated to affect the gas-liquid mass transfer of H(2) and the biogas composition. The best biogas composition (75:6.6:18.4) was obtained at stirring speed 150 rpm and using ceramic diffuser, while the biogas in the control reactor consisted of CH(4) and CO(2) at a ratio of 55:45. The consumed hydrogen was almost completely converted to CH(4), and there was no significant accumulation of VFA in the effluent. The study showed that addition of hydrogen had positive effect on the methanogenesis, but had no obvious effect on the acetogenesis. Both hydrogenotrophic methanogenic activity and the concentration of coenzyme F(420) involved in methanogenesis were increased. The archaeal community was also altered with the addition of hydrogen, and a Methanothermobacter thermautotrophicus related band appeared in a denaturing gradient gel electrophoresis gel from the sample of the reactor with hydrogen addition. Though the addition of hydrogen increased the dissolved hydrogen concentration, the degradation of propionate was still thermodynamically feasible at the reactor conditions.

  13. 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.

  14. 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

  15. 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,...

  16. 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.

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

    Science.gov (United States)

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

    2013-10-01

    As a lignocellulose-based substrate for anaerobic digestion, rice straw is characterized by low density, high water absorbability, and poor fluidity. Its mixing performances in digestion are completely different from traditional substrates such as animal manures. Computational fluid dynamics (CFD) simulation was employed to investigate mixing performances and determine suitable stirring parameters for efficient biogas production from rice straw. The results from CFD simulation were applied in the anaerobic digestion tests to further investigate their reliability. The results indicated that the mixing performances could be improved by triple impellers with pitched blade, and complete mixing was easily achieved at the stirring rate of 80 rpm, as compared to 20-60 rpm. However, mixing could not be significantly improved when the stirring rate was further increased from 80 to 160 rpm. The simulation results agreed well with the experimental results. The determined mixing parameters could achieve the highest biogas yield of 370 mL (g TS)(-1) (729 mL (g TS(digested))(-1)) and 431 mL (g TS)(-1) (632 mL (g TS(digested))(-1)) with the shortest technical digestion time (T 80) of 46 days. The results obtained in this work could provide useful guides for the design and operation of biogas plants using rice straw as substrates. PMID:23873639

  18. Jules Horowitz Reactor: a high performance material testing reactor

    Science.gov (United States)

    Iracane, Daniel; Chaix, Pascal; Alamo, Ana

    2008-04-01

    The physical modelling of materials' behaviour under severe conditions is an indispensable element for developing future fission and fusion systems: screening, design, optimisation, processing, licensing, and lifetime assessment of a new generation of structure materials and fuels, which will withstand high fast neutron flux at high in-service temperatures with the production of elements like helium and hydrogen. JANNUS and other analytical experimental tools are developed for this objective. However, a purely analytical approach is not sufficient: there is a need for flexible experiments integrating higher scales and coupled phenomena and offering high quality measurements; these experiments are performed in material testing reactors (MTR). Moreover, complementary representative experiments are usually performed in prototypes or dedicated facilities such as IFMIF for fusion. Only such a consistent set of tools operating on a wide range of scales, can provide an actual prediction capability. A program such as the development of silicon carbide composites (600-1200 °C) illustrates this multiscale strategy. Facing the long term needs of experimental irradiations and the ageing of present MTRs, it was thought necessary to implement a new generation high performance MTR in Europe for supporting existing and future nuclear reactors. The Jules Horowitz Reactor (JHR) project copes with this context. It is funded by an international consortium and will start operation in 2014. JHR will provide improved performances such as high neutron flux ( 10 n/cm/s above 0.1 MeV) in representative environments (coolant, pressure, temperature) with online monitoring of experimental parameters (including stress and strain control). Experimental devices designing, such as high dpa and small thermal gradients experiments, is now a key objective requiring a broad collaboration to put together present scientific state of art, end-users requirements and advanced instrumentation. To cite this

  19. 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

    , 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...

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

    Science.gov (United States)

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

    2010-10-01

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

  1. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1985-01-17

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

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

    Science.gov (United States)

    Refai, Sarah; Wassmann, Kati; Deppenmeier, Uwe

    2014-08-01

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

  4. 沼气中CO2含量对沼气灶性能的影响及对策%Effects and countermeasures of CO2 content in biogas on performance of biogas stove

    Institute of Scientific and Technical Information of China (English)

    戴万能; 秦朝葵; 杨贤潮; 马飞

    2011-01-01

    采用天然气掺混CO2的方法模拟沼气,在CO2体积分数为30%~50%条件下,测试了典型家用沼气灶的热工性能,研究了应对沼气气质变化的措施.结果表明:随C02含量的降低,沼气灶热流量增大,热效率升高,烟气中CO浓度升高,NOx浓度无显著变化.热流量大于3.26 kW时,现行测试方法不能真实反映热效率与CO2含量的关系.沼气中CO2含量的变化会显著改变沼气灶的热工性能,可能增加用户的抱怨和安全风险.在CO2体积分数小于40%时,根据CO2含量调整供气压力,可使灶具热流量保持稳定,并显著改善CO排放,可能成为沼气组分含量变化的应对措施.%The thermal performance of a typical domestic biogas stove supplied with biogas of different CO2 volume fractions was investigated. Possible technical measures in response to variations in biogas composition were studied as well. Mixed gas of natural gas and CO2 were produced so as to simulate the biogas in which CO2 volume fraction varied from 50% to 30%. With the decrease of CO2 percentage in the mixture, it was found that heat output, heat efficiency and CO emission increased, while NOX emission did not change significantly. When heat output was greater than 3.26 kW, the current testing method could not reflect the relationship between thermal efficiency and CO2 ratio exactly. Variations in the CO2 content in biogas significantly affected the thermal performance of the biogas stove, which maight increase complaints and security risks. When the volume fraction of CO2 was less than 40%, regulating the biogas pressure according to the CO2 content so as to stabilize heat output could significantly improve the CO emission, which may be regarded as a measure to cope with variations of CO2 content in biogas.

  5. 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.

  6. 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)

  7. 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).

  8. 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

  9. 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.

  10. Improvement of biogas production by bioaugmentation.

    Science.gov (United States)

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

    2013-01-01

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

  11. 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)

  12. Complete genome sequence of the novel Porphyromonadaceae bacterium strain ING2-E5B isolated from a mesophilic lab-scale biogas reactor.

    Science.gov (United States)

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

    2015-01-10

    In this study, the whole genome sequence of the mesophilic, anaerobic Porphyromonadaceae bacterium strain ING2-E5B (LMG 28429, DSM 28696) is reported. The new isolate belongs to the phylum Bacteroidetes and was obtained from a biogas-producing lab-scale completely stirred tank reactor (CSTR) optimized for anaerobic digestion of maize silage in co-fermentation with pig and cattle manure. The genome of strain ING2-E5B contains numerous genes encoding proteins and enzymes involved in the degradation of complex carbohydrates and proteinaceous compounds. Moreover, it possesses genes catalyzing the production of volatile fatty acids. Hence, this bacterium was predicted to be involved in hydrolysis and acidogenesis during anaerobic digestion and biomethanation.

  13. 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.)

  14. 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...

  15. Kinetic evaluation and process performance of an upflow anaerobic filter reactor degrading terephthalic acid.

    Science.gov (United States)

    Davutluoglu, Orkun I; Seckin, Galip

    2014-01-01

    The anaerobic degradation of terephthalic acid (TA) as the sole organic carbon source was studied in an upflow anaerobic filter (UAF) reactor. The reactor was seeded with biomass obtained from a full-scale upflow anaerobic sludge bed (UASB) reactor and was used to treat wastewater from a petrochemical facility producing dimethyl terephthalate. The UAF reactor was operated for 252 d with a constant hydraulic retention time of 24 h, and the organic loading rate (OLR) was gradually increased from 1 to 10 g-chemical oxygen demand (COD)/L d. After a lag period of approximately 40 d, the COD removal efficiency increased exponentially and high removal rate values (≈90%) were obtained, except for at highest OLR (10 g-COD/L d). The high removal rates and the robustness of the reactor performance could be attributed to the formation of biofilm as well as granular sludge. The methane production rates (0.22 to 2.15 L/d) correlated well with the removed OLRs (0.3 to 6.8 g-COD/L d) during the various phases of treatment, indicating that the main mechanism of TA degradation occurs via methanogenic reactions. The average methane content of the produced biogas was 70.3%. The modified Stover-Kincannon model was found to be applicable for the anaerobic degradation of TA in UAFs (Umax = 64.5, KB = 69.1 g-COD/L d and Ymax = 0.27 L-CH4/g-CODremoved). These results suggest that UAF reactors are among the most effective reactor configurations for the anaerobic degradation of TA.

  16. 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

  17. 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.

  18. 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.

  19. 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.)

  20. 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.

  1. Glidarc assisted production of synthesis gas from biogas

    Energy Technology Data Exchange (ETDEWEB)

    Czernichowski, A. [Orleans Univ., Department of Physics, 45 - Orleans (France); Czernichowski, M.; Wesolowska, K. [Etudes Chimiques et Physiques (ECP), 45 - La Ferte Saint Aubin (France)

    2003-09-01

    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 upgraded biogas can, for example, be used as fuel in Internal Combustion Engines, be considered as source of Hydrogen for PEM fuel cells or be consumed in other specific fuel cells. Any level of impurities is accepted for our reformer where the discharges provide all necessary energy and catalytic assistance for endothermic process of so-called 'dry' reforming of CH{sub 4}+CO{sub 2} into H{sub 2}+CO. Our tests with 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 presenting up to 7 kW of thermal power. (authors)

  2. 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''.

  3. 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)

  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. 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.

  6. 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...

  7. 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)....

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

    DEFF Research Database (Denmark)

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

    1999-01-01

    Small-subunit rRNA sequences were obtained for two saturated fatty acid-beta-oxidizing syntrophic bacteria, Syntrophomonas sapovorans and Syntrophomonas wolfei LYE, and sequence analysis confirmed their classification as members of the family Syntrophomonadaceae. S, wolfei LYE was closely related...... to S. wolfei subsp. wolfei, but S. sapovorans did not cluster with the other members of the genus Syntrophomonas, Five oligonucleotide probes targeting the small-subunit rRNA of different groups within the family Syntrophomonadaceae, which contains all currently known saturated fatty acid-beta-oxidizing...... fatty acid-beta-oxidizing syntrophic bacteria in methanogenic environments, the microbial community structure of a sample from a full-scale biogas plant was determined. Hybridization results with probes for syntrophic bacteria-and methanogens were compared to specific methanogenic activities...

  9. 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

  10. 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

  11. 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)

  12. 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.

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

    Science.gov (United States)

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

    2015-03-01

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

  14. 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

    of 10 mM by manipulating the feed flow. Other online parameters such as pH, biogas production, total VFA, and other individual VFA were also measured to examine process performance. The experimental results showed that a simple logic control can successfully prevent the reactor from overload......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......, but with fluctuations of the propionate level due to the nature of control approach. The fluctuation of propionate concentration could be reduced, by adding a lower feed flow limit into the control algorithm to prevent undershooting of propionate response. It was found that use of the biogas production as a main...

  15. 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...

  16. 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

  17. 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.

  18. A Computer Simulation of the Effect of the Inert Gas Volume Fraction in Low-Caloric Biogas on the Performance of an Engine

    Directory of Open Access Journals (Sweden)

    Choong Hoon Lee

    2015-10-01

    Full Text Available A computer simulation of a gas engine was performed to investigate the effects of the inert gas volume fraction in biogas on engine performance, specifically the engine torque and the brakespecific fuel consumption (BSFC using GT-Power®. The engine speeds used in the simulation were 900 and 1800 rpm, while the simulated engine loads were 25, 50, 75 and 100%. The volume fraction of the inert gas N2 in the biogas was varied from 20 to 80% with an interval of 10%. In a simulation of a naturally aspirated gas engine which is operated with an 80% volume fraction of N2 in biogas, the optimal air-fuel ratio in terms of the fuel economy and brake power generation was 3.5. In a simulation of a turbo intercooler gas engine operated with an 80% volume fraction of N2 in biogas, the optimal air-fuel ratios with regard to the fuel economy and brake power generation were 5.0 and 3.5, respectively.

  19. 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

  20. Oxidation performance of graphite material in reactors

    Institute of Scientific and Technical Information of China (English)

    Xiaowei LUO; Xinli YU; Suyuan YU

    2008-01-01

    Graphite is used as a structural material and moderator for high temperature gas-cooled reactors (HTGR). When a reactor is in operation, graphite oxida-tion influences the safety and operation of the reactor because of the impurities in the coolant and/or the acci-dent conditions, such as water ingress and air ingress. In this paper, the graphite oxidation process is introduced, factors influencing graphite oxidation are analyzed and discussed, and some new directions for further study are pointed out.

  1. 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.

  2. 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

  3. 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. .

  4. 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...

  5. 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.

  6. 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

  7. 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...

  8. Fuel Cycle Performance of Thermal Spectrum Small Modular Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Worrall, Andrew [ORNL; Todosow, Michael [Brookhaven National Laboratory (BNL)

    2016-01-01

    Small modular reactors may offer potential benefits, such as enhanced operational flexibility. However, it is vital to understand the holistic impact of small modular reactors on the nuclear fuel cycle and fuel cycle performance. The focus of this paper is on the fuel cycle impacts of light water small modular reactors in a once-through fuel cycle with low-enriched uranium fuel. A key objective of this paper is to describe preliminary reactor core physics and fuel cycle analyses conducted in support of the U.S. Department of Energy Office of Nuclear Energy Fuel Cycle Options Campaign. Challenges with small modular reactors include: increased neutron leakage, fewer assemblies in the core (and therefore fewer degrees of freedom in the core design), complex enrichment and burnable absorber loadings, full power operation with inserted control rods, the potential for frequent load-following operation, and shortened core height. Each of these will impact the achievable discharge burn-up in the reactor and the fuel cycle performance. This paper summarizes the results of an expert elicitation focused on developing a list of the factors relevant to small modular reactor fuel, core, and operation that will impact fuel cycle performance. Preliminary scoping analyses were performed using a regulatory-grade reactor core simulator. The hypothetical light water small modular reactor considered in these preliminary scoping studies is a cartridge type one-batch core with 4.9% enrichment. Some core parameters, such as the size of the reactor and general assembly layout, are similar to an example small modular reactor concept from industry. The high-level issues identified and preliminary scoping calculations in this paper are intended to inform on potential fuel cycle impacts of one-batch thermal spectrum SMRs. In particular, this paper highlights the impact of increased neutron leakage and reduced number of batches on the achievable burn-up of the reactor. Fuel cycle performance

  9. 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.)

  10. 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.

  11. 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...

  12. 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

  13. 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...

  14. 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)

  15. Insights into the annotated genome sequence of Methanoculleus bourgensis MS2(T), related to dominant methanogens in biogas-producing plants.

    Science.gov (United States)

    Maus, Irena; Wibberg, Daniel; Stantscheff, Robbin; Stolze, Yvonne; Blom, Jochen; Eikmeyer, Felix-Gregor; Fracowiak, Jochen; König, Helmut; Pühler, Alfred; Schlüter, Andreas

    2015-05-10

    The final step of the biogas production process, the methanogenesis, is frequently dominated by members of the genus Methanoculleus. In particular, the species Methanoculleus bourgensis was identified to play a role in different biogas reactor systems. The genome of the type strain M. bourgensis MS2(T), originally isolated from a sewage sludge digestor, was completely sequenced to analyze putative adaptive genome features conferring competitiveness within biogas reactor environments to the strain. Sequencing and assembly of the M. bourgensis MS2(T) genome yielded a chromosome with a size of 2,789,773 bp. Comparative analysis of M. bourgensis MS2(T) and Methanoculleus marisnigri JR1 revealed significant similarities. The absence of genes for a putative ammonium uptake system may indicate that M. bourgensis MS2(T) is adapted to environments rich in ammonium/ammonia. Specific genes featuring predicted functions in the context of osmolyte production were detected in the genome of M. bourgensis MS2(T). Mapping of metagenome sequences derived from a production-scale biogas plant revealed that M. bourgensis MS2(T) almost completely comprises the genetic information of dominant methanogens present in the biogas reactor analyzed. Hence, availability of the M. bourgensis MS2(T) genome sequence may be valuable regarding further research addressing the performance of Methanoculleus species in agricultural biogas plants.

  16. 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

  17. 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

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

    Science.gov (United States)

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

    2015-01-01

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

  19. Biogas production in an anaerobic sequencing batch reactor by using tequila vinasses: effect of pH and temperature.

    Science.gov (United States)

    Arreola-Vargas, J; Jaramillo-Gante, N E; Celis, L B; Corona-González, R I; González-Álvarez, V; Méndez-Acosta, H O

    2016-01-01

    In recent years, anaerobic digestion has been recognized as a suitable alternative for tequila vinasses treatment due to its high energy recovery and chemical oxygen demand (COD) removal efficiency. However, key factors such as the lack of suitable monitoring schemes and the presence of load disturbances, which may induce unstable operating conditions in continuous systems, have limited its application at full scale. Therefore, the aim of this work was to evaluate the anaerobic sequencing batch reactor (AnSBR) configuration in order to provide a low cost and easy operation alternative for the treatment of these complex effluents. In particular, the AnSBR was evaluated under different pH-temperature combinations: 7 and 32 °C; 7 and 38 °C; 8 and 32 °C and 8 and 38 °C. Results showed that the AnSBR configuration was able to achieve high COD removal efficiencies (around 85%) for all the tested conditions, while the highest methane yield was obtained at pH 7 and 38 °C (0.29 L/g COD added). Furthermore, high robustness was found in all the AnSBR experiments. Therefore, the full-scale application of the AnSBR technology for the treatment of tequila vinasses is quite encouraging, in particular for small and medium size tequila industries that operate under seasonal conditions.

  20. 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

  1. 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...... distribution ratio of 80/20 and 90/10, and total HRT of 15 days. The results showed that the serial CSTR could obtain 11% higher biogas yield compared to the single CSTR. The increased biogas yield in the serial CSTR was mainly from the second reactor, which accounted for 16% and 12% of total biogas yield...... in the 90/10 and 80/20 configuration, respectively. VFA concentration in the serial CSTR was high in the first reactor but very low in the second reactor. The results from organic pulse load test showed that the second reactor in serial CSTR helped utilizing VFA produced from overloading in the first...

  2. Anaerobic digestion of different organic wastes for biogas production and its operational control performed by the modified ADM1.

    Science.gov (United States)

    Zhou, Haidong; Li, Han; Wang, Fengfei

    2012-01-01

    Anaerobic digestion (AD) of different organic wastes for biogas production under variable operating conditions was simulated with a steady-state implementation of the modified IWA Anaerobic Digestion Model No. 1 (ADM1), and an input-output feedback control system using the model as a test platform was developed. The main aim of this study was to compare the characteristics of organic wastes in the AD processes and manage to keep the processes stable based on the results of simulation. The two important operating factors, solid retention time (SRT) and organic loading rate (OLR) (or the ratio of input flows for co-digestion), were investigated. Anaerobic digestion of biowaste was characterized with lower biogas production and instability of the processes, especially at OLR 2.5 kgCOD/m(3)·d or more, although longer SRT could increase the biogas production. Moreover, the co-substrate composed of biowaste and corn silage would lead to instability of the processes and much lower biogas production. Biowaste was, however, preferable to be co-digested with manures of living stock or sewage sludge. Manure could contribute to the stability of the AD processes, and its co-substrates with organic wastes rich in carbohydrates such as biowaste and corn silage would improve the biogas production and the proportion of methane. Longer SRTs would improve the biogas production from manure as well as its co-substrates except the co-substrate with biowaste as the production was not distinctly raised. The test of the developed input-output feedback control system showed that the control system could reject a realistic set of random disturbances and keep the AD processes stable under the desired operational conditions with a minimal use of measurement facilities.

  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. 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...

  5. 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...

  6. Contrast on Biogas Production Performances of Above Ground and Under Ground Digesters%地上和地下式沼气池产气性能对比

    Institute of Scientific and Technical Information of China (English)

    李金怀; 徐铁纯; 蒋湖波; 赵德钦

    2012-01-01

    Biogas production performances of above ground and under ground digesters were contrasted, based on the characteristics of underground digester with water pressure and above ground movable digest- er and the same fermented concentration of pig murine material. The results showed that the biogas and methane production of underground digester was higher than above ground digester, and there was no difference to methane content in two types of digesters. In addition, temperature had influence on biogas production of two types of digesters%针对广西推广的地下水压式沼气池和地上移动式沼气池的特点,以猪粪为发酵原料,并以相同的发酵浓度投料,进行地上和地下式沼气池产气性能对比试验,结果表明:地下水压式沼气池的产气量和产甲烷量都显著高于地上移动式沼气池,而2种形式的沼气池中甲烷含量相差不大。此外,温度对2种形式沼气池的产气性能有一定影响。

  7. 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.

  8. 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.

  9. 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.

  10. 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...

  11. [Influence of Temperature on the Anaerobic Packed Bed Reactor Performance and Methanogenic Community].

    Science.gov (United States)

    Xie, Hai-ying; Wang, Xin; Li, Mu-yuan; Yan, Xu-you; Igarashi, Yasuo; Luo, Feng

    2015-11-01

    This study aimed to analyze the effect of temperature on performance and microbial community structure of an anaerobic packed bed reactor (APBR). The temperature was increased step-wise from room temperature (22 degrees C ± 1 degrees C) to psychrophilic (15 degrees C ± 1 degrees C), mesophilic (37 degrees C ± 1 degrees C) and thermophilic (55 degrees C ± 1 degrees C). The results showed that, in the temperature changing process, the higher the temperature of APBR was, the higher COD removal rate and daily gas production were. After temperature changed to psychrophilic, mesophilic and thermophilic, COD removal rate and daily gas production were 25%, 45%, 60% and 2.3 L x d(-1), 4.0 L x d(-1), 8.5 L x d(-1) respectively. However, there was no significant change in biogas composition (-60%). A sudden temperature change caused a simultaneous increase in the concentration of volatile fatty acids (VFA), which had been fluctuating. Using 16S rRNA gene clone library screening, Euryarchaeota was commonly found, including important methanogens: MBT (Methanobacteriales), Mst (Methanosaetaceae) , Msc (Methanosarcinaceae) and MMB (Methanomicrobiales), as well as thermophilic bacteria and few spring Archaea. However, the diversity of methanogenic groups was reduced, especially at mesophilic. The results of quantitative PCR showed that the 16S rRNA gene concentrations of Mst, MMB and Msc were reduced by temperature changes. Although the relative proportion of every kind of methanogen was significantly affected, Mst was the dominant methanogen. PMID:26911011

  12. 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

  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

    2015-08-31

    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.

  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. Pengaruh Laju Alir Volumetrik Umpan Static In-Line Mixer Terhadap Performance Bioreaktor Pada Pembuatan Biogas Dari Limbah Cair Kelapa Sawit Skala Pilot Plant

    OpenAIRE

    Sitepu, Juliananta

    2015-01-01

    Indonesia as the second country for production CPO in the world is very potesially in biogas industry. Something make it very potensial is POME (Palm Oil Effulent).POME is the most important in biogas because it can be change to biogas. Production biogas is in thermofilik anaerob with recyle sludge 34% through in four tank. They are pretreatment tank, mixing tank, bioreactor, and gravity thickner.The mixing tank is a tank with motor (machine), impeller and any baffle. For...

  17. 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

  18. 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...

  19. 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

  20. 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

  1. 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...

  2. 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.

  3. 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

  4. 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

  5. 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

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

    NARCIS (Netherlands)

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

    1999-01-01

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

  7. 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

  8. 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.)

  9. 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)

  10. 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...

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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

  1. 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

  2. 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

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

    Science.gov (United States)

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

    2016-02-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, H S

    1976-07-01

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

  5. 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...

  6. 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.

  7. Draft genome sequence of Herbinix hemicellulosilytica T3/55 T, a new thermophilic 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

    2015-11-20

    A novel bacterial species was isolated from an industrial-scale biogas plant. The isolate Herbinix hemicellulosilytica T3/55(T) is able to degrade crystalline cellulose. Comparative 16S rRNA gene sequencing demonstrated that the isolate is closely related to environmental samples forming a hitherto unknown sub-cluster within the family Lachnospiraceae. The draft genome sequence of strain T3/55(T) was established and now provides the genetic basis for application of this microorganism in thermophilic degradation of lignocellulosic biomass.

  8. GlidArc-assisted production of synthesis gas from biogas

    Energy Technology Data Exchange (ETDEWEB)

    Czernichowski, A.; Czernichowski, M.; Wesolowska, K. [Etudes Chimiques et Physiques, La Ferte Saint Aubin (France)

    2003-07-01

    This paper elaborates on the use of a biogas reformer process based on the direct use of high-voltage discharges (also called GlidArc) which strike in the flow of renewable feedstock without requiring prior gas separation or purification. The paper describes the partial conversion of a poor biogas into hydrogen and carbon monoxide (syngas). The biogas contained only 35 to 50 volume per cent of methane. The reformer accepts any level of impurities. All the energy and catalytic assistance for endothermic process of dry reforming of methane plus carbon dioxide into hydrogen and carbon monoxide is provided by the discharges. A 1.4-litre reactor operating at atmospheric pressure was used to conduct the tests with simulated biogas, at up to 0.6 kilowatt. This input proved sufficient to process a flow of a poor biogas carrying up to 7 kilowatts of thermal power. 13 refs., 2 tabs., 3 figs.

  9. 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

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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

  15. 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)

  16. Computational Neutronics Methods and Transmutation Performance Analyses for Fast Reactors

    Energy Technology Data Exchange (ETDEWEB)

    R. Ferrer; M. Asgari; S. Bays; B. Forget

    2007-03-01

    The once-through fuel cycle strategy in the United States for the past six decades has resulted in an accumulation of Light Water Reactor (LWR) Spent Nuclear Fuel (SNF). This SNF contains considerable amounts of transuranic (TRU) elements that limit the volumetric capacity of the current planned repository strategy. A possible way of maximizing the volumetric utilization of the repository is to separate the TRU from the LWR SNF through a process such as UREX+1a, and convert it into fuel for a fast-spectrum Advanced Burner Reactor (ABR). The key advantage in this scenario is the assumption that recycling of TRU in the ABR (through pyroprocessing or some other approach), along with a low capture-to-fission probability in the fast reactor’s high-energy neutron spectrum, can effectively decrease the decay heat and toxicity of the waste being sent to the repository. The decay heat and toxicity reduction can thus minimize the need for multiple repositories. This report summarizes the work performed by the fuel cycle analysis group at the Idaho National Laboratory (INL) to establish the specific technical capability for performing fast reactor fuel cycle analysis and its application to a high-priority ABR concept. The high-priority ABR conceptual design selected is a metallic-fueled, 1000 MWth SuperPRISM (S-PRISM)-based ABR with a conversion ratio of 0.5. Results from the analysis showed excellent agreement with reference values. The independent model was subsequently used to study the effects of excluding curium from the transuranic (TRU) external feed coming from the LWR SNF and recycling the curium produced by the fast reactor itself through pyroprocessing. Current studies to be published this year focus on analyzing the effects of different separation strategies as well as heterogeneous TRU target systems.

  17. 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

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

    Science.gov (United States)

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

    2013-12-01

    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.

  19. 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

  20. Candidate materials performance under Supercritical Water Reactor (SCWR) conditions

    Energy Technology Data Exchange (ETDEWEB)

    Toivonen, A.; Penttilae, S.; Rissanen, L. (VTT Technical Research Centre of Finland, Espoo (Finland))

    2010-05-15

    The High Performance Light Water Reactor (HPLWR) is working at super-critical pressure (25 MPa) and a core coolant temperature up to 500 deg C. As an evolutionary step this reactor type follows the development path of modern supercritical coal-fired plants. This paper reviews the results on performance of commercial candidate materials for in-core applications focusing on corrosion, stress corrosion cracking (SCC) and creep issues. General corrosion (oxidation) tests with an inlet oxygen concentration of 125-150 ppb have been performed on several iron and nickel alloys at 300 to 650 deg C and 25 MPa in supercritical water. Stress corrosion cracking (SCC) susceptibility of selected austenitic stainless steels and a high chromium ODS (Oxide Dispersion Strengthened) alloy were also studied in slow strain rate tests (SSRT) in supercritical water at 500 deg C and 650 deg C. Furthermore, constant load creep tests have been performed on selected austenitic steels at 500 deg C and 650 deg C in supercritical water (25 MPa, 1 ppm O{sub 2}) and in an inert atmosphere (He, pressure 1 atm). Based on the materials studies, the current candidate materials for the core internals are austenitic steels with sufficient oxidation and creep resistance up to 500-550 deg C. High chromium austenitic steels and ODS alloys steels are considered for the fuel rod cladding due to their oxidation resistance up to 650 deg C. However, problems with manufacturing and joining of ODS alloys need to be solved. Alloys with high nickel content were not considered for the SCC or creep studies because of the strong effect of Ni on neutronics of the reactor core (orig.)

  1. Biogas Production from Citrus Waste by Membrane Bioreactor

    OpenAIRE

    Rachma Wikandari; Ria Millati; Muhammad Nur Cahyanto2); Taherzadeh, Mohammad J.

    2014-01-01

    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...

  2. 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.

  3. 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.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2010-08-01

    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 temperature zones was essential for optimal biochemical reactions, three finite element models, executed with ANSYS (v. 11.0, Canonsburg, PA), were used to characterize the thermal performance and guide system design: (1) a single device to determine the dimensions of the thermal management structures; (2) a single CFPCR device within an 8 mm × 8 mm area to evaluate the integrity of the thermostatic zones; and (3) a single, straight microchannel representing a single loop of the spiral CFPCR device, accounting for all of the heat transfer modes, to determine whether the PCR cocktail was exposed to the proper temperature cycling. In prior work on larger footprint devices, simple grooves between temperature zones provided sufficient thermal resistance between zones. For the small footprint reactor array, 0.4 mm wide and 1.2 mm high fins were necessary within the groove to cool the PCR cocktail efficiently, with a temperature gradient of 15.8°C/mm, as it flowed from the denaturation zone to the renaturation zone. With temperature tolerance bands of ±2°C defined about the nominal temperatures, more than 72.5% of the microchannel length was located within the desired temperature bands. The residence time of the PCR cocktail in each temperature zone decreased and the transition times between zones increased at higher PCR cocktail flow velocities, leading to less time for the amplification reactions. Experiments demonstrated the performance of the CFPCR devices as a function of flow

  6. Continuous biogas production from fodder beet silage as sole substrate

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, P.A.; Dobler, S.; Rohardt, S. [University of Applied Sciences, Hamburg (Germany). Research Centre of Environmental Bioengineering and Applied Biotechnology; Loock, R.; Buettner, B.; Noeldeke, P.; Brettschuh, A. [Loock Environmental Technologies, Hamburg (Germany)

    2003-07-01

    Since April 2000 a two-step anaerobic plant with two subsequent 500 m{sup 3} reactors has been producing biogas from fodder beet silage (pH 4.1) as the sole substrate. The plant is located at Kirchlengern near Bielefeld, Germany. Initially the reactors were inoculated with swine manure at 37{sup o}C. After a start-up phase the process was sustained at pH 7.5-8.0 by feeding with the silage as sole substrate twice a day. Parallel to the biogas plant at Kirchlengern four one-step laboratory reactors were continuously driven at temperatures of 37{sup o}C, 45{sup o}C, 60{sup o}C and 65{sup o}C. They were fed with the same silage, but only once per day (one impulse). The organic loading rate (OLR) was adjusted to 3.9 g volatile solids (VS)/(l*d) with a concomitant hydraulic retention time (HRT) of 27 d. There was no problem with starting the reactors, but after 86 days the volumetric gas production of the 65{sup o}C reactor ceased and a high amount of approximately 130 mM propionate could be determined. By decreasing the temperature down to 60{sup o}C a stable reactor performance was recovered for a period of at least 250 further days. During impulse feeding it was observed that the quickest recovery of gas production could be observed at 37{sup o}C or at 45{sup o}C. Recovery of 75% gas volume (related to the value before or after impulse feeding) was obtained after 5.5 and 7.5 h of feeding time point whereas the 60{sup o}C reactor needed 16 h. Slight significant differences were seen in the spectrum of volatile fatty acids (VFA) reaching at 37{sup o} or 45{sup o}C its maximum with 10-30 mM total VFA at 2-3 h after feeding. After this the VFA level declined to nearly zero (except for the 60{sup o}C reactor). Therefore the 37{sup o}C reactor was favoured. A double experiment with a second 37{sup o}C reactor was started by a somewhat different inoculation procedure from the remaining 3 reactors, but revealed similar results. By increasing the temperature no significantly

  7. Biogas Production Using Anaerobic Biodigester from Cassava Starch Effluent

    Directory of Open Access Journals (Sweden)

    S. Sunarso

    2010-12-01

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

  8. 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.

  9. 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.

  10. 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...... index, CO2 content and calorific value were found to be controllable by the H2/CO2 ratio fed the methanation reactor. An optimal H2/CO2 ratio of 3.45–3.7 was seen to result in a product gas with high calorific value and Wobbe index. The dynamic reactor simulation verified that the process start...

  11. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

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

  13. 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.

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

    NARCIS (Netherlands)

    RAY, AK

    1995-01-01

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

  15. 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

  16. 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.

  17. Biogas in agriculture. Proceedings; Biogas in der Landwirtschaft. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    The prospects of biogas are good, in spite of a change in boundary conditions (public funds available for biogas plants, reimbursement for biogas-derived electricity). Increasing professionalisation has resulted in higher-quality plants and more efficient technologies. Biogas, both from animal manure and from plant substrates, has become an interesting option for farmers. The conference addressed present and future owners of biogas plants, as well as producers, commercial enterprises, farmers, representatives of authorities, decision-makers and all those who are interested in biogas as an energy source.

  18. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-07-01

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

  20. 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.

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

    Science.gov (United States)

    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 distribution ratio of 80/20 and 90/10, and total HRT of 15 days. The results showed that the serial CSTR could obtain 11% higher biogas yield compared to the single CSTR. The increased biogas yield in the serial CSTR was mainly from the second reactor, which accounted for 16% and 12% of total biogas yield in the 90/10 and 80/20 configuration, respectively. VFA concentration in the serial CSTR was high in the first reactor but very low in the second reactor. The results from organic pulse load test showed that the second reactor in serial CSTR helped utilizing VFA produced from overloading in the first reactor, which improved the effluent quality and conversion efficiency of the serial CSTR.

  2. 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

  3. 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.

  4. 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)

  5. 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

  6. 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)

  7. Biogas 2009. Energy source for the future; Biogas 2009. Energietraeger der Zukunft

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    Within the BIOGAS meeting at 24th to 25th June, 2009 in Stuttgart (Federal Republic of Germany), the following lectures were held: (1) Framework conditions in the background the new European guideline for the promotion of renewable energies (D. Fouquet); (2) Experiences with the Renewable Energy Resources Act and its amendment in Germany (M. Maslaton); (3) From the harvest into the fermenter - influence of the storage on the yield of gas (D. Bannemann, M. Nelles); (4) What can the hydrolysis perform in the fermentation of bio gas? (H. Oechsber, A. Lemmer); (5) Evaluation of the weaknesses by means of an investigation of sixty fermentation plants in Germany (P. Weiland, B. Gemmeke); (6) Effective energy recovery from waste - Fermentation of biological waste - current development, technology and economic efficiency (T. Turk); (7) Methods of disintegration - Are effort and use in relation? (M. Mueller, J. Proeter); (8) Processing of bio gas in Europe - technologies and operational experiences (M. Beil, W. Hohmann); (9) Biomethane - Trade with regenerative energy (K. Huber); (10) Licensing and realisation of plants with biogas supply under consideration of grid access (L. Unterberg); (11) Latest results of the use of additives and adjuvants as well as trace elements in biogas plants (M. Bischoff); (12) Processing of residues of fermentation - technologies, markets and economic efficiency (U. Bruess); (13) Special challenges of the operation of biogas plants in industrial plants (C. Herbes); (14) Nitrogen in biogas plants - Part 1: Nutrient and inhibitor (C. Dornack); (15) Nitrogen in biogas plants - Part 2: Consequences of the process technical design and utilization of gas (G. Langhans); (16) desulphurization in biogas plants (A. Polster, J. Brummack); (17) Process values and measured quantities for the monitoring and control of biogas processes (J. Liebetrau, F. Scholwin); (18) Online process analysis with NIRS (H. Andree); (19) Inline microsensors for the evaluation

  8. 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)

  9. 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)

  10. 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

  11. 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

  12. 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

  13. 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.

  14. 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.)

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

    Science.gov (United States)

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

    2015-07-01

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

  16. 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.

  17. 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.

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

    Science.gov (United States)

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

    2014-02-01

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

  19. 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.

  20. 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

  1. 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.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  3. 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....

  4. 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.

  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. 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

  7. 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.

  8. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-08-01

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

  10. 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)

  11. 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

  12. Effect of Inhibitors on Biogas Laminar Burning Velocity and Flammability Limits in Spark Ignited Premix Combustion

    Directory of Open Access Journals (Sweden)

    Willyanto Anggono

    2014-01-01

    Full Text Available Biogas is the natural byproduct of the decomposition of vegetation or animal manure, of which there are almost in exhaustable supplies in the world, and which does not contribute CO2 or other greenhouse gases to global warming or climate change. Biogas contains 66.4% flammable gas (CH4 and 33.6% inhibitors (CO2 and N2. This study focuses on the effects of inhibitors on biogas laminar burning velocity and flammability limits in spark ignited premix combustion. Spherically expanding laminar premixed flames, freely propagating from spark ignition sources in initially quiescent biogas–air mixtures, are continuously recorded by a high-speed digital camera. Initially, all the experiments in this paper were performed using inhibitorless biogas (biogas without inhibitors at room temperature, at reduced pressure (0.5 atm and at various equivalence ratios (ϕ from the lower flammable limit to the upper flammable limit. The results are compared with those from biogas (containing inhibitors flames at reduced pressure, inhibitorless biogas flames at atmospheric pressure (1 atm, and biogas flames at atmospheric pressure to emphasize the effect of inhibitors on biogas laminar burning velocity and flammability limits. Compared to an inhibitorless biogas-air mixtures, in the biogas-air mixtures, the presence of inhibitors cause a reduction in the laminar burning velocity and the flammable limits become narrower.

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

    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

    was increased in the bioreactor with the jet mixing. The microbial activity would have contributed to the vigorous degradation of organic matter. VFAs were utilized by methanogens for biogas production, which were unable to accumulate during the anaerobic digestion process with the jet mixing, and thus the product inhibition or substrate inhibition was eliminated. The methanogens in the jet mixing bioreactor grew fast since the 10th day, and the peak value was 2.0×108mL-1. During fermentation process in the jet mixing bioreactor, the amount and the activity of hydrolytic bacteria, acetogenic bacteria and methanogens remained at a high level. Meanwhile, the methane content of the biogas increased drastically from about 20% to over 55% before the 10th day, and it ranged between 55% and 65% from the 10th to the 30th 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.%现有中温沼气工程的搅拌方式以机械搅拌和沼液回流搅拌为主,存在产气率低、设备难以维护、长期运行不稳定等问题。该研究设计了一种射流搅拌技术,集沼液回流搅拌和沼气搅拌于一体,试验用于牛粪中温厌氧发酵产沼气。通过沼气产率、营养基质消耗、微生物种类和数量的变化等方面分析射流搅拌强化牛粪中温厌氧发酵产气的效果及机理。结果表明:发酵期30 d内,无搅拌、机械

  14. Microalgal reactors: a review of enclosed system designs and performances.

    Science.gov (United States)

    Carvalho, Ana P; Meireles, Luís A; Malcata, F Xavier

    2006-01-01

    One major challenge to industrial microalgal culturing is to devise and develop technical apparata, cultivation procedures and algal strains susceptible of undergoing substantial increases in efficiency of use of solar energy and carbon dioxide. Despite several research efforts developed to date, there is no such thing as "the best reactor system"- defined, in an absolute fashion, as the one able to achieve maximum productivity with minimum operation costs, irrespective of the biological and chemical system at stake. In fact, choice of the most suitable system is situation-dependent, as both the species of alga available and the final purpose intended will play a role. The need of accurate control impairs use of open-system configurations, so current investigation has focused mostly on closed systems. In this review, several types of closed bioreactors described in the technical literature as able to support production of microalgae are comprehensively presented and duly discussed, using transport phenomenon and process engineering methodological approaches. The text is subdivided into subsections on: reactor design, which includes tubular reactors, flat plate reactors and fermenter-type reactors; and processing parameters, which include gaseous transfer, medium mixing and light requirements. PMID:17137294

  15. 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

  16. 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.)

  17. 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

  18. 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

  19. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Boe, K.; Angelidaki, I.

    2010-10-15

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

  1. 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...

  2. 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.

  3. Effect of substrate and cation requirement on anaerobic volatile fatty acid conversion rates at elevated biogas pressure

    NARCIS (Netherlands)

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

    2013-01-01

    This work studied the anaerobic conversion of neutralized volatile fatty acids (VFA) into biogas under Autogenerative High Pressure Digestion (AHPD) conditions. The effects of the operating conditions on the biogas quality, and the substrate utilisation rates were evaluated using 3 AHPD reactors (0.

  4. 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

  5. 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

  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. 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

  8. 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.

  9. 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)

  10. 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)

  11. 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...

  12. 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)

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. Effect of inoculum and sulfide type on simultaneous hydrogen sulfide removal from biogas and nitrogen removal from swine slurry and microbial mechanism.

    Science.gov (United States)

    Wang, Lan; Wei, Benping; Chen, Ziai; Deng, Liangwei; Song, Li; Wang, Shuang; Zheng, Dan; Liu, Yi; Pu, Xiaodong; Zhang, Yunhong

    2015-12-01

    Four reactors were initiated to study the effect of inoculum and sulfide type on the simultaneous hydrogen sulfide removal from biogas and nitrogen removal from swine slurry (Ssu-Nir) process. Anaerobic sludge, aerobic sludge, and water were used as inocula, and Na2S and biogas were used as a sulfide substrate, respectively. Additionally, 454 pyrosequencing of the 16S rRNA gene was used to explore the bacterial diversity. The results showed that sulfur-oxidizing bacteria (Thiobacillus, 42.2-84.4 %) were dominant in Ssu-Nir process and led to the excellent performance. Aerobic sludge was more suitable for inoculation of the Ssu-Nir process because it is better for rapidly enriching dominant sulfur-oxidizing bacteria (Thiobacillus, 54.4 %), denitrifying sulfur-oxidizing bacteria (40.0 %) and denitrifiers (23.9 %). Lower S(2-) removal efficiency (72.6 %) and NO3 (-) removal efficiency (biogas as a sulfide substrate than when Na2S was used. For the Ssu-Nir process with biogas as the sulfide substrate, limiting H2S absorption caused a high relative abundance of sulfur-oxidizing bacteria, Thiobacillus (84.8 %) and Thiobacillus sayanicus (39.6 %), which in turn led to low relative abundance of denitrifiers (1.6 %) and denitrifying sulfur-oxidizing bacteria (24.4 %), low NO3 (-) removal efficiency, and eventually poor performance.

  18. 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.

  19. 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

  20. 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)

  1. 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.

  2. 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)

  3. 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...

  4. 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.

  5. Continuous dry fermentation of swine manure for biogas production.

    Science.gov (United States)

    Chen, Chuang; Zheng, Dan; Liu, Gang-Jin; Deng, Liang-Wei; Long, Yan; Fan, Zhan-Hui

    2015-04-01

    A down plug-flow anaerobic reactor (DPAR) was designed for the feasibility study on continuous dry fermentation of swine manure without any additional stirring. Using fresh swine manure as the feedstock with TS concentration (w/w) of 20%, 25%, 30%, and 35%, stable volumetric biogas production rates of 2.40, 1.92, 0.911, and 0.644L · (Ld)(-1) and biogas yields of 0.665, 0.532, 0.252, and 0.178 L g(-)(1)VS were obtained respectively, and the TS degradation rates were 46.5%, 45.4%, 53.2%, and 55.6%, respectively. With the increase of feedstock TS concentration, the concentration of ammonia nitrogen grew up to the maximum value of 3500 mg L(-1). Biogas production was obviously inhibited when the concentration of ammonia nitrogen was above 3000 mg L(-1). The maximal volumetric biogas production rate of 2.34 L ·(Ld)(-1) and biogas yield of 0.649 L g(-1)VS were obtained with TS concentration of 25% at 25°C without inhibition. Liquidity experiments showed that TS concentration of digestate could be less than 15.8%, and the flow rate of digestate more than 0.98 m s(-1) when the feedstock TS concentration was less than 35%, which indicated the digestate could be easily discharged from a DPAR. Therefore, it is feasible to conduct a continuous dry fermentation in a DPAR using fresh swine manure as the feedstock with TS concentration less than 35%, whereas the feedstock TS concentration should not exceed 30% to achieve the maximal biogas production rate and biogas yield.

  6. Bioelectrochemical removal of carbon dioxide (CO2): an innovative method for biogas upgrading.

    Science.gov (United States)

    Xu, Heng; Wang, Kaijun; Holmes, Dawn E

    2014-12-01

    Innovative methods for biogas upgrading based on biological/in-situ concepts have started to arouse considerable interest. Bioelectrochemical removal of CO2 for biogas upgrading was proposed here and demonstrated in both batch and continuous experiments. The in-situ biogas upgrading system seemed to perform better than the ex-situ one, but CO2 content was kept below 10% in both systems. The in-situ system's performance was further enhanced under continuous operation. Hydrogenotrophic methanogenesis and alkali production with CO2 absorption could be major contributors to biogas upgrading. Molecular studies showed that all the biocathodes associated with biogas upgrading were dominated by sequences most similar to the same hydrogenotrophic methanogen species, Methanobacterium petrolearium (97-99% sequence identity). Conclusively, bioelectrochemical removal of CO2 showed great potential for biogas upgrading.

  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. 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.

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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.

  15. Augmented biogas production from protein-rich substrates and associated metagenomic changes.

    Science.gov (United States)

    Kovács, Etelka; Wirth, Roland; Maróti, Gergely; Bagi, Zoltán; Nagy, Katalin; Minárovits, János; Rákhely, Gábor; Kovács, Kornél L

    2015-02-01

    This study demonstrates that appropriate adaptation of the microbial community to protein-rich biomass can lead to sustainable biogas production. The process of acclimation to these unusual mono-substrates was controlled by the protease activity of the microbial community. Meat extract (C/N=3.32) and kitchen waste (C/N=12.43) were used as biogas substrates. Metagenome analysis highlighted several mesophilic strains that displayed a preference for protein degradation. Bacillus coagulans, Bacillus subtilis and Pseudomonas fluorescens were chosen for detailed investigation. Pure cultures were added to biogas reactors fed solely with protein-rich substrates. The bioaugmentation resulted in a 50% increase in CH4 production even without any acclimation. The survival and biological activity of the added bacteria were followed in fed-batch fermenters by qPCR. Stable biogas production was observed for an extended period of time in laboratory CSTR reactors fed with biomass of low C/N.

  16. 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.)

  17. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Iracane, Daniel; Bignan, Gilles [CEA Atomic Energy Commission Saclay Batiment 121- 91191 Gif Sur Yvette (France); Lindbaeck, Jan-Erik; Blomgren, Jan [VATTENFALL AB Nuclear Power Jaemtlandsgatan 99 SE-16287 Stockholm (Sweden)

    2010-07-01

    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

  19. 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 ...

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

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Lucie, E-mail: lucie.moeller@ufz.de [UFZ – Helmholtz Centre for Environmental Research, Centre for Environmental Biotechnology, Permoserstrasse 15, 04318 Leipzig (Germany); Eismann, Frank, E-mail: info@antoc.de [Eismann & Stöbe GbR, GeoPark, Geb. A12, Bautzner Strasse 67, 04347 Leipzig (Germany); Wißmann, Daniel, E-mail: d.s.wissmann@gmx.de [University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy (LA740), Garbenstrasse 9, 70599 Stuttgart (Germany); Nägele, Hans-Joachim, E-mail: hajo.naegele@uni-hohenheim.de [University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy (LA740), Garbenstrasse 9, 70599 Stuttgart (Germany); Zielonka, Simon, E-mail: simon.zielonka@uni-hohenheim.de [University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy (LA740), Garbenstrasse 9, 70599 Stuttgart (Germany); Müller, Roland A., E-mail: roland.mueller@ufz.de [UFZ – Helmholtz Centre for Environmental Research, Centre for Environmental Biotechnology, Permoserstrasse 15, 04318 Leipzig (Germany); Zehnsdorf, Andreas, E-mail: andreas.zehnsdorf@ufz.de [UFZ – Helmholtz Centre for Environmental Research, Centre for Environmental Biotechnology, Permoserstrasse 15, 04318 Leipzig (Germany)

    2015-07-15

    Graphical abstract: Display Omitted - Highlights: • Foaming in biogas plants depends on the interactions between substrate and digestate. • Foaming tests enable the evaluation of substrate foaming tendency in biogas plants. • Leipzig foam tester enables foaming tests of substrates prior to use. - Abstract: Excessive foaming in anaerobic digestion occurs at many biogas plants and can cause problems including plugged gas pipes. Unfortunately, the majority of biogas plant operators are unable to identify the causes of foaming in their biogas reactor. The occurrence of foaming is often related to the chemical composition of substrates fed to the reactor. The consistency of the digestate itself is also a crucial part of the foam formation process. Thus, no specific recommendations concerning substrates can be given in order to prevent foam formation in biogas plants. The safest way to avoid foaming is to test the foaming tendency of substrates on-site. A possible solution is offered by an innovative foaming test. With the help of this tool, biogas plant operators can evaluate the foaming disposition of new substrates prior to use in order to adjust the composition of substrate mixes.

  1. 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.

  2. Biogas production from solid pineapple waste

    Energy Technology Data Exchange (ETDEWEB)

    Tanticharoen, M.; Bhumiratana, S.; Tientanacom, S.; Pengsobha, L.

    1984-01-01

    Solid pineapple waste composed of shell and core was used as substrate in anaerobic fermentation producing CH4. The experiments were carried out using four 30-L vessels and no mixing, a 200-L plug-flow reactor, and a 5-cubic m stirred tank. Because of high acidity of the substrate, the loading rate is as low as 2.5 g dry solid added/L-day. The average gas yield is 0.3-0.5 L/g dry substrate. A pretreatment of wet solid with sludge effluent prior loading to the digester resulted in better stability of the biodigester than without pretreatment. These studies showed that loading rate can be much higher than those previously used. The 2-stage process was tested to determine a conversion efficiency of high loading and at much shorter reactor retention times. The results of the entire program indicated that biogas production from cannery pineapple waste is technically feasible.

  3. 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

  4. 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

  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.

  6. 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...

  7. Technological assumptions for biogas purification.

    Science.gov (United States)

    Makareviciene, Violeta; Sendzikiene, Egle

    2015-01-01

    Biogas can be used in the engines of transport vehicles and blended into natural gas networks, but it also requires the removal of carbon dioxide, hydrogen sulphide, and moisture. Biogas purification process flow diagrams have been developed for a process enabling the use of a dolomite suspension, as well as for solutions obtained by the filtration of the suspension, to obtain biogas free of hydrogen sulphide and with a carbon dioxide content that does not exceed 2%. The cost of biogas purification was evaluated on the basis of data on biogas production capacity and biogas production cost obtained from local water treatment facilities. It has been found that, with the use of dolomite suspension, the cost of biogas purification is approximately six times lower than that in the case of using a chemical sorbent such as monoethanolamine. The results showed travelling costs using biogas purified by dolomite suspension are nearly 1.5 time lower than travelling costs using gasoline and slightly lower than travelling costs using mineral diesel fuel.

  8. 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)

  9. 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)

  10. 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.

  11. 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

  12. 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 .

  13. 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

  14. 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.

  15. 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

  16. Biotechnological intensification of biogas production

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-08-15

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

  17. 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.)

  18. 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.)

  19. 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

  20. Nuclear performance of molten salt fusion--fission symbiotic systems for catalyzed DD and DT reactors

    International Nuclear Information System (INIS)

    The nuclear performance of a fusion-fission hybrid reactor having a molten salt composed of Na-Th-F-Be as the blanket fertile material and operating with a catalyzed DD plasma is compared to a similar system utilizing a Li-Th-F-Be salt and operating with a DT plasma. The production of fissile fuel via the 232Th-233U fuel cycle was considered on the basis of its potential nonproliferation aspects. The calculations were performed using one-dimensional discrete ordinates methods to compare neutron balances, fuel producion rates, energy deposition rates, and the radiation damage in the reactor structure

  1. Fuel performance models for high-temperature gas-cooled reactor core design

    International Nuclear Information System (INIS)

    Mechanistic fuel performance models are used in high-temperature gas-cooled reactor core design and licensing to predict failure and fission product release. Fuel particles manufactured with defective or missing SiC, IPyC, or fuel dispersion in the buffer fail at a level of less than 5 x 10-4 fraction. These failed particles primarily release metallic fission products because the OPyC remains intact on 90% of the particles and retains gaseous isotopes. The predicted failure of particles using performance models appears to be conservative relative to operating reactor experience

  2. The nitritation performance of biofilm reactor for treating domestic wastewater under high dissolved oxygen.

    Science.gov (United States)

    Zheng, Zhaoming; Li, Zebing; Ma, Jing; Du, Jia; Chen, Guanghui; Bian, Wei; Li, Jun; Zhao, Baihang

    2016-04-01

    The objective of this study was to investigate the nitritation performance in a biofilm reactor for treating domestic wastewater. The reactor was operated in continuous feed mode from phases 1 to 3. The dissolved oxygen (DO) was controlled at 3.5-7 mg/L throughout the experiment. The biofilm reactor showed excellent nitritation performance after the inoculation of nitrifying sludge, with the hydraulic retention time being reduced from 24 to 7 hr. Above 90% nitrite accumulation ratio (NAR) was maintained in phase 1. Afterwards, nitratation occurred with the low NH4(+)-N concentration in the reactor. The improvement of NH4(+)-N concentration to 20-35 mg/L had a limited effect on the recovery of nitritation. However, nitritation recovered rapidly when sequencing batch feed mode was adopted in phase 4, with the effluent NH4(+)-N concentration above 7 mg/L. The improvement of ammonia oxidizing bacteria (AOB) activity and the combined inhibition effect of free ammonia (FA) and free nitrous acid (FNA) on the nitrite oxidizing bacteria (NOB) were two key factors for the rapid recovery of nitritation. Sludge activity was obtained in batch tests. The results of batch tests had a good relationship with the long term operation performance of the biofilm reactor. PMID:27090719

  3. Commission of the European Communities: Review of fast reactor activities performed during 1991

    International Nuclear Information System (INIS)

    The Commission of the European Community continued its fast reactor activities on the same lines as in previous years, performing harmonisation and research activities. The Fast Reactor Coordinating Committee (FRCC) pursued the exchange of information and the discussions of specific problems, e.g. the influence of LMFBR design characteristics on decommissioning. These discussions were based on the results of a study performed under the CEC Decommissioning Programme. It was concluded that decommissioning of fast reactors, in spite of some specific problems, is not more difficult than that of thermal reactors. In December 1991 the Council of Ministers approved a Reactor Safety programme which will be performed as a concerted action. The programme is mainly centred on the confinement of radioactivity under severe accidents in thermal reactors, but the inclusion of some fast reactor safety aspects could be envisaged. The FRCC has asked the Safety Working Group (SWG) discussed possible topics. So far the development of the CONTAIN code for fast reactors was found most suitable. The group had regular reports on highlights from national research and development programmes and discussed various safety aspects, e.g. the safety options applied to EFR, the safety of metal fuelled or lead cooled fast reactors. The group supported the idea launched by the IWGFR to produce a safety R and D index jointly with IAEA, if all Non-Community countries having a fast reactor programme are participating. The WAC group continued the exchange of information on code developments for severe accident analysis in national laboratories and at the EC Joint Research Centre and discussed specific modelling aspects, e.g. early transition phase phenomena. The group also performed further comparative calculations. An initiative of the IPPE Institute at Obninsk (Russia) to perform comparative calculations for hypothetical accidents with laboratories in Western Europe was supported. The activities of

  4. 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)

  5. Ultrasound pretreatment for enhanced biogas production from olive mill wastewater.

    Science.gov (United States)

    Oz, Nilgun Ayman; Uzun, Alev Cagla

    2015-01-01

    This study investigates applicability of low frequency ultrasound technology to olive mill wastewaters (OMWs) as a pretreatment step prior to anaerobic batch reactors to improve biogas production and methane yield. OMWs originating from three phase processes are characterized with high organic content and complex nature. The treatment of the wastewater is problematic and alternative treatment options should be investigated. In the first part of the study, OMW samples were subjected to ultrasound at a frequency of 20kHz with applied powers varying between 50 and 100W under temperature controlled conditions for different time periods in order to determine the most effective sonication conditions. The level of organic matter solubilization at ultrasound experiments was assessed by calculating the ratio of soluble chemical oxygen demand/total chemical oxygen demand (SCOD/TCOD). The results revealed that the optimum ultrasonic condition for diluted OMW is 20kHz, 0.4W/mL for 10min. The application of ultrasound to OMW increased SCOD/TCOD ratio from 0.59 to 0.79. Statistical analysis (Friedman's tests) show that ultrasound was significantly effective on diluted OMW (p0.05). For raw OMW, this increase has been found to be limited due to high concentration of suspended solids (SS). In the second part of the study, biogas and methane production rates of anaerobic batch reactor fed with the ultrasound pretreated OMW samples were compared with the results of control reactor fed with untreated OMW in order to determine the effect of sonication. A nonparametric statistical procedure, Mann-Whitney U test, was used to compare biogas and methane production from anaerobic batch reactors for control and ultrasound pretreated samples. Results showed that application of low frequency ultrasound to OMW significantly improved both biogas and methane production in anaerobic batch reactor fed with the wastewater (pbiogas and methane compared with the untreated one (control reactor). The

  6. Safety System Design Concept and Performance Evaluation for a Long Operating Cycle Simplified Boiling Water Reactor

    International Nuclear Information System (INIS)

    The long operating cycle simplified boiling water reactor is a reactor concept that pursues both safety and the economy by employing a natural circulation reactor core without a refueling, a passive decay heat removal, and an integrated building for the reactor and turbine. Throughout the entire spectrum of the design basis accident, the reactor core is kept covered by the passive emergency core cooling system. The decay heat is removed by the conventional active low-pressure residual heat removal system. As for a postulated severe accident, the suppression pool water floods the lower part of the reactor pressure vessel (RPV) in the case when core damage occurs, and the in-vessel retention that keeps the melt inside the RPV is achieved by supplying the coolant. The containment adopts a parallel-double-steel-plate structure similar to a hull structure, which contains coolant between the inner and outer walls to absorb the heat transferred from the inside of the containment. Consequently, the containment structure functions as a passive containment cooling system (PCCS) to remove the decay heat in case of an accident. This paper describes the PCCS performance evaluation by using TRAC code to show one of the characteristic plant features. The core damage frequency for internal events was also evaluated to examine the safety level of the plant and to show the adequacy of the safety system design

  7. 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

  8. 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...

  9. Effects of cycle-frequency and temperature on the performance of anaerobic sequencing batch reactors (ASBRs) treating swine waste.

    Science.gov (United States)

    Ndegwa, P M; Hamilton, D W; Lalman, J A; Cumba, H J

    2008-04-01

    Anaerobic digestion of animal waste is a technically viable process for the abatement of adverse environmental impacts caused by animal wastes; however, widespread acceptance has been plagued by poor economics. This situation is dismal if the technology is adapted for treating low strength animal slurries because of large digester-volume requirements and a corresponding high energy input. A possible technology to address these constraints is the anaerobic sequencing batch reactor (ASBR). The ASBR technology has demonstrated remarkable potential to improve the economics of treating dilute animal waste effluents. This paper presents preliminary data on the effects of temperature and frequency-cycle on the operation of an ASBR at a fixed hydraulic retention time (HRT). The results suggest that within the parameter range under consideration, temperature did not affect the biogas yield significantly, however, higher cycle-frequency had a negative effect. The biogas quality (%CH(4)) was not significantly affected by temperature nor by the cycle-frequency. The operating principle of the ASBR follows four phases: feed, react, settle, and decant in a cyclic mode. To improve the biogas production in an ASBR, one long react-phase was preferable compared to three shorter react-phases. Treatment of dilute manure slurries in an ASBR at 20 degrees C was more effective than at 35 degrees C; similarly more bio-stable effluents were obtained at low cycle-frequency. The treatment of dilute swine slurries in an ASBR at the lower temperature (20 degrees C) and lower cycle-frequency is, therefore, recommended for the bio-stabilization of dilute swine wastewaters. The results also indicate that significantly higher VFA degradation occurred at 20 degrees C than at 35 degrees C, suggesting that the treatment of dilute swine slurries in ASBRs for odor control might be more favorable at the lower than at the higher temperatures examined in this study. Volatile fatty acid reduction at the two

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Performance and fuel cycle cost study of the R2 reactor with HEU and LEU fuels

    Energy Technology Data Exchange (ETDEWEB)

    Pond, R.B.; Freese, K.E.; Matos, J.E.

    1984-01-01

    A systematic study of the experiment performance and fuel cycle costs of the 50 MW R2 reactor operated by Studsvik Energiteknik AB has been performed using the current R2 HEU fuel, a variety of LEU fuel element designs, and two core-box/reflector configurations. The results include the relative performance of both in-core and ex-core experiments, control rod worths, and relative annual fuel cycle costs.

  15. Reviewing real-time performance of nuclear reactor safety systems

    Energy Technology Data Exchange (ETDEWEB)

    Preckshot, G.G. [Lawrence Livermore National Lab., CA (United States)

    1993-08-01

    The purpose of this paper is to recommend regulatory guidance for reviewers examining real-time performance of computer-based safety systems used in nuclear power plants. Three areas of guidance are covered in this report. The first area covers how to determine if, when, and what prototypes should be required of developers to make a convincing demonstration that specific problems have been solved or that performance goals have been met. The second area has recommendations for timing analyses that will prove that the real-time system will meet its safety-imposed deadlines. The third area has description of means for assessing expected or actual real-time performance before, during, and after development is completed. To ensure that the delivered real-time software product meets performance goals, the paper recommends certain types of code-execution and communications scheduling. Technical background is provided in the appendix on methods of timing analysis, scheduling real-time computations, prototyping, real-time software development approaches, modeling and measurement, and real-time operating systems.

  16. Reviewing real-time performance of nuclear reactor safety systems

    International Nuclear Information System (INIS)

    The purpose of this paper is to recommend regulatory guidance for reviewers examining real-time performance of computer-based safety systems used in nuclear power plants. Three areas of guidance are covered in this report. The first area covers how to determine if, when, and what prototypes should be required of developers to make a convincing demonstration that specific problems have been solved or that performance goals have been met. The second area has recommendations for timing analyses that will prove that the real-time system will meet its safety-imposed deadlines. The third area has description of means for assessing expected or actual real-time performance before, during, and after development is completed. To ensure that the delivered real-time software product meets performance goals, the paper recommends certain types of code-execution and communications scheduling. Technical background is provided in the appendix on methods of timing analysis, scheduling real-time computations, prototyping, real-time software development approaches, modeling and measurement, and real-time operating systems

  17. Trend analysis for light water reactor units performance

    International Nuclear Information System (INIS)

    Operational performances of LWR units have been analysed. The load factor has been used as the basic measurement in quantifying operational performances of LWR units. The whole operating history, in the sense of the annual and cumulative load factors achieved by all Western commercial PWR and BWR units until the end of 1984, has been taken into consideration. Through the regression analyses some contributing factors (the unit size, vintage and age) have been found that interacting with each other correlate with nuclear power performance. Accordingly some trends in the operational performance of LWR plants have been identified. Furthermore, the annual load factors of duplicate units have been compared with those of their predecessors at the same nuclear power site. The load factors of LWR units supplied by some contractors and/or located in certain countries deviate clearly and regularly from general load factor averages. The U.S. units and the units supplied by U.S. contractors to other countries are especially influential on load factor averages of LWR units. Some estimates for future load factors have been made based only on the load factor trends established by PWR and BWR units up to date

  18. 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...

  19. 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...

  20. 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.

  1. 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)

  2. XSBench. The development and verification of a performance abstraction for Monte Carlo reactor analysis

    International Nuclear Information System (INIS)

    We isolate the most computationally expensive steps of a robust nuclear reactor core Monte Carlo particle transport simulation. The hot kernel is then abstracted into a simplified proxy application, designed to mimic the key performance characteristics of the full application. A series of performance verification tests and analyses are carried out to investigate the low-level performance parameters of both the simplified kernel and the full application. The kernel's performance profile is found to closely match that of the application, making it a convenient test bed for performance analyses on cutting edge platforms and experimental next-generation high performance computing architectures. (author)

  3. GAS TURBINE ENGINES CONSUMING BIOGAS

    Directory of Open Access Journals (Sweden)

    Е. Ясиніцький

    2011-04-01

    Full Text Available A problem of implementation of biofuel for power plants of big capacity was considered in thisarticle. Up to date in the world practice a wide implementation of biogas plants of low and medialcapacity are integrated. It is explained by the big amount of enterprises in which relatively smallvolumes of organic sediment excrete in the process of its activity. An emphasis of article is on thatenterprises, which have big volumes of sediments for utilizing of which module system of medialcapacity biogas plants are non-effective. The possibility of using biogas and biomethane as a fuelfor gas turbine engine is described. The basic problems of this technology and ways of its solutionsare indicated. Approximate profitability of biogas due to example of compressor station locatednearby poultry factory was determined also. Such factors as process characteristics of engine withcapacity of 5 MW, approximate commercial price for natural gas and equipment costs due toofficial sources of “Zorg Ukraine” company was taken into consideration. The necessity forproviding researches on influence of biogas on the process characteristics of gas turbine engine andits reliability, constructing modern domestic purification system for biogas was shown.

  4. 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

  5. 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。

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

    Science.gov (United States)

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

    2015-08-01

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

  7. Zircaloy-4 corrosion performance in modern pressurized water reactors

    International Nuclear Information System (INIS)

    Westinghouse has recently completed an extensive evaluation of contemporary post-irradiation data related to Zircaloy-4 corrosion performance. In addition, all PWR fuel fabricators have noted accelerated corrosion in Zircaloy-4 materials. As a result, Westinghouse has updated its Zircaloy-4 design corrosion model to reflect the new post-irradiation data. The Westinghouse design corrosion model is based on over 2,800 data points of Zircaloy corrosion encompassing a wide range of PWR fuel operating conditions. These evaluations range from annual to 18-month fuel cycles with rod average burnups up to 62 GWD/MTU, fuel thermal duty ranging from light to very aggressive and coolant Li/B strategies including coordinated pH 6.9, modified 2.2ppm Li to pH 7.2 and 7.4 and 'elevated' 3.35ppm Li to pH of 7.2 and 7.4. The most recent data has been primarily from 18-month cycles at high burnup with aggressive duty. It was this data set that prompted the revision of the Westinghouse design corrosion model. The Korea PWRs encompass the entire range of fuel duty from a corrosion perspective and this paper attempts to present a ranking of the Korean PWRs. This ranking will compare the Korean PWR fuel corrosion duty, in a relative sense, to the range of PWR fuel conditions throughout the world. Westinghouse will also present Korean-PWR specific fuel corrosion evaluations for 18-month fuel cycles representative of anticipated cycles. These evaluations will be presented assuming both low-tin Zircaloy-4 and the Westinghouse advanced alloy, ZIRLOTM. The comparison of Zircaloy-4 and ZIRLOTM corrosion performance will illustrate the improvements made by Westinghouse in the development of advanced zirconium alloys for PWR applications. (author)

  8. Analytical model for performance verification of liquid poison injection system of a nuclear reactor

    International Nuclear Information System (INIS)

    Highlights: • One-dimensional modelling of shut down system-2. • Semi-empirical correlation poison jet progression. • Validation of code. - Abstract: Shut down system-2 (SDS-2) in advanced vertical pressure tube type reactor, provides rapid reactor shutdown by high pressure injection of a neutron absorbing liquid called poison, into the moderator in the calandria. Poison inside the calandria is distributed by poison jets issued from holes provided in the injection tubes. Effectiveness of the system depends on the rate and spread of the poison in the moderator. In this study, a transient one-dimensional (1D) hydraulic code, COPJET is developed, to predict the performance of system by predicting progression of poison jet with time. Validation of the COPJET is done with the data available in literature. Thereafter, it is applied for advanced vertical pressure type reactor

  9. Trickle bed reactor model to simulate the performance of commercial diesel hydrotreating unit

    Energy Technology Data Exchange (ETDEWEB)

    C. Murali; R.K. Voolapalli; N. Ravichander; D.T. Gokak; N.V. Choudary [Bharat Petroleum Corporation Ltd., Udyog Kendra (India). Corporate R& amp; D Centre

    2007-05-15

    A two phase mathematical model was developed to simulate the performance of bench scale and commercial hydrotreating reactors. Major hydrotreating reactions, namely, hydrodesulphurization, hydrodearomatization and olefins saturation were modeled. Experiments were carried out in a fixed bed reactor to study the effect of different process variables and these results were used for estimating kinetic parameters. Significant amount of feed vaporization (20-50%) was estimated under normal operating conditions of DHDS suggesting the importance of considering feed vaporization in DHDS modeling. The model was validated with plant operating data, under close to ultra low sulphur levels by correctly accounting for feed vaporization in heat balance relations and appropriate use of hydrodynamic correlations. The model could predict the product quality, reactor bed temperature profiles and chemical hydrogen consumption in commercial plant adequately. 14 refs., 7 figs., 6 tabs.

  10. Subchannel Analysis for enhancing the fuel performance in CANDU reactor

    International Nuclear Information System (INIS)

    The effect of the fuel rod geometry in a fuel bundle using the subchannel code ASSERT has been evaluated to design the fuel bundle having the advanced fuel performance. Based on the configuration of standard 37-element fuel bundle, the element diameter of fuel rods in each ring has been changed while that of fuel rods in other rings is kept as the original size. The dryout power of each element in a fuel bundle has been obtained for the modified fuel bundle and compared with that of a standard fuel bundle. From the calculated mixture enthalpy and void fraction of each subchannel, it was found that the modification of element diameter largely affects to the thermal characteristics of the subchannel on the upper region of a modified element by the buoyancy drift effect. The optimized geometry in a fuel bundle has been suggested from the consideration of the change of void reactivity as well as the dryout power of a bundle. The dependency of the transverse interchange model on the present results has been checked by examining the dryout power of a bundle for the different mixing coefficient and buoyancy drift model

  11. [Effects of the size of magnetic particles of immobilized enzyme reactors on the digestion performance].

    Science.gov (United States)

    Zhang, Jiao; Zhou, Lianqi; Tian, Fang; Zhang, Yangjun; Qian, Xiaohong

    2013-02-01

    We applied immobilized enzyme reactors prepared with different sizes of magnetic particles into protein and proteome digestion. In addition, the influences of different sizes of the magnetic particles were studied on the reunion, enzyme efficiency and leakage sites. The experimental results showed that in comparison with the submicron magnetic particles, the amount of trypsin immobilized on the magnetic nanoparticles was 3. 5 times more than that of the submicron magnetic particles. However, the enzymatic efficiency was at the same level when the same amount of trypsin was used, and the reunion phenomenon was obviously improved when the size of the magnetic nanoparticles increased. Taking the immobilized enzyme reactor of 20 nm magnetic nanoparticles as an example, the digestion performance was further examined. The experimental results showed that rapid digestion could be achieved within 1 mm when the mass ratio of the trypsin and bovine serum albumin was 1:1. The peptide number of 0 missed cleavage site and the sequence coverage changed little after the protein was digested for 10 mm. It was concluded that the digestion efficiency of the immobilized enzyme reactor was much better than that of the in-solution digestion. When the immobilized enzyme reactors and the free trypsin were used for digestion, little differences of the leakage sites were found. Therefore, the immobilized enzyme reactors prepared with different sizes of magnetic particles can be applied in proteomic research for quick and efficient digestion.

  12. 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.

  13. 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.)

  14. Performance of static var compensator control type thyristor controlled reactor and thyristor switched capacitor

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Josias M. de; Yung, Chou Shaw; Rose, Eber H.; Pantoja, Antonio L.A. [ELETRONORTE, Belem, PA (Brazil); Fouesnant, Thomas; Boissier, Luc

    1994-12-31

    This paper has the objective of presenting the philosophy of Static Var Compensator (SVC) Control as well the necessary adjustments in the project of control system to guarantee suitable performance under different operating conditions. The verification on the performance of the SVC control has been done by Transient Network Analyzer (TNA/CEPEL) studies, commissioning tests and a factory tests. The SVC is the type of Thyristor Controlled Reactor (TCR) and Thyristor Switched Capacitor (TSC). (author) 3 refs., 12 figs.

  15. 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.

  16. Size effect of anaerobic granular sludge on biogas production: A micro scale study.

    Science.gov (United States)

    Wu, Jing; Afridi, Zohaib Ur Rehman; Cao, Zhi Ping; Zhang, Zhong Liang; Poncin, Souhila; Li, Huai Zhi; Zuo, Jian E; Wang, Kai Jun

    2016-02-01

    This study investigated the influence of anaerobic granular sludge size on its bioactivity at COD concentration of 1000, 3000 and 6000 mg/L. Based on size, granules were categorized as large (3-3.5 mm), medium (1.5-2 mm) and small (0.5-1 mm). A positive relationship was obtained between granule size and biogas production rate. For instance, at COD 6000 mg/L, large granules had highest biogas production rate of 0.031 m(3)/kgVSS/d while medium and small granules had 0.016 and 0.006 m(3)/kgVSS/d respectively. The results were reaffirmed by applying modified Fick's law of diffusion. Diffusion rates of substrate for large, medium and small granules were 1.67×10(-3), 6.1×10(-4)and 1.8×10(-4) mg/s respectively at that COD. Large granules were highly bio-active due to their internal structure, i.e. big pore size, high porosity and short diffusion distance as compared to medium and small granules, thus large granules could improve the performance of reactor. PMID:26708484

  17. Stable isotope composition of biogas allows early warning of complete process failure as a result of ammonia inhibition in anaerobic digesters.

    Science.gov (United States)

    Lv, Zuopeng; Hu, Meng; Harms, Hauke; Richnow, Hans Hermann; Liebetrau, Jan; Nikolausz, Marcell

    2014-09-01

    Four 15-L lab-scale continuous stirred tank reactors were operated under mesophilic conditions to investigate the effect of ammonia inhibition. Stable isotope fingerprinting of biogas was applied as a process monitoring tool. Ammonia inhibition was initiated by amendment of chicken manure to maize silage fed reactors. During the accumulation of ammonia, the concentration of volatile fatty acids increased while the biogas production and pH decreased. However, in one reactor, an inhibited steady state with stable gas production even at high ammonia levels was achieved, while the other reactor proceeded to complete process failure. A depletion of the δ(13)CH4 and δ(13)CO2 values preceded the process inhibition. Moreover, the stable isotope composition of biogas also forecasted the complete process failure earlier than other standard parameters. The stable isotope analyses of biogas have a potential for mechanistic insights in anaerobic processes, and may be used to pre-warn process failure under stress conditions.

  18. Slaughterhouse fatty waste saponification to increase biogas yield.

    Science.gov (United States)

    Battimelli, A; Torrijos, M; Moletta, R; Delgenès, J P

    2010-05-01

    A thermochemical pretreatment, i.e. saponification, was optimised in order to improve anaerobic biodegradation of slaughterhouse wastes such as aeroflotation grease and flesh fats from cattle carcass. Anaerobic digestion of raw wastes, as well as of wastes saponified at different temperatures (60 degrees C, 120 degrees C and 150 degrees C) was conducted in fed-batch reactors under mesophilic condition and the effect of different saponification temperatures on anaerobic biodegradation and on the long-chain fatty acids (LCFAs) relative composition was assessed. Even after increasing loads over a long period of time, raw fatty wastes were biodegraded slowly and the biogas potentials were lower than those of theoretical estimations. In contrast, pretreated wastes exhibited improved batch biodegradation, indicating a better initial bio-availability, particularly obvious for carcass wastes. However, LCFA relative composition was not significantly altered by the pretreatment. Consequently, the enhanced biodegradation should be attributed to an increased initial bio-availability of fatty wastes without any modification of their long chain structure which remained slowly biodegradable. Finally, saponification at 120 degrees C achieved best performances during anaerobic digestion of slaughterhouse wastes.

  19. Irradiation performance of AGR-1 high temperature reactor fuel

    Energy Technology Data Exchange (ETDEWEB)

    Paul A. Demkowicz; John D. Hunn; Robert N. Morris; Charles A. Baldwin; Philip L. Winston; Jason M. Harp; Scott A. Ploger; Tyler Gerczak; Isabella J. van Rooyen; Fred C. Montgomery; Chinthaka M. Silva

    2014-10-01

    The AGR-1 experiment contained 72 low-enriched uranium oxide/uranium carbide TRISO-coated particle fuel compacts in six capsules irradiated to burnups of 11.2 to 19.5% FIMA, with zero TRISO coating failures detected during the irradiation. The irradiation performance of the fuel–including the extent of fission product release and the evolution of kernel and coating microstructures–was evaluated based on detailed examination of the irradiation capsules, the fuel compacts, and individual particles. Fractional release of 110mAg from the fuel compacts was often significant, with capsule-average values ranging from 0.01 to 0.38. Analysis of silver release from individual compacts indicated that it was primarily dependent on fuel temperature history. Europium and strontium were released in small amounts through intact coatings, but were found to be significantly retained in the outer pyrocrabon and compact matrix. The capsule-average fractional release from the compacts was 1×10 4 to 5×10 4 for 154Eu and 8×10 7 to 3×10 5 for 90Sr. The average 134Cs release from compacts was <3×10 6 when all particles maintained intact SiC. An estimated four particles out of 2.98×105 experienced partial cesium release due to SiC failure during the irradiation, driving 134Cs release in two capsules to approximately 10 5. Identification and characterization of these particles has provided unprecedented insight into the nature and causes of SiC coating failure in high-quality TRISO fuel. In general, changes in coating morphology were found to be dominated by the behavior of the buffer and inner pyrolytic carbon (IPyC), and infrequently observed SiC layer damage was usually related to cracks in the IPyC. Palladium attack of the SiC layer was relatively minor, except for the particles that released cesium during irradiation, where SiC corrosion was found adjacent to IPyC cracks. Palladium, silver, and uranium were found in the SiC layer of irradiated particles, and characterization

  20. 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.

  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. 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.

  3. Biogas production from citrus waste by membrane bioreactor.

    Science.gov (United States)

    Wikandari, Rachma; Millati, Ria; Cahyanto, Muhammad Nur; Taherzadeh, Mohammad J

    2014-01-01

    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. PMID:25167328

  4. 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.)

  5. A bio-electrochemical system for removing inhibitors of anaerobic digestion processes from anaerobic reactors

    DEFF Research Database (Denmark)

    2014-01-01

    reactor to recover ammonia from anaerobic digestion reactor, and thereby alleviate or counteract ammonia inhibition and enhance the conversion of ammonia-rich wastes to biogas. The invention may further reduce overall cost, giving synergistic advantages for both ammonia recycling and biogas plants...

  6. Performance of low smeared density sodium-cooled fast reactor metal fuel

    Science.gov (United States)

    Porter, D. L.; Chichester, H. J. M.; Medvedev, P. G.; Hayes, S. L.; Teague, M. C.

    2015-10-01

    An experiment was performed in the Experimental Breeder Rector-II (EBR-II) in the 1990s to show that metallic fast reactor fuel could be used in reactors with a single, once-through core. To prove the long duration, high burnup, high neutron exposure capability an experiment where the fuel pin was designed with a very large fission gas plenum and very low fuel smeared density (SD). The experiment, X496, operated to only 8.3 at.% burnup because the EBR-II reactor was scheduled for shut-down at that time. Many of the examinations of the fuel pins only funded recently with the resurgence of reactor designs using very high-burnup fuel. The results showed that, despite the low smeared density of 59% the fuel swelled radially to contact the cladding, fission gas release appeared to be slightly higher than demonstrated in conventional 75%SD fuel tests and axial growth was about the same as 75% SD fuel. There were axial positions in some of the fuel pins which showed evidence of fuel restructuring and an absence of fission products with low melting points and gaseous precursors (Cs and Rb). A model to investigate whether these areas may have overheated due to a loss of bond sodium indicates that it is a possible explanation for the fuel restructuring and something to be considered for fuel performance modeling of low SD fuel.

  7. Design of the material performance test apparatus for high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Most materials can be easily corroded or ineffective in carbonaceous atmospheres at high temperatures in the reactor core of the high temperature gas-cooled reactor (HTGR). To solve the problem, a material performance test apparatus was built to provide reliable materials and technical support for relevant experiments of the HTGR. The apparatus uses a center high-purity graphite heater and surrounding thermal insulating layers made of carbon fiber felt to form a strong carbon reducing atmosphere inside the apparatus. Specially designed tungsten rhenium thermocouples which can endure high temperatures in carbonaceous atmospheres are used to control the temperature field. A typical experimental process was analyzed in the paper, which lasted 76 hours including seven stages. Experimental results showed the test apparatus could completely simulate the carbon reduction atmosphere and high temperature environment the same as that confronted in the real reactor and the performance of screened materials had been successfully tested and verified. Test temperature in the apparatus could be elevated up to 1600℃, which covered the whole temperature range of the normal operation and accident condition of HTGR and could fully meet the test requirements of materials used in the reactor. (authors)

  8. Improvement of Membrane Performances to Enhance the Yield of Vanillin in a Pervaporation Reactor

    Directory of Open Access Journals (Sweden)

    Giovanni Camera-Roda

    2014-02-01

    Full Text Available In membrane reactors, the interaction of reaction and membrane separation can be exploited to achieve a “process intensification”, a key objective of sustainable development. In the present work, the properties that the membrane must have to obtain this result in a pervaporation reactor are analyzed and discussed. Then, the methods to enhance these properties are investigated for the photocatalytic synthesis of vanillin, which represents a case where the recovery from the reactor of vanillin by means of pervaporation while it is produced allows a substantial improvement of the yield, since its further oxidation is thus prevented. To this end, the phenomena that control the permeation of both vanillin and the reactant (ferulic acid are analyzed, since they ultimately affect the performances of the membrane reactor. The results show that diffusion of the aromatic compounds takes place in the presence of low concentration gradients, so that the process is controlled by other phenomena, in particular by the equilibrium with the vapor at the membrane-permeate interface. On this basis, it is demonstrated that the performances are enhanced by increasing the membrane thickness and/or the temperature, whereas the pH begins to limit the process only at values higher than 6.5.

  9. PREDICTION OF COMBUSTION CHARACTERISTICS OF A TYPICAL BIOGAS BURNER USING CFD

    Directory of Open Access Journals (Sweden)

    K. MADHUSOODAN PILLAI

    2012-07-01

    Full Text Available Biogas is obtained from anaerobic digestion of biodegradable materials such as agricultural waste, animal waste, and othertype of household solid waste and its main constituents are CH4 and CO2. Effects of the concentration of each species are very important in the biogas combustion. The present study focuses on the effect of inlet velocities of methane and air on the flame temperature in a biogas burner lamp. The model of biogas burner lamp is constructed by using the CFD software GAMBIT and the simulation process was performed by using Fluent Software. The flame temperature obtained is 2172 k when the inlet velocities of methane and air are 0.2m/s and 0.8 m/s respectively. Results of this study will provide valuable data for biogas burner lamp manufacturers.

  10. Anaerobic fermentation of biogas liquid pretreated maize straw by rumen microorganisms in vitro.

    Science.gov (United States)

    Jin, Wenyao; Xu, Xiaochen; Gao, Yang; Yang, Fenglin; Wang, Gang

    2014-02-01

    This study intended to investigate the effect of pretreatment of maize straw with biogas liquid on followed fermentation by rumen microorganisms in vitro. The multiple effects including treated time, temperature and dosage of biogas liquid in pretreatment on the followed fermentation performance were analyzed by orthogonal array. The optimum conditions of pretreatment were 9days, 25°C and 50% (v/w) dosage of biogas liquid, which were indicated by the corresponding crystallinity index, dry matter digestibility (DMD) and acetate limiting-step concentration were 57.5%, 73.76% and 1756mg/L, respectively. The ordering sequence of the influential factors for pretreatment was treated time > temperature > dosage of biogas liquid. The results of fermentation showed that the maize straw pretreated by biogas liquid was an efficient and economic pretreatment method of maize straw.

  11. Physicochemical and Microbial Caracteristics Performency in Wastewater Treated Under Aerobic Reactor

    Directory of Open Access Journals (Sweden)

    Asma B. Rajeb

    2011-01-01

    Full Text Available Problem statement: The current work study the efficiency of biological wastewater treatment by an aerobic reactor which could be used in small agglomerations. RBC reduced physicochemical and microbiological load of wastewater but values remain above Tunisian standard. Approach: Experiments were conducted on a sand filled PVC column fed with wastewater treated by Rotating Biological Contactor (RBC at a pulsed rhythm of 8 sequences per day. For performances study process, physicochemical and bacterial analyses effluent at inlet and outlet of column were realized. Results: The results showed that through filter mass (D10 = 0.55 mm, D60 = 1.3 mm and coefficient uniformity = 2.36 96% of suspended solids, 99% of NH4 +-N (during first phase, 92% of COD, 91% of BOD5 and 46% of phosphorus are retained by surface filtration. The microbial abatement results is E. coli. The microbial water quality is slightly higher than Tunisian standards. The removal of microbial indicators in the considered reactor depends on the depth of the filter and negatively correlated with NO3 --N (r = -0.99, with E. coli at 3rd OPD. Conclusion/Recommendation: Results confirmed that the reactor tested is performed as an advanced treatment system for DBO, COD, SS, NH4 +-N and NO3 --N. Despite that 96% of SS efficiency reduction, clogging is not achieved quickly that due to biofilm detachment phenomena. The removal of microbial indicators in the considered reactor depends on the depth of the filter and negatively correlated with NO3 --N. Disinfection performances for the considered reactor reduce microbial load, however chlore, ozone or UV disinfection should be considered.

  12. 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.

  13. 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.

  14. 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)

  15. 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.

  16. 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

  17. The Denitrifying Biological Phosphorus Removal Performance in Anaerobic/Anoxic Sequencing Batch Reactor: The Effect of Carbon Source

    OpenAIRE

    Gürtekin, Engin; Nusret ŞEKERDAĞ

    2015-01-01

    In this study, the effect of carbon source on denitrifying biological phosphorus removal performance in acetate and glucose fed two anaerobic/anoxic sequencinq batch reactor (SBR) was investigated. Glucose and acetate were used as the substrates. In acetate and glucose fed reactors, the COD (Chemical Oxygen Demand) removal efficiencies were 91,90% and PO4-P removal efficiencies were 87,51% respectively. These results shows that the phosphorus removal efficiency is lower in glucose fed reactor.

  18. Analysis of bacterial communities and bacterial pathogens in a biogas plant by the combination of ethidium monoazide, PCR and Ion Torrent sequencing

    DEFF Research Database (Denmark)

    Luo, Gang; Angelidaki, Irini

    2014-01-01

    The present study investigated the changes of bacterial community composition including bacterial pathogens along a biogas plant, i.e. from the influent, to the biogas reactor and to the post-digester. The effects of post-digestion temperature and time on the changes of bacterial community...... with time were also observed. This could be attributed to varying composition of the influent. Batch experiments showed that the methane recovery from the digested residues (obtained from biogas reactor) was mainly related with post-digestion temperature. However, post-digestion time rather than temperature...

  19. Comparative performance of fixed-film biological filters: Application of reactor theory

    Science.gov (United States)

    Watten, B.J.; Sibrell, P.L.

    2006-01-01

    Nitrification is classified as a two-step consecutive reaction where R1 represents the rate of formation of the intermediate product NO2-N and R2 represents the rate of formation of the final product NO3-N. The relative rates of R1 and R2 are influenced by reactor type characterized hydraulically as plug-flow, plug-flow with dispersion and mixed-flow. We develop substrate conversion models for fixed-film biofilters operating in the first-order kinetic regime based on application of chemical reactor theory. Reactor type, inlet conditions and the biofilm kinetic constants Ki (h-1) are used to predict changes in NH4-N, NO2-N, NO3-N and BOD5. The inhibiting effects of the latter on R1 and R2 were established based on the ?? relation, e.g.:{A formula is presented}where BOD5,max is the concentration that causes nitrification to cease and N is a variable relating Ki to increasing BOD5. Conversion models were incorporated in spreadsheet programs that provided steady-state concentrations of nitrogen and BOD5 at several points in a recirculating aquaculture system operating with input values for fish feed rate, reactor volume, microscreen performance, make-up and recirculating flow rates. When rate constants are standardized, spreadsheet use demonstrates plug-flow reactors provide higher rates of R1 and R2 than mixed-flow reactors thereby reducing volume requirements for target concentrations of NH4-N and NO2-N. The benefit provided by the plug-flow reactor varies with hydraulic residence time t as well as the effective vessel dispersion number, D/??L. Both reactor types are capable of providing net increases in NO2-N during treatment but the rate of decrease in the mixed-flow case falls well behind that predicted for plug-flow operation. We show the potential for a positive net change in NO2-N increases with decreases in the dimensionless ratios K2, (R2 )/K1,( R1 ) and [NO2-N]/[NH4-N] and when the product K1, (R1) t provides low to moderate NH4-N conversions. Maintaining

  20. Proceedings of the Water Reactor Fuel Performance Meeting - WRFPM / Top Fuel 2009

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-06-15

    SFEN, ENS, SNR, ANS, AESJ, CNS KNS, IAEA and NEA are jointly organizing the 2009 International Water Reactor Fuel Performance / TopFuel 2009 Meeting following the 2008 KNS Water Reactor Performance Meeting held during October 19-23, 2008 in Seoul, Korea. This meeting is held annually on a tri-annual rotational basis in Europe, USA and Asia. In 2009, this meeting will be held in Paris, September 6-10, 2009 in coordination with the Global 2009 Conference at the same date and place. That would lead to a common opening session, some common technical presentations, a common exhibition and common social events. The technical scope of the meeting includes all aspects of nuclear fuel from fuel rod to core design as well as manufacturing, performance in commercial and test reactors or on-going and future developments and trends. Emphasis will be placed on fuel reliability in the general context of nuclear 'Renaissance' and recycling perspective. The meeting includes selectively front and/or back end issues that impact fuel designs and performance. In this frame, the conference track devoted to 'Concepts for transportation and interim storage of spent fuels and conditioned waste' will be shared with 'GLOBAL' conference. Technical Tracks: - 1. Fuel Performance, Reliability and Operational Experience: Fuel operating experience and performance; experience with high burn-up fuels; water side corrosion; stress corrosion cracking; MOX fuel performance; post irradiation data on lead fuel assemblies; radiation effects; water chemistry and corrosion counter-measures. - 2. Transient Fuel Behaviour and Safety Related Issues: Transient fuel behavior and criteria (RIA, LOCA, ATWS, Ramp tests..). Fuel safety-related issues such as PCI (pellet cladding interaction), transient fission gas releases and cladding bursting/ballooning during transient events - Advances in fuel performance modeling and core reload methodology, small and large-scale fuel testing

  1. Proceedings of the Water Reactor Fuel Performance Meeting - WRFPM / Top Fuel 2009

    International Nuclear Information System (INIS)

    SFEN, ENS, SNR, ANS, AESJ, CNS KNS, IAEA and NEA are jointly organizing the 2009 International Water Reactor Fuel Performance / TopFuel 2009 Meeting following the 2008 KNS Water Reactor Performance Meeting held during October 19-23, 2008 in Seoul, Korea. This meeting is held annually on a tri-annual rotational basis in Europe, USA and Asia. In 2009, this meeting will be held in Paris, September 6-10, 2009 in coordination with the Global 2009 Conference at the same date and place. That would lead to a common opening session, some common technical presentations, a common exhibition and common social events. The technical scope of the meeting includes all aspects of nuclear fuel from fuel rod to core design as well as manufacturing, performance in commercial and test reactors or on-going and future developments and trends. Emphasis will be placed on fuel reliability in the general context of nuclear 'Renaissance' and recycling perspective. The meeting includes selectively front and/or back end issues that impact fuel designs and performance. In this frame, the conference track devoted to 'Concepts for transportation and interim storage of spent fuels and conditioned waste' will be shared with 'GLOBAL' conference. Technical Tracks: - 1. Fuel Performance, Reliability and Operational Experience: Fuel operating experience and performance; experience with high burn-up fuels; water side corrosion; stress corrosion cracking; MOX fuel performance; post irradiation data on lead fuel assemblies; radiation effects; water chemistry and corrosion counter-measures. - 2. Transient Fuel Behaviour and Safety Related Issues: Transient fuel behavior and criteria (RIA, LOCA, ATWS, Ramp tests..). Fuel safety-related issues such as PCI (pellet cladding interaction), transient fission gas releases and cladding bursting/ballooning during transient events - Advances in fuel performance modeling and core reload methodology, small and large-scale fuel testing facilities. - 3. Advances in Water

  2. The scaling of economic and performance parameters of DT and advanced fuel fusion reactors

    International Nuclear Information System (INIS)

    In this study, the plasma stability index beta and the fusion power density in the plasma were treated as independent variables to determine how they influenced three economic performance parameters of fusion reactors burning the DT and four advanced fusion fuel cycles. The economic/performance parameters included the total power produced per unit length of reactor; the mass per unit length, and the specific mass in kilograms/kilowatt. The scaling of these parameters with beta and fusion power density was examined for a common set of engineering assumptions on the allowable wall loading limits, the maximum magnetic field existing in the plasma, average blanket mass density, etc. It was found that the power per unit length decreased as the plasma power density and beta increased. This is a consequence of the fact that the first wall is a bottleneck in the energy flow from the plasma to the generating equipment, and the wall power flux will exceed wall loading limits if the plasma radius exceeds a critical value. If one wished to build an engineering test reactor which produced a burning plasma at the lowest possible initial cost, and without regard to whether such a reactor would ultimately produce the cheapest power, then one would minimize the mass per unit length. The mass per unit length decreases with increasing plasma power density and beta, with the DT reaction being the most expensive at a fixed plasma power density (because of its thicker blanket), and the least expensive at a fixed value of beta, at least up to values of beta of 50%. The specific mass, in kg/kw, which is a rough measure of the cost of the power generated by the reactor, shows an opposite trend. It increases with increasing plasma power density and beta. At a given plasma power density and low beta, the DT reaction gives the lowest specific mass, but at a fixed beta above 10%, the advanced fuel cycles have the lowest specific mass

  3. 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.)

  4. 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...

  5. The prediction of cladding performance in Ultra long Cycle Fast Reactors

    International Nuclear Information System (INIS)

    As a part of R and D activities for the development of advanced fast reactors, HT9 cladding performance of Ultra long Cycle Fast Reactor (UCFR) is evaluated in various cladding peak temperatures and design power levels (1000MWe and 1000MWe). The key design concept of UCFR is a non refueling during 30 to 60 years operation, and this concept may require the maximum cladding temperature of ∼650 .deg. C peak cladding temperature and cladding radiation damage of over 200dpa (displacements pet atom). Therefore, for the design of UCFR, challenges such as thermal creep, irradiation creep and swelling must be quantitatively evaluated. As a cladding material, HT9 shows distinguishably favorable properties for UCFR, In this study, therefore, key design parameters for the cladding performance will be evaluated for UCFR cladding design and resulted the prediction of life time of cladding in UCFR

  6. Performance of metal and oxide fuels during accidents in a large liquid metal cooled reactor

    Energy Technology Data Exchange (ETDEWEB)

    Cahalan, J.; Wigeland, R. (Argonne National Lab., IL (USA)); Friedel, G. (Internationale Atomreaktorbau GmbH (INTERATOM), Bergisch Gladbach (Germany, F.R.)); Kussmaul, G.; Royl, P. (Kernforschungszentrum Karlsruhe GmbH (Germany, F.R.)); Moreau, J. (CEA Centre d' Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France)); Perks, M. (UKAEA Risley Nuclear Power Development Establishment (UK)

    1990-01-01

    In a cooperative effort among European and US analysts, an assessment of the comparative safety performance of metal and oxide fuels during accidents in a large (3500 MWt), pool-type, liquid-metal-cooled reactor (LMR) was performed. The study focused on three accident initiators with failure to scram: the unprotected loss-of-flow (ULOF), the unprotected transient overpower (UTOP), and the unprotected loss-of-heat-sink (ULOHS). Emphasis was placed on identification of design features that provide passive, self-limiting responses to upset conditions, and quantification of relative safety margins. The analyses show that in ULOF and ULOHS sequences, metal-fueled LMRs with pool-type primary systems provide larger temperature margins to coolant boiling than oxide-fueled reactors of the same design. 3 refs., 4 figs.

  7. Alloy development for irradiation performance in fusion reactors. Annual report, September 1978-September 1979

    International Nuclear Information System (INIS)

    This report is the first annual report of research activities directed toward the development of improved performance alloys for such severe environments as the fusion reactor fist wall. Major project efforts are directed toward definition of alloy performance requirements, alloy design, alloy production and alloy performance evaluation. Rapid solidification from the melt is being used to manipulate alloy microstructure and to produce the desired design properties. Integrated testing and modeling procedures have been developed to minimize testing requirements. Progress during the first project year and future plans are summarized in this annual report

  8. Performance of HUASB reactor for treating paper & Pulp wastewater using Effective Microorganism(EM

    Directory of Open Access Journals (Sweden)

    Er.N.Balasubramanian

    2012-06-01

    Full Text Available Pulp and paper industry is one of the most polluting industries all over the world that uses significant amount of fresh water and produces substantial amount of solid and liquid waste. Wastewater from this industry is potentially polluting nature and before discharge into natural course, it is mandatory to adhere to the discharge norms. Anaerobic treatment of paper processing wastewater has a distinct advantage of recovery of inherent energy in the form of methane gas with less sludge production. A hybrid reactor (HUASB that capitalizes on the positive features of anaerobic filter (AF and up-flow anaerobic sludge blanket (UASB. The main objectiveof the thesis is to find out the performance efficiency of the hybrid up-flow anaerobic sludge blanket (HUASB reactor for treatment of pulp & paper mill wastewater using Effective Microorganism(EM. In this study, a labscale HUASB reactor of 9.68 litres and an effective volume of 7.88 L had been used at ambient temperature with PVC packing materials in the top one third of the reactor.

  9. Treatment of Slaughter House Wastewater in a Sequencing Batch Reactor: Performance Evaluation and Biodegradation Kinetics

    OpenAIRE

    Pradyut Kundu; Anupam Debsarkar; Somnath Mukherjee

    2013-01-01

    Slaughterhouse wastewater contains diluted blood, protein, fat, and suspended solids, as a result the organic and nutrient concentration in this wastewater is vary high and the residues are partially solubilized, leading to a highly contaminating effect in riverbeds and other water bodies if the same is let off untreated. The performance of a laboratory-scale Sequencing Batch Reactor (SBR) has been investigated in aerobic-anoxic sequential mode for simultaneous removal of organic carbon and n...

  10. Analysis of dashpot performance for rotating control drums of a lithium cooled fast reactor concept

    Science.gov (United States)

    Wenzler, C. J.

    1972-01-01

    A dashpot was incorporated in the design of the drive train of the rotating control drum to prevent shock damage to the control drum and drive train at the termination of a scram action. A rotating vane dashpot using reactor coolant lithium as a damping fluid appears to be the best candidate of the various damping devices explored. A performance analysis, results and discussion of vane type dashpots are presented.

  11. Comparative Study of Commercial CFD Software Performance for Prediction of Reactor Internal Flow

    International Nuclear Information System (INIS)

    Even if some CFD software developers and its users think that a state-of-the-art CFD software can be used to reasonably solve at least single-phase nuclear reactor safety problems, there remain limitations and uncertainties in the calculation result. From a regulatory perspective, the Korea Institute of Nuclear Safety (KINS) is presently conducting the performance assessment of commercial CFD software for nuclear reactor safety problems. In this study, to examine the prediction performance of commercial CFD software with the porous model in the analysis of the scale-down APR (Advanced Power Reactor Plus) internal flow, a simulation was conducted with the on-board numerical models in ANSYS CFX R.14 and FLUENT R.14. It was concluded that depending on the CFD software, the internal flow distribution of the scale-down APR was locally somewhat different. Although there was a limitation in estimating the prediction performance of the commercial CFD software owing to the limited amount of measured data, CFX R.14 showed more reasonable prediction results in comparison with FLUENT R.14. Meanwhile, owing to the difference in discretization methodology, FLUENT R.14 required more computational memory than CFX R.14 for the same grid system. Therefore, the CFD software suitable to the available computational resource should be selected for massively parallel computations

  12. 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

  13. Effect of nitrogen and phosphorus on the performance of acidogenic and methanogenic reactors for treatment of biodiesel wastewater

    Directory of Open Access Journals (Sweden)

    Piyarat Boonsawang

    2014-12-01

    Full Text Available A laboratory scale two-stage anaerobic process was studied in order to treat biodiesel wastewater. The first stage represented an acidogenic reactor while the second stage was a methanogenic reactor. The effect of nitrogen and phosphorus on the performance of both reactors was investigated. Biodiesel wastewater was adjusted so that its COD:N and COD:P within 100:0.1–1.1 and 100:0–1, respectively, and fed into the acidogenic reactor. After COD and pH adjustment, wastewater discharged from the acidogenic reactor was fed into the methanogenic reactor. The highest VFA concentration of 8.32 g/l was obtained from the acidogenic reactor at COD:N:P of 100:1.1:0.5. However, the highest CH4 yield of 0.170 l CH4 /g CODremoved was found at COD:N:P of 100:0.6:0.5 from the methanogenic reactor. Moreover, both nitrogen and phosphorus affected the acid composition produced in the acidogenic reactor and the long chain fatty acid consumption in the acidogenic and methanogenic reactors.

  14. Effect of nitrogen and phosphorus on the performance of acidogenic and methanogenic reactors for treatment of biodiesel wastewater

    OpenAIRE

    Piyarat Boonsawang; Athirat Rerngnarong; Chakrit Tongurai; Sumate Chaiprapat

    2014-01-01

    A laboratory scale two-stage anaerobic process was studied in order to treat biodiesel wastewater. The first stage represented an acidogenic reactor while the second stage was a methanogenic reactor. The effect of nitrogen and phosphorus on the performance of both reactors was investigated. Biodiesel wastewater was adjusted so that its COD:N and COD:P within 100:0.1–1.1 and 100:0–1, respectively, and fed into the acidogenic reactor. After COD and pH adjustment, wastewater discharg...

  15. 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

  16. Anaerobic digestion of different feedstocks: impact on energetic and environmental balances of biogas process.

    Science.gov (United States)

    Bacenetti, Jacopo; Negri, Marco; Fiala, Marco; González-García, Sara

    2013-10-01

    The possibility of limiting the global warming is strictly linked to the reduction of GHG emissions. Renewable energy both allows reducing emissions and permits to delay fossil fuel depletion. The anaerobic digestion of animal manure and energy crops is a promising way of reducing GHG emissions. In Italy agricultural biogas production was considerably increased; nowadays there are about 520 agricultural biogas plants. The increasing number of biogas plants, especially of those larger than 500 kW(e) (electrical power), involves a high consumption of energy crops, large transport distances of biomass and digestate and difficulties on thermal energy valorization. In this study the energetic (CED) and environmental (GHG emissions) profiles associated with the production of electricity derived from biogas have been identified. Three biogas plants located in Northern Italy have been analyzed. The study has been carried out considering a cradle-to-grave perspective and thus, special attention has been paid on the feedstock production and biogas production process. The influences on the results taking into account different plant sizes and feeding rate has been assessed in detail. Energy analysis was performed using the Cumulative Energy Demand method (CED). The climate change was calculated for a 100-year time frame based on GHG emissions indicated as CO2 equivalents (eq) and defined by the IPCC (2006). In comparison to the fossil reference system, the electricity production using biogas saves GHG emissions from 0.188 to 1.193 kg CO2eq per kWh(e). Electricity supply from biogas can also contribute to a considerable reduction of the use of fossil energy carriers (from -3.97 to 10.08 MJ(fossil) per kWh(e)). The electricity production from biogas has a big potential for energy savings and reduction of GHG emissions. Efficient utilization of the cogenerated heat can substantially improve the GHG balance of electricity production from biogas.

  17. The Jules Horowitz Reactor : A new high Performances European MTR (Material Testing Reactor) with modern experimental capacities : Toward an International User Facility

    International Nuclear Information System (INIS)

    The Jules Horowitz Reactor (JHR) is a new Material Testing Reactor (MTR) currently under construction at CEA Cadarache research centre in the south of France. It will be a major Research facility in support to the development and the qualification of materials and fuels under irradiation with sizes and environment conditions relevant for nuclear power plants in order to optimise and demonstrate safe operations of existing power reactors as well as to support future reactor design. It will represent also an important Research Infrastructure for scientific studies dealing with material and fuel behaviour under irradiation. The JHR will contribute also to secure the production of radioisotope for medical application. This is a key public health stake. The construction of JHR which was started in 2007 is on-going. The first operation is planned before the end of this decade.The design of the reactor will provide an essential facility supporting the programs for the nuclear energy for the next 50 years. JHR is designed to provide high neutron flux (enhancing the maximum available today in MTRs), to run highly instrumented experiments to support advanced modelling giving prediction beyond experimental points, and to operate experimental devices giving environment conditions (pressure, temperature, flux, coolant chemistry, ···) relevant for water reactors, for gas cooled thermal or fast reactors, for sodium fast reactors, ···So, the reactor will perform R and D programs for the optimization of the present generation of NPP, support the development of the next generation of NPP (mainly LWR) and also offer irradiation possibilities for future reactors. In parallel to the construction of the reactor, the preparation of an international community around JHR is continuing; this is an important topic as building and gathering a strong international community in support to MTR experiments is a key-issue for the R and D in nuclear energy field. Consequently, CEA is

  18. Physiochemical, exergetic and economical analysis of biogas reforming: hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Antonio Carlos Caetano de; Silveira, Jose Luz [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Guaratingueta, SP (Brazil)]. E-mails: caetanodesouza@yahoo.com.br; caetano@feg.unesp.br; joseluz@feg.unesp.br

    2008-07-01

    The utilization of biogas for production of hydrogen-rich syngas through thermochemical processes such as steam reforming and dry reforming is suggested in this study. Ultimately, these gases could be utilized by fuel cells to generate electricity and heat. The composition of biogas depends strongly on conditions where this gas is produced (thermodynamic conditions such as temperature and pressure where biogas' feedstocks are utilized, beyond composition of own feedstock and utilized technology for biogas processing). Physicochemical analysis was performed with objective to evaluate the composition of syngas generated through reforming process, making a special attention to the content of hydrogen in the cited syngas. The adopted biogas in this study was based on the biogas generated in a small wastewater treatment system installed in Sao Paulo State University (UNESP) at Guaratingueta. The volume of constituents was 61.8% CH{sub 4} and 34.4% CO{sub 2} after purification. Some traces of O{sub 2} and N{sub 2} were encountered. The suggested thermodynamic conditions detected in physical-chemical and exergetic analysis was in a range of 600- 900 deg C and 1 atm. This pressure was adopted since in this way, an equipment of pressurization and depressurization is not necessary, diminishing the costs of installation and utilization of energy. Basing on this temperature, the generation of hydrogen-rich biogas is devoted with low utilization of energy which in this case is necessary as heat source. The exergetic analysis has as objective to determinate the most convenient thermodynamic conditions for studied hydrogen production process. Calculations concerning rational and exergetic efficiencies were developed. Basing on this analysis, the suggested conditions were 1 atm and maximum 700 deg C. Ultimately, an economic analysis was performed to evaluate the cost of produced hydrogen depending on of imposed conditions such as cost of installation of studied reformer

  19. Performance Evaluation of a Printed Circuit Steam Generator for Integral Reactors: A Feasibility Test

    Energy Technology Data Exchange (ETDEWEB)

    Han, Hun Sik; Kang, Han-Ok; Yoon, Juhyeon; Kim, Young In; Kim, Keung Koo [KAERI, Daejeon (Korea, Republic of); Seo, Jang-won; Choi, Brain [Alfa Laval Korea Ltd., Daejeon (Korea, Republic of)

    2015-05-15

    SMART (System-integrated Modular Advanced ReacTor) is a small-sized integral type pressurized water reactor. It adopts advanced design features such as structural safety improvement, system simplification, and component modularization to achieve highly enhanced safety and improved economics. The design issues related to further safety enhancement and cost reduction have received significant attention to increase its competitiveness in the global small reactor market. For the cost reduction, it is important to design the reactor vessel as small as possible. Thus, it is necessary to reduce the volume of main components such as a steam generator. Its manufacturing processes of the chemical etching and diffusion bonding provide high effectiveness, high compactness, and inherent structural safety under high temperatures and high pressures. Thus, it is expected to be an alternative to the conventional shell and tube type steam generator in SMART. In this paper, simple thermal-hydraulic performance measurement of a small-scale printed circuit steam generator (PCSG) is conducted to investigate the feasibility of applying it to SMART. The simple thermal-hydraulic performance of the PCSG has been experimentally evaluated. A small-scale PCHE is employed to investigate the feasibility of operating it as a steam generator. The performance assessment reveals that the PCSG stably produces superheated steam, and the increased degree of superheat is obtained at lower water flow rate. However, the flow instability is increased with the decrease of the water flow rate. Thus, it is required to apply the orifice design into the cold side plate to suppress the density-wave oscillations. The pressure drops and heat transfer rates increase with the water flow rate.

  20. 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.

  1. 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)

  2. Performance of evaluation of methanogenic microbial inoculant and its effect of biogas production in pilot scale test%产甲烷复合菌剂的性能评价及中试试验产气效果

    Institute of Scientific and Technical Information of China (English)

    王渝昆; 袁月祥; 李东; 胡亚东; 黄显波; 昊深; 刘晓风; 彭绪亚; 闫志英

    2014-01-01

    constructed based on the physiological, biochemical characteristics and antagonisms of strain RY3, SH4, G1, G2 and G3. The performances of the inoculant under different pH values, temperatures and application rates of the methanogenic microbial inoculant were evaluated. It showed that the 5 strains had different physiological and biochemical characteristics as well as complementary roles. There were no antagonisms among 5 strains. The methanogenic microbial inoculant grew at pH value 5.5-10.5. Methane productions were 1 706.7-2 026.7μmols at pH value 5.5-9.5 after 3 days’ culture, that of different pH values showed no significant difference respectively. The results indicated that the methanogenic microbial inoculant is resistant to acid and alkali changes. The inoculant grew at 15-70℃ and methane productions were 1 906.9-2 028 μmols at 30-60℃ after 3 days’ culture, that of different temperatures treatment showed no significant difference respectively. The results indicated that the methanogenic microbial inoculant is adapted to a wide temperature range. At 20℃, total biogas yield of treatments 2%, 5%, 10% before 14 day were 234, 422 and 950 mL, and the methane concentration of treatments 2%, 5%, 10% on the 14th day were 46.9%, 51.2% and 58.9%respectively corresponding the treatments with 2%, 5%and 10%inoculation dosages of the methanogenic microbial inoculant. At 50℃, total biogas yield before 14 d were 2728, 3291 and 3 832 mL and the methane concentration on 14th day were 62.7%, 63.1%and 63.8%respectively corresponding the treatments with 2%, 5%and 10%inoculation dosages of the methanogenic microbial inoculant. The results indicated that the inoculation could shorten the starting time for methane production compared to the controls without inoculant at 20 and 50℃. Pilot tests by kinetic analysis indicated that inoculant could still shorten the starting time for methane production compared to the control using anaerobic active sludge as inoculant. At 20

  3. Treatment efficiency and VFA composition of a thermophilic anaerobic contact reactor treating food industry wastewater

    International Nuclear Information System (INIS)

    The objective of this study was to examine the effects of organic loading rate and hydraulic retention time on volatile fatty acid composition and treatment efficiency of high rate thermophilic anaerobic contact reactor (TACR) treating potato-chips wastewaters. The operational performance of TACR was monitored from start-up by assessing chemical oxygen demand (COD) removal efficiencies, volatile fatty acid (VFA) production and biogas composition. The reactor was studied at different organic loading rates (OLRs) ranging from 0.6 to 8 kg COD/m3 d. The COD removal efficiencies were found to be 86-97% and the methane percentage of the biogas produced was 68-89% during the OLRs studied. The approximate methane yield was found to be 0.42 m3 CH4/kg CODremoved. The major intermediate products of anaerobic digestion were acetate, propionate, iso-butyrate, butyrate, iso-valerate, valerate, iso-caproate and caproate. The use of thermophilic anaerobic contact reactor offers a sustainable technology for the treatment of potato-chips wastewaters since high COD removal efficiencies and high methane percentage in the biogas produced can be attained even at high OLRs.

  4. Treatment efficiency and VFA composition of a thermophilic anaerobic contact reactor treating food industry wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Sentuerk, E.; Ince, M. [Gebze Institute of Technology, Department of Environmental Engineering, Gebze, 41400, Kocaeli (Turkey); Onkal Engin, G., E-mail: guleda@gyte.edu.tr [Gebze Institute of Technology, Department of Environmental Engineering, Gebze, 41400, Kocaeli (Turkey)

    2010-04-15

    The objective of this study was to examine the effects of organic loading rate and hydraulic retention time on volatile fatty acid composition and treatment efficiency of high rate thermophilic anaerobic contact reactor (TACR) treating potato-chips wastewaters. The operational performance of TACR was monitored from start-up by assessing chemical oxygen demand (COD) removal efficiencies, volatile fatty acid (VFA) production and biogas composition. The reactor was studied at different organic loading rates (OLRs) ranging from 0.6 to 8 kg COD/m{sup 3} d. The COD removal efficiencies were found to be 86-97% and the methane percentage of the biogas produced was 68-89% during the OLRs studied. The approximate methane yield was found to be 0.42 m{sup 3} CH{sub 4}/kg COD{sub removed}. The major intermediate products of anaerobic digestion were acetate, propionate, iso-butyrate, butyrate, iso-valerate, valerate, iso-caproate and caproate. The use of thermophilic anaerobic contact reactor offers a sustainable technology for the treatment of potato-chips wastewaters since high COD removal efficiencies and high methane percentage in the biogas produced can be attained even at high OLRs.

  5. Performance Analysis of Micro Gas Turbine Using Different Kinds of Biogas Fuel%使用不同生物质气的微型燃气轮机性能分析

    Institute of Scientific and Technical Information of China (English)

    吴旺松; 翁一武

    2012-01-01

    The gas composition and calorific value have great impacts on the gas turbine performance.Usually gas turbine can only use the designed fuel,but in fact the fuel composition often changes.Some typical gas compositions and low caloric values after biomass gasification are introduced.Then by calculation and simulation,this paper analyzes the influence rule of biogas calorific value on micro gas turbine performance,and explores the feasibility of using off-designed fuel in micro gas turbine.%指出燃气的成分和热值对燃气轮机性能的影响很大,一般情况下燃气轮机只能使用设计指定的燃料,但实际上常常会有燃料成分发生变化的情况。介绍了几种典型的生物质气化后的燃气成份与低位热值。通过模拟计算分析生物质气的热值变化对微型燃气轮机性能的影响规律,分析微型燃气轮机使用非设计燃料的可行性。

  6. Improved Performances of a Fluidized Bed Photo reactor by a Microscale Illumination System

    International Nuclear Information System (INIS)

    The performances of a gas-solid two-dimensional fluidized bed reactor in photo catalytic selective oxidation reactions, irradiated with traditional UV lamps or with a microscale illumination system based on UV emitting diodes (UV A-LEDs), have been compared. In the photo catalytic oxidative dehydrogenation of cyclohexane to benzene on MoOx/TiO2-A12O3 catalyst the use of UV A-LEDs modules allowed to achieve a cyclohexane conversion and benzene yield higher than those obtained with traditional UV lamps. The better performances with UV A-LEDs are due to the UV A-LEDs small dimensions and small-angle emittance, which allow photons beam be directed towards the photo reactor windows, reducing the dispersion outside of photo reactor or the optical path length. As a consequence, the effectively illuminated mass of catalyst is greater. We have found that this illumination system is efficient for photo-oxidative dehydrogenation of cyclohexane to cyclohexene on sulphated MoOx-A12O3 and ethanol to acetaldehyde on VOx/TiO2.

  7. EXPERIMENTAL EVALUATION OF THE THERMAL PERFORMANCE OF A WATER SHIELD FOR A SURFACE POWER REACTOR

    Energy Technology Data Exchange (ETDEWEB)

    REID, ROBERT S. [Los Alamos National Laboratory; PEARSON, J. BOSIE [Los Alamos National Laboratory; STEWART, ERIC T. [Los Alamos National Laboratory

    2007-01-16

    Water based reactor shielding is being investigated for use on initial lunar surface power systems. A water shield may lower overall cost (as compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. Natural convection in a 100 kWt lunar surface reactor shield design is evaluated with 2 kW power input to the water in the Water Shield Testbed (WST) at the NASA Marshall Space Flight Center. The experimental data from the WST is used to validate a CFD model. Performance of the water shield on the lunar surface is then predicted with a CFD model anchored to test data. The experiment had a maximum water temperature of 75 C. The CFD model with 1/6-g predicts a maximum water temperature of 88 C with the same heat load and external boundary conditions. This difference in maximum temperature does not greatly affect the structural design of the shield, and demonstrates that it may be possible to use water for a lunar reactor shield.

  8. Neutronic and Thermal-hydraulic Modelling of High Performance Light Water Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Seppaelae, Malla [VTT Technical Research Centre of Finland, P.O.Box 1000, FI02044 VTT (Finland)

    2008-07-01

    High Performance Light Water Reactor (HPLWR), which is studied in EU project 'HPLWR2', uses water at supercritical pressures as coolant and moderator to achieve higher core outlet temperature and thus higher efficiency compared to present reactors. At VTT Technical Research Centre of Finland, functionality of the thermal-hydraulics in the coupled reactor dynamics code TRAB3D/ SMABRE was extended to supercritical pressures for the analyses of HPLWR. Input models for neutronics and thermal-hydraulics were made for TRAB3D/ SMABRE according to the latest HPLWR design. A preliminary analysis was performed in which the capability of SMABRE in the transition from supercritical pressures to subcritical pressures was demonstrated. Parameterized two-group cross sections for TRAB3D neutronics were received from Hungarian Academy of Sciences KFKI Atomic Energy Research Institute together with a subroutine for handling them. PSG, a new Monte Carlo transport code developed at VTT, was also used to generate two-group constants for HPLWR and comparisons were made with the KFKI cross sections and MCNP calculations. (author)

  9. Influences of iron and calcium carbonate on wastewater treatment performances of algae based reactors.

    Science.gov (United States)

    Zhao, Zhimiao; Song, Xinshan; Wang, Wei; Xiao, Yanping; Gong, Zhijie; Wang, Yuhui; Zhao, Yufeng; Chen, Yu; Mei, Mengyuan

    2016-09-01

    The influences of iron and calcium carbonate (CaCO3) addition in wastewater treatments reactors performance were investigated. Adding different concentrations of Fe(3+) (5, 10, 30 and 50mmol/m(3)), iron and CaCO3 powder led to changes in algal characteristics and physico-chemical and microbiological properties. According to the investigation results, nutrient removal efficiency in algae based reactors was obviously increased by the addition of 10mmol/m(3) Fe(3+), iron (5mmol/m(3)) and CaCO3 powder (0.2gm(-3)) and the removal efficiencies of BOD5, TN, and TP in Stage 2 were respectively increased by 28%, 8.9%, and 22%. The improvements in physico-chemical performances were verified by microbial community tests (bacteria quantity, activity and community measured in most probable number, extracellular enzymes activity, and Biolog Eco Plates). Microbial variations indicated the coexistence of Fe ions and carbonate-bicarbonate, which triggered the synergistic effect of physico-chemical action and microbial factors in algae based reactors. PMID:27214163

  10. Performance Estimation of Supercritical Co2 Micro Modular Reactor (MMR) for Varying Cooling Air Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Yoonhan; Kim, Seong Gu; Cho, Seong Kuk; Lee, Jeong Ik [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2015-05-15

    A Small Modular Reactor (SMR) receives interests for the various application such as electricity co-generation, small-scale power generation, seawater desalination, district heating and propulsion. As a part of SMR development, supercritical CO2 Micro Modular Reactor (MMR) of 36.2MWth in power is under development by the KAIST research team. To enhance the mobility, the entire system including the power conversion system is designed for the full modularization. Based on the preliminary design, the thermal efficiency is 31.5% when CO2 is sufficiently cooled to the design temperature. A supercritical CO2 MMR is designed to supply electricity to the remote regions. The ambient temperature of the area can influence the compressor inlet temperature as the reactor is cooled with the atmospheric air. To estimate the S-CO2 cycle performance for various environmental conditions, A quasi-static analysis code is developed. For the off design performance of S-CO2 turbomachineries, the experimental result of Sandia National Lab (SNL) is utilized.

  11. Treatment of slaughter house wastewater in a sequencing batch reactor: performance evaluation and biodegradation kinetics.

    Science.gov (United States)

    Kundu, Pradyut; Debsarkar, Anupam; Mukherjee, Somnath

    2013-01-01

    Slaughterhouse wastewater contains diluted blood, protein, fat, and suspended solids, as a result the organic and nutrient concentration in this wastewater is vary high and the residues are partially solubilized, leading to a highly contaminating effect in riverbeds and other water bodies if the same is let off untreated. The performance of a laboratory-scale Sequencing Batch Reactor (SBR) has been investigated in aerobic-anoxic sequential mode for simultaneous removal of organic carbon and nitrogen from slaughterhouse wastewater. The reactor was operated under three different variations of aerobic-anoxic sequence, namely, (4+4), (5+3), and (3+5) hr. of total react period with two different sets of influent soluble COD (SCOD) and ammonia nitrogen (NH4(+)-N) level 1000 ± 50 mg/L, and 90 ± 10 mg/L, 1000 ± 50 mg/L and 180 ± 10 mg/L, respectively. It was observed that from 86 to 95% of SCOD removal is accomplished at the end of 8.0 hr of total react period. In case of (4+4) aerobic-anoxic operating cycle, a reasonable degree of nitrification 90.12 and 74.75% corresponding to initial NH4(+)-N value of 96.58 and 176.85 mg/L, respectively, were achieved. The biokinetic coefficients (k, K(s), Y, k(d)) were also determined for performance evaluation of SBR for scaling full-scale reactor in future operation.

  12. Commercial-Scale Performance Predictions for High-Temperature Electrolysis Plants Coupled to Three Advanced Reactor Types

    Energy Technology Data Exchange (ETDEWEB)

    M. G. McKellar; J. E. O' Brien; J. S. Herring

    2007-09-01

    This report 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 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.

  13. The safety culture change process performed in Polish research reactor MARIA

    International Nuclear Information System (INIS)

    The Safety Culture Change Process Performed in research reactor MARIA is described in this paper. The essential issues fulfilled in realization of the Safety Culture Enhancement Programme are related to the attitude and behaviour of top management, co-operating groups, operational personnel, relations between the operating organization and the supervising and advising organizations. Realization of this programme is based on changing the employees understanding of safety, changing their attitudes and behaviours by means of adequate training, requalification process and performing the broad self-assessment programme. Also a high level Quality Assurance Programme helps in development of the Safety Culture. (author)

  14. Comparing neutronics codes performance in analyzing a fresh-fuelled research reactor core

    International Nuclear Information System (INIS)

    Highlights: • Calculation of neutron fluence rate with different neutronic codes is examined. • MCNP, TRIPOLI and CITATION were used for neutron fluence rate calculations. • The recently converted core of the Portuguese Research Reactor (RPI) was used. • Fresh fuel of low enrichment in U-235 was assumed. • Thermal, epithermal and fast neutron fluence rates were computed. - Abstract: In this paper the relative performance of different simulation approaches is examined, focusing on the neutron fluence rate distribution in a nuclear reactor core. The main scope of the work is to benchmark and validate the neutronics code systems utilized in the Greek Research Reactor (GRR-1) for a high-density Low Enriched Uranium (LEU) core of compact size. For this purpose the recently converted core of the Portuguese Research Reactor (RPI), fueled with fresh, low enrichment in U-235 fuel, was simulated with the stochastic code TRIPOLI and the deterministic code system XSDRN/CITATION. RPI was selected on the basis that it is a similar to GRR-1 pool-type reactor, using same fuel and control rods type, as well as same types of coolant, moderator and reflector. The neutron fluence rate in RPI was computed using each numerical approach with changed approximations. In this frame the stochastic code TRIPOLI was tested using two different nuclear data libraries, i.e., ENDF/B-VI versus JEFF3.1, and two different ways of source definition, i.e., “point sources”, placed in the center of each fuel cell, versus a “distributed source”, where each fuel volume was considered as a neutron source. The deterministic code system XSDRN/CITATION was tested with respect to the definition of the transverse leakages associated to each one-dimensional, user-defined core zone, as analyzed by the XSDRN code in order to provide the zone equivalent cross sections. Thermal, epithermal and fast neutron fluence rates were computed and local values found in a 15 cm segment immediately below the

  15. The Effect of Hydrodynamics on Riser Reactor Performance of the FCCU

    Directory of Open Access Journals (Sweden)

    Digieneni Yousuo

    2016-09-01

    Full Text Available The effect of hydrodynamics on the riser reactor performance was studied. The simulation was carried out using COMSOL Multiphysics software. The simulation results showed that reaction rate increased with increase in temperature. The results also showed that an increase in pressure leads to an increases in the velocity of the riser reactor. A maximum on gasoline yield appears when the gas oil inlet temperature is 600K,the catalyst inlet temperature is 1100K and the steam inlet temperature is 400K making gasoline yield between 52% to 55%. A minimum on Coke yield appears when the gas oil inlet temperature is 300K, the catalyst inlet temperature is 800K and the steam inlet temperature is 200K making coke yield between 1% to 2%.

  16. Removal performance and microbial communities in a sequencing batch reactor treating hypersaline phenol-laden wastewater.

    Science.gov (United States)

    Jiang, Yu; Wei, Li; Zhang, Huining; Yang, Kai; Wang, Hongyu

    2016-10-01

    Hypersaline phenol-rich wastewater is hard to be treated by traditional biological systems. In this work, a sequencing batch reactor was used to remove phenol from hypersaline wastewater. The removal performance was evaluated in response to the variations of operating parameters and the microbial diversity was investigated by 454 pyrosequencing. The results showed that the bioreactor had high removal efficiency of phenol and was able to keep stable with the increase of initial phenol concentration. DO, pH, and salinity also affected the phenol removal rate. The most abundant bacterial group was phylum Proteobacteria in the two working conditions, and class Gammaproteobacteria as well as Alphaproteobacteria was predominant subgroup. The abundance of bacterial clusters was notably different along with the variation of operation conditions, resulting in changes of phenol degradation rates. The high removal efficiency of phenol suggested that the reactor might be promising in treating phenol-laden industrial wastewater in high-salt condition. PMID:27359064

  17. 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

  18. 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.

  19. Nuclear Systems Enhanced Performance Program, Maintenance Cycle Extension in Advanced Light Water Reactor Design

    Energy Technology Data Exchange (ETDEWEB)

    Professor Neill Todreas

    2001-10-01

    A renewed interest in new nuclear power generation in the US has spurred interest in developing advanced reactors with features which will address the public's concerns regarding nuclear generation. However, it is economic performance which will dictate whether any new orders for these plants will materialize. Economic performance is, to a great extent, improved by maximizing the time that the plant is on-line generating electricity relative to the time spent off-line conducting maintenance and refueling. Indeed, the strategy for the advanced light water reactor plant IRIS (International Reactor, Innovative and Secure) is to utilize an eight year operating cycle. This report describes a formalized strategy to address, during the design phase, the maintenance-related barriers to an extended operating cycle. The top-level objective of this investigation was to develop a methodology for injecting component and system maintainability issues into the reactor plant design process to overcome these barriers. A primary goal was to demonstrate the applicability and utility of the methodology in the context of the IRIS design. The first step in meeting the top-level objective was to determine the types of operating cycle length barriers that the IRIS design team is likely to face. Evaluation of previously identified regulatory and investment protection surveillance program barriers preventing a candidate operating PWR from achieving an extended (48 month) cycle was conducted in the context of the IRIS design. From this analysis, 54 known IRIS operating cycle length barriers were identified. The resolution methodology was applied to each of these barriers to generate design solution alternatives for consideration in the IRIS design. The methodology developed has been demonstrated to narrow the design space to feasible design solutions which enable a desired operating cycle length, yet is general enough to have broad applicability. Feedback from the IRIS design team

  20. Performance evaluation of a continuous flow photocatalytic reactor for wastewater treatment.

    Science.gov (United States)

    Rezaei, Mohammad; Rashidi, Fariborz; Royaee, Sayed Javid; Jafarikojour, Morteza

    2014-11-01

    A novel photocatalytic reactor for wastewater treatment was designed and constructed. The main part of the reactor was an aluminum tube in which 12 stainless steel circular baffles and four quartz tube were placed inside of the reactor like shell and tube heat exchangers. Four UV-C lamps were housed within the space of the quartz tubes. Surface of the baffles was coated with TiO2. A simple method was employed for TiO2 immobilization, while the characterization of the supported photocatalyst was based on the results obtained through performing some common analytical methods such as X-ray diffraction (XRD), scanning electron microscope (SEM), and BET. Phenol was selected as a model pollutant. A solution of a known initial concentration (20, 60, and 100 ppmv) was introduced to the reactor. The reactor also has a recycle flow to make turbulent flow inside of the reactor. The selected recycle flow rate was 7 × 10(-5) m(3).s(-1), while the flow rate of feed was 2.53 × 10(-7), 7.56 × 10(-7), and 1.26 × 10(-6) m(3).s(-1), respectively. To evaluate performance of the reactor, response surface methodology was employed. A four-factor three-level Box-Behnken design was developed to evaluate the reactor performance for degradation of phenol. Effects of phenol inlet concentration (20-100 ppmv), pH (3-9), liquid flow rate (2.53 × 10(-7)-1.26 × 10(-6) m(3).s(-1)), and TiO2 loading (8.8-17.6 g.m(-2)) were analyzed with this method. The adjusted R (2) value (0.9936) was in close agreement with that of corresponding R (2) value (0.9961). The maximum predicted degradation of phenol was 75.50 % at the optimum processing conditions (initial phenol concentration of 20 ppmv, pH ∼ 6.41, and flow rate of 2.53 × 10(-7) m(3).s(-1) and catalyst loading of 17.6 g.m(-2)). Experimental degradation of phenol determined at the optimum conditions was 73.7 %. XRD patterns and SEM images at the optimum conditions revealed that crystal size is approximately 25

  1. 有机胺基氨基酸盐混合吸收剂对沼气中CO2的分离特性%Performance of CO2 removal from biogas by using amine-based amino acid salts blended absorbents

    Institute of Scientific and Technical Information of China (English)

    贺清尧; 蔡凯; 晏水平; 艾平; 王媛媛; 张衍林

    2015-01-01

    This paper investigated the CO2 absorption performance from biogas and regeneration characteristics using N-methyldiethanolamine-based(MDEA)blended solvents respectively promoted by monoethanolamine(MEA),MEA-based glycinate(MEAGLY) and MEA-based sarcosinate ( MEASAR ) in a bubbling CO2 absorption/regeneration reactor. Results showed that the CO2 absorption rates of blended solvents increased with the adding amount of promoters,but CO2 desorption rates decreased. During the period of temperature increase from the absorption range to regeneration range,all the CO2-rich solvents were regenerated,and the blended solvents performed better than the single solvents in CO2 regeneration efficiency. In addition,when mass ratio of MDEA to promoter was 3∶2 in the blended solvents,the absorption-regeneration performances were optimal. CO2 removal costs from biogas of different absorbents were also assessed and compared. Compared to the single MEA with 30%mass fraction,the blended solvents,MDEA/MEAGLY and MDEA/MEA in which the total mass fraction was 30%and the ratio of MDEA to MEAGLY or MEA was 3﹕2 had the lower CO2 removal costs by about 12%and 30%,respectively. So MDEA/MEAGLY and MDEA/MEA might be the promising alternatives to replace MEA in the future.%在鼓泡式CO2吸收和再生装置中,研究了N-甲基二乙醇胺(MDEA)/乙醇胺(MEA)、MDEA/乙醇胺基甘氨酸(MEAGLY)和MDEA/乙醇胺基肌氨酸(MEASAR)混合吸收剂的沼气CO2吸收及再生特性。结果表明:混合吸收剂的沼气CO2吸收速率随MEA、MEAGLY和MEASAR等添加剂添加量的增加而提高,但再生速率却呈现下降趋势。再生过程中,吸收剂在升温阶段均发生了CO2再生,且混合吸收剂再生效果要优于单一吸收剂。综合考虑CO2吸收速率、再生速率和CO2循环携带量,MDEA与活化剂质量配比为3∶2时所组成的混合吸收剂的沼气CO2吸收-再生综合性能最优。沼气CO2分离成本对比分析

  2. 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 ...

  3. Choosing co-substrates to supplement biogas production from animal slurry - A life cycle assessment of the environmental consequences

    DEFF Research Database (Denmark)

    Croxatto Vega, Giovanna Catalina; Ten Hoeve, Marieke; Birkved, Morten;

    2014-01-01

    Biogas production from animal slurry can provide substantial contributions to reach renewable energy targets, yet due to the low methane potential of slurry, biogas plants depend on the addition of co-substrates to make operations profitable. The environmental performance of three underexploited co...

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    Biogas production is an economically attractive technology that has gained momentum worldwide over the past years. Biogas is produced by a biologically mediated process, widely known as "anaerobic digestion." This process is performed by a specialized and complex microbial community, in which dif...

  5. 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.

  6. Biogas production using water hyacinths to meet collective energy needs in a sahelian country

    OpenAIRE

    Almoustapha, O.; Kenfack, S.; Millogo-Rasolodimby, J.

    2009-01-01

    This paper presents a pilot project that investigates the possibility of producing biogas from a mixture of water hyacinth and fresh rumen residue – replacing firewood as a source of fuel – to meet the energy needs of a maternity facility in Niamey (Niger). The discontinuous-type installation (batch reactors) is made up of six digesters measuring 5 m3 each. The output during hot and cool seasons, 0.52 m3 and 0.29 m3 respectively of biogas per m3 of digester per day, has met the energy needs of...

  7. Biogas production: This is how the Swedes do it

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    In Sweden, biogas is produced according to the Abetong-Sabema process. Thermophilic microorganisms are employed for anaerobic digestion. At 55/sup 0/C, residence time is 3 to 5 days. In contrast to other facilities in application, this means a reduction of the digestion space by a factor of six or seven and, thus, reduced investments. Desinfection of the manure takes place under these high temperatures. With a facility operating since 1978, liquid manure is pumped directly from the stable into a 20 cbm prechamber located in the interior of the gas reactor. The liquid manure is heated to 55/sup 0/C and then discharged into the 240 cbm main chamber where the liquid manure is constantly stirred in order to avoid float layers and deposits. The biogas is compressed, stored and combusted in a Fiat ''Totem'' engine producing electricity and hot water. The facility produces 210,000 cbm of biogas. 310,000 kWh of electricity and 590 kWh of heat are available as useful energy. App. 60% of the total energy can be utilized under Swedish conditions. A 40 cbm facility employs a horizontal cylindric main chamber and a separate prechamber. This facility will work without stirring.

  8. Intensification of biogas production using pretreatment based on hydrodynamic cavitation.

    Science.gov (United States)

    Patil, Pankaj N; Gogate, Parag R; Csoka, Levente; Dregelyi-Kiss, Agota; Horvath, Miklos

    2016-05-01

    The present work investigates the application of hydrodynamic cavitation (HC) for the pretreatment of wheat straw with an objective of enhancing the biogas production. The hydrodynamic cavitation reactor is based on a stator and rotor assembly. The effect of three different speeds of rotor (2300, 2500, 2700 rpm), wheat straw to water ratios (0.5%, 1% and 1.5% wt/wt) and also treatment times as 2, 4 and 6 min have been investigated in the work using the design of experiments (DOE) approach. It was observed that the methane yield of 31.8 ml was obtained with untreated wheat straw whereas 77.9 ml was obtained with HC pre-treated wheat straw confirming the favourable changes during the pre-treatment. The combined pre-treatment using KOH and HC gave maximum yield of biogas as 172.3 ml. Overall, it has been established that significant enhancement in the biogas production can be obtained due to the pretreatment using HC which can also be further intensified by combination with chemical treatment. PMID:26639635

  9. Intensification of biogas production using pretreatment based on hydrodynamic cavitation.

    Science.gov (United States)

    Patil, Pankaj N; Gogate, Parag R; Csoka, Levente; Dregelyi-Kiss, Agota; Horvath, Miklos

    2016-05-01

    The present work investigates the application of hydrodynamic cavitation (HC) for the pretreatment of wheat straw with an objective of enhancing the biogas production. The hydrodynamic cavitation reactor is based on a stator and rotor assembly. The effect of three different speeds of rotor (2300, 2500, 2700 rpm), wheat straw to water ratios (0.5%, 1% and 1.5% wt/wt) and also treatment times as 2, 4 and 6 min have been investigated in the work using the design of experiments (DOE) approach. It was observed that the methane yield of 31.8 ml was obtained with untreated wheat straw whereas 77.9 ml was obtained with HC pre-treated wheat straw confirming the favourable changes during the pre-treatment. The combined pre-treatment using KOH and HC gave maximum yield of biogas as 172.3 ml. Overall, it has been established that significant enhancement in the biogas production can be obtained due to the pretreatment using HC which can also be further intensified by combination with chemical treatment.

  10. Anaerobic digestion of corn stovers for methane production in a novel bionic reactor.

    Science.gov (United States)

    Zhang, Meixia; Zhang, Guangming; Zhang, Panyue; Fan, Shiyang; Jin, Shuguang; Wu, Dan; Fang, Wei

    2014-08-01

    To improve the biogas production from corn stovers, a new bionic reactor was designed and constructed. The bionic reactor simulated the rumen digestion of ruminants. The liquid was separated from corn stovers and refluxed into corn stovers again, which simulated the undigested particles separated from completely digested materials and fed back again for further degradation in ruminant stomach. Results showed that the bionic reactor was effective for anaerobic digestion of corn stovers. The liquid amount and its reflux showed an obvious positive correlation with biogas production. The highest biogas production rate was 21.6 ml/gVS-addedd, and the total cumulative biogas production was 256.5 ml/gVS-added. The methane content in biogas ranged from 52.2% to 63.3%. The degradation of corn stovers were greatly enhanced through simulating the animal digestion mechanisms in this bionic reactor. PMID:24923659

  11. Anaerobic digestion of corn stovers for methane production in a novel bionic reactor.

    Science.gov (United States)

    Zhang, Meixia; Zhang, Guangming; Zhang, Panyue; Fan, Shiyang; Jin, Shuguang; Wu, Dan; Fang, Wei

    2014-08-01

    To improve the biogas production from corn stovers, a new bionic reactor was designed and constructed. The bionic reactor simulated the rumen digestion of ruminants. The liquid was separated from corn stovers and refluxed into corn stovers again, which simulated the undigested particles separated from completely digested materials and fed back again for further degradation in ruminant stomach. Results showed that the bionic reactor was effective for anaerobic digestion of corn stovers. The liquid amount and its reflux showed an obvious positive correlation with biogas production. The highest biogas production rate was 21.6 ml/gVS-addedd, and the total cumulative biogas production was 256.5 ml/gVS-added. The methane content in biogas ranged from 52.2% to 63.3%. The degradation of corn stovers were greatly enhanced through simulating the animal digestion mechanisms in this bionic reactor.

  12. Performance studies of a new core cooling monitor in a boiling water reactor

    International Nuclear Information System (INIS)

    Performance studies of a new type of core cooling monitors have been carried out in the Barsebaeck Nuclear Power Station during the operation periods 1988-10-04 to 1989-07-05, 1989-08-03 to 1990-09-05 and 1990-09-28 to 1991-07-04. The results showed that the monitors, which were placed inside the reactor core, are very sensitive to variations of the reactor operating conditions, and that 34 months of irradiation did not influence the signals from the monitors. Experiments were also carried out in a 160 bar loop, where sudden uncovers of the monitors were achieved by decreasing the liquid level of the coolant surrounding the monitors. The experiments included the pressures of 5, 20, 50, 70 and 155 bar, and the responses to uncover were in the ranges between 11 and 82 mV/sec or a total step change of 2 V at typical BWR conditions. This is of the order of two decades higher than the responses from monitors based on thermocouple readings. The monitors can be operated in two modes, the core cooling mode and the temperature mode. In the former mode the electrical current is 3-4 A, and in the latter mode, where the monitor actually serves as a thermometer, the current is in the order of 50-100 mA. In the laboratory the monitors have been studied for temperatures up to 1265 deg. C, which is very useful in case of a severe reactor accident. Thus, during such events the temperatures in the reactor core could be followed up to this level and the monitors could also be used to activate certain safety equipment. The function as well as the design of the instrument is verified in laboratory experiments, computer calculations and reactor tests and is now ready for implementation in the BWR instrumentation. In summary: 1. The proposed monitor can operate in two modes; the core cooling mode and the temperature mode. 2. Laboratory studies have shown that the responses to uncover are two decades higher than signals from monitors based on thermocouple readings. 3. No effects of

  13. 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

  14. Techno-Economic Analysis of Biogas Utilization as an Alternative Fuel

    Directory of Open Access Journals (Sweden)

    Merry Indahsari Devi

    2014-07-01

    Full Text Available This paper will discuss the feasibility and economic analysis of biogas energy as a supply for the diesel engine generator. The techno-economic analysis was performed by using three parameters which are Net Present Value (NPV, Internal Rate of Return (IRR, and Payback Period (PP as the feasibility indicators of the biogas power plant project. Calculation of substitution was obtained from the comparison between data of diesel engine using diesel fuel and dual-fuel with biogas. Economic calculations include the substitution percentage of diesel fuel by biogas for dual-fuel. Meanwhile, the calculation of savings was based on the ratio of energy content between diesel fuel and biogas. The eventual outcome is determined using economic comparison between the use of diesel fuel and dual-fuel mode. Feasibility shows that the pilot plant of 1 to 6 kWh using diesel fuel and dual-fuel are not feasible while techno-economic parameter analysis shows that NPV<0, IRRbiogas power plant project is feasible in some conditions such as there is no labor cost, and 5 and 6 kWh will be feasible under the assumption that expenses for machine maintenance is eliminated. However, even when applying both conditions where biogas is feasible, diesel fuel is still not.

  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. Comparative study of stability and half-life of enzymes and enzyme aggregates implemented in anaerobic biogas processes

    Energy Technology Data Exchange (ETDEWEB)

    Binner, Roman; Schmack, Doris; Reuter, Monika [Research and Development Department, Schmack Biogas GmbH, Schwandorf (Germany); Menath, Veronika; Huber, Harald; Thomm, Michael [University of Regensburg, Department of Microbiology, Regensburg (Germany); Bischof, Franz [University of Applied Sciences Amberg-Weiden, Faculty of Mechanical Engineering/Environmental Engineering, Amberg (Germany)

    2011-03-15

    Anaerobic digestion of mainly energy crops gains more and more importance in developing a sustainable energy supply. Therefore, the optimization of gas yield plays a major role in specific research attempts and economical considerations. One possibility to increase natural polymer degradation and concomitantly energy efficiency is the addition of exoenzymes to biogas facilities to enforce the primary degradation steps for biogas production. Therefore, in the present study, the stability and activity of five externally added enzyme mixtures to anaerobic biogas processes were investigated. Protein assays using soluble fractions of different biogas plants incubated together with the enzyme mixtures revealed that, within about 10 min, the externally added enzymes were mostly degraded. This very low stability in biogas reactors makes it unlikely that the addition of enzymes contributes significantly to degradation of macromolecules in the biogas process. Even the addition of protease inhibitors did not protect the added enzyme mixtures from degradation in most experiments. Furthermore, the influence of added enzymes on the viscosity of the biomass was tested. Only a marginal effect was obtained, when applying a tenfold higher concentration of added enzymes as proposed for practical use. The same result was achieved when commercially available enzymes were added to technical-scale fermentations using corn silage as monosubstrate. Therefore, these studies did not provide evidence that the addition of external enzymes into anaerobic degradation systems increases the methane yield in biogas facilities. (orig.)

  17. [Performance and substrate inhibition kinetics model of nitritation process in inverse turbulent bed reactor].

    Science.gov (United States)

    Jin, Ren-Cun; Yang, Guang-Feng; Ma, Chun; Zheng, Ping

    2011-01-01

    The performance of a nitritation inverse turbulent bed (ITB) reactor was tested and the substrate inhibition kinetics characteristics of the reactor were analyzed. The results showed that a rapid reactor startup could be realized within 20 d with a strategy that combined the biofilm attachment method named "precoating carrier treatment" and "rapid suspending sludge discharge", with the feeding strategy named "low strength, high load". When operated at a hydraulic retention time of 3 h and influent NH4(+) -N of 700 mg x L(-1), corresponding to a nitrogen loading rate of 5.60 kg x (m3 x d)(-1), a maximum NH4(+) -N removal rate of 4.25 kg x (m3 x d)(-1) was observed. The maximum NO2(-) -N production rate was as high as 3.70 kg x (m3 x d)(-1). Four inhibition kinetic models (Haldane, Edwards, Aiba and Luong) were analyzed through non-linear regression to represent the inhibitions caused by substrate of nitritation process and the parameters of models were gained, which were r(max) of 1.84 kg x (m3 x d)(-1), K(IH) of 97.4 mg x L(-1) and K(m) of 0.188 mg x L(-1) for Haldane model, and r(max) of 1.83 kg x (m3 x d)(-1) and K(IA) of 114 mg x L(-1) for Aiba model. It was proposed that Haldane and Aiba models well fitted the process data harvested in the ITB reactor.

  18. Irradiation performance of (Th,Pu)O2 fuel under Pressurized Water Reactor conditions

    Science.gov (United States)

    Boer, B.; Lemehov, S.; Wéber, M.; Parthoens, Y.; Gysemans, M.; McGinley, J.; Somers, J.; Verwerft, M.

    2016-04-01

    This paper examines the in-pile safety performance of (Th,Pu)O2 fuel pins under simulated Pressurized Water Reactor (PWR) conditions. Both sol-gel and SOLMAS produced (Th,Pu)O2 fuels at enrichments of 7.9% and 12.8% in Pu/HM have been irradiated at SCK·CEN. The irradiation has been performed under PWR conditions (155 bar, 300 °C) in a dedicated loop of the BR-2 reactor. The loop is instrumented with flow and temperature monitors at inlet and outlet, which allow for an accurate measurement of the deposited enthalpy. Between 2004 and 2006, four fuel segments were irradiated, with on-line recording of centerline temperature and rod pressure of the two instrumented rods and intermittent non-destructive hot-cell investigations of the other two non-instrumented rods. At the end of 2006, the instrumented rods were unloaded for hot-cell investigations. The hot-cell investigations reduced uncertainties in the power history to build a reliable and consistent irradiation history which can be used to assess and validate fuel performance codes. The on-line recorded temperatures of the instrumented rods are presented in this paper and are compared to corresponding calculations on the basis of the power history. One of the non-instrumented rods was re-inserted in the reactor in 2012 and attained a peak burnup level of 37 GWd/tHM by the end of 2014. The combined data set of on-line measurements and post irradiation examinations enables further code validation. In this context, the results of the in-house MACROS code of SCK·CEN have been compared with the experimental results. The code contains dedicated (Th,Pu)O2 models for the calculation of the thermal conductivity as a function of the burnup and models that determine the radial power profile within the pellet.

  19. Performance and kinetic process analysis of an Anammox reactor in view of application for landfill leachate treatment.

    Science.gov (United States)

    Gao, Junling; Chys, Michael; Audenaert, Wim; He, Yanling; Van Hulle, Stijn W H

    2014-01-01

    Anammox has shown its promise and low cost for removing nitrogen from high strength wastewater such as landfill leachate. A reactor was inoculated with nitrification-denitrification sludge originating from a landfill leachate treating waste water treatment plant. During the operation, the sludge gradually converted into red Anammox granular sludge with high and stable Anammox activity. At a maximal nitrogen loading rate of 0.6 g N l(-1) d(-1), the reactor presented ammonium and nitrite removal efficiencies of above 90%. In addition, a modified Stover-Kincannon model was applied to simulate and assess the performance of the Anammox reactor. The Stover-Kincannon model was appropriate for the description of the nitrogen removal in the reactor with the high regression coefficient values (R2 = 0.946) and low Theil's inequality coefficient (TIC) values (TIC reactor should be 3.69 g N l(-1) d(-).

  20. Effect of Thermal Degradation on High Temperature Ultrasonic Transducer Performance in Small Modular Reactors

    Science.gov (United States)

    Bilgunde, Prathamesh N.; Bond, Leonard J.

    Prototype ultrasonic NDT transducers for use in immersion in coolants for small modular reactors have shown low signal to noise ratio. The reasons for the limitations in performance at high temperature are under investigation, and include changes in component properties. This current work seeks to quantify the issue of thermal expansion and degradation of the piezoelectric material in a transducer using a finite element method. The computational model represents an experimental set up for an ultrasonic transducer in a pulse-echo mode immersed in a liquid sodium coolant. Effect on transmitted and received ultrasonic signal due to elevated temperature (∼200oC) has been analysed.

  1. Performance of anaerobic fixed film down-flow reactor for spent wash treatment

    International Nuclear Information System (INIS)

    The performance of a bench scale 'anaerobic fixed-film down-flow bioreactor' with glass bead as a packing material for treatment of high strength wastewater (spent wash) in terms of percent Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD) removal at various temperatures has been studied. The reactor is operated at temperatures ranging from 35 deg. C to 51 deg. for hydraulic retention time (HRT) of 15 days. For this hydraulic retention time, experimental results show that COD removal is 60-64.8 % and BOD removal is 65.3 - 70%. The maximum percent COD and BOD removal is observed at 41 deg. C. (author)

  2. CONVERSION OF ORGANIC MANURE INTO BIOGAS

    Directory of Open Access Journals (Sweden)

    Dario Brdarić

    2009-12-01

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

  3. Small-scale household biogas digesters

    DEFF Research Database (Denmark)

    Bruun, Sander; Jensen, Lars Stoumann; Khanh Vu, Van Thi;

    2014-01-01

    There are a number of advantages to small-scale biogas production on farms, including savings on firewood or fossil fuels and reductions in odour and greenhouse gas emissions. For these reasons, governments and development aid agencies have supported the installation of biogas digesters. However......, biogas digesters are often poorly managed and there is a lack of proper distribution systems for biogas. This results in methane being released inadvertently through leaks in digesters and tubing, and intentionally when production exceeds demand. As methane has a global warming potential 25 times greater......% of the produced biogas is released, depending on the type of fuel that has been replaced. The limited information available as regards methane leaking from small-scale biogas digesters in developing countries indicates that emissions may be as high as 40%. With the best estimates of global numbers of small...

  4. The economics of biogas in Denmark

    DEFF Research Database (Denmark)

    Jacobsen, Brian H.; Laugesen, Frederik Møller; Dubgaard, Alex

    2013-01-01

    Denmark has been one of the leading European Countries in using Biogas for Combined Heat and Power (CHP), since the 1980’ties. However, in the last two decades, the increase has been limited. A new energy policy aimed at increasing the profitability of Biogas was introduced in the spring of 2012....... The analysis here shows that the new agreement will improve the profitability of biogas plants and increase the biogas production although the political ambition of an increase from 4 PJ to 14 PJ by 2020 seems unlikely. The analysis shows that biogas plants can be profitable even if the input is a mix....... Even without an investment subsidy of 30%, the case 2012, is profitable. Financing the biogas plants is a challenge. The interest used of 4.25% requires bank guaranties which in practice can be hard to get. Using a more likely interest of 7-8% reduces the yearly profit to 400.000 €. The socioeconomic...

  5. Biogas production on dairy farms: A Croatia case study

    Directory of Open Access Journals (Sweden)

    Nikola Bilandžija

    2013-03-01

    Full Text Available In order to determine the differences in the production and composition of biogas as well as the quality of digested residue from anaerobic digestion of the raw materials generated by dairy farms in Croatia, investigations were undertaken in the biogas laboratory facility of the Faculty of Agriculture. The investigated raw materials were: dairy manure, corn silage, haylage and equal-measure mix (1/3 of all raw materials. For each substrate, three runs of experiments were performed with the same overall hydraulic retention time (40 days and temperature of digestion (35 °C in mesophilic conditions. The investigations found that the most efficient production of biogas was from corn silage. As for biogas composition, it was acceptable in all investigated samples both in energy and environmental terms. Digested residues, which are mildly alkaline, have low dry matter content. About 70 % of dry matter content is organic. On the basis of N:P:K analysis and the analysis of biogenic elements values and heavy metal values, it can be concluded that digested residues of all input raw materials can be used in agricultural production.

  6. Applied research performed and in progress by using a Triga nuclear reactor

    International Nuclear Information System (INIS)

    The TRIGA reactor of ENEA Casaccia has been used in different applied research fields among which particularly the following applications of neutron activation analysis (NAA) are reported: a) Environmental. The results are referred to the determination of about 30 microelements in marine suspended particulate matter and sediments. A study was also performed on the impurities of the filters used for environmental studies and an intercomparison was carried out on two sediments distributed by the Joint Research Center, Ispra, Euratom. b) Forensic. Many applications of NAA have been performed in this field on request of Italian Courts for determination of gunshot residues, particularly on paraffin gloves and clothes of person suspected to have handled and/or fired a gun; also the firing distance was determined in some cases. c) Plant nutrition. The uptake of cobalt and zinc has been studied in pot and the tolerance index was established in cooperation with the Istituto di Cerealicoltura Roma. d) Geological. The rare earth concentrations normalized with respect to the chondritic rocks can be utilized for petrogenetic studies and some determinations have been performed both by thermal and epithermal NAA on some rock samples. A program of utilization of the TRIGA reactor in the field of the preparation of a Ir-191m generator has been provided for applications in the pediatric angiography. For this purpose a cooperation with the Clinical Physiology Institute of National Research Council of Pisa has been established. (author)

  7. Sodium effects on mechanical performance and consideration in high temperature structural design for advanced reactors

    International Nuclear Information System (INIS)

    Sodium environmental effects are key limiting factors in the high temperature structural design of advanced sodium-cooled reactors. A guideline is needed to incorporate environmental effects in the ASME design rules to improve the performance reliability over long operating times. This paper summarizes the influence of sodium exposure on mechanical performance of selected austenitic stainless and ferritic/martensitic steels. Focus is on Type 316SS and mod.9Cr-1Mo. The sodium effects were evaluated by comparing the mechanical properties data in air and sodium. Carburization and decarburization were found to be the key factors that determine the tensile and creep properties of the steels. A beneficial effect of sodium exposure on fatigue life was observed under fully reversed cyclic loading in both austenitic stainless steels and ferritic/martensitic steels. However, when hold time was applied during cyclic loading, the fatigue life was significantly reduced. Based on the mechanical performance of the steels in sodium, consideration of sodium effects in high temperature structural design of advanced fast reactors is discussed.

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

    NARCIS (Netherlands)

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

  9. Stability of an anaerobic reactor with support means in the treatment of cassava through the monitoring of relationship AV/AT specific and production of biogas; Estabilidade de um reator anaerobio com meio suporte no tratamento da manipueira atraves do monitoramento da relacao AV/AT e producao especifica de biogas

    Energy Technology Data Exchange (ETDEWEB)

    Kunzleri, Kathia; Watthier, Elisangela; Gomes, Simone D.; Miguel, Joao F.A. [Universidade Estadual do Oeste do Parana (UNIOESTE), Cascavel, PR (Brazil); Andreani, Cristina Lurdes [Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brasilia, DF (Brazil)

    2010-07-01

    This study aimed to evaluate the removal of different organic loading in an anaerobic reactor for treatment of cassava wastewater, and as a medium bamboo rings. Cassava wastewater study is derived from a starch industry. The wastewater was characterized following the method described in Standard Methods for Examination of Water and Wastewater. The reactor was constructed of PVC, with a volume of 6.8 liters. The results were evaluated by variance analysis (parametric ANOVA) using the software Statistica 7.0. We observed a higher yield for the charge of 5, 601 (4) gDQO / L day, the ratio av/at was below 0.5 thus ensuring system stability. (author)

  10. Prediction of Hydraulic Performance of a Scaled-Down Model of SMART Reactor Coolant Pump

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Sun Guk; Park, Jin Seok; Yu, Je Yong; Lee, Won Jae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-08-15

    An analysis was conducted to predict the hydraulic performance of a reactor coolant pump (RCP) of SMART at the off-design as well as design points. In order to reduce the analysis time efficiently, a single passage containing an impeller and a diffuser was considered as the computational domain. A stage scheme was used to perform a circumferential averaging of the flux on the impeller-diffuser interface. The pressure difference between the inlet and outlet of the pump was determined and was used to compute the head, efficiency, and break horse power (BHP) of a scaled-down model under conditions of steady-state incompressible flow. The predicted curves of the hydraulic performance of an RCP were similar to the typical characteristic curves of a conventional mixed-flow pump. The complex internal fluid flow of a pump, including the internal recirculation loss due to reverse flow, was observed at a low flow rate.

  11. Feasibility of biohydrogen production from cheese whey using a UASB reactor: Links between microbial community and reactor performance

    Energy Technology Data Exchange (ETDEWEB)

    Castello, E.; Garcia y Santos, C.; Borzacconi, L. [Chemical Engineering Institute, School of Engineering, University of the Republic, Herrera y Reissig 565, Montevideo (Uruguay); Iglesias, T.; Paolino, G.; Wenzel, J.; Etchebehere, C. [Microbiology Department, School of Science and School of Chemistry, University of the Republic, General Flores 2124, Montevideo (Uruguay)

    2009-07-15

    The present study examines the feasibility of producing hydrogen by dark fermentation using unsterilised cheese whey in a UASB reactor. A lab-scale UASB reactor was operated for more than 250 days and unsterilised whey was used as the feed. The evolution of the microbial community was studied during reactor operation using molecular biology tools (T-RFLP, 16S rRNA cloning library and FISH) and conventional microbiological techniques. The results showed that hydrogen can be produced but in low amounts. For the highest loading rate tested (20 gCOD/L.d), hydrogen production was 122 mL H{sub 2}/L.d. Maintenance of low pH (mean = 5) was insufficient to control methanogenesis; methane was produced concomitantly with hydrogen, suggesting that the methanogenic biomass adapted to the low pH conditions. Increasing the loading rate to values of 2.5 gCOD/gVSS.d favoured hydrogen production in the reactor. Microbiological studies showed the prevalence of fermentative organisms from the genera Megasphaera, Anaerotruncus, Pectinatus and Lactobacillus, which may be responsible for hydrogen production. However, the persistence of methanogenesis and the presence of other fermenters, not clearly recognised as hydrogen producers indicates that competition for the substrate may explain the low hydrogen production. (author)

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

    Science.gov (United States)

    Treu, Laura; Kougias, Panagiotis G; Campanaro, Stefano; Bassani, Ilaria; Angelidaki, Irini

    2016-09-01

    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 is comprised by a consortium of unknown species. A comparative analysis between the genome bins of the current study and those extracted from a previous metagenomic assembly demonstrated a similar phylogenetic distribution of the main taxa. Finally, this analysis led to the identification of a subset of common microbes that could be considered as the core essential group in biogas production. PMID:27243603

  13. Risk assessment of biogas in kitchens

    OpenAIRE

    Leroux, Carole; Modelon, Hugues; Rousselle, Christophe; Bellenfant, Gaël; Ramalho, Olivier; Jaeg, Jean-Paul; Zdanevitch, Isabelle; Naja, Ghinwa M.

    2009-01-01

    The health risk associated with human exposure to pollutants while using biogas for cooking was assessed following the methodology described by the US - National Research Council. Information of hazardous compounds and compositions of several biogas types were extracted from scientific literature. Compositions were dependent on the biogas origin (production process). First, a quantitative approach was conducted to identify substances with a high health risk based on their Human Toxicity Value...

  14. Cavitation for improved sludge conversion into biogas

    OpenAIRE

    Stoop, A.H.; Bakker, T.W.; Kramer, H.J.M.

    2015-01-01

    In several studies the beneficial influence of pre-treatment of waste activated sludge with cavitation on the biogas production was demonstrated. It is however, still not fully certain whether this effect should be mainly contributed to an increase in conversion rate of organics into biogas by anaerobic bacteria, and how much cavitation increases the total biogas yield. An increase in yield is only the case if cavitation can further disrupt otherwise inaccessible cell membrane structures and ...

  15. ORGANIC WASTE USED IN AGRICULTURAL BIOGAS PLANTS

    Directory of Open Access Journals (Sweden)

    Joanna Kazimierowicz

    2014-04-01

    Full Text Available Treatment of organic waste is an ecological and economical problem. Searching method for disposal of these wastes, interest is methane fermentation. The use of this process in agricultural biogas plants allows disposal of hazardous waste, obtaining valuable fertilizer, while the production of ecologically clean fuel – biogas. The article presents the characteristics of organic waste from various industries, which make them suitable for use as substrates in agricultural biogas plants.

  16. ORGANIC WASTE USED IN AGRICULTURAL BIOGAS PLANTS

    OpenAIRE

    Joanna Kazimierowicz

    2014-01-01

    Treatment of organic waste is an ecological and economical problem. Searching method for disposal of these wastes, interest is methane fermentation. The use of this process in agricultural biogas plants allows disposal of hazardous waste, obtaining valuable fertilizer, while the production of ecologically clean fuel – biogas. The article presents the characteristics of organic waste from various industries, which make them suitable for use as substrates in agricultural biogas plants.

  17. Tratamento térmico de lodo anaeróbio com utilização do biogás gerado em reatores UASB: avaliação da autossustentabilidade do sistema e do efeito sobre a higienização e a desidratação do lodo Thermal treatment of anaerobic sludge utilizing biogas produced in UASB reactors: evaluation of system self-sustainability and the effect on sludge hygienization and dehydration

    Directory of Open Access Journals (Sweden)

    Eduardo Sales Machado Borges

    2009-09-01

    Full Text Available O presente trabalho objetiva avaliar a eficiência do biogás gerado em reatores UASB como fonte de energia para higienização térmica do lodo excedente, atentando-se ainda para a autossustentabilidade do sistema e para a avaliação do desaguamento do lodo tratado termicamente. Foi desenvolvido em um aparato experimental em escala de demonstração constituído de reator UASB, reservatório de biogás, reator térmico e leitos de secagem. A autossustentabilidade foi verificada por meio de balanço térmico teórico e de testes experimentais de higienização térmica. Estes testes indicaram que o aproveitamento da energia térmica do biogás foi suficiente para aquecer o lodo em temperaturas de 55 a 65ºC, durante três a cinco horas, possibilitando a completa eliminação de ovos viáveis de helmintos. No entanto, o processo de desidratação se mostrou muito mais difícil para o lodo tratado termicamente.The objective of this research was to determine how effectively biogas produced in UASB reactors could be used as a source of heat for the thermal hygienization of excess anaerobic sludge, whether the system can operate on a self-sustained basis and how the dehydration of the thermally treated sludge behave. The experiments were conducted in a demonstration-scale setup comprising UASB reactor, biogas holder, thermal reactor and sludge drying beds. The self-sustainability of the system was evaluated by the systemâ€TMs theoretical thermal balance and by experimental hygienization tests. These tests indicated that the recovery of thermal energy from the biogas was sufficient to heat the sludge at temperatures in the range of 55 to 65ºC, for three to five hours, allowing the complete elimination of viable helminth eggs. However, the dehydration process showed to be much more difficult for the thermally treated sludge.

  18. Static and dynamic performance tests of nuclear powered ship Mutsu reactor (report on nuclear ship Mutsu power-up tests)

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Toshihisa; Kusunoki, Tsuyoshi; Ochiai, Masa-aki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Tanaka, Yoshimi; Inoue, Kimio; Yao, Toshiaki; Kamai, Satoshi; Kitamura, Toshikatsu

    1992-08-01

    The power-up tests of the Mutsu reactor were performed from March 29th 1990 to December 14th. The tests were divided into six phases: The tests Phase 0 and Phase 1 were done in the state that the ship was moored at the quay of Sekinehama port in March and April; The tests Phase 2, Phase 3, Phase 4, and Phase 5 were done on the Pacific Ocean from July to December. Present report describes the test results on the static and dynamic plant performance. On static plant performance tests, there are 13 test items including measurements of primary system heat balance at low and high power levels, a virgin run of feed water pump with SG steam, a change-over test of steam supply of auxiliary boiler to SG. On the dynamic plant performance, there are 11 test items including a test of reactor power auto-control system, a test of main feed water auto-control system, a test of small load variation, a load increasing test, a turbine trip test, tests of ahead and astern maneuvering, a test of single loop operation, and a reactor scram test. The reactor power for each item`s test was increased step by step from zero power to the goal of rated power of 100 %, 36 MWt. In order to confirm proper reactor system performance, criteria were laid down for the static and dynamic tests: for example, (1) reactor scram shall not occur, (2) pressurizer relief valve and steam generator safety valve shall not work, and (3) after the transients reactor systems shall become the steady state without manual adjustment of the reactor control system. The test results satisfied these criteria and some of test data showed that reactor had much more margin in any performance for design. It is verified, therefore, that the Mutsu reactor systems have adequate performances as a marine reactor and that one is capable to respond smoothly and safely to the load of ship`s demand. (author).

  19. Static and dynamic performance tests of nuclear powered ship Mutsu reactor (report on nuclear ship Mutsu power-up tests)

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Toshihisa; Kusunoki, Tsuyoshi; Ochiai, Masa-aki (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment); Tanaka, Yoshimi; Inoue, Kimio; Yao, Toshiaki; Kamai, Satoshi; Kitamura, Toshikatsu.

    1992-08-01

    The power-up tests of the Mutsu reactor were performed from March 29th 1990 to December 14th. The tests were divided into six phases: The tests Phase 0 and Phase 1 were done in the state that the ship was moored at the quay of Sekinehama port in March and April; The tests Phase 2, Phase 3, Phase 4, and Phase 5 were done on the Pacific Ocean from July to December. Present report describes the test results on the static and dynamic plant performance. On static plant performance tests, there are 13 test items including measurements of primary system heat balance at low and high power levels, a virgin run of feed water pump with SG steam, a change-over test of steam supply of auxiliary boiler to SG. On the dynamic plant performance, there are 11 test items including a test of reactor power auto-control system, a test of main feed water auto-control system, a test of small load variation, a load increasing test, a turbine trip test, tests of ahead and astern maneuvering, a test of single loop operation, and a reactor scram test. The reactor power for each item's test was increased step by step from zero power to the goal of rated power of 100 %, 36 MWt. In order to confirm proper reactor system performance, criteria were laid down for the static and dynamic tests: for example, (1) reactor scram shall not occur, (2) pressurizer relief valve and steam generator safety valve shall not work, and (3) after the transients reactor systems shall become the steady state without manual adjustment of the reactor control system. The test results satisfied these criteria and some of test data showed that reactor had much more margin in any performance for design. It is verified, therefore, that the Mutsu reactor systems have adequate performances as a marine reactor and that one is capable to respond smoothly and safely to the load of ship's demand. (author).

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

    OpenAIRE

    WAN AZLINA WAN AB KARIM GHANI; AZNI IDRIS

    2009-01-01

    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 perfor...