WorldWideScience

Sample records for biogenic methane production

  1. Enhancement of Biogenic Coalbed Methane Production and Back Injection of Coalbed Methane Co-Produced Water

    Energy Technology Data Exchange (ETDEWEB)

    Song Jin

    2007-05-31

    Biogenic methane is a common constituent in deep subsurface environments such as coalbeds and oil shale beds. Coalbed methane (CBM) makes significant contributions to world natural gas industry and CBM production continues to increase. With increasing CBM production, the production of CBM co-produced water increases, which is an environmental concern. This study investigated the feasibility in re-using CBM co-produced water and other high sodic/saline water to enhance biogenic methane production from coal and other unconventional sources, such as oil shale. Microcosms were established with the selected carbon sources which included coal, oil shale, lignite, peat, and diesel-contaminated soil. Each microcosm contained either CBM coproduced water or groundwater with various enhancement and inhibitor combinations. Results indicated that the addition of nutrients and nutrients with additional carbon can enhance biogenic methane production from coal and oil shale. Methane production from oil shale was much greater than that from coal, which is possibly due to the greater amount of available Dissolved Organic Carbon (DOC) from oil shale. Inconclusive results were observed from the other sources since the incubation period was too low. WRI is continuing studies with biogenic methane production from oil shale.

  2. Sources of biogenic methane to form marine gas hydrates: In situ production or upward migration?

    Energy Technology Data Exchange (ETDEWEB)

    Paull, C.K.; Ussler, W. III; Borowski, W.S.

    1993-09-01

    Potential sources of biogenic methane in the Carolina Continental Rise -- Blake Ridge sediments have been examined. Two models were used to estimate the potential for biogenic methane production: (1) construction of sedimentary organic carbon budgets, and (2) depth extrapolation of modern microbial production rates. While closed-system estimates predict some gas hydrate formation, it is unlikely that >3% of the sediment volume could be filled by hydrate from methane produced in situ. Formation of greater amounts requires migration of methane from the underlying continental rise sediment prism. Methane may be recycled from below the base of the gas hydrate stability zone by gas hydrate decomposition, upward migration of the methane gas, and recrystallization of gas hydrate within the overlying stability zone. Methane bubbles may also form in the sediment column below the depth of gas hydrate stability because the methane saturation concentration of the pore fluids decreases with increasing depth. Upward migration of methane bubbles from these deeper sediments can add methane to the hydrate stability zone. From these models it appears that recycling and upward migration of methane is essential in forming significant gas hydrate concentrations. In addition, the depth distribution profiles of methane hydrate will differ if the majority of the methane has migrated upward rather than having been produced in situ.

  3. Physiology and Genetics of Biogenic Methane-Production from Acetate

    Energy Technology Data Exchange (ETDEWEB)

    Sowers, Kevin R

    2013-04-04

    Biomass conversion catalyzed by methanogenic consortia is a widely available, renewable resource for both energy production and waste treatment. The efficiency of this process is directly dependent upon the interaction of three metabolically distinct groups of microorganisms; the fermentative and acetogenic Bacteria and the methanogenic Archaea. One of the rate limiting steps in the degradation of soluble organic matter is the dismutation of acetate, a predominant intermediate in the process, which accounts for 70 % or more of the methane produced by the methanogens. Acetate utilization is controlled by regulation of expression of carbon monoxide dehydrogensase (COdh), which catalyzes the dismutation of acetate. However, physiological and molecular factors that control differential substrate utilization have not been identified in these Archaea. Our laboratory has identified sequence elements near the promoter of the gene (cdh) encoding for COdh and we have confirmed that these sequences have a role in the in vivo expression of cdh. The current proposal focuses on identifying the regulatory components that interact with DNA and RNA elements, and identifying the mechanisms used to control cdh expression. We will determine whether expression is controlled at the level of transcription or if it is mediated by coordinate interaction of transcription initiation with other processes such as transcription elongation rate and differential mRNA stability. Utilizing recently sequenced methanosarcinal genomes and a DNA microarray currently under development genes that encode regulatory proteins and transcription factors will be identified and function confirmed by gene disruption and subsequent screening on different substrates. Functional interactions will be determined in vivo by assaying the effects of gene dosage and site-directed mutagenesis of the regulatory gene on the expression of a cdh::lacZ operon fusion. Results of this study will reveal whether this critical

  4. Microbially-Enhanced Coal Bed Methane: Strategies for Increased Biogenic Production

    Science.gov (United States)

    Davis, K.; Barhart, E. P.; Schweitzer, H. D.; Cunningham, A. B.; Gerlach, R.; Hiebert, R.; Fields, M. W.

    2014-12-01

    Coal is the largest fossil fuel resource in the United States. Most of this coal is deep in the subsurface making it costly and potentially dangerous to extract. However, in many of these deep coal seams, methane, the main component of natural gas, has been discovered and successfully harvested. Coal bed methane (CBM) currently accounts for approximately 7.5% of the natural gas produced in the U.S. Combustion of natural gas produces substantially less CO2 and toxic emissions (e.g. heavy metals) than combustion of coal or oil thereby making it a cleaner energy source. In the large coal seams of the Powder River Basin (PRB) in southeast Montana and northeast Wyoming, CBM is produced almost entirely by biogenic processes. The in situ conversion of coal to CBM by the native microbial community is of particular interest for present and future natural gas sources as it provides the potential to harvest energy from coal seams with lesser environmental impacts than mining and burning coal. Research at Montana State University has shown the potential for enhancing the subsurface microbial processes that produce CBM. Long-term batch enrichments have investigated the methane enhancement potential of yeast extract as well as algal and cyanobacterial biomass additions with increased methane production observed with all three additions when compared to no addition. Future work includes quantification of CBM enhancement and normalization of additions. This presentation addresses the options thus far investigated for increasing CBM production and the next steps for developing the enhanced in situ conversion of coal to CBM.

  5. Biogenic Methane from Coal: The Oxidation Factor

    Science.gov (United States)

    Gallagher, L. K.; Glossner, A. W.; Landkamer, L.; Figueroa, L. A.; Mandernack, K. W.; Munakata Marr, J.

    2011-12-01

    Vast reserves of coal represent an untapped resource that can be used to produce methane gas, a cleaner energy alternative compared to standard fossil fuels. Microorganisms have demonstrated the ability to utilize coal as a carbon source, producing biogenic methane. With increasing demand for cleaner energy resources, understanding and enhancing biogenic methane production has become an area of active research. The conversion of coal to methane by microorganisms has been demonstrated experimentally by a number of research groups, but the state of the coal used as a substrate has not always been reported and may impact biogenic methane production. Microcosm experiments were designed in order to assess how the oxidation state of coal might influence methane production (e.g. as in a dewatered coal-bed natural gas system). Oxidized and un-oxidized coal samples from the Powder River Basin were incubated in microcosms inoculated with an enrichment culture that was derived from coal. Microcosms were characterized by headspace gas analysis, organic acid production, functional gene abundance (qPCR), and pyrosequencing of the 16S rRNA gene. Although the microbial consortium demonstrated the ability to utilize both oxidized and un-oxidized coal as a sole carbon source to generate methane, it was produced in higher quantities from the un-oxidized coal. This microbial community was dominated by Methanobacteriaceae (45%), epsilon-Proteobacteria (32%) and delta-Proteobacteria (13%). The results of this study provide a basis to develop strategies to enhance biogenic methane production from coal, as well as demonstrate the need for careful substrate preparation for inter-study comparisons.

  6. Methane production in terrestrial arthropods

    Energy Technology Data Exchange (ETDEWEB)

    Hackstein, J.H.P.; Stumm, C.K. (Catholic Univ. of Nijmegen (Netherlands))

    1994-06-07

    The authors have screened more than 110 representatives of the different taxa of terrestrial arthropods for methane production in order to obtain additional information about the origins of biogenic methane. Methanogenic bacteria occur in the hindguts of nearly all tropical representatives of millipedes (Diplopoda), cockroaches (Blattaria), termites (Isoptera), and scarab beetles (Scarabaeidae), while such methanogens are absent from 66 other arthropod species investigated. Three types of symbiosis were found: in the first type, the arthropod's hindgut is colonized by free methanogenic bacteria; in the second type, methanogens are closely associated with chitinous structures formed by the host's hindgut; the third type is mediated by intestinal anaerobic protists with intracellular methanogens. Such symbiotic associations are likely to be a characteristic property of the particular taxon. Since these taxa represent many families with thousands of species, the world populations of methane-producing arthropods constitute an enormous biomass. The authors show that arthropod symbionts can contribute substantially to atmospheric methane.

  7. Bioassay for estimating the biogenic methane-generating potential of coal samples

    Science.gov (United States)

    Jones, E.J.P.; Voytek, M.A.; Warwick, P.D.; Corum, M.D.; Cohn, A.; Bunnell, J.E.; Clark, A.C.; Orem, W.H.

    2008-01-01

    Generation of secondary biogenic methane in coal beds is likely controlled by a combination of factors such as the bioavailability of coal carbon, the presence of a microbial community to convert coal carbon to methane, and an environment supporting microbial growth and methanogenesis. A set of treatments and controls was developed to bioassay the bioavailability of coal for conversion to methane under defined laboratory conditions. Treatments included adding a well-characterized consortium of bacteria and methanogens (enriched from modern wetland sediments) and providing conditions to support endemic microbial activity. The contribution of desorbed methane in the bioassays was determined in treatments with bromoethane sulfonic acid, an inhibitor of microbial methanogenesis. The bioassay compared 16 subbituminous coal samples collected from beds in Texas (TX), Wyoming (WY), and Alaska (AK), and two bituminous coal samples from Pennsylvania (PA). New biogenic methane was observed in several samples of subbituminous coal with the microbial consortium added, but endemic activity was less commonly observed. The highest methane generation [80????mol methane/g coal (56??scf/ton or 1.75??cm3/g)] was from a south TX coal sample that was collected from a non-gas-producing well. Subbituminous coals from the Powder River Basin, WY and North Slope Borough, AK contained more sorbed (original) methane than the TX coal sample and generated 0-23????mol/g (up to 16??scf/ton or 0.5??cm3/g) new biogenic methane in the bioassay. Standard indicators of thermal maturity such as burial depth, nitrogen content, and calorific value did not explain differences in biogenic methane among subbituminous coal samples. No original methane was observed in two bituminous samples from PA, nor was any new methane generated in bioassays of these samples. The bioassay offers a new tool for assessing the potential of coal for biogenic methane generation, and provides a platform for studying the

  8. Deposition of Biogenic Iron Minerals in a Methane Oxidizing Microbial Mat

    Directory of Open Access Journals (Sweden)

    Christoph Wrede

    2013-01-01

    Full Text Available The syntrophic community between anaerobic methanotrophic archaea and sulfate reducing bacteria forms thick, black layers within multi-layered microbial mats in chimney-like carbonate concretions of methane seeps located in the Black Sea Crimean shelf. The microbial consortium conducts anaerobic oxidation of methane, which leads to the formation of mainly two biomineral by-products, calcium carbonates and iron sulfides, building up these chimneys. Iron sulfides are generated by the microbial reduction of oxidized sulfur compounds in the microbial mats. Here we show that sulfate reducing bacteria deposit biogenic iron sulfides extra- and intracellularly, the latter in magnetosome-like chains. These chains appear to be stable after cell lysis and tend to attach to cell debris within the microbial mat. The particles may be important nuclei for larger iron sulfide mineral aggregates.

  9. Deposition of biogenic iron minerals in a methane oxidizing microbial mat.

    Science.gov (United States)

    Wrede, Christoph; Kokoschka, Sebastian; Dreier, Anne; Heller, Christina; Reitner, Joachim; Hoppert, Michael

    2013-01-01

    The syntrophic community between anaerobic methanotrophic archaea and sulfate reducing bacteria forms thick, black layers within multi-layered microbial mats in chimney-like carbonate concretions of methane seeps located in the Black Sea Crimean shelf. The microbial consortium conducts anaerobic oxidation of methane, which leads to the formation of mainly two biomineral by-products, calcium carbonates and iron sulfides, building up these chimneys. Iron sulfides are generated by the microbial reduction of oxidized sulfur compounds in the microbial mats. Here we show that sulfate reducing bacteria deposit biogenic iron sulfides extra- and intracellularly, the latter in magnetosome-like chains. These chains appear to be stable after cell lysis and tend to attach to cell debris within the microbial mat. The particles may be important nuclei for larger iron sulfide mineral aggregates.

  10. Enhanced Microbial Pathways for Methane Production from Oil Shale

    Energy Technology Data Exchange (ETDEWEB)

    Paul Fallgren

    2009-02-15

    Methane from oil shale can potentially provide a significant contribution to natural gas industry, and it may be possible to increase and continue methane production by artificially enhancing methanogenic activity through the addition of various substrate and nutrient treatments. Western Research Institute in conjunction with Pick & Shovel Inc. and the U.S. Department of Energy conducted microcosm and scaled-up reactor studies to investigate the feasibility and optimization of biogenic methane production from oil shale. The microcosm study involving crushed oil shale showed the highest yield of methane was produced from oil shale pretreated with a basic solution and treated with nutrients. Incubation at 30 C, which is the estimated temperature in the subsurface where the oil shale originated, caused and increase in methane production. The methane production eventually decreased when pH of the system was above 9.00. In the scaled-up reactor study, pretreatment of the oil shale with a basic solution, nutrient enhancements, incubation at 30 C, and maintaining pH at circumneutral levels yielded the highest rate of biogenic methane production. From this study, the annual biogenic methane production rate was determined to be as high as 6042 cu. ft/ton oil shale.

  11. Methylotrophic methanogenesis governs the biogenic coal bed methane formation in Eastern Ordos Basin, China.

    Science.gov (United States)

    Guo, Hongguang; Yu, Zhisheng; Liu, Ruyin; Zhang, Hongxun; Zhong, Qiding; Xiong, Zhenghe

    2012-12-01

    To identify themethanogenic pathways present in a deep coal bed methane (CBM) reservoir associated with Eastern Ordos Basin in China, a series of geochemical and microbiological studies was performed using gas and water samples produced from the Liulin CBM reservoir. The composition and stable isotopic ratios of CBM implied a mixed biogenic and thermogenic origin of the methane. Archaeal 16S rRNA gene analysis revealed the dominance of the methylotrophic methanogen Methanolobus in the water produced. The high potential of methane production by methylotrophic methanogens was found in the enrichments using the water samples amended with methanol and incubated at 25 and 35 °C. Methylotrophic methanogens were the dominant archaea in both enrichments as shown by polymerase chain reaction (PCR)–denaturing gradient gel electrophoresis (DGGE). Bacterial 16S rRNA gene analysis revealed that fermentative, sulfate-reducing, and nitrate-reducing bacteria inhabiting the water produced were a factor in coal biodegradation to fuel methanogens. These results suggested that past and ongoing biodegradation of coal by methylotrophic methanogens and syntrophic bacteria, as well as thermogenic CBM production, contributed to the Liulin CBM reserves associated with the Eastern Ordos Basin.

  12. Biochemically enhanced methane production from coal

    Science.gov (United States)

    Opara, Aleksandra

    For many years, biogas was connected mostly with the organic matter decomposition in shallow sediments (e.g., wetlands, landfill gas, etc.). Recently, it has been realized that biogenic methane production is ongoing in many hydrocarbon reservoirs. This research examined microbial methane and carbon dioxide generation from coal. As original contributions methane production from various coal materials was examined in classical and electro-biochemical bench-scale reactors using unique, developed facultative microbial consortia that generate methane under anaerobic conditions. Facultative methanogenic populations are important as all known methanogens are strict anaerobes and their application outside laboratory would be problematic. Additional testing examined the influence of environmental conditions, such as pH, salinity, and nutrient amendments on methane and carbon dioxide generation. In 44-day ex-situ bench-scale batch bioreactor tests, up to 300,000 and 250,000 ppm methane was generated from bituminous coal and bituminous coal waste respectively, a significant improvement over 20-40 ppm methane generated from control samples. Chemical degradation of complex hydrocarbons using environmentally benign reagents, prior to microbial biodegradation and methanogenesis, resulted in dissolution of up to 5% bituminous coal and bituminous coal waste and up to 25% lignite in samples tested. Research results confirm that coal waste may be a significant underutilized resource that could be converted to useful fuel. Rapid acidification of lignite samples resulted in low pH (below 4.0), regardless of chemical pretreatment applied, and did not generate significant methane amounts. These results confirmed the importance of monitoring and adjusting in situ and ex situ environmental conditions during methane production. A patented Electro-Biochemical Reactor technology was used to supply electrons and electron acceptor environments, but appeared to influence methane generation in a

  13. Terrestrial plant methane production

    DEFF Research Database (Denmark)

    Mikkelsen, Teis Nørgaard; Bruhn, Dan; Møller, Ian M.

    We evaluate all experimental work published on the phenomenon of aerobic methane (CH4) generation in terrestrial plants. We conclude that the phenomenon is true. Four stimulating factors have been observed to induce aerobic plant CH4 production, i.e. cutting injuries, increasing temperature...

  14. A contribution of hydrogenotrophic methanogenesis to the biogenic coal bed methane reserves of Southern Qinshui Basin, China.

    Science.gov (United States)

    Guo, Hongguang; Yu, Zhisheng; Thompson, Ian P; Zhang, Hongxun

    2014-11-01

    The activity of methanogens and related bacteria which inhabit the coal beds is essential for stimulating new biogenic coal bed methane (CBM) production from the coal matrix. In this study, the microbial community structure and methanogenesis were investigated in Southern Qinshui Basin in China, and the composition and stable isotopic ratios of CBM were also determined. Although geochemical analysis suggested a mainly thermogenic origin for CBM, the microbial community structure and activities strongly implied the presence of methanogens in situ. 454 pyrosequencing analysis combined with methyl coenzyme-M reductase (mcrA) gene clone library analysis revealed that the archaeal communities in the water samples from both coal seams were similar, with the dominance of hydrogenotrophic methanogen Methanobacterium. The activity and potential of these populations to produce methane were confirmed by the observation of methane production in enrichments supplemented with H2 + CO2 and formate, and the only archaea successfully propagated in the tested water samples was from the genus Methanobacterium. 454 pyrosequencing analysis also recovered the diverse bacterial communities in the water samples, which have the potential to play a role in the coal biodegradation fueling methanogens. These results suggest that the biogenic CBM was generated by coal degradation via the hydrogenotrophic methanogens and related bacteria, which also contribute to the huge CBM reserves in Southern Qinshui Basin, China.

  15. Factors influencing biogenic amines accumulation in dairy products

    Directory of Open Access Journals (Sweden)

    Daniel M. eLinares

    2012-05-01

    Full Text Available Fermented foods are within the food products more often complained of having caused biogenic amines poisoning. Concerning milk-based fermented foods, cheese is the main product likely to contain significant levels of biogenic amines, specially tyramine, histamine and putrescine. Prompted by the increasing awareness of the risks related to dietary uptake of high biogenic amine loads, in this review we report about cheese elaboration and processing technological aspects affecting biogenic amines levels. Synthesis of biogenic amines is possible only when three conditions converge: i availability of the substrate amino acids; ii presence of microorganisms with the appropriate catabolic pathway activated; and iii environmental conditions favorable to the decarboxilation activity. These conditions depend on several factors such as milk treatment (pasteurization, use of starter cultures, NaCl concentration, time and temperature of ripening and preservation, pH… which will be discussed in this chapter.

  16. Preliminary investigation of biogenic gas production in Indonesian low rank coals and implications for a renewable energy source

    Science.gov (United States)

    Susilawati, Rita; Papendick, Sam L.; Gilcrease, Patrick C.; Esterle, Joan S.; Golding, Suzanne D.; Mares, Tennille E.

    2013-11-01

    Indonesia has abundant coal resources at depths suitable to contain substantial volumes of naturally occurring methane, which are currently being explored. Most Indonesian coals are thermally immature, but are composed of hydrogen-rich organic components that are presumed to make them excellent substrates for biogenic methane production. Gas isotope results from pilot wells in South Sumatra, reported in this study, are interpreted to indicate biogenic origins for the methane. Corresponding formation water samples were collected and incubated, and show the presence of indigenous microbial communities capable of producing methane from Indonesian and Australian coal. Although these results are only preliminary, they are promising and support the possibility of Indonesia developing bio renewable energy from coal seams.

  17. Biogenic amines in meat and fermented meat products

    Directory of Open Access Journals (Sweden)

    Joanna Stadnik

    2010-09-01

    Full Text Available Recent trends in food quality and safety promote an increasing search for trace compounds that can affect human health. Biogenic amines belong to this group of substances. They can cause distinctive pharmacological, physiological and toxic effects in organisms. Their amounts are usually increasing as a consequence of the use of poor quality raw materials, during controlled or spontaneous microbial fermentation or in the course of food spoilage. The origin of biogenic amines makes them suitable as chemical indicators of the hygienic quality and freshness of some foods being associated to the degree of food fermentation or degradation. The development of appropriate manufacturing technologies to obtain products free or nearly free from biogenic amines is a challenge for the meat industry. This review briefly summarises current knowledge on the biological implications of biogenic amines on human health and collects data on the factors affecting their formation in meat and fermented meat products.

  18. Estimates for biogenic non-methane hydrocarbons and nitric oxide emissions in the Valley of Mexico

    Science.gov (United States)

    Velasco, Erik

    Biogenic non-methane hydrocarbons (NMHC), 2-methyl-3-buten-2-ol (methylbutenol or MBO) and nitrogen oxide (NO) emissions were estimated for the Valley of Mexico developing a spatially and temporally resolved emission inventory for air quality models. The modeling domain includes all the Metropolitan Mexico City Area, the surrounding forests and agriculture fields. The estimates were based on several sources of land use and land cover data and a biogenic emission model; the biomass density and tree characteristics were obtained from reforestation program data. The biogenic emissions depend also on climatic conditions, mainly temperature and solar radiation. The temperature was obtained from a statistical revision of the last 10 yr data reported by the Mexico City Automatic Atmospheric Monitoring Network, while the solar radiation data were obtained from measurements performed in a typical oak forest in the Valley and from sources of total solar radiation data for Mexico City. The results indicated that 7% of total hydrocarbon emissions in Mexico Valley are due to vegetation and NO emissions from soil contribute with 1% to the total NO x emissions.

  19. A 21st-century shift from fossil-fuel to biogenic methane emissions indicated by 13CH4

    Science.gov (United States)

    Schaefer, Hinrich; Fletcher, Sara E. Mikaloff; Veidt, Cordelia; Lassey, Keith R.; Brailsford, Gordon W.; Bromley, Tony M.; Dlugokencky, Edward J.; Michel, Sylvia E.; Miller, John B.; Levin, Ingeborg; Lowe, Dave C.; Martin, Ross J.; Vaughn, Bruce H.; White, James W. C.

    2016-04-01

    Between 1999 and 2006, a plateau interrupted the otherwise continuous increase of atmospheric methane concentration [CH4] since preindustrial times. Causes could be sink variability or a temporary reduction in industrial or climate-sensitive sources. We reconstructed the global history of [CH4] and its stable carbon isotopes from ice cores, archived air, and a global network of monitoring stations. A box-model analysis suggests that diminishing thermogenic emissions, probably from the fossil-fuel industry, and/or variations in the hydroxyl CH4 sink caused the [CH4] plateau. Thermogenic emissions did not resume to cause the renewed [CH4] rise after 2006, which contradicts emission inventories. Post-2006 source increases are predominantly biogenic, outside the Arctic, and arguably more consistent with agriculture than wetlands. If so, mitigating CH4 emissions must be balanced with the need for food production.

  20. A 21st-century shift from fossil-fuel to biogenic methane emissions indicated by ¹³CH₄.

    Science.gov (United States)

    Schaefer, Hinrich; Mikaloff Fletcher, Sara E; Veidt, Cordelia; Lassey, Keith R; Brailsford, Gordon W; Bromley, Tony M; Dlugokencky, Edward J; Michel, Sylvia E; Miller, John B; Levin, Ingeborg; Lowe, Dave C; Martin, Ross J; Vaughn, Bruce H; White, James W C

    2016-04-01

    Between 1999 and 2006, a plateau interrupted the otherwise continuous increase of atmospheric methane concentration [CH4] since preindustrial times. Causes could be sink variability or a temporary reduction in industrial or climate-sensitive sources. We reconstructed the global history of [CH4] and its stable carbon isotopes from ice cores, archived air, and a global network of monitoring stations. A box-model analysis suggests that diminishing thermogenic emissions, probably from the fossil-fuel industry, and/or variations in the hydroxyl CH4 sink caused the [CH4] plateau. Thermogenic emissions did not resume to cause the renewed [CH4] rise after 2006, which contradicts emission inventories. Post-2006 source increases are predominantly biogenic, outside the Arctic, and arguably more consistent with agriculture than wetlands. If so, mitigating CH4 emissions must be balanced with the need for food production.

  1. Methane production from plant biomass

    Energy Technology Data Exchange (ETDEWEB)

    Zauner, E.

    1985-01-01

    Methane fermentations of plant biomass were performed to increase basic knowledge necessary for development of suitable conversion technologies. Effects of bacterial inoculants, substrate compounds and varied process conditions were analyzed in batch and continuous fermentation experiments. Use of enriched bacterial populations precultured and adapted to plant materials was proved to be advantageous for inoculation. Methane yields and productivities as well as chemical and bacterial composition of digester fluids were determined at various loading rates and retention times during fermentation of different grass and maize silages. Recycling for favorable amounts of decomposed effluent for neutralization of supplied acid raw materials was important to achieve high methane yields. Quantity and composition of acido-, aceto- and methanogenic bacteria were not essentially influenced by changed fermentation conditions. Results of these laboratory examinations have to be completed by long run and scale up experiments to develop control parameters for plant biogas digesters.

  2. The effect of coal bed dewatering and partial oxidation on biogenic methane potential

    Science.gov (United States)

    Jones, Elizabeth J.P.; Harris, Steve H.; Barnhart, Elliott P.; Orem, William H.; Clark, Arthur C.; Corum, Margo D.; Kirshtein, Julie D.; Varonka, Matthew S.; Voytek, Mary A.

    2013-01-01

    Coal formation dewatering at a site in the Powder River Basin was associated with enhanced potential for secondary biogenic methane determined by using a bioassay. We hypothesized that dewatering can stimulate microbial activity and increase the bioavailability of coal. We analyzed one dewatered and two water-saturated coals to examine possible ways in which dewatering influences coal bed natural gas biogenesis by looking at differences with respect to the native coal microbial community, coal-methane organic intermediates, and residual coal oxidation potential. Microbial biomass did not increase in response to dewatering. Small Subunit rRNA sequences retrieved from all coals sampled represented members from genera known to be aerobic, anaerobic and facultatively anaerobic. A Bray Curtis similarity analysis indicated that the microbial communities in water-saturated coals were more similar to each other than to the dewatered coal, suggesting an effect of dewatering. There was a higher incidence of long chain and volatile fatty acid intermediates in incubations of the dewatered coal compared to the water-saturated coals, and this could either be due to differences in microbial enzymatic activities or to chemical oxidation of the coal associated with O2 exposure. Dilute H2O2 treatment of two fractions of structural coal (kerogen and bitumen + kerogen) was used as a proxy for chemical oxidation by O2. The dewatered coal had a low residual oxidation potential compared to the water-saturated coals. Oxidation with 5% H2O2 did increase the bioavailability of structural coal, and the increase in residual oxidation potential in the water saturated coals was approximately equivalent to the higher methanogenic potential measured in the dewatered coal. Evidence from this study supports the idea that coal bed dewatering could stimulate biogenic methanogenesis through partial oxidation of the structural organics in coal once anaerobic conditions are restored.

  3. Re-assessing H and C Isotope Signatures of Biogenic Methane in Coalbeds and Shales: Metabolic Pathways and Alternative Influences

    Science.gov (United States)

    Vinson, D. S.; McIntosh, J. C.; Blair, N. E.; Martini, A. M.

    2013-12-01

    Hydrogen and carbon isotopes of microbial methane have long been applied to distinguish metabolic pathways of methanogenesis (utilization of acetate vs. H2+CO2 by methanogens). However, application of isotopic tools in hydrocarbon and biodegradation systems requires improved understanding of what is actually recorded by C and H isotopes of biogenic methane. Unlike culture studies where the fractionation factors of methanogenic pathways have been defined, field-collected gas or water samples represent net apparent isotope signatures influenced by a variety of overlapping water-rock-microbial interaction processes. Understanding these processes is important for modeling subsurface carbon cycling and biostimulation efforts for enhanced microbial gas production. Briefly, trends are apparent from a re-analysis of recently published water and gas isotope data from biogenic coalbed methane and shale gas systems: (1) δ13C-CH4 and the relationship between δ13C-CH4 and δ13C-CO2 (α13CCO2-CH4=(δ13C-CO2 + 1000)/(δ13C-CH4 +1000)), can also record the competition between methanogenesis and non-methanogenic processes (e.g. sulfate reduction), rather than simply recording the pathways of methanogenesis itself; and (2) Interpretation of δ2H-CH4 and δ2H-H2O can be inconsistent with δ13C-based fingerprinting techniques and indeed could be highly influenced by isotope exchange between water and methane precursors. This study provides an alternative approach for interpreting δ13C in shallow biogenic gas which considers that Corg may be consumed by competing, highly-fractionating and less-fractionating processes (e.g. methanogenesis and sulfate reduction, respectively). Whereas variation in apparent α13CCO2-CH4 could be inferred to indicate variation of metabolic pathways (that is, acetate fermentation vs. CO2 reduction) in some coalbed methane systems such as the Powder River Basin, the influx of sulfate relative to the overall Corg biodegradation rate could also be an

  4. High-temperature removal of sulphur for biogenic gas products; Hochtemperatur-Entschwefelung fuer biogene Produktgase. Design und Optimierung - Schlussbericht/Jahresbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schildhauer, T.; Biollaz, S.

    2009-12-15

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a project concerning the development of basics ideas on the design and optimisation of high-temperature methods for the removal of sulphur from biogenic gas products. Tests made as part of the 'Methane from Wood' project at pilot installations in Switzerland and Austria are discussed. Low temperature and high-temperature methods are examined and discussed. A number of sulphur compounds were tested. Also, experiments made using nickel, HDS and CPO catalysers are discussed.

  5. Methane production from steam-exploded bamboo.

    Science.gov (United States)

    Kobayashi, Fumihisa; Take, Harumi; Asada, Chikako; Nakamura, Yoshitoshi

    2004-01-01

    To convert unutilized plant biomass into a useful energy source, methane production from bamboo was investigated using a steam explosion pretreatment. Methane could not be produced from raw bamboo but methane production was enhanced by steam explosion. The maximum amount of methane produced, i.e., about 215 ml, was obtained from 1 g of exploded bamboo at a steam pressure of 3.53 MPa and a steaming time of 5 min. A negative correlation between the amount of methane produced and the amount of Klason lignin was observed in the methane fermentation of steam-exploded bamboo.

  6. Are methane production and cattle performance related?

    Science.gov (United States)

    Methane is a product of fermentation of feed in ruminant animals. Approximately 2 -12% of the gross energy consumed by cattle is released through enteric methane production. There are three primary components that contribute to the enteric methane footprint of an animal. Those components are dry ...

  7. Biogenic non-methane hydrocarbons (NMHC). Nature`s contribution to regional and global atmospheric chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Klockow, D.; Hoffman, T. [Inst. of Spectrochemistry and Applied Spectroscopy, Dortmund (Germany)

    1995-12-31

    Terrestrial vegetation provides an important source of volatile hydrocarbons, especially isoprene, monoterpenes and in addition possibly sesquiterpenes as well as oxygenated compounds. Although there exist considerable uncertainties in the estimation of the magnitude of these biogenic NMHC emissions, it is generally accepted that the majority of global NMHC release is from natural and not from anthropogenic sources. Taking into consideration the high reactivity of the mostly unsaturated biogenic emissions, their impact on tropospheric processes can be assumed to be of great importance. Together with anthropogenic NO{sub x} emissions, the highly reactive natural alkenes can act as precursors in photochemical oxidant formation and contribute to regional-scale air pollution. Their oxidation in the atmosphere and the subsequent gas-to-particle conversion of the products lead to the formation of organic aerosols. Because of the formation of phytotoxic compounds, the interaction of the biogenic hydrocarbons with ozone inside or outside the leaves and needles of plants has been suggested to play a role in forest decline. (author)

  8. Separating methane emissions from biogenic sources and natural gas by vertical column enhancements of ammonia, ethane, and methane in the Colorado Front Range

    Science.gov (United States)

    Chiu, R.; Volkamer, R. M.; Blumenstock, T.; Hase, F.; Hannigan, J. W.; Kille, N.; Frey, M.; Kumar Sha, M.; Orphal, J.

    2015-12-01

    Methane sources in the Colorado Front Range include biogenic sources from cattle feedlots and natural gas operations. Although numerous studies have measured methane emissions, there remains significant uncertainty regarding the relative contributions of these various methane emission sources. Here we present data from a March 2015 field campaign that deployed two Bruker EM27 Sun Fourier Transform Spectrometers (FTS) and the University of Colorado Solar Occultation Flux (CU-SOF) FTS in Eaton, Colorado; the former were used to measure enhancements in the methane vertical column densities (VCD), while the latter was used to measure ethane and ammonia VCDs. A third EM27 FTS was deployed to a background site in Westminster, Colorado which was far removed from cattle and petroleum operations. Northerly winds make possible the determination of methane VCD column enhancement from Westminster to Eaton. All instruments were compared during several background days at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado. This presentation explores the potential of methane source attribution using ammonia as a tracer for feedlot emissions and ethane as a tracer for petroleum emissions.

  9. Methane production and methane consumption: a review of processes underlying wetland methane fluxes.

    NARCIS (Netherlands)

    Segers, R.

    1998-01-01

    Potential rates of both methane production and methane consumption vary over three orders of magnitude and their distribution is skew. These rates are weakly correlated with ecosystem type, incubation temperature, in situ aeration, latitude, depth and distance to oxic/anoxic interface. Anaerobic car

  10. Abiotic production of methane in terrestrial planets.

    Science.gov (United States)

    Guzmán-Marmolejo, Andrés; Segura, Antígona; Escobar-Briones, Elva

    2013-06-01

    On Earth, methane is produced mainly by life, and it has been proposed that, under certain conditions, methane detected in an exoplanetary spectrum may be considered a biosignature. Here, we estimate how much methane may be produced in hydrothermal vent systems by serpentinization, its main geological source, using the kinetic properties of the main reactions involved in methane production by serpentinization. Hydrogen production by serpentinization was calculated as a function of the available FeO in the crust, given the current spreading rates. Carbon dioxide is the limiting reactant for methane formation because it is highly depleted in aqueous form in hydrothermal vent systems. We estimated maximum CH4 surface fluxes of 6.8×10(8) and 1.3×10(9) molecules cm(-2) s(-1) for rocky planets with 1 and 5 M⊕, respectively. Using a 1-D photochemical model, we simulated atmospheres with volume mixing ratios of 0.03 and 0.1 CO2 to calculate atmospheric methane concentrations for the maximum production of this compound by serpentinization. The resulting abundances were 2.5 and 2.1 ppmv for 1 M⊕ planets and 4.1 and 3.7 ppmv for 5 M⊕ planets. Therefore, low atmospheric concentrations of methane may be produced by serpentinization. For habitable planets around Sun-like stars with N2-CO2 atmospheres, methane concentrations larger than 10 ppmv may indicate the presence of life.

  11. Authigenic carbonate mounds from active methane seeps on the southern Aquitaine Shelf (Bay of Biscay, France): Evidence for anaerobic oxidation of biogenic methane and submarine groundwater discharge during formation

    Science.gov (United States)

    Pierre, Catherine; Demange, Jérome; Blanc-Valleron, Marie-Madeleine; Dupré, Stéphanie

    2017-02-01

    The widespread methane emissions that were discovered in 2013 on the Aquitaine Shelf at water depth between 140 and 220 m are associated with authigenic carbonate crusts that cover meter-high subcircular reliefs of 10-100 m in diameter. These authigenic carbonates are primarily aragonite plus calcite and dolomite, which cement the fine- to medium-grained sandy sediment. The carbonate cement is often pierced by numerous circular cavities of 5-10 μm in diameter that are considered to be moulds of gas bubbles. Conversely, micron-sized cavities in the aragonite crystals are attributed to dissolution features, in relation to the production of CO2 during the aerobic oxidation of methane. The oxygen isotopic compositions of bulk carbonate (+1.7 to +3.7‰) and aragonite cements obtained from microsampling (-0.1 to +1.4‰) indicate that these carbonates were precipitated in mixtures of seawater and freshwater, i.e., in the context of submarine groundwater discharge at the seafloor. The carbon isotopic compositions of authigenic carbonates (-51.9 to -38.1‰) and of aragonite cements (-49.9 to -29.3‰) show that the dissolved inorganic carbon of pore fluids was mostly produced by the anaerobic oxidation of biogenic methane and also partly from the groundwater system.

  12. Estimating methane gas production in peat soils of the Florida Everglades using hydrogeophysical methods

    Science.gov (United States)

    Wright, William; Comas, Xavier

    2016-04-01

    The spatial and temporal variability in production and release of greenhouse gases (such as methane) in peat soils remains uncertain, particularly for low-latitude peatlands like the Everglades. Ground penetrating radar (GPR) is a hydrogeophysical tool that has been successfully used in the last decade to noninvasively investigate carbon dynamics in peat soils; however, application in subtropical systems is almost non-existent. This study is based on four field sites in the Florida Everglades, where changes in gas content within the soil are monitored using time-lapse GPR measurements and gas releases are monitored using gas traps. A weekly methane gas production rate is estimated using a mass balance approach, considering gas content estimated from GPR, gas release from gas traps and incorporating rates of diffusion, and methanotrophic consumption from previous studies. Resulting production rates range between 0.02 and 0.47 g CH4 m-2 d-1, falling within the range reported in literature. This study shows the potential of combining GPR with gas traps to monitor gas dynamics in peat soils of the Everglades and estimate methane gas production. We also show the enhanced ability of certain peat soils to store gas when compared to others, suggesting that physical properties control biogenic gas storage in the Everglades peat soils. Better understanding biogenic methane gas dynamics in peat soils has implications regarding the role of wetlands in the global carbon cycle, particularly under a climate change scenario.

  13. Sulfide and methane production in sewer sediments.

    Science.gov (United States)

    Liu, Yiwen; Ni, Bing-Jie; Ganigué, Ramon; Werner, Ursula; Sharma, Keshab R; Yuan, Zhiguo

    2015-03-01

    Recent studies have demonstrated significant sulfide and methane production by sewer biofilms, particularly in rising mains. Sewer sediments in gravity sewers are also biologically active; however, their contribution to biological transformations in sewers is poorly understood at present. In this study, sediments collected from a gravity sewer were cultivated in a laboratory reactor fed with real wastewater for more than one year to obtain intact sediments. Batch test results show significant sulfide production with an average rate of 9.20 ± 0.39 g S/m(2)·d from the sediments, which is significantly higher than the areal rate of sewer biofilms. In contrast, the average methane production rate is 1.56 ± 0.14 g CH4/m(2)·d at 20 °C, which is comparable to the areal rate of sewer biofilms. These results clearly show that the contributions of sewer sediments to sulfide and methane production cannot be ignored when evaluating sewer emissions. Microsensor and pore water measurements of sulfide, sulfate and methane in the sediments, microbial profiling along the depth of the sediments and mathematical modelling reveal that sulfide production takes place near the sediment surface due to the limited penetration of sulfate. In comparison, methane production occurs in a much deeper zone below the surface likely due to the better penetration of soluble organic carbon. Modelling results illustrate the dependency of sulfide and methane productions on the bulk sulfate and soluble organic carbon concentrations can be well described with half-order kinetics.

  14. Aerobic methane production from organic matter

    NARCIS (Netherlands)

    Vigano, I.

    2010-01-01

    Methane, together with H2O, CO2 and N2O, is an important greenhouse gas in the Earth’s atmosphere playing a key role in the radiative budget. It has been known for decades that the production of the reduced compound CH4 is possible almost exclusively in anoxic environments per opera of one of the mo

  15. Biogenic carbon fluxes from global agricultural production and consumption

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Julie; West, Tristram O.; Le Page, Yannick LB; Kyle, G. Page; Zhang, Xuesong; Collatz, George; Imhoff, Marc L.

    2015-10-01

    Quantification of biogenic carbon fluxes from agricultural lands is needed to generate comprehensive bottom-up estimates of net carbon exchange for global and regional carbon monitoring. We estimated global agricultural carbon fluxes associated with annual crop net primary production (NPP), harvested biomass, and consumption of biomass by humans and livestock. These estimates were combined for a single estimate of net carbon exchange (NCE) and spatially distributed to 0.05 degree resolution using MODIS satellite land cover data. Global crop NPP in 2011 was estimated at 5.25 ± 0.46 Pg C yr-1, of which 2.05 ± 0.05 Pg C yr-1 was harvested and 0.54 Pg C yr-1 was collected from crop residues for livestock fodder. Total livestock feed intake in 2011 was 2.42 ± 0.21 Pg C yr-1, of which 2.31 ± 0.21 Pg C yr-1 was emitted as CO2, 0.07 ± 0.01 Pg C yr-1 was emitted as CH4, and 0.04 Pg C yr-1 was contained within milk and egg production. Livestock grazed an estimated 1.27 Pg C yr-1 in 2011, which constituted 52.4% of total feed intake. Global human food intake was 0.57 ± 0.03 Pg C yr-1 in 2011, the majority of which is respired as CO2. Completed global cropland carbon budgets accounted for the ultimate use of ca. 80% of harvested biomass. The spatial distribution of these fluxes may be used for global carbon monitoring, estimation of regional uncertainty, and for use as input to Earth system models.

  16. Methane production from marine microalgae Isochrysis galbana.

    Science.gov (United States)

    Santos, Nathalia O; Oliveira, Suzana M; Alves, Larissa C; Cammarota, Magali C

    2014-04-01

    Methane production from marine microalgae Isochrysis galbana was assessed before and after mechanical and chemical pretreatments. Mechanical pretreatment resulted in a 61.7% increase in soluble Chemical Oxygen Demand. Different hydrolysis conditions were evaluated by varying temperature - T, sulfuric acid concentration - AC and biomass suspension concentration (measured as particulate COD - CODp) using an experimental design. The most significant interaction occurred between AC and T and the hydrolysis condition that showed the best result in the anaerobic digestion step was the condition at 40°C with addition of 0.2% (v/v) acid for 16h (9.27LCH4/kgVS). The low methane yields were attributed to inhibitory sodium concentrations for anaerobic digestion. Eliminating inhibitory sodium in the anaerobic digestion by biomass prewashing, there was a 71.5% increase in methane yield for biomass after acid hydrolysis, demonstrating the need for pretreatment and reduction in sodium concentration in the anaerobic digestion.

  17. Methane production in simulated hybrid bioreactor landfill.

    Science.gov (United States)

    Xu, Qiyong; Jin, Xiao; Ma, Zeyu; Tao, Huchun; Ko, Jae Hac

    2014-09-01

    The aim of this work was to study a hybrid bioreactor landfill technology for landfill methane production from municipal solid waste. Two laboratory-scale columns were operated for about ten months to simulate an anaerobic and a hybrid landfill bioreactor, respectively. Leachate was recirculated into each column but aeration was conducted in the hybrid bioreactor during the first stage. Results showed that leachate pH in the anaerobic bioreactor maintained below 6.5, while in the hybrid bioreactor quickly increased from 5.6 to 7.0 due to the aeration. The temporary aeration resulted in lowering COD and BOD5 in the leachate. The volume of methane collected from the hybrid bioreactor was 400 times greater than that of the anaerobic bioreactor. Also, the methane production rate of the hybrid bioreactor was improved within a short period of time. After about 10 months' operation, the total methane production in the hybrid bioreactor was 212 L (16 L/kgwaste).

  18. Contemporary and projected biogenic fluxes of methane and nitrous oxide in North American terrestrial ecosystems

    Science.gov (United States)

    The importance of methane (CH4) and nitrous oxide (N2O) in determining global climate change has been increasingly recognized, but terrestrial CH4 and N2O budgets and the underlying mechanisms remain far from certain. Accurate estimation of terrestrial CH4 and N2O budgets would be a critical step fo...

  19. Microbial methane production in deep aquifer associated with the accretionary prism in Japan.

    Science.gov (United States)

    Kimura, Hiroyuki; Nashimoto, Hiroaki; Shimizu, Mikio; Hattori, Shohei; Yamada, Keita; Koba, Keisuke; Yoshida, Naohiro; Kato, Kenji

    2010-04-01

    To identify the methanogenic pathways present in a deep aquifer associated with an accretionary prism in Southwest Japan, a series of geochemical and microbiological studies of natural gas and groundwater derived from a deep aquifer were performed. Stable carbon isotopic analysis of methane in the natural gas and dissolved inorganic carbon (mainly bicarbonate) in groundwater suggested that the methane was derived from both thermogenic and biogenic processes. Archaeal 16S rRNA gene analysis revealed the dominance of H(2)-using methanogens in the groundwater. Furthermore, the high potential of methane production by H(2)-using methanogens was shown in enrichments using groundwater amended with H(2) and CO(2). Bacterial 16S rRNA gene analysis showed that fermentative bacteria inhabited the deep aquifer. Anaerobic incubations using groundwater amended with organic substrates and bromoethanesulfonate (a methanogen inhibitor) suggested a high potential of H(2) and CO(2) generation by fermentative bacteria. To confirm whether or not methane is produced by a syntrophic consortium of H(2)-producing fermentative bacteria and H(2)-using methanogens, anaerobic incubations using the groundwater amended with organic substrates were performed. Consequently, H(2) accumulation and rapid methane production were observed in these enrichments incubated at 55 and 65 degrees C. Thus, our results suggested that past and ongoing syntrophic biodegradation of organic compounds by H(2)-producing fermentative bacteria and H(2)-using methanogens, as well as a thermogenic reaction, contributes to the significant methane reserves in the deep aquifer associated with the accretionary prism in Southwest Japan.

  20. [Effect of temperature on methane production and oxidation in soils].

    Science.gov (United States)

    Ding, Weixin; Cai, Zucong

    2003-04-01

    The influence of temperature and its mechanism on methane production and oxidation in soils were reviewed in this paper. Temperature can alter the soil ability to produce methane through changing types of dominant methanogens in archaeal community. Dominant methanogen is Methanosarcinaceae at higher temperature which can utilize both H2/CO2 and acetate as the precursor to produce methane, while Methanosaetaceae at lower temperature which only use acetate as the precursor and produce far less methane than do Methanosarcinaceae. Increasing soil temperature apparently raises soil ability to produce methane, which is called temperature effectiveness and expressed as Q10 with a range from 1.5 to 28 and an average of 4.1. There is an obviously positive correlation between temperature effectiveness (Q10) on methane production and substrate content. As compared to methane production, effect of temperature on methane oxidation is lower, which may be related to the strong affinity of methanotrophs for methane.

  1. Microwave Hydrogen Production from Methane

    Science.gov (United States)

    2012-04-01

    Reaction 2 to H2/CO2 products according to Reaction 3 at temperatures in the range of 200-400 °C in the presence of an iron-chromium or copper alloys...hydrogen for a 5-kW fuel cell system. The capital and operating costs of the technology will be estimated and compared to compressed hydrogen delivery and onsite electrolysis .

  2. Identification of Methanogens and Controls on Methane Production in Incubations of Natural Methane Seep Sediments

    Science.gov (United States)

    Kevorkian, R.; Lloyd, K. G.

    2014-12-01

    Methane, the most abundant hydrocarbon in Earth's atmosphere, is produced in large quantities in sediments underlying the world's oceans. Very little of this methane makes it to surface sediments as it is consumed by Anaerobic Methanotrophs (ANME's) in consortia with Sulfate Reducing Bacteria (SRB). Less is known about which organisms are responsible for methane production in marine sediments, and whether that production is under thermodynamic control based on hydrogen concentrations. Although ANMEs have been found to be active in methanogenic sediments and incubations, it is currently unknown whether they are able to grow in methanogenic conditions. We demonstrated with bottle incubations of methane seep sediment taken from Cape Lookout Bight, NC, that hydrogen controls methane production. While sulfate was present the hydrogen concentration was maintained at below 2 nM. Only after the depletion of sulfate allowed hydrogen concentrations to rise above 5 nM did we see production of methane. The same sediments when spiked with methane gas demonstrated its complete removal while sulfate reduction occurred. Quantitative PCR shows that ANME-2 and ANME-1 increase in 16S copy number as methane increases. Total direct cell counts demonstrate a decline in cells with the decrease of sulfate until a recovery corresponding with production of methane. Our results strongly suggest that hydrogen concentrations influence what metabolic processes can occur in marine sediments, and that ANME-1 and ANME-2 are able to grow on the energy provided from methane production.

  3. Comparison of biogenic methane emissions from unmanaged estuaries, lakes, oceans, rivers and wetlands

    Science.gov (United States)

    Ortiz-Llorente, M. J.; Alvarez-Cobelas, M.

    2012-11-01

    A literature review of quantitative data was carried out to conduct a cross-system study on methane emissions relating peak emissions (PE) and annual emissions (AE) in five types of non-managed ecosystems: estuaries, lakes, oceans, streams and wetlands. PE spanned eight orders of magnitude (0.015 μg CH4 m-2 h-1-300 mg CH4 m-2 h-1) while AE spanned seven (0.078-19044 g CH4 m-2 yr-1). PE and AE were strongly related worldwide (r2 = 0.93). There was no relationship between AE and latitude, with highly variable PE across latitudes and climates. The coefficient of variation (CV) was greatest for emissions in oceans and estuaries, while the highest emission rate was recorded in wetlands and lakes. Efflux from coastal areas and estuaries was higher than that from upwelling areas and deep seas. Concerning wetland types, marshes showed the highest PE with the highest wetland emissions occurring in sites dominated by big helophytes. Non-stratifying- and eutrophic lakes displayed more emissions than other lake types, but there was no environmental variable that might predict methane emissions from lakes on a worldwide basis. Generally, most ecosystem types followed a seasonal pattern of emissions, with a maximum in summer, except in estuaries which did not show any distinct pattern. Regarding the importance of hot spots within most ecosystems, more spatial variability of CH4 emissions was observed in lakes than in wetlands and oceans; however, no relationship between emissions and spatial variability was found. A positive relationship, albeit weak, was found between methane flux and either temperature or irradiance in wetlands; a narrow range of both negative and positive values of the water table promoted CH4 emissions. Previously, little was known about the factors controlling efflux from river and marine environments. Our study suggests that local conditions are important in controlling CH4 emissions, because the variability explained by the more commonly studied abiotic

  4. Potential for biohydrogen and methane production from olive pulp

    DEFF Research Database (Denmark)

    Gavala, Hariklia N.; Skiadas, Ioannis V.; Ahring, Birgitte Kiær;

    2005-01-01

    The present study investigates the potential for thermophilic biohydrogen and methane production from olive pulp, which is the semi-solid residue coming from the two-phase processing of olives. It focussed on: a) production of methane from the raw olive pulp, b) anaerobic bio-production of hydrogen...... and hydrogen-effluent was as high as 19 mmole CH4 per g TS. This suggests that olive pulp is an ideal substrate for methane production and it shows that biohydrogen production can be very efficiently coupled with a subsequent step for methane production....

  5. Dry fermented sausages of Southern Italy: a comparison of free amino acids and biogenic amines between industrial and homemade products.

    Science.gov (United States)

    Leggio, Antonella; Belsito, Emilia L; De Marco, Rosaria; Di Gioia, Maria L; Liguori, Angelo; Siciliano, Carlo; Spinella, Mariagiovanna

    2012-04-01

    This paper compares some important parameters and the free amino acid and biogenic amine contents of cured industrial and homemade meat products. To this aim, industrial and homemade "soppressata" and "salsiccia", typical dry fermented sausages produced in Southern Italy, were analyzed. The homemade sausages showed a higher level of free biogenic amines than that manufactured industrially, most likely because biogenic amine formation in industrial products is limited by the use of starter cultures. The industrial sausages are characterized by a higher total free amino acid content than the homemade products. Overall, free amino acid and biogenic amine contents demonstrated that appreciable differences exist between homemade and industrial sausages.

  6. BIOGENIC AMINES CONTENT IN SELECTED COMMERCIAL FERMENTED PRODUCTS OF ANIMAL ORIGIN

    Directory of Open Access Journals (Sweden)

    Vendula Pachlová

    2012-08-01

    Full Text Available The aim of this study was to monitor of biogenic amines contents in commercial fermented products, especially various type of ripening cheeses and fermented meat products (15 cheese samples and nine dry fermented meat products obtained from Czech Republic, Slovak Republic, Poland, and Germany. Furthermore, the changes in samples during storage were also observed. The samples were stored at 6±1°C. The samples were taken the first day of storage and the last day of shelf-life. The biogenic amines content was determined using ion-exchange liquid chromatography with post-column derivatization and photometric detection. The content of biogenic amines increased during storage. The highest biogenic amines content at the end of storage was observed in Dutch-type cheeses and in Smear cheeses, in both the concentrations exceeded 1 000 mg.kg-1. Latter mentioned amount may have serious negative impact on consumer health. The lowest concentration of biogenic amines was detected in Blue cheese.

  7. Biogenic hydrogen production from organic raw materials and residues; Biogene Wasserstofferzeugung aus organischen Roh- und Reststoffen

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, M.; Rechtenbach, D.; Stegmann, R. [Technische Univ. Hamburg-Harburg, Hamburg (Germany). Inst. fuer AbfallRessourcenWirtschaft

    2007-02-15

    Hydrogen (H{sub 2}) is considered as an energy source for the future. Laboratory scale thermophilic fermentation tests were carried out in three different test systems (500 ml Sensomat system, 6 l anaerobic test system (ATS) and a 30 l continuously stirred tank reactor CSTR). Hydrogen was produced from glucose and agricultural products as substrates in batch and discontinuous tests at 60 C. The inoculum consisted of heat-treated digested sewage sludge. The best specific hydrogen production of 280 Nml H{sub 2}/g VSS was achieved with glucose at a pH 5.5 in batch operation in the CSTR. Corn starch produced 211 Nml H{sub 2}/g VSS and potato starch 123 Nml H{sub 2}/g VSS. The agricultural products sugar beet, fodder beet, potato, turnip, corn and bio-waste potato peel showed good potential for biological hydrogen production with conversion yields between 24 - 60%. In the discontinuous test system, hydrogen production rates of between 0.4 Nl/(l{sub R}.d) and 1.3 Nl/(l{sub R}.d) were produced, corresponding to yields of between 83 to 445 Nml H{sub 2}/g VSS. (orig.)

  8. Observations of oxidation products above a forest imply biogenic emissions of very reactive compounds

    Directory of Open Access Journals (Sweden)

    R. Holzinger

    2005-01-01

    Full Text Available Vertical gradients of mixing ratios of volatile organic compounds have been measured in a Ponderosa pine forest in Central California (38.90° N, 120.63° W, 1315m. These measurements reveal large quantities of previously unreported oxidation products of short lived biogenic precursors. The emission of biogenic precursors must be in the range of 13-66µmol m-2h-1 to produce the observed oxidation products. That is 6-30 times the emissions of total monoterpenes observed above the forest canopy on a molar basis. These reactive precursors constitute a large fraction of biogenic emissions at this site, and are not included in current emission inventories. When oxidized by ozone they should efficiently produce secondary aerosol and hydroxyl radicals.

  9. Modeling methane emissions and methane inventories for cattle production systems in Mexico

    OpenAIRE

    2014-01-01

    Anaerobic fermentation of structural carbohydrates in the rumen of bovines produces waste products such as volatile fatty acids, fermentation heat, carbon dioxide and methane gas. Methane is a greenhouse gas having several times the global warming potential of CO 2 . The purpose of the present paper is to provide a realistic estimate of the national inventory of methane produced by the enteric fermentation of cattle, based on a simulation model and to provide estimates of CH 4 produced by cat...

  10. A model for methane production in sewers.

    Science.gov (United States)

    Chaosakul, Thitirat; Koottatep, Thammarat; Polprasert, Chongrak

    2014-09-19

    Most sewers in developing countries are combined sewers which receive stormwater and effluent from septic tanks or cesspools of households and buildings. Although the wastewater strength in these sewers is usually lower than those in developed countries, due to improper construction and maintenance, the hydraulic retention time (HRT) could be relatively long and resulting considerable greenhouse gas (GHG) production. This study proposed an empirical model to predict the quantity of methane production in gravity-flow sewers based on relevant parameters such as surface area to volume ratio (A/V) of sewer, hydraulic retention time (HRT) and wastewater temperature. The model was developed from field survey data of gravity-flow sewers located in a peri-urban area, central Thailand and validated with field data of a sewer system of the Gold Coast area, Queensland, Australia. Application of this model to improve construction and maintenance of gravity-flow sewers to minimize GHG production and reduce global warming is presented.

  11. Biogenic amine content, histamine-forming bacteria, and adulteration of pork in tuna sausage products.

    Science.gov (United States)

    Kung, Hsien-Feng; Tsai, Yung-Hsiang; Chang, Shih-Chih; Hong, Tang-Yao

    2012-10-01

    Twenty-five tuna sausage products were purchased from retail markets in Taiwan. The rates of occurrence of biogenic amines, histamine-forming bacteria, and adulteration by pork and poultry were determined. The average content of various biogenic amines in all tested samples was less than 2.0 mg/100 g (sausage. The fish species in the tuna sausage samples were identified as Thunnus albacares for 22 samples (88%), Thunnus alalunga for 1 sample (4%), and Thunnus thynnus for 1 sample (4%), whereas the remaining sample was identified as Makaira nigricans (blue marlin).

  12. Influence of headspace pressure on methane production in Biochemical Methane Potential (BMP) tests.

    Science.gov (United States)

    Valero, David; Montes, Jesús A; Rico, José Luis; Rico, Carlos

    2016-02-01

    The biochemical methane potential test is the most commonly applied method to determine methane production from organic wastes. One of the parameters measured is the volume of biogas produced which can be determined manometrically by keeping the volume constant and measuring increases in pressure. In the present study, the effect of pressure accumulation in the headspace of the reactors has been studied. Triplicate batch trials employing cocoa shell, waste coffee grounds and dairy manure as substrates have been performed under two headspace pressure conditions. The results obtained in the study showed that headspace overpressures higher than 600mbar affected methane production for waste coffee grounds. On the contrary, headspace overpressures within a range of 600-1000mbar did not affect methane production for cocoa shell and dairy manure. With the analyses performed in the present work it has not been possible to determine the reasons for the lower methane yield value obtained for the waste coffee grounds under high headspace pressures.

  13. Terrestrial plant methane production and emission.

    Science.gov (United States)

    Bruhn, Dan; Møller, Ian M; Mikkelsen, Teis N; Ambus, Per

    2012-03-01

    In this minireview, we evaluate all experimental work published on the phenomenon of aerobic methane (CH(4) ) generation in terrestrial plants and plant. Clearly, despite much uncertainty and skepticism, we conclude that the phenomenon is true. Four stimulating factors have been observed to induce aerobic plant CH(4) production, i.e. cutting injuries, increasing temperature, ultraviolet radiation and reactive oxygen species. Further, we analyze rates of measured emission of aerobically produced CH(4) in pectin and in plant tissues from different studies and argue that pectin is very far from the sole contributing precursor. In consequence, scaling up of aerobic CH(4) emission needs to take into consideration other potential sources than pectin. Due to the large uncertainties related to effects of stimulating factors, genotypic responses and type of precursors, we conclude that current attempts for upscaling aerobic CH(4) into a global budget is inadequate. Thus it is too early to draw the line under the aerobic methane emission in plants. Future work is needed for establishing the relative contribution of several proven potential CH(4) precursors in plant material.

  14. Ruminal Methane Production on Simple Phenolic Acids Addition in in Vitro Gas Production Method

    OpenAIRE

    A. Jayanegara

    2009-01-01

    Methane production from ruminants contributes to total global methane production, which is an important contributor to global warming. In this experiment, six sources of simple phenolic acids (benzoic, cinnamic, phenylacetic, caffeic, p-coumaric and ferulic acids) at two different levels (2 and 5 mM) added to hay diet were evaluated for their potential to reduce enteric methane production using in vitro Hohenheim gas production method. The measured variables were gas production, methane, orga...

  15. Contribution by the methanogenic endosymbionts of anaerobic ciliates to methane production in Dutch freshwater sediments

    NARCIS (Netherlands)

    Hoek, van A.H.A.M.; Alen, T.A.; Vogels, G.D.; Hackstein, J.H.P.

    2006-01-01

    Biogenic methane contributes substantially to the atmospheric methane concentration and thus to global warming. This trace gas is predominantly produced by strictly anaerobic methanogenic archaea, which thrive in the most divergent ecological niches, e. g. paddy fields, sediments, landfills, and the

  16. Toxic Effects of Pollutants on Methane Production of River Sediment

    NARCIS (Netherlands)

    van Vlaardingen PLA; van Beelen P

    1992-01-01

    The effects of five compounds on the endogenous methane production of sediment samples of the river Rhine were examined. The concentrations of a toxicant that inhibited the methane production for 10% and 50% are called EC10 and EC50. Benzene, 1,2- dichloroethane, pentachlorophenol and chloroform h

  17. Hydrogen production from methane reforming: thermodynamic assessment

    Energy Technology Data Exchange (ETDEWEB)

    Assis, A.J.; Hori, Carla E.; Avila Neto, Cicero; Franco, Tatiana [Federal University of Uberlandia (UFU), MG (Brazil). School of Chemical Engineering]. E-mail: adilsonjassis@gmail.com

    2008-07-01

    The main contributions of this study are to conduct a comparative thermodynamic analysis of methane reforming reactions and to asses the influence of key operational variables on chemical equilibrium using an in-house code, developed in the open-source software Scilab{sup c} INRIA-ENPC (www.scilab.org). Equilibrium compositions are calculated by two distinct methods: evaluation of equilibrium constants and Lagrange multipliers. Both methods result in systems of non-linear algebraic equations, solved numerically using the Scilab function 'fsolve'. Comparison between experimental and simulated equilibrium data, published in the literature, was used to validate the simulated results. Effects of temperature, pressure, initial H{sub 2}O/CH{sub 4} ratio (steam reforming), initial CH{sub 4}:CO{sub 2}:N{sub 2} ratio (dry reforming) and initial O{sub 2}/CH{sub 4} ratio (partial oxidation) on the reaction products were evaluated. (author)

  18. Methanization of biogenic synthetic gases with respect to direct reaction of higher hydrocarbons; Methanisierung biogener Synthesegase mit Hinblick auf die direkte Umsetzung von hoeheren Kohlenwasserstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Kienberger, Thomas

    2010-07-01

    The present work deals with a process for the methanation of the synthesis-gas from allothermal fluidized bed gasification. In the proposed process, the tar and sulfur contaminated syngas is used in a fixed-bed methanation reactor without further gas treatment. Commercial nickel catalysts are applied, which offer the opportunity to bring the gas to stoichiometry, in order to remove sulfur compounds by adsorption and to reform the synthesis-gas tar-content directly in the methanation reactor. An increased catalyst consumption turns out to be disadvantageous for the process. For process development in the course of this work, a biomass-fueled allothermic fluidized bed gasifier (Q{sub BR}=5kW) as well as a polytropic temperature-controlled methanation-reactor was constructed, built up and put into operation. It is possible to operate the system fully remote-controlled, which enables long-term tests without staff on site. Within the step of modelling with the software package ASPEN Plus in advance of experiments, parametric studies of both, the gasifier as well as of the process of methanation, were performed. As a major result, it can be shown that due to the use of nickel as methanation-catalyst-material, the educt gas-conversion is independent of the synthesis-gas's H{sub 2}/CO-ratio. Gasification tests were made to investigate the allothermic fluidized bed gasifier, in order to find an optimum point of operation for the downstream methane-synthesis. In the found point of operation, due to a sufficient water-content in the synthesis gas, from the thermodynamic perspective, carbon deposits on the methanation-catalyst can be avoided. The synthesis gas has a gravimetric tar-load of 10,4 g/Nm{sup 3}, furthermore hydrogen sulfide (H{sub 2}S) with a concentration of around 8 ppm{sub v} was measured as the representative sulfur component. It this gas is led to the methanation-reactor, in contrast to attempts with a clean synthesis-gas, the equilibrium

  19. Ecosystem and physiological controls over methane production in northern wetlands

    Science.gov (United States)

    Valentine, David W.; Holland, Elisabeth A.; Schimel, David S.

    1994-01-01

    Peat chemistry appears to exert primary control over methane production rates in the Canadian Northern Wetlands Study (NOWES) area. We determined laboratory methane production rate potentials in anaerobic slurries of samples collected from a transect of sites through the NOWES study area. We related methane production rates to indicators of resistance to microbial decay (peat C: N and lignin: N ratios) and experimentally manipulated substrate availability for methanogenesis using ethanol (EtOH) and plant litter. We also determined responses of methane production to pH and temperature. Methane production potentials declined along the gradient of sites from high rates in the coastal fens to low rates in the interior bogs and were generally highest in surface layers. Strong relationships between CH4 production potentials and peat chemistry suggested that methanogenesis was limited by fermentation rates. Methane production at ambient pH responded strongly to substrate additions in the circumneutral fens with narrow lignin: N and C: N ratios (delta CH4/delta EtOH = 0.9-2.3 mg/g) and weakly in the acidic bogs with wide C: N and lignin: N ratios (delta CH4/delta EtOH = -0.04-0.02 mg/g). Observed Q(sub 10) values ranged from 1.7 to 4.7 and generally increased with increasing substrate availability, suggesting that fermentation rates were limiting. Titration experiments generally demonstrated inhibition of methanogenesis by low pH. Our results suggest that the low rates of methane emission observed in interior bogs during NOWES likely resulted from pH and substrate quality limitation of the fermentation step in methane production and thus reflect intrinsically low methane production potentials. Low methane emission rates observed during NOWES will likely be observed in other northern wetland regions with similar vegetation chemistry.

  20. Potential for biohydrogen and methane production from olive pulp

    Energy Technology Data Exchange (ETDEWEB)

    Gavala, H.N.; Skiadas, I.V. [Patras Univ., Patras (Greece). Dept. of Chemical Engineering, Laboratory of Biochemical Engineering and Environmental Technology]|[Denmark Technical Univ., Lyngby (Denmark). Environmental Microbiology and Biotechnology Group; Ahring, B.K. [Denmark Technical Univ., Lyngby (Denmark). Environmental Microbiology and Biotechnology Group; Lyberatos, G. [Patras Univ., Patras (Greece). Dept. of Chemical Engineering, Laboratory of Biochemical Engineering and Environmental Technology

    2004-07-01

    Biomass rich in carbohydrates is a potential source of hydrogen. Fermentative hydrogen production includes the transformation of sugars into volatile fatty acids (VFA) without a major effect on the organic content. This study examined the potential for thermophilic biohydrogen and methane production from olive pulp, the semi-solid residue resulting from the two-phase processing of olives. Formation of VFA during acidogenesis of organic matter precedes methanogenesis. Therefore, anaerobic digestion can potentially be coupled with a preliminary step for hydrogen production. This study focused on production of methane from the raw olive pulp; anaerobic bio-production of hydrogen from the olive pulp; and, subsequent anaerobic treatment of the hydrogen-effluent with production of methane. Continuous and batch experiments were performed. The methane potential of the raw olive pulp and hydrogen effluent was up to 19 mmole of methane per gram of total solids. It was concluded that olive pulp is a suitable substrate for methane production and that biohydrogen can be coupled with a subsequent step for methane production. 12 refs., 7 tabs., 2 figs.

  1. Detection and quantification of biogenic amines in fermented food products sold in Botswana.

    Science.gov (United States)

    Magwamba, Clement; Matsheka, Maitshwarelo Ignatius; Mpuchane, Sisai; Gashe, Berhanu Abegaz

    2010-09-01

    The incidence and concentrations associated with four important biogenic amines in leading commercial fermented beverages consumed in Botswana were determined using high-performance liquid chromatography. In 87 sorghum brew and 84 sour milk (madila, amasi) samples tested, putrescine was the most prevalent biogenic amine (63 and 61%, respectively), while histamine was the least prevalent (24 and 8%, respectively). Cadaverine was the most frequently detected biogenic amine in 79 of the commercial sour maize beverage (mageu/mahewu) samples tested (found in 70% of the samples), while tyramine was the least detected (occurring in 3% of the samples). In sorghum brew and sour milk, tyramine was found to be the most concentrated (mean concentration of 2.08 mg/100 ml and 3.2 mg/100 ml, respectively), and histamine was found to be the least concentrated (mean concentration of 0.94 mg/100 ml and 0.31 mg/100 ml, respectively). Overall, the biogenic amine concentrations of all three fermented products were within acceptable limits. However, one sorghum brew sample had a histamine content of 5.8 mg/ 100 ml, which was above the 5.0 mg/100 g allowable limit suggested by the U.S. Food and Drug Administration.

  2. Relationship between selection for feed efficiency and methane production

    Science.gov (United States)

    Enteric methane is a product of fermentation in the gastro-intestinal tract of ruminants. A group of archaea bacteria collectively called “methanogens” are responsible for the synthesis of methane. In ruminants, the methanogens grow in the reticulum-rumen complex and in the cecum. Most of the met...

  3. Thermophilic methane production and oxidation in compost.

    Science.gov (United States)

    Jäckel, Udo; Thummes, Kathrin; Kämpfer, Peter

    2005-04-01

    Methane cycling within compost heaps has not yet been investigated in detail. We show that thermophilic methane oxidation occurred after a lag phase of up to one day in 4-week old, 8-week old and mature (>10-week old) compost material. The potential rate of methane oxidation was between 2.6 and 4.1 micromol CH4(gdw)(-1)h(-1). Profiles of methane concentrations within heaps of different ages indicated that 46-98% of the methane produced was oxidised by methanotrophic bacteria. The population size of thermophilic methanotrophs was estimated at 10(9) cells (gdw)(-1), based on methane oxidation rates. A methanotroph (strain KTM-1) was isolated from the highest positive step of a serial dilution series. This strain belonged to the genus Methylocaldum, which contains thermotolerant and thermophilic methanotrophs. The closest relative organism on the basis of 16S rRNA gene sequence identity was M. szegediense (>99%), a species originally isolated from hot springs. The temperature optimum (45-55 degrees C) for methane oxidation within the compost material was identical to that of strain KTM-1, suggesting that this strain was well adapted to the conditions in the compost material. The temperatures measured in the upper layer (0-40 cm) of the compost heaps were also in this range, so we assume that these organisms are capable of effectively reducing the potential methane emissions from compost.

  4. Forest cockchafer larvae as methane production hotspots in soils and their importance for net soil methane fluxes

    Science.gov (United States)

    Görres, Carolyn-Monika; Kammann, Claudia; Murphy, Paul; Müller, Christoph

    2016-04-01

    Certain groups of soil invertebrates, namely scarab beetles and millipedes, are capable of emitting considerable amounts of methane due to methanogens inhabiting their gut system. It was already pointed out in the early 1990's, that these groups of invertebrates may represent a globally important source of methane. However, apart from termites, the importance of invertebrates for the soil methane budget is still unknown. Here, we present preliminary results of a laboratory soil incubation experiment elucidating the influence of forest cockchafer larvae (Melolontha hippocastani FABRICIUS) on soil methane cycling. In January/February 2016, two soils from two different management systems - one from a pine forest (extensive use) and one from a vegetable field (intensive use) - were incubated for 56 days either with or without beetle larvae. Net soil methane fluxes and larvae methane emissions together with their stable carbon isotope signatures were quantified at regular intervals to estimate gross methane production and gross methane oxidation in the soils. The results of this experiment will contribute to testing the hypothesis of whether methane production hotspots can significantly enhance the methane oxidation capacity of soils. Forest cockchafer larvae are only found in well-aerated sandy soils where one would usually not suspect relevant gross methane production. Thus, besides quantifying their contribution to net soil methane fluxes, they are also ideal organisms to study the effect of methane production hotspots on overall soil methane cycling. Funding support: Reintegration grant of the German Academic Exchange Service (DAAD) (#57185798).

  5. Evaluating biochemical methane production from brewer's spent yeast.

    Science.gov (United States)

    Sosa-Hernández, Ornella; Parameswaran, Prathap; Alemán-Nava, Gibrán Sidney; Torres, César I; Parra-Saldívar, Roberto

    2016-09-01

    Anaerobic digestion treatment of brewer's spent yeast (SY) is a viable option for bioenergy capture. The biochemical methane potential (BMP) assay was performed with three different samples (SY1, SY2, and SY3) and SY1 dilutions (75, 50, and 25 % on a v/v basis). Gompertz-equation parameters denoted slow degradability of SY1 with methane production rates of 14.59-4.63 mL/day and lag phases of 10.72-19.7 days. Performance and kinetic parameters were obtained with the Gompertz equation and the first-order hydrolysis model with SY2 and SY3 diluted 25 % and SY1 50 %. A SY2 25 % gave a 17 % of TCOD conversion to methane as well as shorter lag phase (methane production. Methane capture and biogas composition were dependent upon the SY source, and co-digestion (or dilution) can be advantageous.

  6. Methane and carbon dioxide ratio in excreted air for quantification of the methane production from ruminants

    DEFF Research Database (Denmark)

    Madsen, Jørgen; Bjerg, Bjarne Schmidt; Hvelplund, Torben

    2010-01-01

    This technical note presents a simple, fast, reliable and cheap method to estimate the methane (CH4) production from animals by using the CH4 and carbon dioxide (CO2) concentrations in air near the animals combined with an estimation of the total CO2 production from information on intake of metab......This technical note presents a simple, fast, reliable and cheap method to estimate the methane (CH4) production from animals by using the CH4 and carbon dioxide (CO2) concentrations in air near the animals combined with an estimation of the total CO2 production from information on intake...

  7. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Donn McGuire; Thomas Williams; Bjorn Paulsson; Alexander Goertz

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a drilling hazard by the oil and gas industry for years. Drilling engineers working in Russia, Canada and the USA have documented numerous problems, including drilling kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrates as a potential energy source agree that the resource potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained from physical samples taken from actual hydrate-bearing rocks. This gas-hydrate project is a cost-shared partnership between Maurer Technology, Anadarko Petroleum, Noble Corporation, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The project team drilled and continuously cored the Hot Ice No. 1 well on Anadarko-leased acreage beginning in FY 2003 and completed in 2004. An on-site core analysis laboratory was built and used for determining physical characteristics of hydrates and surrounding rock. After the well was logged, a 3D vertical seismic profile (VSP) was recorded to calibrate the shallow geologic section with seismic data and to investigate techniques to better resolve lateral subsurface variations of potential hydrate-bearing strata. Paulsson Geophysical Services, Inc. deployed their 80 level 3C clamped borehole seismic receiver array in the wellbore to record samples every 25 ft. Seismic vibrators were successively positioned at 1185 different surface positions in a circular pattern around the wellbore. This technique generated a 3D image of the subsurface. Correlations were

  8. PEaCH4 v.2.0: A modelling platform to predict early diagenetic processes in marine sediments with a focus on biogenic methane - Case study: Offshore Namibia

    Science.gov (United States)

    Arning, Esther T.; Häußler, Steffen; van Berk, Wolfgang; Schulz, Hans-Martin

    2016-07-01

    The modelling of early diagenetic processes in marine sediments is of interest in marine science, and in the oil and gas industry, here, especially with respect to methane occurrence and gas hydrate formation as resources. Early diagenesis in marine sediments evolves from a complex web of intertwining (bio)geochemical reactions. It comprises microbially catalysed reactions and inorganic mineral-water-gas interactions. A model that will describe and consider all of these reactions has to be complex. However, it should be user-friendly, as well as to be applicable for a broad community and not only for experts in the field of marine chemistry. The presented modelling platform PeaCH4 v.2.0 combines both aspects, and is Microsoft Excel©-based. The modelling tool is PHREEQC (version 2), a computer programme for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations. The conceptual PEaCH4 model is based on the conversion of sediment-bound degradable organic matter. PEaCH4 v.2.0 was developed to quantify and predict early diagenetic processes in marine sediments with the focus on biogenic methane formation and its phase behaviour, and allows carbon mass balancing. In regard to the irreversible degradation of organic matter, it comprises a "reaction model" and a "kinetic model" to predict methane formation. Both approaches differ in their calculations and outputs as the "kinetic model" considers the modelling time to integrate temperature dependent biogenic methane formation in its calculations, whereas the "reaction model" simply relies on default organic matter degradation. With regard to the inorganic mineral-water-gas interactions, which are triggered by irreversible degradation of organic matter, PEaCH4 v.2.0 is based on chemical equilibrium thermodynamics, appropriate mass-action laws, and their temperature dependent equilibrium constants. The programme is exemplarily presented with the example of upwelling sediments off Namibia

  9. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Thomas E. Williams; Keith Millheim; Bill Liddell

    2005-03-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Oil-field engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in Arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrates agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is a cost-shared partnership between Maurer Technology, Anadarko Petroleum, Noble Corporation, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to help identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. As part of the project work scope, team members drilled and cored the HOT ICE No. 1 on Anadarko leases beginning in January 2003 and completed in March 2004. Due to scheduling constraints imposed by the Arctic drilling season, operations at the site were suspended between April 21, 2003 and January 30, 2004. An on-site core analysis laboratory was designed, constructed and used for determining physical characteristics of frozen core immediately after it was retrieved from the well. The well was drilled from a new and innovative Anadarko Arctic Platform that has a greatly reduced footprint and environmental impact. Final efforts of the project were to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists for future hydrate operations. Unfortunately, no gas hydrates were encountered in this well; however, a wealth of information was generated

  10. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Thomas E. Williams; Keith Millheim; Buddy King

    2004-07-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is in the final stages of a cost shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The work scope drilled and cored a well The HOT ICE No.1 on Anadarko leases beginning in FY 2003 and completed in 2004. An on-site core analysis laboratory was built and utilized for determining the physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. The final efforts of the project are to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists developing reservoir models. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in this report.

  11. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Thomas E. Williams; Keith Millheim; Buddy King

    2004-06-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is in the final stages of a cost shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The work scope drilled and cored a well The HOT ICE No.1 on Anadarko leases beginning in FY 2003 and completed in 2004. An on-site core analysis laboratory was built and utilized for determining the physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. The final efforts of the project are to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists developing reservoir models. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in this report.

  12. Calculation of methane production from enteric fermentation in dairy cows

    OpenAIRE

    Smink, M.C.J.; Hoek, MR; Bannink, A.; Dijkstra, J.

    2005-01-01

    Doel van deze studie is om een inschatting te maken van de methaanproductie door melkkoeien vanaf 1990 tot nu. Tevens zijn de effecten van voer onderzochtThe aim of this study is to calculate methane production by dairy cows during the period 1990 till present. A dynamic mechanistic model of rumen fermentation and digestion will be used which represents the effect of detailed dietary characteristics on methane production

  13. 800 year ice-core record of nitrogen deposition in Svalbard linked to ocean productivity and biogenic emissions

    Directory of Open Access Journals (Sweden)

    I. A. Wendl

    2014-09-01

    Full Text Available We present the records of the two nitrogen species nitrate (NO3− and ammonium (NH4+ analysed in a new ice core from Lomonosovfonna, Svalbard, in the Eurasian Arctic covering the period 1222–2009. We investigate the emission sources and the influence of melt on the records. During the 20th century both records are influenced by anthropogenic pollution from Eurasia. In pre-industrial times NO3− is highly correlated with methane-sulfonate (MSA on decadal time-scales, which we explain by a fertilising effect. Enhanced atmospheric NO3− concentrations and the corresponding nitrogen input to the ocean trigger the growth of dimethyl-sulfide-(DMS-producing phytoplankton. Increased DMS production results in elevated fluxes to the atmosphere where it is oxidised to MSA. Eurasia was presumably the main source area also for pre-industrial NO3−, but a more exact source apportionment could not be performed based on our data. This is different for NH4+, where biogenic ammonia (NH3 emissions from Siberian boreal forests were identified as the dominant source of pre-industrial NH4+. Changes in melt at the Lomonosovfonna glacier are excluded as major driving force for the decadal variations of the investigated compounds.

  14. The methane production of poultry slaughtering residues and effects of pre-treatments on the methane production of poultry feather.

    Science.gov (United States)

    Salminen, E; Einola, J; Rintala, J

    2003-09-01

    The biological methane production rate and yield of different poultry slaughtering residues were studied. Poultry offal, blood, and bonemeal were rich in proteins and lipids and showed high methane yields, 0.7-0.9, 0.5, and 0.6-0.7 m3 kg(-1) volatile solids(added), respectively (270-340, 100, and 150-170 m3 ton(-1) wet weight). Blood and bonemeal produced methane rapidly, whereas the methane production of offal was more delayed probably due to long-chain fatty acid inhibition. The length of delay depended on the source and concentration of inoculum and incubation temperature, sewage sludge at 35 degrees C having the shortest delay of a few days, while granular sludge did not produce methane within 94 days of incubation. Feather showed a somewhat lower methane yield, 0.21 m3 kg(-1) volatile solids(added) (50 m3 ton(-1) wet weight). Combined thermal (120 degrees C, 5 min) and enzymatic (commercial alkaline endopeptidase, 2-10 g l(-1)) pre-treatments increased its methane yield by 37 to 51%. Thermal (70-120 degrees C, 5-60 min), chemical (NaOH 2-10 g l(-1), 2-24 h), and enzymatic pre-treatments were less effective, with methane yield increasing by 5 to 32%. Based on the present results, anaerobic digestion of the studied poultry slaughtering residues appears a promising possibility because of the high methane yield and nitrogen content of these residues (8 to 14% N of total solids), whereas pre-treatments were shown to improve the methane production of feather.

  15. Methane productivity of manure, straw and solid fractions of manure

    DEFF Research Database (Denmark)

    Møller, H.B.; Sommer, S.G.; Ahring, Birgitte Kiær

    2004-01-01

    The methane productivity of manure in terms of volatile solids (VS), volume and livestock production was determined. The theoretical methane productivity is higher in pig (516 1 kg(-1) VS) and sow (530 1 kg(-1) VS) manure than in dairy cattle manure (469 1 kg(-1) VS), while the ultimate methane...... yield in terms of VS is considerably higher in pig (356 1 kg(-1) VS) and sow manure (275 1 kg(-1) VS) than in dairy cattle manure (148 1 kg(-1) VS). Methane productivity based on livestock units (LU) shows the lowest methane productivity for sows (165 m(3) CH4 LU-1), while the other animal categories...... are in the same range (282-301 m(3) CH4 LU-1). Pre-treatment of manure by separation is a way of making fractions of the manure that have a higher gas potential per volume. Theoretical methane potential and biodegradability of three types of fractions deriving from manure separation were tested. The volumetric...

  16. Using stable isotopes of hydrogen to quantify biogenic and thermogenic atmospheric methane sources: A case study from the Colorado Front Range

    Science.gov (United States)

    Townsend-Small, Amy; Botner, E. Claire; Jimenez, Kristine L.; Schroeder, Jason R.; Blake, Nicola J.; Meinardi, Simone; Blake, Donald R.; Sive, Barkley C.; Bon, Daniel; Crawford, James H.; Pfister, Gabriele; Flocke, Frank M.

    2016-11-01

    Global atmospheric concentrations of methane (CH4), a powerful greenhouse gas, are increasing, but because there are many natural and anthropogenic sources of CH4, it is difficult to assess which sources may be increasing in magnitude. Here we present a data set of δ2H-CH4 measurements of individual sources and air in the Colorado Front Range, USA. We show that δ2H-CH4, but not δ13C, signatures are consistent in air sampled downwind of landfills, cattle feedlots, and oil and gas wells in the region. Applying these source signatures to air in ground and aircraft samples indicates that at least 50% of CH4 emitted in the region is biogenic, perhaps because regulatory restrictions on leaking oil and natural gas wells are helping to reduce this source of CH4. Source apportionment tracers such as δ2H may help close the gap between CH4 observations and inventories, which may underestimate biogenic as well as thermogenic sources.

  17. Methyl chavicol: characterization of its biogenic emission rate, abundance, and oxidation products in the atmosphere

    Directory of Open Access Journals (Sweden)

    N. C. Bouvier-Brown

    2009-03-01

    Full Text Available We report measurements of ambient atmospheric mixing ratios for methyl chavicol and determine its biogenic emission rate. Methyl chavicol, a biogenic oxygenated aromatic compound, is abundant within and above Blodgett Forest, a ponderosa pine forest in the Sierra Nevada Mountains of California. Methyl chavicol was detected simultaneously by three in-situ instruments – a gas chromatograph with mass spectrometer detector (GC-MS, a proton transfer reaction mass spectrometer (PTR-MS, and a thermal desorption aerosol GC-MS (TAG – and found to be abundant within and above Blodgett Forest. Methyl chavicol atmospheric mixing ratios are strongly correlated with 2-methyl-3-buten-2-ol (MBO, a light- and temperature-dependent biogenic emission from the ponderosa pine trees at Blodgett Forest. Scaling from this correlation, methyl chavicol emissions account for 4–68% of the carbon mass emitted as MBO in the daytime, depending on the season. From this relationship, we estimate a daytime basal emission rate of 0.72–10.2 μgCg−1 h−1, depending on needle age and seasonality. We also present the first observations of its oxidation products (4-methoxybenzaldehyde and 4-methyoxy benzene acetaldehyde in the ambient atmosphere. Methyl chavicol is a major essential oil component of many plant species. This work suggests that methyl chavicol plays a significant role in the atmospheric chemistry of Blodgett Forest, and potentially other sites, and should be included explicitly in both biogenic volatile organic carbon emission and atmospheric chemistry models.

  18. Methyl chavicol: characterization of its biogenic emission rate, abundance, and oxidation products in the atmosphere

    Directory of Open Access Journals (Sweden)

    N. C. Bouvier-Brown

    2008-11-01

    Full Text Available We report measurements of ambient atmospheric mixing ratios for methyl chavicol and determine its biogenic emission rate. Methyl chavicol, a biogenic oxygenated aromatic compound, is abundant within and above Blodgett Forest, a ponderosa pine forest in the Sierra Nevada Mountains of California. Methyl chavicol was detected simultaneously by three in-situ instruments – a gas chromatograph with mass spectrometer detector (GC-MS, a proton transfer reaction mass spectrometer (PTR-MS, and a thermal desorption aerosol GC-MS (TAG – and found to be abundant within and above Blodgett Forest, a ponderosa pine forest in the Sierra Nevada Mountains of California. Methyl chavicol atmospheric mixing ratios are strongly correlated with 2-methyl-3-buten-2-ol (MBO, a light- and temperature-dependent biogenic emission from the ponderosa pine trees at Blodgett Forest. Scaling from this correlation, methyl chavicol emissions account for 4–68% of the carbon mass emitted as MBO in the daytime, depending on the season. From this relationship, we estimate a daytime basal emission rate of 0.72–10.2 μgCg−1h−1, depending on needle age and seasonality. We also present the first observations of its oxidation products (4-methoxybenzaldehyde and 4-methyoxy benzene acetaldehyde in the ambient atmosphere. Methyl chavicol is a major essential oil component of many plant species. This work suggests that methyl chavicol plays a significant role in the atmospheric chemistry of Blodgett Forest, and potentially other sites, and should be included explicitly in both biogenic volatile organic carbon emission and atmospheric chemistry models.

  19. Detection and Production of Methane Hydrate

    Energy Technology Data Exchange (ETDEWEB)

    George Hirasaki; Walter Chapman; Gerald Dickens; Colin Zelt; Brandon Dugan; Kishore Mohanty; Priyank Jaiswal

    2011-12-31

    This project seeks to understand regional differences in gas hydrate systems from the perspective of as an energy resource, geohazard, and long-term climate influence. Specifically, the effort will: (1) collect data and conceptual models that targets causes of gas hydrate variance, (2) construct numerical models that explain and predict regional-scale gas hydrate differences in 2-dimensions with minimal 'free parameters', (3) simulate hydrocarbon production from various gas hydrate systems to establish promising resource characteristics, (4) perturb different gas hydrate systems to assess potential impacts of hot fluids on seafloor stability and well stability, and (5) develop geophysical approaches that enable remote quantification of gas hydrate heterogeneities so that they can be characterized with minimal costly drilling. Our integrated program takes advantage of the fact that we have a close working team comprised of experts in distinct disciplines. The expected outcomes of this project are improved exploration and production technology for production of natural gas from methane hydrates and improved safety through understanding of seafloor and well bore stability in the presence of hydrates. The scope of this project was to more fully characterize, understand, and appreciate fundamental differences in the amount and distribution of gas hydrate and how this would affect the production potential of a hydrate accumulation in the marine environment. The effort combines existing information from locations in the ocean that are dominated by low permeability sediments with small amounts of high permeability sediments, one permafrost location where extensive hydrates exist in reservoir quality rocks and other locations deemed by mutual agreement of DOE and Rice to be appropriate. The initial ocean locations were Blake Ridge, Hydrate Ridge, Peru Margin and GOM. The permafrost location was Mallik. Although the ultimate goal of the project was to understand

  20. Terrestrial plant methane production and emission

    DEFF Research Database (Denmark)

    Bruhn, Dan; Møller, Ian M.; Mikkelsen, Teis Nørgaard

    2012-01-01

    In this minireview, we evaluate all experimental work published on the phenomenon of aerobic methane (CH4) generation in terrestrial plants and plant. Clearly, despite much uncertainty and skepticism, we conclude that the phenomenon is true. Four stimulating factors have been observed to induce...... aerobic CH4 into a global budget is inadequate. Thus it is too early to draw the line under the aerobic methane emission in plants. Future work is needed for establishing the relative contribution of several proven potential CH4 precursors in plant material....

  1. Energy from anaerobic methane production. [Sweden

    Energy Technology Data Exchange (ETDEWEB)

    1982-02-01

    Since 1970 Swedish researchers have been testing the ANAMET (anaerobic-aerobic-methane) process, which involves converting industrial wastewaters via an initial anaerobic microbiological step followed by an aerobic one. Recycling the biomass material in each step allows shorter hydraulic retention times without decreasing stability or solids reduction. Since the first ANAMET plants began operating at a Swedish sugar factory in 1972, 17 more plants have started up or are under construction. Moreover, the ANAMET process has engendered to offshoot BIOMET (biomass-methane) process, a thermophilic anaerobic scheme that can handle sugar-beet pulp as well as grass and other soft, fast-growing biomasses.

  2. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Richard Sigal; Kent Newsham; Thomas Williams; Barry Freifeld; Timothy Kneafsey; Carl Sondergeld; Shandra Rai; Jonathan Kwan; Stephen Kirby; Robert Kleinberg; Doug Griffin

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. The work scope drilled and cored a well The Hot Ice No. 1 on Anadarko leases beginning in FY 2003 and completed in 2004. An on-site core analysis laboratory was built and utilized for determining the physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. The final efforts of the project are to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists developing reservoir models. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in this report. The Hot Ice No. 1 well was drilled from the surface to a measured depth of 2300 ft. There was almost 100% core recovery from the bottom of surface casing at 107 ft to total depth. Based on the best estimate of the bottom of the methane hydrate stability zone (which used new data obtained from Hot Ice No. 1 and new analysis of data from adjacent wells), core was recovered over its complete range. Approximately 580 ft of porous, mostly frozen, sandstone and 155 of conglomerate were recovered in the Ugnu Formation and approximately 215 ft of porous sandstone were recovered in the West Sak Formation. There were gas shows in the bottom

  3. Methane production from acid hydrolysates of Agave tequilana bagasse: evaluation of hydrolysis conditions and methane yield.

    Science.gov (United States)

    Arreola-Vargas, Jorge; Ojeda-Castillo, Valeria; Snell-Castro, Raúl; Corona-González, Rosa Isela; Alatriste-Mondragón, Felipe; Méndez-Acosta, Hugo O

    2015-04-01

    Evaluation of diluted acid hydrolysis for sugar extraction from cooked and uncooked Agave tequilana bagasse and feasibility of using the hydrolysates as substrate for methane production, with and without nutrient addition, in anaerobic sequencing batch reactors (AnSBR) were studied. Results showed that the hydrolysis over the cooked bagasse was more effective for sugar extraction at the studied conditions. Total sugars concentration in the cooked and uncooked bagasse hydrolysates were 27.9 g/L and 18.7 g/L, respectively. However, 5-hydroxymethylfurfural was detected in the cooked bagasse hydrolysate, and therefore, the uncooked bagasse hydrolysate was selected as substrate for methane production. Interestingly, results showed that the AnSBR operated without nutrient addition obtained a constant methane production (0.26 L CH4/g COD), whereas the AnSBR operated with nutrient addition presented a gradual methane suppression. Molecular analyses suggested that methane suppression in the experiment with nutrient addition was due to a negative effect over the archaeal/bacterial ratio.

  4. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Thomas E. Williams; Keith Millheim; Bill Liddell

    2004-11-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is a cost-shared partnership between Maurer Technology, Anadarko Petroleum, Noble Corporation, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to help identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. As part of the project work scope, team members drilled and cored a well (the Hot Ice No. 1) on Anadarko leases beginning in January 2003 and completed in March 2004. Due to scheduling constraints imposed by the Arctic drilling season, operations at the site were suspended between April 21, 2003 and January 30, 2004. An on-site core analysis laboratory was constructed and used for determining physical characteristics of frozen core immediately after it was retrieved from the well. The well was drilled from a new and innovative Anadarko Arctic Platform that has a greatly reduced footprint and environmental impact. Final efforts of the project were to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists for future hydrate operations. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained

  5. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Thomas E. Williams; Keith Millheim; Bill Liddell

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is a cost-shared partnership between Maurer Technology, Anadarko Petroleum, Noble Corporation, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to help identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. As part of the project work scope, team members drilled and cored a well (the Hot Ice No. 1) on Anadarko leases beginning in January 2003 and completed in March 2004. Due to scheduling constraints imposed by the Arctic drilling season, operations at the site were suspended between April 21, 2003 and January 30, 2004. An on-site core analysis laboratory was constructed and used for determining physical characteristics of frozen core immediately after it was retrieved from the well. The well was drilled from a new and innovative Anadarko Arctic Platform that has a greatly reduced footprint and environmental impact. Final efforts of the project were to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists for future hydrate operations. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained

  6. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Ali Kadaster; Bill Liddell; Tommy Thompson; Thomas Williams; Michael Niedermayr

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project was a cost-shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The work scope included drilling and coring a well (Hot Ice No. 1) on Anadarko leases beginning in FY 2003 and completed in 2004. During the first drilling season, operations were conducted at the site between January 28, 2003 to April 30, 2003. The well was spudded and drilled to a depth of 1403 ft. Due to the onset of warmer weather, work was then suspended for the season. Operations at the site were continued after the tundra was re-opened the following season. Between January 12, 2004 and March 19, 2004, the well was drilled and cored to a final depth of 2300 ft. An on-site core analysis laboratory was built and implemented for determining physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. Final efforts of the project are to correlate geology, geophysics, logs, and drilling and

  7. Kinetics of Methane Production from Swine Manure and Buffalo Manure.

    Science.gov (United States)

    Sun, Chen; Cao, Weixing; Liu, Ronghou

    2015-10-01

    The degradation kinetics of swine and buffalo manure for methane production was investigated. Six kinetic models were employed to describe the corresponding experimental data. These models were evaluated by two statistical measurements, which were root mean square prediction error (RMSPE) and Akaike's information criterion (AIC). The results showed that the logistic and Fitzhugh models could predict the experimental data very well for the digestion of swine and buffalo manure, respectively. The predicted methane yield potential for swine and buffalo manure was 487.9 and 340.4 mL CH4/g volatile solid (VS), respectively, which was close to experimental values, when the digestion temperature was 36 ± 1 °C in the biochemical methane potential assays. Besides, the rate constant revealed that swine manure had a much faster methane production rate than buffalo manure.

  8. Raton basin coalbed methane production picking up in Colorado

    Science.gov (United States)

    Hemborg, H. Thomas

    1996-01-01

    Coalbed methane production in the Raton basin of south-central Colorado and northeast New Mexico has gone over pilot testing and entered the development stage which is expected to last several years. The development work is restricted to roughly a 25 mile by 15 mile wide `fairway' centered about 20 miles west of Trinidad, Colorado. At last count, 85 wells were producing nearly 17.5 MMcfd of coalbed methane from the basin's Raton and Vermejo formation coals.

  9. Biomass gasification for the production of methane

    NARCIS (Netherlands)

    Nanou, P.

    2013-01-01

    Biomass is very promising as a sustainable alternative to fossil resources because it is a renewable source that contains carbon, an essential building block for gaseous and liquid fuels. Methane is the main component of natural gas, which is a fuel used for heating, power generation and transportat

  10. Biogenic metallic nanoparticles as catalyst for bioelectricity production: A novel approach in microbial fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Saravanakumar, Kandasamy, E-mail: saravana732@gmail.com [School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai (China); State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai (China); Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, Shanghai (China); MubarakAli, Davoodbasha [Microbial Genetic Engineering Laboratory, Division of Bioengineering, College of Life Science and Bioengineering, Incheon National University, Songdo 406772, Incheon (Korea, Republic of); Department of Microbiology, School of Lifesciences, Bharathidasan University, Tiruchirappalli 620024 (India); Kathiresan, Kandasamy [Centre of Advanced Study in Marine Biology, Faculty of Marine Sciences, Annamalai University, Parangipettai 608 502, Tamil Nadu (India); Thajuddin, Nooruddin [Department of Microbiology, School of Lifesciences, Bharathidasan University, Tiruchirappalli 620024 (India); Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia); Alharbi, Naiyf S. [Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia); Chen, Jie, E-mail: jiechen59@sjtu.edu.cn [School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai (China); State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai (China); Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, Shanghai (China)

    2016-01-15

    Highlights: • Trichoderma sp., showed an abilities to synthesis of AgNPs and AuNPs with an excellent stability. • AuNPs significantly enhanced the bioelectricity production by MFC of anaerobic fermentation as catalyst. • Maximum bioelectricity production was optimized and obtained the voltage of 432.80 mA using RSM. - Abstract: The present work aimed to use the biogenic metallic nanoparticles as catalyst for bioelectricity production in microbial fuel cell (MFC) approach under anaerobic condition. Silver and gold nanoparticles (AuNPs) were synthesized using Trichoderma sp. Particle size and cystallinity were measured by X-ray diffraction revealed the crystalline structure with average size of 36.17 nm. Electron microscopic studies showed spherical shaped silver nanoparticles (AgNPs) and cubical shaped AuNPs with size ranges from 50 to 150 nm. The concentration of biogenic metallic nanoparticles as catalyst for enhanced bioelectricity generations and estimated by response surface methodology (RSM) and found at the greatest of 342.80 mA under optimized conditions are time interval, temperature, nanoparticles used as 63 h, 28 ± 2.0 °C, 22.54 mg l{sup −1} (AgNPs) and 25.62 mg l{sup −1} (AuNPs) in a batch reactor. AuNPs acted as an excellent catalyst to enhance the bioelectricity production. This novel technique could be used for eco-friendly, economically feasible and facile electricity production.

  11. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Donn McGuire; Steve Runyon; Richard Sigal; Bill Liddell; Thomas Williams; George Moridis

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is in the final stages of a cost-shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. Hot Ice No. 1 was planned to test the Ugnu and West Sak sequences for gas hydrates and a concomitant free gas accumulation on Anadarko's 100% working interest acreage in section 30 of Township 9N, Range 8E of the Harrison Bay quadrangle of the North Slope of Alaska. The Ugnu and West Sak intervals are favorably positioned in the hydrate-stability zone over an area extending from Anadarko's acreage westward to the vicinity of the aforementioned gas-hydrate occurrences. This suggests that a large, north-to-south trending gas-hydrate accumulation may exist in that area. The presence of gas shows in the Ugnu and West Sak reservoirs in wells situated eastward and down dip of the Hot Ice location indicate that a free-gas accumulation may be trapped by gas hydrates. The Hot Ice No. 1 well was designed to core from the surface to the base of the West Sak interval using the

  12. Methane and hydrogen production from crop biomass through anaerobic digestion

    Energy Technology Data Exchange (ETDEWEB)

    Pakarinen, O.

    2011-07-01

    The feasibility of methane and hydrogen production from energy crops through anaerobic digestion was evaluated in this thesis. The effects of environmental conditions, e.g. pH and temperature, as well as inoculum source on H{sub 2} yield were studied in batch assays. In addition, the effects of pre-treatments on methane and hydrogen yield as well as the feasibility of two-stage H{sub 2} + CH{sub 4} production was evaluated. Moreover, the effect of storage on methane yield of grasses was evaluated. Monodigestion of grass silage for methane production was studied, as well as shifting the methanogenic process to hydrogenic. Hydrogen production from grass silage and maize was shown to be possible with heat-treated inoculum in batch assays, with highest H{sub 2} yields of 16.0 and 9.9 ml gVS{sub added}-1 from untreated grass silage and maize, respectively. Pre-treatments (NaOH, HCl and water-extraction) showed some potential in increasing H{sub 2} yields, while methane yields were not affected. Two-stage H{sub 2} + CH{sub 4} producing process was shown to improve CH{sub 4} yields when compared to traditional one-stage CH{sub 4} process. Methane yield from grass silage monodigestion in continuously stirred tank reactor (CSTR) with organic loading rate (OLR) of 2 kgVS (m3d)-1 and hydraulic retention time (HRT) of 30 days was at most 218 l kgVS{sub fed}-1. Methanogenic process was shifted to hydrogenic by increasing the OLR to 10 kgVS (m3d)-1 and shortening the HRT to 6 days. Highest H{sub 2} yield from grass silage was 42 l kgVS{sub fed}-1 with a maximum H{sub 2} content of 24 %. Energy crops can be successfully stored even for prolonged periods without decrease in methane yield. However, under sub-optimal storage conditions loss in volatile solids (VS) content and methane yield can occur. According to present results energy crops such as grass silage and maize can be converted to hydrogen or methane in AD process. Hydrogen energy yields are typically only 2-5 % of the

  13. San Juan Basin, USA; coalbed methane development and production

    Energy Technology Data Exchange (ETDEWEB)

    Gluskoter, H. [US Geological Survey, Reston, VA (USA)

    2002-07-01

    Twenty one slides/overheads outline the talk on production of coalbed methane from sedimentary basins in the USA. Figures are given for production and reserves for the year 2000. The San Juan basin's geologic structure, containing resources of the Cretaceous coal age, primarily in the Fruitland Formation, is described. 4 refs.

  14. Genetic and temporal relations between formation waters and biogenic methane: Upper Devonian Antrim Shale, Michigan Basin, USA

    Science.gov (United States)

    Martini, A. M.; Walter, L. M.; Budai, J. M.; Ku, T. C. W.; Kaiser, C. J.; Schoell, M.

    1998-05-01

    Controversy remains regarding how well geochemical criteria can distinguish microbial from thermogenic methane. Natural gas in most conventional deposits has migrated from a source rock to a reservoir, rarely remaining associated with the original or cogenetic formation waters. We investigated an unusual gas reservoir, the Late Devonian Antrim Shale, in which large volumes of variably saline water are coproduced with gas. The Antrim Shale is organic-rich, of relatively low thermal maturity, extensively fractured, and is both source and reservoir for methane that is generated dominantly by microbial activity. This hydrogeologic setting permits integration of chemical and isotopic compositions of coproduced water and gas, providing a unique opportunity to characterize methane generating mechanisms. The well-developed fracture network provides a conduit for gas and water mass transport within the Antrim Shale and allows invasion of meteoric water from overlying aquifers in the glacial drift. Steep regional concentration gradients in chemical and isotopic data are observed for formation waters and gases; dilute waters grade into dense brines (300,000 ppm) over lateral distances of less than 30 km. Radiogenic ( 14C and 3H) and stable isotope ( 18O and D) analyses of shallow Antrim Shale formation waters and glacial drift groundwaters indicate recharge times from modern to 20,000 yr BP. Carbon isotope compositions of methane from Antrim Shale wells are typical of the established range for thermogenic or mixed gas (δ 13C = -47 to -56‰). However, the unusually high δ 13C values of CO 2 coproduced with methane (˜+22‰) and dissolved inorganic carbon (DIC) in formation waters (˜+28‰) require bacterial mediation. The δD values of methane and coproduced formation water provide the strongest evidence of bacterial methanogenesis. Methane/[ethane + propane] ratios and δ 13C values for ethane indicate: (1) the presence of a thermogenic gas component that increases

  15. Anaerobic digestion of giant reed for methane production.

    Science.gov (United States)

    Yang, Liangcheng; Li, Yebo

    2014-11-01

    As a fast growing plant, giant reed has good potential to be used as a feedstock for methane production via anaerobic digestion (AD). The effect of total solids (TS) content, an AD operating parameter, was studied. Results showed that increasing TS from 8% to 38% decreased methane yield, due to the inhibition of volatile fatty acids (VFAs) and total ammonia nitrogen (TAN); while the maximum volumetric methane production was obtained at 20-23% TS. Comparison of solid-state AD (SS-AD) at 20% TS and liquid AD (L-AD) at 8% TS was conducted at feedstock to effluent (F/E) ratios of 2.0, 3.5, and 5.0. The best performance was achieved at an F/E of 2.0, with methane yields of 129.7 and 150.8L-CH4/kg-VS for SS-AD and L-AD, respectively. Overall organic components were degraded by 17.7-28.5% and 24.0-26.6% in SS-AD and L-AD, respectively; among which cellulose showed the highest degradation rate and the highest contribution to methane production.

  16. Production of Methane and Water from Crew Plastic Waste

    Science.gov (United States)

    Captain, Janine; Santiago, Eddie; Parrish, Clyde; Strayer, Richard F.; Garland, Jay L.

    2008-01-01

    Recycling is a technology that will be key to creating a self sustaining lunar outpost. The plastics used for food packaging provide a source of material that could be recycled to produce water and methane. The recycling of these plastics will require some additional resources that will affect the initial estimate of starting materials that will have to be transported from earth, mainly oxygen, energy and mass. These requirements will vary depending on the recycling conditions. The degredation products of these plastics will vary under different atmospheric conditions. An estimate of the the production rate of methane and water using typical ISRU processes along with the plastic recycling will be presented.

  17. Optimization of microwave pretreatment conditions to maximize methane production and methane yield in mesophilic anaerobic sludge digestion.

    Science.gov (United States)

    Park, W J; Ahn, J H

    2011-10-01

    The objective of this study was to find optimum microwave pretreatment conditions for methane production and methane yield in anaerobic sludge digestion. The sludge was pretreated using a laboratory-scale industrial microwave unit (2450 MHz frequency). Microwave temperature increase rate (TIR) (2.9-17.1 degrees C/min) and final temperature (FT) (52-108 degrees C) significantly affected solubilization, methane production, and methane yield. Solubilization degree (soluble chemical oxygen demand (COD)/total COD) in the pretreated sludge (3.3-14.7%) was clearly higher than that in the raw sludge (2.6%). Within the design boundaries, the optimum conditions for maximum methane production (2.02 L/L) were TIR = 9.1 degrees C/min and FT = 90 degrees C, and the optimum conditions for maximum methane yield (809 mL/g VS(removed)) were TIR 7.1 degrees C/min and FT = 92 degrees C.

  18. Bacterial bioaugmentation for improving methane and hydrogen production from microalgae

    Science.gov (United States)

    2013-01-01

    Background The recalcitrant cell walls of microalgae may limit their digestibility for bioenergy production. Considering that cellulose contributes to the cell wall recalcitrance of the microalgae Chlorella vulgaris, this study investigated bioaugmentation with a cellulolytic and hydrogenogenic bacterium, Clostridium thermocellum, at different inoculum ratios as a possible method to improve CH4 and H2 production of microalgae. Results Methane production was found to increase by 17?~?24% with the addition of C. thermocellum, as a result of enhanced cell disruption and excess hydrogen production. Furthermore, addition of C. thermocellum enhanced the bacterial diversity and quantities, leading to higher fermentation efficiency. A two-step process of addition of C. thermocellum first and methanogenic sludge subsequently could recover both hydrogen and methane, with a 9.4% increase in bioenergy yield, when compared with the one-step process of simultaneous addition of C. thermocellum and methanogenic sludge. The fluorescence peaks of excitation-emission matrix spectra associated with chlorophyll can serve as biomarkers for algal cell degradation. Conclusions Bioaugmentation with C. thermocellum improved the degradation of C. vulgaris biomass, producing higher levels of methane and hydrogen. The two-step process, with methanogenic inoculum added after the hydrogen production reached saturation, was found to be an energy-efficiency method for hydrogen and methane production. PMID:23815806

  19. Water Management Strategies for Improved Coalbed Methane Production in the Black Warrior Basin

    Energy Technology Data Exchange (ETDEWEB)

    Pashin, Jack; McIntyre-Redden, Marcella; Mann, Steven; Merkel, David

    2013-10-31

    The modern coalbed methane industry was born in the Black Warrior Basin of Alabama and has to date produced more than 2.6 trillion cubic feet of gas and 1.6 billion barrels of water. The coalbed gas industry in this area is dependent on instream disposal of co-produced water, which ranges from nearly potable sodium-bicarbonate water to hypersaline sodium-chloride water. This study employed diverse analytical methods to characterize water chemistry in light of the regional geologic framework and to evaluate the full range of water management options for the Black Warrior coalbed methane industry. Results reveal strong interrelationships among regional geology, water chemistry, and gas chemistry. Coalbed methane is produced from multiple coal seams in Pennsylvanian-age strata of the Pottsville Coal Interval, in which water chemistry is influenced by a structurally controlled meteoric recharge area along the southeastern margin of the basin. The most important constituents of concern in the produced water include chlorides, ammonia compounds, and organic substances. Regional mapping and statistical analysis indicate that the concentrations of most ionic compounds, metallic substances, and nonmetallic substances correlate with total dissolved solids and chlorides. Gas is effectively produced at pipeline quality, and the only significant impurity is N{sub 2}. Geochemical analysis indicates that the gas is of mixed thermogenic-biogenic origin. Stable isotopic analysis of produced gas and calcite vein fills indicates that widespread late-stage microbial methanogenesis occurred primarily along a CO{sub 2} reduction metabolic pathway. Organic compounds in the produced water appear to have helped sustain microbial communities. Ammonia and ammonium levels increase with total dissolved solids content and appear to have played a role in late-stage microbial methanogenesis and the generation of N{sub 2}. Gas production tends to decline exponentially, whereas water production

  20. Skeletonema cf. costatum biogenic silica production rate determinated by PDMPO method

    Science.gov (United States)

    Zhang, Guicheng; Leng, Xiaoyun; Feng, Yuanyuan; Li, Xia; Sun, Jun

    2017-04-01

    Diatoms are the only ecological phytoplankton that require silicic acid for growth. They are also the dominant contributor of ocean's total primary productivity. Generation and circulation with silica walls, which the siliceous organisms form, is an important component of the marine biological pump. It is crucial to the study of the operational mechanisms of biological pump with different sea areas. Moreover, it is the key link to the study of global silicon cycle. This paper introduces the basic mechanism of the formation of diatom silica walls and a new way of researching silicic acid metabolism, namely the 2-(4-pyridyl)-5-((4-(2-dimethylaminoethylaminocarbamoyl)- methoxy)phenyl)oxazole (PDMPO) dyeing method. Under a fluorescence microscope after excitation with bright green fluorescence, it can combine with silicic acid to form a complex into the Si deposition within diatom cells. The advantage of this method is that it can monitor the metabolism of silicate after adding PDMPO. For experimentation and sample collection in each of the specified time points, samples were determinated through the unutilized silicic acid, silica dissoluble intracellular and Si deposition within diatom cells, not only using hot alkaline digestions method but also PDMPO dyeing method. Results showed a good linear relationship between PDMPO fluorescent value and biogenic silica concentration. It was also indicated that PDMPO had no deleterious impact on Skeletonema cf. costatum growth for 34 h and was useful for tracking newly-deposited biogenic silica in diatoms' frustules.

  1. CHANGES IN COUNTS OF MICROORGANISMS AND BIOGENIC AMINES PRODUCTION DURING THE MANUFACTURE OF FERMENTED SAUSAGES POLIČAN

    Directory of Open Access Journals (Sweden)

    Libor Kalhotka

    2012-10-01

    Full Text Available Poličan is classic raw fermented sausage with low acidity. Dry fermented sausages Poličan were used for the analysis and drawn once a week during production from ripening chambers of meat-packing plants. Those sausages ripened for 35 days under controlled temperature and humidity conditions. The aim of this article is to evaluate microorganisms accompanying ripening of fermented sausages Poličan and characterize relationships between activity of microorganisms and content of biogenic amines. Lactic acid bacteria are the most important group of microorganisms. Their counts are relatively high already at the beginning of ripening - about 106 CFU.g-1. During the first week of ripening, their numbers increased to 107 CFU.g-1 and has not changed much further. Due to the minimal counts of coliform bacteria and micromycetes at the end of ripening, both series of these products can be considered as good and safe. In freshly made sausages, the amount of biogenic amines was low. Spermidine, spermine and tyramine were quantitatively the most important. During ripening, the content of biogenic amines was increasing. Significant difference in biogenic amines between I. and II. series was found only for tyramine which was detected in difference exceeding 100 mg.kg-1 at the end of ripening. Sausages from II. series with high levels of tyramine may present a risk for sensitive individuals. Due to low levels of biogenic amines, other samples may be regarded as unproblematic.

  2. Calculation of methane production from enteric fermentation in dairy cows

    NARCIS (Netherlands)

    Smink, M.C.J.; Hoek, van der K.W.; Bannink, A.; Dijkstra, J.

    2005-01-01

    Doel van deze studie is om een inschatting te maken van de methaanproductie door melkkoeien vanaf 1990 tot nu. Tevens zijn de effecten van voer onderzochtThe aim of this study is to calculate methane production by dairy cows during the period 1990 till present. A dynamic mechanistic model of rumen f

  3. Methane and hydrogen production by human intestinal anaerobic bacteria.

    Science.gov (United States)

    McKay, L F; Holbrook, W P; Eastwood, M A

    1982-06-01

    The gas above liquid cultures of a variety of human intestinal anaerobic bacteria was sampled and analysed by headspace gas chromatography. Hydrogen production was greatest with strains of the genus Clostridium, intermediate with anaerobic cocci and least with Bacteroides sp. Very few strains produced methane although small amounts were detected with one strain of B. thetaiotaomicron, C. perfringens and C. histolyticum. There may be a relationship between these anaerobic bacteria and several gastrointestinal disorders in which there is a build up of hydrogen or methane in the intestines.

  4. Zero valent iron significantly enhances methane production from waste activated sludge by improving biochemical methane potential rather than hydrolysis rate.

    Science.gov (United States)

    Liu, Yiwen; Wang, Qilin; Zhang, Yaobin; Ni, Bing-Jie

    2015-02-05

    Anaerobic digestion has been widely applied for waste activated sludge (WAS) treatment. However, methane production from anaerobic digestion of WAS is usually limited by the slow hydrolysis rate and/or poor biochemical methane potential of WAS. This work systematically studied the effects of three different types of zero valent iron (i.e., iron powder, clean scrap and rusty scrap) on methane production from WAS in anaerobic digestion, by using both experimental and mathematical approaches. The results demonstrated that both the clean and the rusty iron scrap were more effective than the iron powder for improving methane production from WAS. Model-based analysis showed that ZVI addition significantly enhanced methane production from WAS through improving the biochemical methane potential of WAS rather than its hydrolysis rate. Economic analysis indicated that the ZVI-based technology for enhancing methane production from WAS is economically attractive, particularly considering that iron scrap can be freely acquired from industrial waste. Based on these results, the ZVI-based anaerobic digestion process of this work could be easily integrated with the conventional chemical phosphorus removal process in wastewater treatment plant to form a cost-effective and environment-friendly approach, enabling maximum resource recovery/reuse while achieving enhanced methane production in wastewater treatment system.

  5. The evolution and distribution of methane in Lake Champlain sediments

    Energy Technology Data Exchange (ETDEWEB)

    Thibodeau, P.M. (Univ. of Vermont, Burlington, VT (United States). Dept. of Geology)

    1993-03-01

    Regions of Lake Champlain sediments are acoustically impenetrable to the energy emitted from high resolution, low energy sub-bottom seismic profiling apparatus. This anomolous behavior is caused by the presence of interstitial methane gas which absorbs the wave energy and thus prevents the formation of well-defined seismic boundaries. Through gas chromatographic and carbon isotope analyses, the methane gas contained in the recent sediments of Lake Champlain has been demonstrated to be biogenic in origin. The production of biogenic methane occurs as a result of a series of coupled oxidation-reduction reactions occurring within the upper two meters beneath the sediment-water interface.

  6. Polyhydroxyalkanoates in waste activated sludge enhances anaerobic methane production through improving biochemical methane potential instead of hydrolysis rate

    Science.gov (United States)

    Wang, Qilin; Sun, Jing; Zhang, Chang; Xie, Guo-Jun; Zhou, Xu; Qian, Jin; Yang, Guojing; Zeng, Guangming; Liu, Yiqi; Wang, Dongbo

    2016-01-01

    Anaerobic sludge digestion is the main technology for sludge reduction and stabilization prior to sludge disposal. Nevertheless, methane production from anaerobic digestion of waste activated sludge (WAS) is often restricted by the poor biochemical methane potential and slow hydrolysis rate of WAS. This work systematically investigated the effect of PHA levels of WAS on anaerobic methane production, using both experimental and mathematical modeling approaches. Biochemical methane potential tests showed that methane production increased with increased PHA levels in WAS. Model-based analysis suggested that the PHA-based method enhanced methane production by improving biochemical methane potential of WAS, with the highest enhancement being around 40% (from 192 to 274 L CH4/kg VS added; VS: volatile solid) when the PHA levels increased from 21 to 143 mg/g VS. In contrast, the hydrolysis rate (approximately 0.10 d‑1) was not significantly affected by the PHA levels. Economic analysis suggested that the PHA-based method could save $1.2/PE/y (PE: population equivalent) in a typical wastewater treatment plant (WWTP). The PHA-based method can be easily integrated into the current WWTP to enhance methane production, thereby providing a strong support to the on-going paradigm shift in wastewater management from pollutant removal to resource recovery.

  7. Solar enriched methane production: Assessment of plant potentialities and applications

    Directory of Open Access Journals (Sweden)

    Vincenzo Piemonte

    2010-04-01

    Full Text Available The crucial environmental issue due to fossil fuel use in our society and industries and more and more perceived by the communities is stimulating the development of innovative technologies with the scope of reducing GHGs and pollutants emissions, improving plants efficiency and exploiting renewable energy sources. The idea proposed in the present work links this context: a novel hybrid plant for the production of a mixture of methane and hydrogen (20%vol, called enriched-methane, from a steam reforming reactor whose heat duty is supplied by a concentrating solar power (CSP plant by means of a molten salt stream is here conceived, modelled and assessed. The enriched-methane mixture can be applied in methane internal combustion engines (ICE reducing CO, CO2, unburned emissions and improving engine efficiency. Moreover, the residual sensible heat of solar-heated molten salt stream can be used to generate medium-pressure steam and to produce electricity by a steam-turbine. Therefore, the plant proposed is co-generative, producing both hydrogen and electricity from a solar source. The behaviour of methane steam reforming reactor is simulated by means of a 2D mathematical model and the design of a cogenerative solar plant is proposed, evaluating its potentialities in terms of MWh of electricity produced and number of vehicles fed by enriched-methane. A single CSP module (surface requirement = 1.5 hectares coupled with a 4-tubes-and-shell shaped reactor is able to produce 686 tons/year of hydrogen, equivalent to 3.430 tons/year of 20%vol H2-CH4 mixture and 3.097 MWh/year of clean electricity.

  8. Chemical and stable isotopic evidence for water/rock interaction and biogenic origin of coalbed methane, Fort Union Formation, Powder River Basin, Wyoming and Montana U.S.A

    Science.gov (United States)

    Rice, C.A.; Flores, R.M.; Stricker, G.D.; Ellis, M.S.

    2008-01-01

    Significant amounts (> 36??million m3/day) of coalbed methane (CBM) are currently being extracted from coal beds in the Paleocene Fort Union Formation of the Powder River Basin of Wyoming and Montana. Information on processes that generate methane in these coalbed reservoirs is important for developing methods that will stimulate additional production. The chemical and isotopic compositions of gas and ground water from CBM wells throughout the basin reflect generation processes as well as those that affect water/rock interaction. Our study included analyses of water samples collected from 228 CBM wells. Major cations and anions were measured for all samples, ??DH2O and ??18OH2O were measured for 199 of the samples, and ??DCH4 of gas co-produced with water was measured for 100 of the samples. Results show that (1) water from Fort Union Formation coal beds is exclusively Na-HCO3-type water with low dissolved SO4 content (median < 1??mg/L) and little or no dissolved oxygen (< 0.15??mg/L), whereas shallow groundwater (depth generally < 120??m) is a mixed Ca-Mg-Na-SO4-HCO3 type; (2) water/rock interactions, such as cation exchange on clay minerals and precipitation/dissolution of CaCO3 and SO4 minerals, account for the accumulation of dissolved Na and depletion of Ca and Mg; (3) bacterially-mediated oxidation-reduction reactions account for high HCO3 (270-3310??mg/L) and low SO4 (median < 0.15??mg/L) values; (4) fractionation between ??DCH4 (- 283 to - 328 per mil) and ??DH2O (- 121 to - 167 per mil) indicates that the production of methane is primarily by biogenic CO2 reduction; and (5) values of ??DH2O and ??18OH2O (- 16 to - 22 per mil) have a wide range of values and plot near or above the global meteoric water line, indicating that the original meteoric water has been influenced by methanogenesis and by being mixed with surface and shallow groundwater.

  9. Hydrogen production from methane through catalytic partial oxidation reactions

    Science.gov (United States)

    Freni, S.; Calogero, G.; Cavallaro, S.

    This paper reviews recent developments in syn-gas production processes used for partial methane oxidation with and/or without steam. In particular, we examined different process charts (fixed bed, fluidised bed, membrane, etc.), kinds of catalysts (powders, foams, monoliths, etc.) and catalytically active phases (Ni, Pt, Rh, etc.). The explanation of the various suggested technical solutions accounted for the reaction mechanism that may selectively lead to calibrated mixtures of CO and H 2 or to the unwanted formation of products of total oxidation (CO 2 and H 2O) and pyrolysis (coke). Moreover, the new classes of catalysts allow the use of small reactors to treat large amounts of methane (monoliths) or separate hydrogen in situ from the other reaction products (membrane). This leads to higher conversions and selectivity than could have been expected thermodynamically. Although catalysts based on Rh are extremely expensive, they can be used to minimise H 2O formation by maximising H 2 yield.

  10. Can aquatic worms enhance methane production from waste activated sludge?

    Science.gov (United States)

    Serrano, Antonio; Hendrickx, Tim L G; Elissen, Hellen H J; Laarhoven, Bob; Buisman, Cees J N; Temmink, Hardy

    2016-07-01

    Although literature suggests that aquatic worms can help to enhance the methane production from excess activated sludge, clear evidence for this is missing. Therefore, anaerobic digestion tests were performed at 20 and at 30°C with sludge from a high-loaded membrane bioreactor, the aquatic worm Lumbriculus variegatus, feces from these worms and with mixtures of these substrates. A significant synergistic effect of the worms or their feces on methane production from the high-loaded sludge or on its digestion rate was not observed. However, a positive effect on low-loaded activated sludge, which generally has a lower anaerobic biodegradability, cannot be excluded. The results furthermore showed that the high-loaded sludge provides an excellent feed for L. variegatus, which is promising for concepts where worm biomass is considered a resource for technical grade products such as coatings and glues.

  11. A methane production feasibility model for central anaerobic digesters

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, J.L. (Western Ontario University, London, Canada); Peters, N. (Fundacao de Tecnologia Industrial, Botafogo, Brazil)

    1981-01-01

    A mathematical model was developed for prediction of the practicability of building and operating large centrally located anaerobic digesters for producing methane gas from animal manure. The assumptions were that the manure would be collected from the feedlots and that the product gas would be supplied to an existing pipeline. The model takes account of the farm locations and calculates transportation costs for various numbers of digesters. Digester sizes for each distribution and installation and operating costs are computed. Revenue was then determined on the basis of methane production and fertilizer value recovery. The utility of the model is shown through a study of farms in southwestern Ontario where many small feedlots exist. The results of the study indicate a gas production cost of roughly $0.18/cu m.

  12. The Influence of Pyrogenic, Biogenic and Anthropogenic Emissions on Ozone Production Downwind from Boreal Forest Fires

    Science.gov (United States)

    Finch, Douglas; Palmer, Paul

    2016-04-01

    Boreal forest fires emit pollutants that can have a strong influence on downwind surface ozone concentrations, with potential implications for exceeding air quality regulations. The influence of the mixing of pyrogenic, biogenic and anthropogenic emissions on ozone is not well understood. Using the nested 0.5° latitude x 0.667° longitude GEOS-Chem chemical transport model we track biomass burning plumes in North America. We identify the changes in key chemical reactions within these plumes as well as the sensitivity of ozone to the different emission sources. We illustrate the importance of this method using a case study of a multi-day forest fire during the BORTAS aircraft campaign over eastern Canada during summer 2011. We focus on emissions from the fire on the 17th of July and follow the plume for eight days. After the initial 24 hours of pyrogenic emissions the main source of VOCs is biogenic with increasing emissions from anthropogenic sources including outflow from Quebec City and Newfoundland. Using a Lagrangian framework, we show that the ozone production efficiency (OPE) of this plume decreases steadily as it moves away from the fire but increases rapidly as the plume reaches the east coast of Canada. Using a Eulerian framework we show that ozone mixing ratios of a east coast receptor region increase by approximately 15% even though the ozone tendency of the regional air mass is negative, which we find is due to the arrival of ozone precursors in the plume. We also consider the contribution of anthropogenic outflow over Nova Scotia that originates from the eastern seaboard of the United States to the local chemistry. Using these sensitivity model runs we generate a chemical reaction narrative for the plume trajectory that helps to understand the attribution of observed ozone variations.

  13. Methyl chloride production from methane over lanthanum-based catalysts.

    Science.gov (United States)

    Podkolzin, Simon G; Stangland, Eric E; Jones, Mark E; Peringer, Elvira; Lercher, Johannes A

    2007-03-07

    The mechanism of selective production of methyl chloride by a reaction of methane, hydrogen chloride, and oxygen over lanthanum-based catalysts was studied. The results suggest that methane activation proceeds through oxidation-reduction reactions on the surface of catalysts with an irreducible metal-lanthanum, which is significantly different from known mechanisms for oxidative chlorination. Activity and spectroscopic measurements show that lanthanum oxychloride (LaOCl), lanthanum trichloride (LaCl3), and lanthanum phases with an intermediate extent of chlorination are all active for this reaction. The catalyst is stable with no noticeable deactivation after three weeks of testing. Kinetic measurements suggest that methane activation proceeds on the surface of the catalyst. Flow and pulse experiments indicate that the presence of hydrogen chloride is not required for activity, and its role appears to be limited to maintaining the extent of catalyst chlorination. In contrast, the presence of gas-phase oxygen is essential for catalytic activity. Density-functional theory calculations suggest that oxygen can activate surface chlorine species by adsorbing dissociatively and forming OCl surface species, which can serve as an active site for methane activation. The proposed mechanism, thus, involves changing of the formal oxidation state of surface chlorine from -1 to +1 without any changes in the oxidation state of the underlying metal.

  14. Development of mixed inoculum for methane enriched biogas production.

    Science.gov (United States)

    Singh, Ranjeet; Mandal, S K; Jain, V K

    2010-10-01

    Inocula were collected from four different sources such as Jajmau tannery waste treatment plant (ITW), Jajmau municipal waste treatment (IMW), Unnao distillery (IDW) and a batch reactor, in which the sludge of a field scale biogas reactor was added to cow dung slurry to develop inoculum (IBS). A combination of these mixed inocula were used for biogas production at 35°C in laboratory scale reactor (10 L capacity) and the average yield of biogas (0.547 Lg(-1) volatile solid (VS)) and methane (0.323 Lg(-1)VS) in 41 d was higher in case of mixed inoculum IMW (1) (IMW+IBS), with maximum methane content in biogas (68% during 27-30 d), as compared to other mixed inocula as well as control i.e. ITW (1) (ITW+IBS), IDW(1) (IDW+IBS) and IBS. The corresponding yields of gas were biogas (0.505, 0.536 and 0.456 Lg(-1)VS), methane (0.288, 0.305, and 0.245 Lg(-1)VS) where as, the corresponding maximum methane content in biogas was 62% during 29-33d, 64% during 29-33 d and 62% during 27-29 d in ITW(1), IDW(1) and IBS.

  15. Hydrogen production by catalytic partial oxidation of methane

    OpenAIRE

    Enger, Bjørn Christian

    2008-01-01

    Hydrogen production by catalytic partial oxidation of natural gas was investigated using tools ranging from theoretical calculations to experimental work and sophisticated characterization techniques.Catalytic partial oxidation (CPO) was carried out in a conventional continuous flow experimental apparatus using a xed-bed reactor, and operating at 1 atm and furnace temperatures in the range from ambient to 1073 K. The feed typically consisted of a mixture of methane and air, with a CH4/O2 rati...

  16. Electrochemically assisted methane production in a biofilm reactor

    Science.gov (United States)

    Villano, Marianna; Monaco, Gianluca; Aulenta, Federico; Majone, Mauro

    Microbial electrolysis is a new technology for the production of value-added products, such as gaseous biofuels, from waste organic substrates. This study describes the performance of a methane-producing microbial electrolysis cell (MEC) operated at ambient temperature with a Geobacter sulfurreducens microbial bioanode and a methanogenic microbial biocathode. The cell was initially operated at a controlled cathode potential of -850 mV (vs. standard hydrogen electrode, SHE) in order to develop a methanogenic biofilm capable of reducing carbon dioxide to methane gas using abiotically produced hydrogen gas or directly the polarized electrode as electron donors. Subsequently, G. sulfurreducens was inoculated at the anode and the MEC was operated at a controlled anode potential of +500 mV, with acetate serving as electron donor. The rate of methane production at the cathode was found to be primarily limited by the acetate oxidation kinetics and in turn by G. sulfurreducens concentration at the anode of the MEC. Temperature had also a main impact on acetate oxidation kinetics, with an apparent activation energy of 58.1 kJ mol -1.

  17. Effect of azithromycin on enhancement of methane production from waste activated sludge.

    Science.gov (United States)

    Nguyen, Minh Tuan; Maeda, Toshinari; Mohd Yusoff, Mohd Zulkhairi; Ogawa, Hiroaki I

    2014-07-01

    In the methane production from waste activated sludge (WAS), complex bacterial interactions in WAS have been known as a major contribution to methane production. Therefore, the influence of bacterial community changes toward methane production from WAS was investigated by an application of antibiotics as a simple means for it. In this study, azithromycin (Azm) as an antibiotic was mainly used to observe the effect on microbial changes that influence methane production from WAS. The results showed that at the end of fermentation, Azm enhanced methane production about twofold compared to control. Azm fostered the growth of acid-producing bacterial communities, which synthesized more precursors for methane formation. DGGE result showed that the hydrolysis as well as acetogenesis stage was improved by the dominant of B1, B2 and B3 strains, which are Clostridium species. In the presence of Azm, the total population of archaeal group was increased, resulting in higher methane productivity achievement.

  18. Estimation of future methane production from Hellenic landfills

    Energy Technology Data Exchange (ETDEWEB)

    Tsatsarelis, T.; Karagiannidis, A. [Aristotle Univ., Thessaloniki (Greece). Lab. of Heat Transfer and Environmental Engineering

    2009-07-15

    Organic waste decomposition leads to the production of Landfill Gas (LFG). LFG mainly consists of methane (CH{sub 4}) and carbon dioxide (CO{sub 2}). It is common understanding now that LFG should be considered either as a significant source of pollution and risk (if migrating uncontrollably to the air and ground), or as a significant source of renewable energy (if extracted and processed accordingly). There are two possible solutions for dealing with LFG emissions. In the case of low methane ratios, LFG should be extracted and flared or oxidized in biofilters. On the other hand, in the case of high methane content, LFG becomes an evidently valuable energy resource, as it is then able to sustain the fuelling of engines producing electricity and thermal energy. More specifically, it can be used as a supplementary or primary fuel to increase the production of electric power, as a pipeline quality gas and vehicle fuel, or even as a supply of heat and carbon dioxide for greenhouses and various industrial processes. Technologies that utilize LFG include internal combustion engines, gas turbines, fuel cells and boiler systems. The main objective of this research was to predict expected methane generation in Hellenic sanitary landfills, in order to evaluate its potential for energy production and to ensure health and safety in and around these sites on the long term. The study was performed for the period 2008--2028 with the use of a multi-phase model and included a sensitivity analysis in order to determine the impact of certain waste parameters. In this context, two 'extreme' reference scenarios were formulated and assessed, one anticipating fulfillment of the EU landfill directive (which sets limits to the amount of biodegradable and packaging materials to be deposited in sanitary landfills) whereas a second (do-nothing scenario) assuming no such timely compliance. The model used here for methane estimation is a multi-phase model developed by the Norwegian

  19. Ruminal Methane Production on Simple Phenolic Acids Addition in in Vitro Gas Production Method

    Directory of Open Access Journals (Sweden)

    A. Jayanegara

    2009-04-01

    Full Text Available Methane production from ruminants contributes to total global methane production, which is an important contributor to global warming. In this experiment, six sources of simple phenolic acids (benzoic, cinnamic, phenylacetic, caffeic, p-coumaric and ferulic acids at two different levels (2 and 5 mM added to hay diet were evaluated for their potential to reduce enteric methane production using in vitro Hohenheim gas production method. The measured variables were gas production, methane, organic matter digestibility (OMD, and short chain fatty acids (SCFA. The results showed that addition of cinnamic, caffeic, p-coumaric and ferulic acids at 5 mM significantly (P p-coumaric > ferulic > cinnamic. The addition of simple phenols did not significantly decrease OMD. Addition of simple phenols tends to decrease total SCFA production. It was concluded that methane decrease by addition of phenolic acids was relatively small, and the effect of phenolic acids on methane decrease depended on the source and concentration applied.

  20. Evaluation of Phytoremediation of Coal Bed Methane Product Water and Waters of Quality Similar to that Associated with Coal Bed Methane Reserves of the Powder River Basin, Montana and Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    James Bauder

    2008-09-30

    U.S. emphasis on domestic energy independence, along with advances in knowledge of vast biogenically sourced coalbed methane reserves at relatively shallow sub-surface depths with the Powder River Basin, has resulted in rapid expansion of the coalbed methane industry in Wyoming and Montana. Techniques have recently been developed which constitute relatively efficient drilling and methane gas recovery and extraction techniques. However, this relatively efficient recovery requires aggressive reduction of hydrostatic pressure within water-saturated coal formations where the methane is trapped. Water removed from the coal formation during pumping is typically moderately saline and sodium-bicarbonate rich, and managed as an industrial waste product. Current approaches to coalbed methane product water management include: surface spreading on rangeland landscapes, managed irrigation of agricultural crop lands, direct discharge to ephermeral channels, permitted discharge of treated and untreated water to perennial streams, evaporation, subsurface injection at either shallow or deep depths. A Department of Energy-National Energy Technology Laboratory funded research award involved the investigation and assessment of: (1) phytoremediation as a water management technique for waste water produced in association with coalbed methane gas extraction; (2) feasibility of commercial-scale, low-impact industrial water treatment technologies for the reduction of salinity and sodicity in coalbed methane gas extraction by-product water; and (3) interactions of coalbed methane extraction by-product water with landscapes, vegetation, and water resources of the Powder River Basin. Prospective, greenhouse studies of salt tolerance and water use potential of indigenous, riparian vegetation species in saline-sodic environments confirmed the hypothesis that species such as Prairie cordgrass, Baltic rush, American bulrush, and Nuttall's alkaligrass will thrive in saline-sodic environments

  1. Bacteria isolated from Korean black raspberry vinegar with low biogenic amine production in wine.

    Science.gov (United States)

    Song, Nho-Eul; Cho, Hyoun-Suk; Baik, Sang-Ho

    2016-01-01

    A high concentration of histamine, one of the biogenic amines (BAs) usually found in fermented foods, can cause undesirable physiological side effects in sensitive humans. The objective of this study is to isolate indigenous Acetobacter strains from naturally fermented Bokbunja vinegar in Korea with reduced histamine production during starter fermentation. Further, we examined its physiological and biochemical properties, including BA synthesis. The obtained strain MBA-77, identified as Acetobacter aceti by 16S rDNA homology and biochemical analysis and named A. aceti MBA-77. A. aceti MBA-77 showed optimal acidity % production at pH 5; the optimal temperature was 25°C. When we prepared and examined the BAs synthesis spectrum during the fermentation process, Bokbunja wine fermented with Saccharomyces cerevisiae showed that the histamine concentration increased from 2.72 of Bokbunja extract to 5.29mg/L and cadaverine and dopamine was decreased to 2.6 and 10.12mg/L, respectively. Bokbunja vinegar prepared by A. aceti MBA-77 as the starter, the histamine concentration of the vinegar preparation step was decreased up to 3.66mg/L from 5.29mg/L in the wine preparation step. To our knowledge, this is the first report to demonstrate acetic acid bacteria isolated from Bokbunja seed vinegar with low spectrum BA and would be useful for wellbeing vinegar preparation.

  2. Biogenic amine production by Lactococcus lactis subsp. cremoris strains in the model system of Dutch-type cheese.

    Science.gov (United States)

    Flasarová, Radka; Pachlová, Vendula; Buňková, Leona; Menšíková, Anna; Georgová, Nikola; Dráb, Vladimír; Buňka, František

    2016-03-01

    The aim of this study was to compare the biogenic amine production of two starter strains of Lactococcus lactis subsp. cremoris (strains from the Culture Collection of Dairy Microorganisms - CCDM 824 and CCDM 946) with decarboxylase positive activity in a model system of Dutch-type cheese during a 90-day ripening period at 10°C. During ripening, biogenic amine and free amino acid content, microbiological characteristics and proximate chemical properties were observed. By the end of the ripening period, the putrescine content in both samples with the addition of the biogenic amine producing strain almost evened out and the concentration of putrescine was >800mg/kg. The amount of tyramine in the cheeses with the addition of the strain of CCDM 824 approached the limit of 400mg/kg by the end of ripening. In the cheeses with the addition of the strain of CCDM 946 it even exceeded 500mg/kg. In the control samples, the amount of biogenic amines was insignificant.

  3. Extraction of soluble substances from organic solid municipal waste to increase methane production.

    Science.gov (United States)

    Campuzano, Rosalinda; González-Martínez, Simón

    2015-02-01

    This work deals with the analysis of the methane production from Mexico City's urban organic wastes after separating soluble from suspended substances. Water was used to extract soluble substances under three different water to waste ratios and after three extraction procedures. Methane production was measured at 35 °C during 21 days using a commercial methane potential testing device. Results indicate that volatile solids extraction increases with dilution rate to a maximum of 40% at 20 °C and to 43% at 93 °C. The extracts methane production increases with the dilution rate as a result of enhanced dissolved solids extraction. The combined (extract and bagasse) methane production reached, in 6 days, 66% of the total methane produced in 21 days. The highest methane production rates were measured during the first six days.

  4. Biogas crops grown in energy crop rotations: Linking chemical composition and methane production characteristics.

    Science.gov (United States)

    Herrmann, Christiane; Idler, Christine; Heiermann, Monika

    2016-04-01

    Methane production characteristics and chemical composition of 405 silages from 43 different crop species were examined using uniform laboratory methods, with the aim to characterise a wide range of crop feedstocks from energy crop rotations and to identify main parameters that influence biomass quality for biogas production. Methane formation was analysed from chopped and over 90 days ensiled crop biomass in batch anaerobic digestion tests without further pre-treatment. Lignin content of crop biomass was found to be the most significant explanatory variable for specific methane yields while the methane content and methane production rates were mainly affected by the content of nitrogen-free extracts and neutral detergent fibre, respectively. The accumulation of butyric acid and alcohols during the ensiling process had significant impact on specific methane yields and methane contents of crop silages. It is proposed that products of silage fermentation should be considered when evaluating crop silages for biogas production.

  5. Production of Excited Atomic Hydrogen from Methane

    Science.gov (United States)

    Machacek, J. R.; Andrianarijaona, V. M.; Furst, J. E.; Gay, T. J.; Kilcoyne, A. L. D.; Landers, A. L.; McLaughlin, K. W.

    2009-05-01

    We have measured the production of Lyα and Hα fluorescence from atomic H for the photodissociation of CH4 by linearly-polarized photons with energies between 20 and 65 eV. Comparison between our Lyα relative cross section and that previously reported [1] show different peak height ratios. This also occurs in the Hα cross section when compared to previous data [2]. We do not observe as significant a drop in either cross section above 35 eV. Our measurements were taken with pressures two orders of magnitude lower than those used in ref. [1]. We present comparisons between data sets and a discussion of possible systematic effects. [1] H. Fukuzawa et al., J. Phys. B. 38, 565 (2005). [2] M. Kato et al., J. Phys. B. 35, 4383 (2002). Support provided by the NSF (Grant PHY-0653379), DOE (LBNL/ALS) and ANSTO (Access to Major Research Facilities Programme).

  6. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Thomas E. Williams; Keith Millheim; Buddy King

    2004-03-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is in the second year of a three-year endeavor being sponsored by Maurer Technology, Noble, and Anadarko Petroleum, in partnership with the DOE. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition. We plan to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. We also plan to design and implement a program to safely and economically drill, core and produce gas from arctic hydrates. The current work scope is to drill and core a well on Anadarko leases in FY 2003 and 2004. We are also using an on-site core analysis laboratory to determine some of the physical characteristics of the hydrates and surrounding rock. The well is being drilled from a new Anadarko Arctic Platform that will have minimal footprint and environmental impact. We hope to correlate geology, geophysics, logs, and drilling and production data to allow reservoir models to be calibrated. Ultimately, our goal is to form an objective technical and economic evaluation of reservoir potential in Alaska.

  7. Process-based modelling of biogenic monoterpene emissions combining production and release from storage

    Directory of Open Access Journals (Sweden)

    G. Schurgers

    2009-05-01

    Full Text Available Monoterpenes, primarily emitted by terrestrial vegetation, can influence atmospheric ozone chemistry, and can form precursors for secondary organic aerosol. The short-term emissions of monoterpenes have been well studied and understood, but their long-term variability, which is particularly important for atmospheric chemistry, has not. This understanding is crucial for the understanding of future changes.

    In this study, two algorithms of terrestrial biogenic monoterpene emissions, the first one based on the short-term volatilization of monoterpenes, as commonly used for temperature-dependent emissions, and the second one based on long-term production of monoterpenes (linked to photosynthesis combined with emissions from storage, were compared and evaluated with measurements from a Ponderosa pine plantation (Blodgett Forest, California. The measurements were used to parameterize the long-term storage of monoterpenes, which takes place in specific storage organs and which determines the temporal distribution of the emissions over the year. The difference in assumptions between the first (emission-based method and the second (production-based method, which causes a difference in upscaling from instantaneous to daily emissions, requires roughly a doubling of emission capacities to bridge the gap to production capacities. The sensitivities to changes in temperature and light were tested for the new methods, the temperature sensitivity was slightly higher than that of the short-term temperature dependent algorithm.

    Applied on a global scale, the first algorithm resulted in annual total emissions of 29.6 Tg C a−1, the second algorithm resulted in 31.8 Tg C a−1 when applying the correction factor 2 between emission capacities and production capacities. However, the exact magnitude of such a correction is spatially varying and hard to determine as a global average.

  8. Methane production and methanogen levels in steers that differ in residual gain

    Science.gov (United States)

    Methane gas released by cattle is a product of fermentation in the digestive tract. The two primary sites of methane fermentation in ruminants are the reticulum-rumen complex, and the cecum. Methane release from cattle represents a 2 to 12% loss of the energy intake. Reducing the proportion of fe...

  9. Biofilm-forming capacity in biogenic amine-producing bacteria isolated from dairy products.

    Directory of Open Access Journals (Sweden)

    Maria eDiaz

    2016-05-01

    Full Text Available Biofilms on the surface of food industry equipment are reservoirs of potentially food-contaminating bacteria - both spoilage and pathogenic. However, the capacity of biogenic amine (BA-producers to form biofilms has remained largely unexamined. BAs are low molecular weight, biologically active compounds that in food can reach concentrations high enough to be a toxicological hazard. Fermented foods, especially some types of cheese, accumulate the highest BA concentrations of all. The present work examines the biofilm-forming capacity of 56 BA-producing strains belonging to three genera and 10 species (12 Enterococcus faecalis, 6 Enterococcus faecium, 6 Enterococcus durans, 1 Enterococcus hirae, 12 Lactococcus lactis, 7 Lactobacillus vaginalis, 2 Lactobacillus curvatus, 2 Lactobacillus brevis, 1 Lactobacillus reuteri and 7 Lactobacillus parabuchneri, all isolated from dairy products. Strains of all the tested species - except for L. vaginalis - were able to produce biofilms on polystyrene and adhered to stainless steel. However, the biomass produced in biofilms was strain-dependent. These results suggest that biofilms may provide a route via which fermented foods can become contaminated by BA-producing microorganisms.

  10. Control of Methane Production and Exchange in Northern Peatlands

    Science.gov (United States)

    Crill, Patrick

    1997-01-01

    This proposal has successfully supported studies that have developed unique long ten-n datasets of methane (CH4) emissions and carbon dioxide (CO2) exchange in order to quantify the controls on CH4 production and exchange especially the linkages to the carbon cycle in northern peatlands. The primary research site has been a small fen in southeastern New Hampshire where a unique multi-year data baseline of CH4 flux measurements was begun (with NASA funding) in 1989. The fen has also been instrumented for continuous hydrological and meteorological observations and year-round porewater sampling. Multiyear datasets of methane flux are very valuable and very rare. Datasets using the same sampling techniques at the same sites are the only way to assess the effect of the integrated ecosystem response to climatological variability. The research has had two basic objectives: 1. To quantify the effect of seasonal and interannual variability on CH4flux. 2. To examine process level controls on methane dynamics.

  11. 基于本源菌的褐煤生物气生成过程与可能途径%Processes and Possible Pathways of Biogenic Coalbed Methane Generation From Lignites Based on Parent Methanogen

    Institute of Scientific and Technical Information of China (English)

    王爱宽; 秦勇; 兰凤娟

    2012-01-01

    Using the parent anaerobic methanogen flora enriched from lignites in the Zhaotong basin, Yunnan, a simulation experiment was carried out in order to analyze the process and possible approach of the biogenic coalbed gas (CBG) generation. Results showed that the process of the biogenic CBG generation in a period of 130 days underwent at least two gas generation peaks with the higher gas generation rate at the first peak than that at the secondary peak. Gas produced during the first peak came mainly from the huminite group and the biodegradation of the inertinite and liptinite groups was strengthened relatively during the secondary peak. Plots of the carbon isotopic composition to the hydrogen isotopic composition of the simulated methane indicated a major approach of the acetate fermentation by which the biogenic methane was generated. During the stimulation process, the methane concentration raised with the drop of the carbon dioxide concentration. Carbon isotopic composition of the methane tended to become lighter and the hydrogen isotope composition to become heavier in the late period of the simulation process. These data indicate the carbon dioxide-reduction of the partial methane generated in the late period of the stimulation.%利用富集培养得到的本源产甲烷菌群对云南昭通褐煤样品进行生物气模拟实验,分析了褐煤生物气生成过程与可能途径.结果显示,为期130 d的褐煤生物气生成过程至少经历了两个产气高峰,第一高峰产气率高于第二高峰.本文认为第一高峰期间生气母质主要为褐煤中的腐殖组分,第二高峰期间类脂组和惰质组的微生物降解程度相对增强.甲烷碳氢同位素组成显示,模拟生物气主要通过乙酸发酵途径生成.模拟过程中,甲烷浓度和二氧化碳浓度具有相互消长的变化趋势,甲烷碳同位素组成在模拟后期有变轻趋势,氢同位素则趋于变重,表明模拟过程后期生成的部分甲烷具有二氧化碳还原成因.

  12. Biogenic methane production in formation waters from a large gas field in the North Sea.

    Science.gov (United States)

    Gray, Neil D; Sherry, Angela; Larter, Stephen R; Erdmann, Michael; Leyris, Juliette; Liengen, Turid; Beeder, Janiche; Head, Ian M

    2009-05-01

    Methanogenesis was investigated in formation waters from a North Sea oil rimmed gas accumulation containing biodegraded oil, which has not been subject to seawater injection. Activity and growth of hydrogenotrophic methanogens was measured but acetoclastic methanogenesis was not detected. Hydrogenotrophic methanogens showed activity between 40 and 80 degrees C with a temperature optimum (ca. 70 degrees C) consistent with in situ reservoir temperatures. They were also active over a broad salinity range, up to and consistent with the high salinity of the waters (90 g l(-1)). These findings suggest the methanogens are indigenous to the reservoir. The conversion of H(2) and CO(2) to CH(4) in methanogenic enrichments was enhanced by the addition of inorganic nutrients and was correlated with cell growth. Addition of yeast extract also stimulated methanogenesis. Archaeal 16S rRNA gene sequences recovered from enrichment cultures were closely related to Methanothermobacter spp. which have been identified in other high-temperature petroleum reservoirs. It has recently been suggested that methanogenic oil degradation may be a major factor in the development of the world's heavy oils and represent a significant and ongoing process in conventional deposits. Although an oil-degrading methanogenic consortium was not enriched from these samples the presence and activity of communities of fermentative bacteria and methanogenic archaea was demonstrated. Stimulation of methanogenesis by addition of nutrients suggests that in situ methanogenic biodegradation of oil could be harnessed to enhance recovery of stranded energy assets from such petroleum systems.

  13. Measurements of methane emissions at natural gas production sites in the United States

    OpenAIRE

    Allen, David T.; Torres, Vincent M.; Thomas, James; Sullivan, David W.; Harrison, Matthew; Hendler, Al; Herndon, Scott C.; Kolb, Charles E.; Fraser, Matthew P.; Hill, A. Daniel; Lamb, Brian K.; Miskimins, Jennifer; Sawyer, Robert F.; Seinfeld, John H.

    2013-01-01

    Engineering estimates of methane emissions from natural gas production have led to varied projections of national emissions. This work reports direct measurements of methane emissions at 190 onshore natural gas sites in the United States (150 production sites, 27 well completion flowbacks, 9 well unloadings, and 4 workovers). For well completion flowbacks, which clear fractured wells of liquid to allow gas production, methane emissions ranged from 0.01 Mg to 17 Mg (mean = 1.7 Mg; 95% confiden...

  14. Enhanced methane production via repeated batch bioaugmentation pattern of enriched microbial consortia.

    Science.gov (United States)

    Yang, Zhiman; Guo, Rongbo; Xu, Xiaohui; Wang, Lin; Dai, Meng

    2016-09-01

    Using batch and repeated batch cultivations, this study investigated the effects of bioaugmentation with enriched microbial consortia (named as EMC) on methane production from effluents of hydrogen-producing stage of potato slurry, as well as on the indigenous bacterial community. The results demonstrated that the improved methane production and shift of the indigenous bacterial community structure were dependent on the EMC/sludge ratio and bioaugmentation patterns. The methane yield and production rate in repeated batch bioaugmentation pattern of EMC were, respectively, average 15% and 10% higher than in one-time bioaugmentation pattern of EMC. DNA-sequencing approach showed that the enhanced methane production in the repeated batch bioaugmentation pattern of EMC mainly resulted from the enriched iron-reducing bacteria and the persistence of the introduced Syntrophomonas, which led to a rapid degradation of individual VFAs to methane. The findings contributed to understanding the correlation between the bioaugmentation of microbial consortia, community shift, and methane production.

  15. A data-driven model for maximization of methane production in a wastewater treatment plant.

    Science.gov (United States)

    Kusiak, Andrew; Wei, Xiupeng

    2012-01-01

    A data-driven approach for maximization of methane production in a wastewater treatment plant is presented. Industrial data collected on a daily basis was used to build the model. Temperature, total solids, volatile solids, detention time and pH value were selected as parameters for the model construction. First, a prediction model of methane production was built by a multi-layer perceptron neural network. Then a particle swarm optimization algorithm was used to maximize methane production based on the model developed in this research. The model resulted in a 5.5% increase in methane production.

  16. Biogenic amines in beer

    OpenAIRE

    Čiháková, Dagmar

    2016-01-01

    This thesis deals with the technological process of brewing beer, describes the raw materials needed for its production, and points out the useful and harmful substances contained in beer as biogenic amines (BA). Furthermore, there are described the issues of biogenic amines in food and primarily in beer, which is a histamine, putrescine, cadaverine, tyramine and tryptamine. In the practical section BA was determined in lager bottom-fermented beers from local microbreweries and large industri...

  17. Modeling methane emissions by cattle production systems in Mexico

    Science.gov (United States)

    Castelan-Ortega, O. A.; Ku Vera, J.; Molina, L. T.

    2013-12-01

    Methane emissions from livestock is one of the largest sources of methane in Mexico. The purpose of the present paper is to provide a realistic estimate of the national inventory of methane produced by the enteric fermentation of cattle, based on an integrated simulation model, and to provide estimates of CH4 produced by cattle fed typical diets from the tropical and temperate climates of Mexico. The Mexican cattle population of 23.3 million heads was divided in two groups. The first group (7.8 million heads), represents cattle of the tropical climate regions. The second group (15.5 million heads), are the cattle in the temperate climate regions. This approach allows incorporating the effect of diet on CH4 production into the analysis because the quality of forages is lower in the tropics than in temperate regions. Cattle population in every group was subdivided into two categories: cows (COW) and other type of cattle (OTHE), which included calves, heifers, steers and bulls. The daily CH4 production by each category of animal along an average production cycle of 365 days was simulated, instead of using a default emission factor as in Tier 1 approach. Daily milk yield, live weight changes associated with the lactation, and dry matter intake, were simulated for the entire production cycle. The Moe and Tyrrell (1979) model was used to simulate CH4 production for the COW category, the linear model of Mills et al. (2003) for the OTHE category in temperate regions and the Kurihara et al. (1999) model for the OTHE category in the tropical regions as it has been developed for cattle fed tropical diets. All models were integrated with a cow submodel to form an Integrated Simulation Model (ISM). The AFRC (1993) equations and the lactation curve model of Morant and Gnanasakthy (1989) were used to construct the cow submodel. The ISM simulates on a daily basis the CH4 production, milk yield, live weight changes associated with lactation and dry matter intake. The total daily CH

  18. Stimulation of commercial coal seam methane production aimed at improving mining technology

    OpenAIRE

    2016-01-01

    The relevance of the current research is due to the urgent need to revise the existing normative bases and procedures involved in intensive development of coal-methane deposits and commercial production of coal seam methane. The article presents the analysis of data on coal production volume and amount of methane emitted into the atmosphere in Kuzbass. There is a need to develop the exploration techniques that would allow implementing pre-mining gas drainage of coal seams and provide the comp...

  19. Biogenic gas in the Cambrian-Ordovcian Alum Shale (Denmark and Sweden)

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, H.M.; Wirth, R.; Biermann, S.; Arning, E.T. [Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ, Potsdam (Germany); Krueger, M.; Straaten, N. [BGR Hannover (Germany); Bechtel, A. [Montanuniv. Leoben (Austria); Berk, W. van [Technical Univ. of Clausthal (Germany); Schovsbo, N.H. [Geological Survey of Denmark and Greenland - GEUS, Copenhagen (Denmark); Crabtree, Stephen [Gripen Gas (Sweden)

    2013-08-01

    Shale gas is mainly produced from thermally mature black shales. However, biogenic methane also represents a resource which is often underestimated. Today biogenic methane is being produced from the Upper Devonian Antrim Shale in the Michigan Basin which was the most successfully exploited shale gas system during the 1990-2000 decade in the U.S.A. before significant gas production from the Barnett Shale started (Curtis et al., 2008). The Cambro-Ordovician Alum Shale in northern Europe has thermal maturities ranging from overmature in southern areas (Denmark and southern Sweden) to immature conditions (central Sweden). Biogenic methane is recorded during drilling in central Sweden. The immature Alum Shale in central Sweden has total organic carbon (TOC) contents up to 20 wt%. The hydrogen index HI ranges from 380 to 560 mgHC/gTOC at very low oxygen index (OI) values of around 4 mg CO{sub 2}/gTOC, Tmax ranges between 420 - 430 C. The organic matter is highly porous. In general, the Alum Shale is a dense shale with intercalated sandy beds which may be dense due to carbonate cementation. Secondary porosity is created in some sandy beds due to feldspar dissolution and these beds serve as gas conduits. Methane production rates with shale as substrate in the laboratory are dependent on the kind of hydrocarbon-degrading microbial enrichment cultures used in the incubation experiments, ranging from 10-620 nmol/(g*d). In these experiments, the CO{sub 2} production rate was always higher than for methane. Like the northern part of North America, also Northern European has been covered by glaciers during the Pleistocene and similar geological processes may have developed leading to biogenic shale gas formation. For the Antrim Shale one hypothesis suggests that fresh waters, recharged from Pleistocene glaciation and modern precipitation, suppressed basinal brine salinity along the northern margins of the Michigan Basin to greater depths and thereby enhancing methanogenesis

  20. Microbial methane production in oxygenated water column of an oligotrophic lake.

    Science.gov (United States)

    Grossart, Hans-Peter; Frindte, Katharina; Dziallas, Claudia; Eckert, Werner; Tang, Kam W

    2011-12-01

    The prevailing paradigm in aquatic science is that microbial methanogenesis happens primarily in anoxic environments. Here, we used multiple complementary approaches to show that microbial methane production could and did occur in the well-oxygenated water column of an oligotrophic lake (Lake Stechlin, Germany). Oversaturation of methane was repeatedly recorded in the well-oxygenated upper 10 m of the water column, and the methane maxima coincided with oxygen oversaturation at 6 m. Laboratory incubations of unamended epilimnetic lake water and inoculations of photoautotrophs with a lake-enrichment culture both led to methane production even in the presence of oxygen, and the production was not affected by the addition of inorganic phosphate or methylated compounds. Methane production was also detected by in-lake incubations of lake water, and the highest production rate was 1.8-2.4 nM⋅h(-1) at 6 m, which could explain 33-44% of the observed ambient methane accumulation in the same month. Temporal and spatial uncoupling between methanogenesis and methanotrophy was supported by field and laboratory measurements, which also helped explain the oversaturation of methane in the upper water column. Potentially methanogenic Archaea were detected in situ in the oxygenated, methane-rich epilimnion, and their attachment to photoautotrophs might allow for anaerobic growth and direct transfer of substrates for methane production. Specific PCR on mRNA of the methyl coenzyme M reductase A gene revealed active methanogenesis. Microbial methane production in oxygenated water represents a hitherto overlooked source of methane and can be important for carbon cycling in the aquatic environments and water to air methane flux.

  1. Hydrogen production from methane using oxygen-permeable ceramic membranes

    Science.gov (United States)

    Faraji, Sedigheh

    Non-porous ceramic membranes with mixed ionic and electronic conductivity have received significant interest in membrane reactor systems for the conversion of methane and higher hydrocarbons to higher value products like hydrogen. However, hydrogen generation by this method has not yet been commercialized and suffers from low membrane stability, low membrane oxygen flux, high membrane fabrication costs, and high reaction temperature requirements. In this dissertation, hydrogen production from methane on two different types of ceramic membranes (dense SFC and BSCF) has been investigated. The focus of this research was on the effects of different parameters to improve hydrogen production in a membrane reactor. These parameters included operating temperature, type of catalyst, membrane material, membrane thickness, membrane preparation pH, and feed ratio. The role of the membrane in the conversion of methane and the interaction with a Pt/CeZrO2 catalyst has been studied. Pulse studies of reactants and products over physical mixtures of crushed membrane material and catalyst have clearly demonstrated that a synergy exists between the membrane and the catalyst under reaction conditions. The degree of catalyst/membrane interaction strongly impacts the conversion of methane and the catalyst performance. During thermogravimetric analysis, the onset temperature of oxygen release for BSCF was observed to be lower than that for SFC while the amount of oxygen release was significantly greater. Pulse injections of CO2 over crushed membranes at 800°C have shown more CO2 dissociation on the BSCF membrane than the SFC membrane, resulting in higher CO formation on the BSCF membrane. Similar to the CO2 pulses, when CO was injected on the samples at 800°C, CO2 production was higher on BSCF than SFC. It was found that hydrogen consumption on BSCF particles is 24 times higher than that on SFC particles. Furthermore, Raman spectroscopy and temperature programmed desorption studies of

  2. Effect of natural zeolite on methane production for anaerobic digestion of ammonium rich organic sludge.

    Science.gov (United States)

    Tada, Chika; Yang, Yingnan; Hanaoka, Toshiaki; Sonoda, Akinari; Ooi, Kenta; Sawayama, Shigeki

    2005-03-01

    The effect of an inorganic additive on the methane production from NH(4+)-rich organic sludge during anaerobic digestion was investigated using different kinds of inorganic adsorbent zeolites (mordenite, clinoptilolite, zeolite 3A, zeolite 4A), clay mineral (vermiculite), and manganese oxides (hollandite, birnessite). The additions of inorganic materials resulted in significant NH4+ removals from the natural organic sludge ([NH4+]=1, 150 mg N/l), except for the H-type zeolite 3A and birnessite. However, an enhanced methane production was only achieved using natural mordenite. Natural mordenite also enhanced the methane production from the sludge with a markedly high NH4+ concentration (4500 mg N/l) during anaerobic digestion. Chemical analyses of the sludge after the digestion showed considerable increases in the Ca2+ and Mg2+ concentrations in the presence of natural mordenite, but not with synthetic zeolite 3A. The effect of Ca2+ or Mg2+ addition on the methane production was studied using Na(+)-exchanges mordenite and Ca2+ or Mg(2+)-enriched sludge. The simultaneous addition of Ca2+ ions and Na(+)-exchanged mordenite enhanced the methane production; the amount of produced methane was about three times greater than that using only the Na(+)-exchanged mordenite. In addition, comparing the methane production by the addition of natural mordenite or Ca2+ ions, the methane production with natural mordenite was about 1.7 times higher than that with only Ca2+ ions. The addition of 5% and 10% natural mordenite were suitable condition for obtaining a high methane production. These results indicated that the Ca2+ ions, which are released from natural mordenite by a Ca2+/NH4+ exchange, enhanced the methane production of the organic waste at a high NH4+ concentration. Natural mordenite has a synergistic effect on the Ca2+ supply as well on the NH4+ removal during anaerobic digestion, which is effective for the mitigation of NH4+ inhibition against methane production.

  3. Stimulation of commercial coal seam methane production aimed at improving mining technology

    Science.gov (United States)

    Shubina, E. A.; Lukyanov, V. G.

    2016-09-01

    The relevance of the current research is due to the urgent need to revise the existing normative bases and procedures involved in intensive development of coal-methane deposits and commercial production of coal seam methane. The article presents the analysis of data on coal production volume and amount of methane emitted into the atmosphere in Kuzbass. There is a need to develop the exploration techniques that would allow implementing pre-mining gas drainage of coal seams and provide the companies with the guidance on coal seam methane drainage in very gassy coal mines. Commercial production of methane should become an integral part of economy and energy balance of the Russian Federation, which, in its turn, would enhance environmental protection due to reducing methane emissions, the largest source of greenhouse effect.

  4. A process-based mathematical model on methane production with emission indices for control.

    Science.gov (United States)

    Chakraborty, A; Bhattacharaya, D K

    2006-08-01

    In this paper, a process-based mathematical model is developed for the production of methane through biodegradation. It is a three-dimensional model given by ordinary differential equations. The results of the analysis of the model are interpreted through three emission indices, which are introduced for the first time. The estimation of either one or all of them can interpret the feasibility of the equilibrium and the long-term emission tendency of methane. The vulnerability of the methane production process with respect to soil temperature effects in methanogenic phase has been discussed and a feasible condition within a specified temperature range has defined for the nonvulnerability of the methane production process and also it has shown that under the same condition, zero-emission process of methane will be nonvulnerable with respect to the soil temperature effects in methanogenic phase. Lastly, condition for zero emission of methane is also obtained and it is interpreted through the emission indices.

  5. Measurement methods to assess methane production of individual dairy cows in a barn

    NARCIS (Netherlands)

    Wu, L.

    2016-01-01

    Abstract Mitigation of methane production from dairy cows is critical to reduce the dairy industry’s contribution to the production of greenhouse gases. None of current used methane measurement methods are flawless and application of the methods is limited to assess the effect

  6. Effects of mixing on methane production during thermophilic anaerobic digestion of manure

    DEFF Research Database (Denmark)

    Kaparaju, Prasad Laxmi-Narasimha; Buendia, Inmaculada M.; Ellegaard, Lars;

    2008-01-01

    /feeding) on methane production was investigated in three lab-scale continuously stirred tank reactors. On comparison to continuous mixing, intermittent and minimal mixing strategies improved methane productions by 1.3% and 12.5%, respectively. Pilot-scale studies also supported the lab-scale results with an average 7...

  7. Potential for CO2 sequestration and enhanced coalbed methane production in the Netherlands

    NARCIS (Netherlands)

    Hamelinck, C.N.; Schreurs, H.; Faaij, A.P.C.; Ruijg, G.J.; Jansen, Daan; Pagnier, H.; Bergen, F. van; Wolf, K.-H.; Barzandji, O.; Bruining, H.

    2006-01-01

    This study investigated the technical and economic feasibility of using CO2 for the enhanced production of coal bed methane (ECBM) in the Netherlands. This concept could lead to both CO2 storage by adsorbing CO2 in deep coal layers that are not suitable for mining, as well as production of methane.

  8. Biogenic oxidized organic functional groups in aerosol particles from a mountain forest site and their similarities to laboratory chamber products

    Directory of Open Access Journals (Sweden)

    R. E. Schwartz

    2010-02-01

    Full Text Available Submicron particles collected at Whistler, British Columbia, at 1020 masl during May and June 2008 on Teflon filters were analyzed by Fourier transform infrared (FTIR and X-ray fluorescence (XRF techniques for organic functional groups (OFG and elemental composition. Organic mass (OM ranged from less than 0.5 to 3.1μg m−3, with a project mean and standard deviation of 1.3±1.0 μg m−3 and 0.21±0.16 μg m−3 for OM and sulfate, respectively. On average, organic hydroxyl, alkane, and carboxylic acid groups represented 34%, 33%, and 23% of OM, respectively. Ketone, amine and organosulfate groups constituted 6%, 5%, and <1% of the average organic aerosol composition, respectively. Measurements of volatile organic compounds (VOC, including isoprene and monoterpenes from biogenic VOC (BVOC emissions and their oxidation products (methyl-vinylketone/methacrolein, MVK/MACR, were made using co-located proton transfer reaction mass spectrometry (PTR-MS. We present chemically-specific evidence of OFG associated with BVOC emissions. Positive matrix factorization (PMF analysis attributed 65% of the campaign OM to biogenic sources, based on the correlations of one factor to monoterpenes and MVK/MACR. The remaining fraction was attributed to anthropogenic sources based on a correlation to sulfate. The functional group composition of the biogenic factor (consisting of 32% alkane, 25% carboxylic acid, 2% organic hydroxyl, 16% ketone, and 6% amine groups was similar to that of secondary organic aerosol (SOA reported from the oxidation of BVOCs in laboratory chamber studies, providing evidence that the magnitude and chemical composition of biogenic SOA simulated in the laboratory is similar to that found in actual atmospheric conditions. The biogenic factor OM is also correlated to dust elements, indicating that dust may act as a non-acidic SOA sink. This role is supported by the organic functional group composition and

  9. Biogenic oxidized organic functional groups in aerosol particles from a mountain forest site and their similarities to laboratory chamber products

    Directory of Open Access Journals (Sweden)

    R. E. Schwartz

    2010-06-01

    Full Text Available Submicron particles collected at Whistler, British Columbia, at 1020 m a.s.l. during May and June 2008 on Teflon filters were analyzed by Fourier transform infrared (FTIR and X-ray fluorescence (XRF techniques for organic functional groups (OFG and elemental composition. Organic mass (OM concentrations ranged from less than 0.5 to 3.1 μg m−3, with a project mean and standard deviation of 1.3±1.0 μg m−3 and 0.21±0.16 μg m−3 for OM and sulfate, respectively. On average, organic hydroxyl, alkane, and carboxylic acid groups represented 34%, 33%, and 23% of OM, respectively. Ketone, amine and organosulfate groups constituted 6%, 5%, and <1% of the average organic aerosol composition, respectively. Measurements of volatile organic compounds (VOC, including isoprene and monoterpenes from biogenic VOC (BVOC emissions and their oxidation products (methyl-vinylketone / methacrolein, MVK/MACR, were made using co-located proton transfer reaction mass spectrometry (PTR-MS. We present chemically-specific evidence of OFG associated with BVOC emissions. Positive matrix factorization (PMF analysis attributed 65% of the campaign OM to biogenic sources, based on the correlations of one factor to monoterpenes and MVK/MACR. The remaining fraction was attributed to anthropogenic sources based on a correlation to sulfate. The functional group composition of the biogenic factor (consisting of 32% alkane, 25% carboxylic acid, 21% organic hydroxyl, 16% ketone, and 6% amine groups was similar to that of secondary organic aerosol (SOA reported from the oxidation of BVOCs in laboratory chamber studies, providing evidence that the magnitude and chemical composition of biogenic SOA simulated in the laboratory is similar to that found in actual atmospheric conditions. The biogenic factor OM is also correlated to dust elements, indicating that dust may act as a non-acidic SOA sink. This role is supported by the organic functional

  10. Biogenic amines at a low level of evolution: Production, functions and regulation in the unicellular Tetrahymena.

    Science.gov (United States)

    Csaba, György

    2015-06-01

    The unicellular eukaryote Tetrahymena synthesize, store and secrete biogenic amines (histamine, serotonin, epinephrine, dopamine, melatonin) and also can take up amines from the milieu. It also has (G-protein-coupled) receptors (binding sites) for these amines as well, as second messengers. The factors infuencing the mentioned processes are shown. For certain amines the genes and the coded enzymes are demonstrated. The amines influence phagocytosis, cell division, ciliary regeneration, glucose metabolism and chemotaxis. There are interhormone actions between the amines, and between the amines and other hormones produced by Tetrahymena. The critical review discusses the role of amines in the early stages of evolution and compares this to their functions in mammals. It tries to give answer how and why biogenic amines were selected to hormones, and why new functions formed for them in higher ranked animals, preserving also the ancient ones.

  11. Biogenic Amines as Quality Marker in Organic and Fair-Trade Cocoa-Based Products

    Directory of Open Access Journals (Sweden)

    Donatella Restuccia

    2016-08-01

    Full Text Available In this study, the quantitative determination of eight biogenic amines (cadaverine, serotonin, histamine, spermidine, spermine, tyramine, putrescine and β-phenylethylamine by an liquid chromatography method with evaporative light scattering detection was performed. The analysis of several samples of conventional, organic and fair trade cocoa-derivatives showed that organic and fair trade samples always contain much lower amine concentrations in comparison with their conventional counterparts, supporting the idea that biogenic amines can be regarded as cocoa quality markers. Irrespective of the kind of sample, results also showed that the most abundant amines were histamine, tyramine, spermidine, putrescine and spermine while β-phenylethylamine, cadaverine and serotonine have been found more rarely, all the amines never reaching dangerous amounts for consumer health. With the aim to confirm the experimental results, clustering analysis was performed on samples and instrumental results using principal component analysis.

  12. The prediction of the methane production in landfill affected by the temperature

    Directory of Open Access Journals (Sweden)

    Zhou Lianying

    2015-01-01

    Full Text Available The functional relationship between the generation rate coefficient and temperature was developed for quantitative prediction of the temperature effect in this paper. The methane production of the landfill was predicted under the condition of the seasonal variation. The results showed that considering the temperature effect, the methane production is higher than the methane production without temperature effect of the 0.14×106 m3~0.28×106m3.With the depth increasing, the effect of the atmospheric temperature fluctuation on the temperature change of the landfill was weakened. The temperature has a significant effect on the methane production in the landfill. The temperature effect should be considered when simulate the long time effect of the landfill methane production.

  13. Temperature regulates methane production through the function centralization of microbial community in anaerobic digestion.

    Science.gov (United States)

    Lin, Qiang; De Vrieze, Jo; He, Guihua; Li, Xiangzhen; Li, Jiabao

    2016-09-01

    Temperature is crucial for the performance of anaerobic digestion process. In this study of anaerobic digestion of swine manure, the relationship between the microbial gene expression and methane production at different temperatures (25-55°C) was revealed through metatranscriptomic analysis. Daily methane production and total biogas production increased with temperature up to 50°C, but decreased at 55°C. The functional gene expression showed great variation at different temperatures. The function centralization (opposite to alpha-diversity), assessed by the least proportions of functional pathways contributing for at least 50% of total reads positively correlated to methane production. Temperature regulated methane production probably through reducing the diversity of functional pathways, but enhancing central functional pathways, so that most of cellular activities and resource were invested in methanogenesis and related pathways, enhancing the efficiency of conversion of substrates to methane. This research demonstrated the importance of function centralization for efficient system functioning.

  14. Methane production during storage of anaerobically digested municipal organic waste.

    Science.gov (United States)

    Hansen, Trine Lund; Sommer, Svend G; Gabriel, Søren; Christensen, Thomas H

    2006-01-01

    Anaerobic digestion of source-separated municipal organic waste is considered feasible in Denmark. The limited hydraulic retention in the biogas reactor (typically 15 d) does not allow full degradation of the organic waste. Storage of anaerobically digested municipal organic waste can therefore be a source of methane (CH4) emission that may contribute significantly to the potential global warming impact from the waste treatment system. This study provides a model for quantifying the CH4 production from stored co-digested municipal organic waste and estimates the production under typical Danish climatic conditions, thus quantifying the potential global warming impact from storage of the digested municipal organic waste before its use on agricultural land. Laboratory batch tests on CH4 production as well as temperature measurements in eight full-scale storage tanks provided data for developing a model estimating the CH4 production in storage tanks containing digested municipal organic waste. The temperatures measured in separate storage tanks on farms receiving digested slurry were linearly correlated with air temperature. In storage tanks receiving slurry directly from biogas reactors, significantly higher temperatures were measured due to the high temperatures of the effluent from the reactor. Storage tanks on Danish farms are typically emptied in April and have a constant inflow of digested material. During the warmest months the content of digested material is therefore low, which limits the yearly CH4 production from storage.

  15. Steam Methane Reforming System for Hydrogen Production: Advanced Exergetic Analysis

    Directory of Open Access Journals (Sweden)

    Tatiana Morosuk

    2012-02-01

    Full Text Available Steam methane reforming (SMR is one of the most promising processes for the production of hydrogen. Therefore, the overall thermodynamic efficiency of this process is of particular importance. The thermodynamic inefficiencies in a thermal system are related to exergy destruction and exergy loss. However, a conventional exergetic analysis cannot evaluate the mutual interdependencies among the system components nor the real potential for improving the energy conversion system being considered. One of the tools under development for the improvement of energy conversion systems from the thermodynamic viewpoint is the advanced exergetic analysis. In this paper, the avoidable part of the exergy destruction is estimated and the interactions among components of the overall system are evaluated in terms of endogenous and exogenous exergy destruction. The assumptions required for these calculations are discussed in detail, especially for those components that are typically used in chemical processes. Results of this paper suggest options for increasing the thermodynamic efficiency of hydrogen production by steam-methane reforming.

  16. Evidence for methane production by the marine algae Emiliania huxleyi

    Science.gov (United States)

    Lenhart, Katharina; Klintzsch, Thomas; Langer, Gerald; Nehrke, Gernot; Bunge, Michael; Schnell, Sylvia; Keppler, Frank

    2016-06-01

    Methane (CH4), an important greenhouse gas that affects radiation balance and consequently the earth's climate, still has uncertainties in its sinks and sources. The world's oceans are considered to be a source of CH4 to the atmosphere, although the biogeochemical processes involved in its formation are not fully understood. Several recent studies provided strong evidence of CH4 production in oxic marine and freshwaters, but its source is still a topic of debate. Studies of CH4 dynamics in surface waters of oceans and large lakes have concluded that pelagic CH4 supersaturation cannot be sustained either by lateral inputs from littoral or benthic inputs alone. However, regional and temporal oversaturation of surface waters occurs frequently. This comprises the observation of a CH4 oversaturating state within the surface mixed layer, sometimes also termed the "oceanic methane paradox". In this study we considered marine algae as a possible direct source of CH4. Therefore, the coccolithophore Emiliania huxleyi was grown under controlled laboratory conditions and supplemented with two 13C-labeled carbon substrates, namely bicarbonate and a position-specific 13C-labeled methionine (R-S-13CH3). The CH4 production was 0.7 µg particular organic carbon (POC) g-1 d-1, or 30 ng g-1 POC h-1. After supplementation of the cultures with the 13C-labeled substrate, the isotope label was observed in headspace CH4. Moreover, the absence of methanogenic archaea within the algal culture and the oxic conditions during CH4 formation suggest that the widespread marine algae Emiliania huxleyi might contribute to the observed spatially and temporally restricted CH4 oversaturation in ocean surface waters.

  17. Predicted growth of world urban food waste and methane production.

    Science.gov (United States)

    Adhikari, Bijaya K; Barrington, Suzelle; Martinez, José

    2006-10-01

    Landfill gas emissions are one of the largest anthropogenic sources of methane especially because of food waste (FW). To prevent these emissions growing with world population, future FW best management practices need to be evaluated. The objective of this paper was therefore to predict FW production for 2025 if present management practices are maintained, and then, to compare the impact of scenario 1: encouraging people to stay in rural areas and composting 75% of their FW, and; of scenario 2, where in addition to scenario 1, composting or anaerobically digesting 75% of urban FW (UFW). A relationship was established between per capita gross domestic product (GDP) and the population percentage living in urban areas (%UP), as well as production of municipal solid waste (MSW) and UFW. With estimated GDP and population growth per country, %UP and production of MSW and UFW could be predicted for 2025. A relatively accurate (R(2) > 0.85) correlation was found between GDP and %UP, and between GDP and mass of MSW and FW produced. On a global scale, MSW and UFW productions were predicted to increase by 51 and 44%, respectively, from 2005 to 2025. During the same period, and because of its expected economic development, Asia was predicted to experience the largest increase in UFW production, of 278 to 416 Gkg. If present MSW management trends are maintained, landfilled UFW was predicted to increase world CH4 emissions from 34 to 48 Gkg and the landfill share of global anthropogenic emissions from 8 to 10%. In comparison with maintaining present FW management practices, scenario 1 can lower UFW production by 30% and maintain the landfill share of the global anthropogenic emissions at 8%. With scenario 2, the landfill share of global anthropogenic emissions could be further reduced from 8 to 6% and leachate production could be reduced by 40%.

  18. Coal-bed methane in Alberta : ownership and incidental production

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, A.

    2006-04-05

    Some of the challenges facing the emerging coal-bed methane (CBM) industry in Alberta include concerns regarding water protection, compression noise, well spacing and fracturing issues. One of the most fundamental questions regarding CBM is who in fact owns the resource and what rules oversee its production. The characteristics, development potential and origins of split title ownership of CBM in North America were examined in this paper. The history of freehold and Crown-owned land and the law regarding ownership and incidental production of petroleum, natural gas and bitumen in split-title situations were reviewed. The legal status of CBM in other jurisdictions was also examined. The issues of ownership and incidental production in Alberta were also discussed. The basic common law ownership principles regarding mineral ownership were applied to the characteristics of CBM in situ to conclude its possible owner in Alberta. The extension of established incidental mineral production principles to CBM were examined in the context of its characteristics. The official governmental position on CBM issues and the prospect of future legislative intervention were identified and the implications for industry and resource companies were also presented. The paper presented several recommendations including that Alberta should legislate to eliminate any right of recovery for historical or current venting of CBM during coal mining in order to remove a cloud of uncertainty over the industry. refs.

  19. Optimizing anaerobic digestion by selection of the immobilizing surface for enhanced methane production.

    Science.gov (United States)

    Adu-Gyamfi, Nicholas; Ravella, Sreenivas Rao; Hobbs, Phil J

    2012-09-01

    Maximizing methane production while maintaining an appreciable level of process stability is a crucial challenge in the anaerobic digestion industry. In this study, the role of six parameters: the type of immobilizing supports, loading rate, inoculum levels, C:N ratio, trace nutrients concentrations and mixing rate, on methane production were investigated under thermophilic conditions (55 ± 1°C) with synthetic substrate medium. The immobilizing supports were Silica gel, Sand, Molecular Sieve and Dowex Marathon beads. A Taguchi Design of Experiment (DOE) methodology was employed to determine the effects of different parameters using an L(16) orthogonal array. Overall, immobilizing supports influenced methane production substantially (contributing 61.3% of the observed variation in methane yield) followed by loading rate and inoculum which had comparable influence (17.9% and 17.7% respectively). Optimization improved methane production by 153% (from 183 to 463 ml CH(4)l(-1)d(-1)).

  20. Improved methane production from brown algae under high salinity by fed-batch acclimation.

    Science.gov (United States)

    Miura, Toyokazu; Kita, Akihisa; Okamura, Yoshiko; Aki, Tsunehiro; Matsumura, Yukihiko; Tajima, Takahisa; Kato, Junichi; Nakashimada, Yutaka

    2015-01-01

    Here, a methanogenic microbial community was developed from marine sediments to have improved methane productivity from brown algae under high salinity. Fed-batch cultivation was conducted by adding dry seaweed at 1wt% total solid (TS) based on the liquid weight of the NaCl-containing sediment per round of cultivation. The methane production rate and level of salinity increased 8-fold and 1.6-fold, respectively, at the 10th round of cultivation. Moreover, the rate of methane production remained high, even at the 10th round of cultivation, with accumulation of salts derived from 10wt% TS of seaweed. The salinity of the 10th-round culture was equivalent to 5% NaCl. The improved methane production was attributed to enhanced acetoclastic methanogenesis because acetate became rapidly converted to methane during cultivation. The family Fusobacteriaceae and the genus Methanosaeta, the acetoclastic methanogen, predominated in bacteria and archaea, respectively, after the cultivation.

  1. Enhanced methane productivity from lignocellulosic biomasses using aqueous ammonia soaking pretreatment

    DEFF Research Database (Denmark)

    Jurado, Esperanza; Skiadas, Ioannis; Gavala, Hariklia N.

    2012-01-01

    as feedstock. AAS presents certain advantages as a pretreatment method. Ammonia is safe to handle, non-polluting and non-corrosive and can be easily recovered due to its high volatility[3]. In all three cases, an increment in methane potential has been observed. Methane production after 50 days exhibited......The continuously increasing demand for renewable energy sources, such as methane, renders anaerobic digestion to one of the most promising technologies for renewable energy production. In fact, anaerobic digestion for methane production has become a major part of the rapidly growing renewable...... energy sector. Biogas is part of a rapidly growing renewable energy sector, which expands at a rate of 20-30 % globally [1]. However, the increasing demand for methane production cannot be satisfied by the use of anaerobic digestion only from waste/wastewater treatment. Energy crops as well...

  2. Hydrogen production by catalytic partial oxidation of methane

    Energy Technology Data Exchange (ETDEWEB)

    Enger, Bjoern Christian

    2008-12-15

    Hydrogen production by catalytic partial oxidation of natural gas was investigated using tools ranging from theoretical calculations to experimental work and sophisticated characterization techniques. Catalytic partial oxidation (CPO) was carried out in a conventional continuous flow experimental apparatus using a fixed-bed reactor, and operating at 1 atm and furnace temperatures in the range from ambient to 1073 K. The feed typically consisted of a mixture of methane and air, with a CH{sub 4}/O{sub 2} ratio of 2, and the average bed residence time was in the range 10-250 ms. Steam methane reforming (SMR) was carried out in the same apparatus at similar temperatures and pressure in a feed consisting of methane, nitrogen and water, with a steam to carbon ratio of 2.0-4.0. Temperature programmed (TP) techniques, including oxidation (TPO), reduction (TPR), reaction (TPCPO) and methane dissociation (TPMD) was used to characterize catalytic properties such as ignition temperatures, the catalyst reducibility and activation energies. Dispersions from catalyst surface area measurements were compared to X-ray diffraction (XRD) techniques and electron microscopy (SEM, TEM,STEM) to obtain information on catalyst particle sizes and dispersion. X-ray photoelectron spectroscopy (XPS) provided information on the specific catalyst surface composition, which was compared to results on the bulk structure obtained by XRD. The effect of modifying cobalt catalysts supported on alumina was investigated by adding small amounts of Ni, Fe, Cr, Re, Mn, W, Mo, V and Ta oxides. The idea behind this work was to investigate whether the cobalt crystals were decorated, covered or encircled by a modifier and to what extent this affected catalyst performance. The choice of modifiers in this study was based on the principle that in any chemical process it may be just as important to identify groups of elements that have negative effects as identifying the best promoters. It was found that the

  3. A Critical Review of Methane Trapping Mechanism to Optimize CBM Production

    Directory of Open Access Journals (Sweden)

    Saleem Qadir Tunio

    2012-12-01

    Full Text Available Optimizing Coal Bed Methane (CBM production depends on the trapping mechanism of methane in the micro pores of coal bed. Methane is trapped in coal beds by adsorption on the free surface. The free surface is mainly available as the micro pores and partly as different cleats. The average percentage of micro pores (1.2x10-7 cm diameter in a coal increases with rank and ranges from 19.3% in lignites to 75% in anthracites. The effective molecular diameter of adsorbed methane is 4.1x10-8 cm suggesting a maximum of three molecules can be accommodated in a unit micro pore. The commitment of optimized production of methane depends on the amount adsorbed on the coal surface. Methane in the micro pore can be accommodated either by solution in pore water or adsorption or as free gas under pressure. If it is dissolved in water, then for CBM production it is not useful because the dissolved gas will be expelled during dewatering phase of the well completion. It is only the free gas and the adsorbed gas that need to be evaluated for optimized production. Langmuir assumed a mono-layer of adsorption in selective locales on the adsorbent whereas many of the present day models assumed multi-layers of adsorbates (BET: Stephen Brunauer, Paul Emmett and Edward Teller. Problem arises with the concept of layering during adsorption process whereby it is difficult to think of adsorption of methane over a methane layer. With higher pressure methane can be accommodated as free gas but will not be adsorbed on any methane surface. It is therefore necessary to understand how methane molecule is trapped in the micro pores of the coal bed in order to optimize the CBM production.

  4. Marine biomass system: anaerobic digestion and production of methane

    Energy Technology Data Exchange (ETDEWEB)

    Haven, K.F.; Henriquez, M.; Ritschard, R.L.

    1979-04-01

    Two approaches to kelp conversion to methane are described. First, a large (10.56 mi/sup 2/) oceanic farm using an artificial substrate and an upwelling system to deliver nutrient-rich deep ocean water to the kelp bed is described. This system can yield as much as 50 tons of kelp (dry ash free - DAF) per acre-year. Kelp are harvested by a specially designed 30,000 DWT ship and delivered to an onshore processing plant as a ground kelp slurry. The second system involves the use of a natrual coastal kelp bed. Growth rates in this bed are stimulated by a nutrient rich sewer outfall. A conceptual model is presented for calculation of the growth rate of kelp in this natural bed which can reach 15 tons (DAF) per acre-year. The harvest activity and processing plant are similar to those for oceanic farm system. In the next section of this report, the overall concept of kelp production and conversion to methane is discussed. In Section III the general design of the ocean farm system is presented and discussed while Section IV contains a similar description for the natural bed system. Section V presents the capital requirements and operational labor, resources and material requirements. Section VI describes the environmental residuals created by the operation of either system and, to the extent possible, quantifies the rate at which these residuals are generated. In addition to the technical data reported herein, cost data have been generated for the various processes and components utilized in each solar technology. The requirements for costing information basically arise from the need to compute parameters such as investment demands, employment patterns, material demands and residual levels associated with each technology for each of several national and regional scenarios.

  5. Soil redox and pH effects on methane production in a flooded rice soil

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Z.P.; DeLaune, R.D.; Masscheleyn, P.H.; Patrick, W.H.

    1993-01-01

    Methane formation in soil is a microbiological process controlled by many factors. Of them soil redox potential (Eh) and soil pH are considered as critical controls. A laboratory incubation experiment was conducted to study the critical initiation soil Eh, the optimum soil pH, and the interaction of Eh and pH on methane production. A small decrease in pH resulting from the introduction of acidic materials significantly decreased methane production. However, a slight increase in soil pH (about 0.2 unit higher than the natural soil suspension pH) resulted in an enhancement of methane production by 11-20 percent and 24-25 percent at controlled Eh of -250 mV and -200 mV, respectively. Results suggest that decrease in methane emission could be obtained by a small reduction in soil pH in Crowley soil.

  6. Key factors influencing the potential of catch crops for methane production.

    Science.gov (United States)

    Molinuevo-Salces, Beatriz; Fernández-Varela, Raquel; Uellendahl, Hinrich

    2014-08-01

    Catch crops are grown in crop rotation primarily for soil stabilization. The excess biomass of catch crops was investigated for its potential as feedstock for biogas production. Ten variables affecting catch crop growth and methane potential were evaluated. Field trials and methane potential were studied for 14 different catch crops species, with 19 samples harvested in 2010 and 36 harvested in 2011. Principal component analysis was applied to the data to identify the variables characterizing the potential for the different catch crops species for methane production. Two principal components explained up to 84.6% and 71.6% of the total variation for 2010 and 2011 samples, respectively. Specific methane yield, climate conditions (rainfall and temperature) and total nitrogen in the biomass were the variables classifying the different catch crops. Catch crops in the Brassicaceae and Graminaceae botanical families showed the highest methane yield. This study demonstrates the importance of the crop species when choosing a suitable catch crop for biogas production.

  7. Relationships linking primary production, sea ice melting, and biogenic aerosol in the Arctic

    Science.gov (United States)

    Becagli, S.; Lazzara, L.; Marchese, C.; Dayan, U.; Ascanius, S. E.; Cacciani, M.; Caiazzo, L.; Di Biagio, C.; Di Iorio, T.; di Sarra, A.; Eriksen, P.; Fani, F.; Giardi, F.; Meloni, D.; Muscari, G.; Pace, G.; Severi, M.; Traversi, R.; Udisti, R.

    2016-07-01

    This study examines the relationships linking methanesulfonic acid (MSA, arising from the atmospheric oxidation of the biogenic dimethylsulfide, DMS) in atmospheric aerosol, satellite-derived chlorophyll a (Chl-a), and oceanic primary production (PP), also as a function of sea ice melting (SIM) and extension of the ice free area in the marginal ice zone (IF-MIZ) in the Arctic. MSA was determined in PM10 samples collected over the period 2010-2012 at two Arctic sites, Ny Ålesund (78.9°N, 11.9°E), Svalbard islands, and Thule Air Base (76.5°N, 68.8°W), Greenland. PP is calculated by means of a bio-optical, physiologically based, semi-analytical model in the potential source areas located in the surrounding oceanic regions (Barents and Greenland Seas for Ny Ålesund, and Baffin Bay for Thule). Chl-a peaks in May in the Barents sea and in the Baffin Bay, and has maxima in June in the Greenland sea; PP follows the same seasonal pattern of Chl-a, although the differences in absolute values of PP in the three seas during the blooms are less marked than for Chl-a. MSA shows a better correlation with PP than with Chl-a, besides, the source intensity (expressed by PP) is able to explain more than 30% of the MSA variability at the two sites; the other factors explaining the MSA variability are taxonomic differences in the phytoplanktonic assemblages, and transport processes from the DMS source areas to the sampling sites. The taxonomic differences are also evident from the slopes of the correlation plots between MSA and PP: similar slopes (in the range 34.2-36.2 ng m-3of MSA/(gC m-2 d-1)) are found for the correlation between MSA at Ny Ålesund and PP in Barents Sea, and between MSA at Thule and PP in the Baffin Bay; conversely, the slope of the correlation between MSA at Ny Ålesund and PP in the Greenland Sea in summer is smaller (16.7 ng m-3of MSA/(gC m-2 d-1)). This is due to the fact that DMS emission from the Barents Sea and Baffin Bay is mainly related to the MIZ

  8. Free nitrous acid (FNA)-based pretreatment enhances methane production from waste activated sludge.

    Science.gov (United States)

    Wang, Qilin; Ye, Liu; Jiang, Guangming; Jensen, Paul D; Batstone, Damien J; Yuan, Zhiguo

    2013-10-15

    Anaerobic digestion of waste activated sludge (WAS) is currently enjoying renewed interest due to the potential for methane production. However, methane production is often limited by the slow hydrolysis rate and/or poor methane potential of WAS. This study presents a novel pretreatment strategy based on free nitrous acid (FNA or HNO2) to enhance methane production from WAS. Pretreatment of WAS for 24 h at FNA concentrations up to 2.13 mg N/L substantially enhanced WAS solubilization, with the highest solubilization (0.16 mg chemical oxygen demand (COD)/mg volatile solids (VS), at 2.13 mg HNO2-N/L) being six times that without FNA pretreatment (0.025 mg COD/mg VS, at 0 mg HNO2-N/L). Biochemical methane potential tests demonstrated methane production increased with increased FNA concentration used in the pretreatment step. Model-based analysis indicated FNA pretreatment improved both hydrolysis rate and methane potential, with the highest improvement being approximately 50% (from 0.16 to 0.25 d(-1)) and 27% (from 201 to 255 L CH4/kg VS added), respectively, achieved at 1.78-2.13 mg HNO2-N/L. Further analysis indicated that increased hydrolysis rate and methane potential were related to an increase in rapidly biodegradable substrates, which increased with increased FNA dose, while the slowly biodegradable substrates remained relatively static.

  9. Bioelectrochemical enhancement of methane production in low temperature anaerobic digestion at 10 °C

    NARCIS (Netherlands)

    Liu, Dandan; Zhang, Lei; Chen, Si; Buisman, Cees; Heijne, ter Annemiek

    2016-01-01

    Anaerobic digestion at low temperature is an attractive technology especially in moderate climates, however, low temperature results in low microbial activity and low rates of methane formation. This study investigated if bioelectrochemical systems (BESs) can enhance methane production from organ

  10. Semi-industrial production of methane from textile wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Opwis, Klaus; Mayer-Gall, Thomas; Gutmann, Jochen S. [Deutsches Textilforschungszentrum Nord-West e.V., Krefeld (DE)] (and others)

    2012-12-15

    The enzymatic desizing of starch-sized cotton fabrics leads to wastewaters with an extremely high chemical oxygen demand due to its high sugar content. Nowadays, these liquors are still disposed without use, resulting in a questionable ecological pollution and high emission charges for cotton finishing manufacturers. In this paper, an innovative technology for the production of energy from textile wastewaters from cotton desizing was developed. Such desizing liquors were fermented by methane-producing microbes to biogas. For this purpose, a semi-industrial plant with a total volume of more than 500 L was developed and employed over a period of several weeks. The robust and trouble-free system produces high amounts of biogas accompanied by a significant reduction of the COD of more than 85%. With regard to growing standards and costs for wastewater treatment and disposal, the new process can be an attractive alternative for textile finishing enterprises in wastewater management, combining economic and ecological benefits. Moreover, the production of biogas from textile wastewaters can help to overcome the global energy gap within the next decades, especially with respect to the huge dimension of cotton pretreatment and, therefore, huge desizing activities worldwide.

  11. Effects of exogenous aerobic bacteria on methane production and biodegradation of municipal solid waste in bioreactors.

    Science.gov (United States)

    Ge, Sai; Liu, Lei; Xue, Qiang; Yuan, Zhiming

    2016-09-01

    Landfill is the most common and efficient ways of municipal solid waste (MSW) disposal and the landfill biogas, mostly methane, is currently utilized to generate electricity and heat. The aim of this work is to study the effects and the role of exogenous aerobic bacteria mixture (EABM) on methane production and biodegradation of MSW in bioreactors. The results showed that the addition of EABM could effectively enhance hydrolysis and acidogenesis processes of MSW degradation, resulting in 63.95% reduction of volatile solid (VS), the highest methane production rate (89.83Lkg(-1) organic matter) ever recorded and a threefold increase in accumulative methane production (362.9L) than the control (127.1L). In addition, it is demonstrated that white-rot fungi (WRF) might further promote the methane production through highly decomposing lignin, but the lower pH value in leachate and longer acidogenesis duration may cause methane production reduced. The data demonstrated that methane production and biodegradation of MSW in bioreactors could be significantly enhanced by EABM via enhanced hydrolysis and acidogenesis processes, and the results are of great economic importance for the future design and management of landfill.

  12. Enhanced methane production from pig slurry with pulsed electric field pre-treatment.

    Science.gov (United States)

    Safavi, Seyedeh Masoumeh; Unnthorsson, Runar

    2017-03-08

    Intensive amount of manure produced in pig breeding sectors represents negative impact on the environment and requires optimal management. Anaerobic digestion as a well-known manure management process was optimized in this experimental study by pulsed electric field (PEF) pre-treatment. The effect of PEF on methane production was investigated at three different intensities (15, 30 and 50 kWh/m(3)). The results indicate that the methane production and chemical oxygen demand (COD) removal was improved by continuous escalation of applied intensity, up to 50 kWh/m(3). In comparison with untreated slurry, methane production and COD removal were increased up to 58% and 44%, respectively.

  13. Formation of methane hazard in longwall coal mines with increasingly higher production capacity

    Institute of Scientific and Technical Information of China (English)

    Krause Eugeniusz; Skiba Jacek

    2014-01-01

    Increasingly higher hard coal production capacity in Upper Silesian Coal Basin (Poland) in the last two decades led to significant increase of methane hazard occurrence in the workings of exploitation areas. An increase of methane content in the exploited seams and in the surrounding strata, associated with increasing depth of mining, results in higher methane emission into the longwall areas from exploited seams and degassing seams in the mining-induced de-stressed zone. Operational experience gained by the collieries confirms that reducing methane release during longwall operations often requires decreas-ing operating speed of a shearer in a shift. The paper presents an analysis of the parameters and factors, which have critical influence on the formation of methane hazard in longwall areas with high production capacity.

  14. NREL Advancements in Methane Conversion Lead to Cleaner Air, Useful Products

    Energy Technology Data Exchange (ETDEWEB)

    2016-06-01

    Researchers at NREL leveraged the recent on-site development of gas fermentation capabilities and novel genetic tools to directly convert methane to lactic acid using an engineered methanotrophic bacterium. The results provide proof-of-concept data for a gas-to-liquids bioprocess that concurrently produces fuels and chemicals from methane. NREL researchers developed genetic tools to express heterologous genes in methanotrophic organisms, which have historically been difficult to genetically engineer. Using these tools, researchers demonstrated microbial conversion of methane to lactate, a high-volume biochemical precursor predominantly utilized for the production of bioplastics. Methane biocatalysis offers a means to concurrently liquefy and upgrade natural gas and renewable biogas, enabling their utilization in conventional transportation and industrial manufacturing infrastructure. Producing chemicals and fuels from methane expands the suite of products currently generated from biorefineries, municipalities, and agricultural operations, with the potential to increase revenue and significantly reduce greenhouse gas emissions.

  15. Hydrogen and methane production from household solid waste in the two-stage fermentation process

    DEFF Research Database (Denmark)

    Lui, D.; Liu, D.; Zeng, Raymond Jianxiong

    2006-01-01

    A two-stage process combined hydrogen and methane production from household solid waste was demonstrated working successfully. The yield of 43 mL H-2/g volatile solid (VS) added was generated in the first hydrogen production stage and the methane production in the second stage was 500 mL CH4/g VS....... Furthermore, this study also provided direct evidence in the dynamic fermentation process that, hydrogen production increase was reflected by acetate to butyrate ratio increase in liquid phase. (c) 2006 Elsevier Ltd. All rights reserved.......A two-stage process combined hydrogen and methane production from household solid waste was demonstrated working successfully. The yield of 43 mL H-2/g volatile solid (VS) added was generated in the first hydrogen production stage and the methane production in the second stage was 500 mL CH4/g VS...... added. This figure was 21% higher than the methane yield from the one-stage process, which was run as control. Sparging of the hydrogen reactor with methane gas resulted in doubling of the hydrogen production. PH was observed as a key factor affecting fermentation pathway in hydrogen production stage...

  16. Effects of Rumen Protozoa of Brahman Heifers and Nitrate on Fermentation and In vitro Methane Production.

    Science.gov (United States)

    Nguyen, S H; Li, L; Hegarty, R S

    2016-06-01

    Two experiments were conducted assessing the effects of presence or absence of rumen protozoa and dietary nitrate addition on rumen fermentation characteristics and in vitro methane production in Brahman heifers. The first experiment assessed changes in rumen fermentation pattern and in vitro methane production post-refaunation and the second experiment investigated whether addition of nitrate to the incubation would give rise to methane mitigation additional to that contributed by defaunation. Ten Brahman heifers were progressively adapted to a diet containing 4.5% coconut oil distillate for 18 d and then all heifers were defaunated using sodium 1-(2-sulfonatooxyethoxy) dodecane (Empicol). After 15 d, the heifers were given a second dose of Empicol. Fifteen days after the second dosing, all heifers were allocated to defaunated or refaunated groups by stratified randomisation, and the experiment commenced (d 0). On d 0, an oral dose of rumen fluid collected from unrelated faunated cattle was used to inoculate 5 heifers and form a refaunated group so that the effects of re-establishment of protozoa on fermentation characteristics could be investigated. Samples of rumen fluid collected from each animal using oesophageal intubation before feeding on d 0, 7, 14, and 21 were incubated for in vitro methane production. On d 35, 2% nitrate (as NaNO3) was included in in vitro incubations to test for additivity of nitrate and absence of protozoa effects on fermentation and methane production. It was concluded that increasing protozoal numbers were associated with increased methane production in refaunated heifers 7, 14, and 21 d after refaunation. Methane production rate was significantly higher from refaunated heifers than from defaunated heifers 35 d after refaunation. Concentration and proportions of major volatile fatty acids, however, were not affected by protozoal treatments. There is scope for further reducing methane output through combining defaunation and dietary

  17. Effect of the interaction between a low tyramine-producing Lactobacillus and proteolytic staphylococci on biogenic amine production during ripening and storage of dry sausages.

    Science.gov (United States)

    Bover-Cid, S; Izquierdo-Pulido, M; Vidal-Carou, M C

    2001-04-11

    The interaction between tyrosine-decarboxylase and proteolytic activities of a Lactobacillus curvatus and Staphylococcus xylosus, respectively, on biogenic amine production during the ripening and the storage of dry fermented sausages was investigated. Water content, pH, proteolysis parameters, microbial counts, and biogenic amine contents were monitored in spontaneously and starter fermented sausages. The use of proteolytic staphylococci as starter resulted in a higher content of non-protein nitrogen and total free amino acids. Tyramine was the main amine produced in all batches. However, tyrosine-decarboxylase activity of the L. curvatus starter strain was weak and yielded lower amounts of tyramine than those produced by the wild mioroflora in the control batch. Association between tyramine production and proteolysis could only be established in a defectively dried batch. Putrescine and cadaverine accumulation was efficiently reduced in the starter-mediated fermentation, in agreement with the lower development of enterobacteria. Phenylethylamine and tryptamine were only detected in the spontaneously fermented sausages, while histamine, spermine and spermidine did not vary during the ripening. Biogenic amine levels and related parameters showed significant changes during the storage of dry sausages depending on the temperature and the batch. As a general rule, changes in the pH, proteolysis, microbial counts, and biogenic amine contents were stronger at 19 degrees C than at 4 degrees C. The results suggest that refrigeration would be advisable for preventing further accumulation of biogenic amines during the storage of dry fermented sausages.

  18. Evaluation of Phytoremediation of Coal Bed Methane Product Water and Waters of Quality Similar to that Associated with Coal Bed Methane Reserves of the Powder River Basin, Montana and Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    James Bauder

    2008-09-30

    U.S. emphasis on domestic energy independence, along with advances in knowledge of vast biogenically sourced coalbed methane reserves at relatively shallow sub-surface depths with the Powder River Basin, has resulted in rapid expansion of the coalbed methane industry in Wyoming and Montana. Techniques have recently been developed which constitute relatively efficient drilling and methane gas recovery and extraction techniques. However, this relatively efficient recovery requires aggressive reduction of hydrostatic pressure within water-saturated coal formations where the methane is trapped. Water removed from the coal formation during pumping is typically moderately saline and sodium-bicarbonate rich, and managed as an industrial waste product. Current approaches to coalbed methane product water management include: surface spreading on rangeland landscapes, managed irrigation of agricultural crop lands, direct discharge to ephermeral channels, permitted discharge of treated and untreated water to perennial streams, evaporation, subsurface injection at either shallow or deep depths. A Department of Energy-National Energy Technology Laboratory funded research award involved the investigation and assessment of: (1) phytoremediation as a water management technique for waste water produced in association with coalbed methane gas extraction; (2) feasibility of commercial-scale, low-impact industrial water treatment technologies for the reduction of salinity and sodicity in coalbed methane gas extraction by-product water; and (3) interactions of coalbed methane extraction by-product water with landscapes, vegetation, and water resources of the Powder River Basin. Prospective, greenhouse studies of salt tolerance and water use potential of indigenous, riparian vegetation species in saline-sodic environments confirmed the hypothesis that species such as Prairie cordgrass, Baltic rush, American bulrush, and Nuttall's alkaligrass will thrive in saline-sodic environments

  19. Biogeochemistry of microbial coal-bed methane

    Science.gov (United States)

    Strc, D.; Mastalerz, Maria; Dawson, K.; MacAlady, J.; Callaghan, A.V.; Wawrik, B.; Turich, C.; Ashby, M.

    2011-01-01

    Microbial methane accumulations have been discovered in multiple coal-bearing basins over the past two decades. Such discoveries were originally based on unique biogenic signatures in the stable isotopic composition of methane and carbon dioxide. Basins with microbial methane contain either low-maturity coals with predominantly microbial methane gas or uplifted coals containing older, thermogenic gas mixed with more recently produced microbial methane. Recent advances in genomics have allowed further evaluation of the source of microbial methane, through the use of high-throughput phylogenetic sequencing and fluorescent in situ hybridization, to describe the diversity and abundance of bacteria and methanogenic archaea in these subsurface formations. However, the anaerobic metabolism of the bacteria breaking coal down to methanogenic substrates, the likely rate-limiting step in biogenic gas production, is not fully understood. Coal molecules are more recalcitrant to biodegradation with increasing thermal maturity, and progress has been made in identifying some of the enzymes involved in the anaerobic degradation of these recalcitrant organic molecules using metagenomic studies and culture enrichments. In recent years, researchers have attempted lab and subsurface stimulation of the naturally slow process of methanogenic degradation of coal. Copyright ?? 2011 by Annual Reviews. All rights reserved.

  20. BIOGAS PRODUCTION BY ENCAPSULATED METHANE-PRODUCING BACTERIA

    Directory of Open Access Journals (Sweden)

    Mohammad J. Taherzadeh

    2011-11-01

    Full Text Available Encapsulation of methane-producing bacteria was carried out with the objective of enhancing the rate of biogas production. Encapsulation with a one-step liquid-droplet-forming technique was employed for the natural membrane, resulting in spherical capsules with an average diameter and a membrane thickness of 4.3 and 0.2 mm, respectively. The capsules were made from alginate, using chitosan or Ca2+ as counter-ions, together with the addition of carboxymethylcellulose (CMC. A Durapore® membrane (hydrophilic PVDF with a pore size of 0.1 µm was used for synthetic encapsulating sachets having width and length dimensions 3×3 and 3×6 cm2 for holding the bacteria. During the digesting process, the dissolved substrates penetrated through the capsule membrane, and biogas inside the capsules was able to escape by diffusion. The results indicate encapsulation to be a promising method of digestion, with a high density of anaerobic bacteria. The method holds considerable potential for further development of membranes and their applications.

  1. Potential and existing mechanisms of enteric methane production in ruminants

    Directory of Open Access Journals (Sweden)

    Junyi Qiao

    2014-10-01

    Full Text Available Enteric methane (CH4 emissions in ruminants have attracted considerable attention due to their impact on greenhouse gases and the contribution of agricultural practices to global warming. Over the last two decades, a number of approaches have been adopted to mitigate CH4 emissions. However, the mechanisms of methanogenesis have still not been fully defined. According to the genome sequences of M. ruminantium in the rumen and of M. AbM4 in the abomasum, the pathways of carbon dioxide (CO2 reduction and formate oxidation to CH4 have now been authenticated in ruminants. Furthermore, in the light of species or genera description of methanogens, the precursors of methanogenesis discovered in the rumen and research advances in related subjects, pathways of acetate dissimilation via Methanosarcina and Methanosaeta as well as metabolism of methanol to CH4 might be present in the rumen, although neither process has yet been experimentally demonstrated in the rumen. Herein the research advances in methanogenesic mechanisms including existing and potential mechanisms are reviewed in detail. In addition, further research efforts to understand the methanogenesis mechanism should focus on isolation and identification of more specific methanogens, and their genome sequences. Such increased knowledge will provide benefits in terms of improved dietary energy utilization and a reduced contribution of enteric CH4 emissions to total global greenhouse gas emissions from the ruminant production system.

  2. EMG System for Production of Methane From Carbon Dioxide Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Sustainable Innovations, LLC, is developing an Electrochemical Methane Generator (EMG), which comprises a novel method of converting CO2 and H2O to hydrocarbon fuels...

  3. Methane Production and Carbon Capture by Hydrate Swapping

    DEFF Research Database (Denmark)

    Mu, Liang; von Solms, Nicolas

    2016-01-01

    gas molecules in the structural lattice. In this work, we quantitatively investigate the swapping behavior from injection of pure carbon dioxide and the (CO2 + N2) binary gas mixture through artificial hydrate-bearing sandstone samples by use of a core-flooding experimental apparatus. A total of 13...... of pure carbon dioxide in swapping methane from its hydrate phase; the methane recovery efficiency in brine water systems is enhanced relative to pure water systems. The replenishment of a fresh (CO2 + N2) gas mixture into the vapor phase can be considered as an efficient extraction method because 46...... in small hydrate cages, as long as the equilibrium formation pressure of (CO2 + N2) binary gas hydrate is below that of methane hydrate, even though adding nitrogen to carbon dioxide reduces the thermodynamic driving force for the formation of a new hydrate. When other conditions are similar, the methane...

  4. Methane production from coal by a single methanogen

    Science.gov (United States)

    Mayumi, Daisuke; Mochimaru, Hanako; Tamaki, Hideyuki; Yamamoto, Kyosuke; Yoshioka, Hideyoshi; Suzuki, Yuichiro; Kamagata, Yoichi; Sakata, Susumu

    2016-10-01

    Coal-bed methane is one of the largest unconventional natural gas resources. Although microbial activity may greatly contribute to coal-bed methane formation, it is unclear whether the complex aromatic organic compounds present in coal can be used for methanogenesis. We show that deep subsurface-derived Methermicoccus methanogens can produce methane from more than 30 types of methoxylated aromatic compounds (MACs) as well as from coals containing MACs. In contrast to known methanogenesis pathways involving one- and two-carbon compounds, this “methoxydotrophic” mode of methanogenesis couples O-demethylation, CO2 reduction, and possibly acetyl-coenzyme A metabolism. Because MACs derived from lignin may occur widely in subsurface sediments, methoxydotrophic methanogenesis would play an important role in the formation of natural gas not limited to coal-bed methane and in the global carbon cycle.

  5. Characteristics of the organic fraction of municipal solid waste and methane production: A review.

    Science.gov (United States)

    Campuzano, Rosalinda; González-Martínez, Simón

    2016-08-01

    Anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) is a viable alternative for waste stabilization and energy recovery. Biogas production mainly depends on the type and amount of organic macromolecules. Based on results from different authors analysing OFMSW from different cities, this paper presents the importance of knowing the OFMSW composition to understand how anaerobic digestion can be used to produce methane. This analysis describes and discusses physical, chemical and bromatological characteristics of OFMSW reported by several authors from different countries and cities and their relationship to methane production. The main conclusion is that the differences are country and not city dependant. Cultural habits and OFMSW management systems do not allow a generalisation but the individual analysis for specific cities allow understanding the general characteristics for a better methane production. Not only are the OFMSW characteristics important but also the conditions under which the methane production tests were performed.

  6. Microbial electrolysis contribution to anaerobic digestion of waste activated sludge, leading to accelerated methane production

    DEFF Research Database (Denmark)

    Liu, Wenzong; Cai, Weiwei; Guo, Zechong

    2016-01-01

    -AD) wasused to accelerate methane production for energy recovery from WAS. Carbon bioconversion wasaccelerated by ME producing H2 at the cathode. MPR was enhanced to 91.8 gCH4/m3 reactor/d in themicrobial electrolysis ME-AD reactor, thus improving the rate by 3 times compared to control conditions (30.6 gCH4......Methane production rate (MPR) in waste activated sludge (WAS) digestion processes is typically limitedby the initial steps of complex organic matter degradation, leading to a limited MPR due to sludgefermentation speed of solid particles. In this study, a novel microbial electrolysis AD reactor (ME....../m3 reactor/d in AD). The methane production yield reached 116.2 mg/g VSS in the ME-ADreactor. According to balance calculation on electron transfer and methane yield, the increasedmethane production was mostly dependent on electron contribution through the ME system. Thus, theuse of the novel ME...

  7. Study on Production of Hydrogen from Methane for Proton Exchange Membrane Fuel Cell

    Institute of Scientific and Technical Information of China (English)

    宋正昶; 李传统

    2001-01-01

    The hydrogen production from methane for proton exchange membrane fuel cell (PEMFC) was studied experimentally. The conversion rate of methane under different steam-carbon ratios, the effect of the different excess air ratios on the constituents of the gas produced, the permeability of hydrogen under different pressure differences, and the effect of different system pressure on the reaction enthalpy of hydrogen were obtained. The results lay the basis for the production of hydrogen applicable to PEMFC, moreover, provide a new way for the comprehensive utilization of the coal bed methane.

  8. Economic tools for realization of methane production project on Kuzbass coal deposits

    Science.gov (United States)

    Sharf, I.; Sokolova, M.; Kochetkova, O.; Dmitrieva, N.

    2016-09-01

    Environmental issues and, above all, issues related to the release of greenhouse gases into the atmosphere, such as coal bed methane, actualize the challenge of searching a variety of options for its disposal. The difference in the macroeconomic, industrial, geological and infrastructural features determine the need to choose the most cost-effective option for using of methane emitted from the coal deposits. Various economic ways to improve the profitability of production are viewed on the basis of the analysis of methane production project from Kuzbass coal deposits, Kemerovo region, Russia.

  9. ASSESSMENT OF ISTRIAN COAL BED METHANE PRODUCTION POSSIBILITY

    Directory of Open Access Journals (Sweden)

    Mario Klanfar

    2010-12-01

    Full Text Available The potential of coal bed methane has not been evaluated in Croatia so far. For several selected sites in Labin basin data on the composition of coal and the depths and thicknesses of coal layers were collected. Assessment and comparison of the methane content in coal by using the Langmuir isotherm, the general curves of sorption and Kim's method was made and evaluation of the quality of each assessment as well. The analysis resulted with coal bed methane content between 9.5 m3/t 11.73 m3/t calculated by Kim's equation. By comparing the sorption of pure methane and sorption of CO2, in order to maintain the pressure in a coal bed and higher recovery of methane, the CO2 could be one of the options for injecting fluid. Geometry of coal layers was not defined and therefore it is not possible to estimate the total content of methane (the paper is published in Croatian.

  10. The kinetics of methane production from co-digestion of cattle manure.

    Science.gov (United States)

    Bakhov, Zh K; Korazbekova, K U; Lakhanova, K M

    2014-08-01

    In this article, the kinetics of methane production from co-digestion of liquid manure from cattle with the addition of winemaking waste, food waste and biowaste was investigated in order to describe and evaluate methanogenesis in terms of growth curve of methanogenic bacteria. Experiments were carried out in "Hohenheim"n biogas yield testing system at the temperature of 37 degrees C. The cumulative methane yield was 0.330 ± 0.038, 0.277 ± 0.041, 0.1480 ± 013 and 0.250 ± 0.025 m3 CH4 per kg oDM in normal condition, respectively in mono-digestion and co-digestion of liquid manure from cattle with winemaking, food and biowaste. The kinetic Gompertz parameters of methane production (P-potential yield of methane, R(m)-maximum methane production rate and λ-duration of lag phase) were analyzed. The highest potential methane yield (P) showed co-fermentation of liquid manure from cattle with biowaste 0.387 Nm3 (kg oDM)(-1), the highest methane production rate (R(m)) was 0.022 ± 0.003 Nm3 (kg oDM)(-1) day(-1) for mono-digestion of cattle slurry, the lowest 0.006 Nm3 (kg oDM)(-1) day(-1) was obtained during co-digestion with food waste. Duration of lag phase (λ) was within 10.17-14.60 days for all samples. Additional, the duration of digestion to produce 95% of the potential methane yield and efficient methane production was determined.

  11. Warming Increases the Proportion of Primary Production Emitted as Methane from Freshwater Mesocosms

    OpenAIRE

    Yvon-Durocher, Gabriel; Montoya, José M; Woodward, Guy; Jones, J. Iwan; Trimmer, Mark

    2010-01-01

    Abstract Methane and carbon dioxide are the dominant gaseous end products of the remineralisation of organic carbon and also the two largest contributors to the anthropogenic greenhouse effect. We investigated whether warming altered the balance of methane efflux relative to primary production and ecosystem respiration in a freshwater mesocosm experiment. Whole ecosystem CH4 efflux was strongly related to temperature with an apparent activation energy of 0.85eV. Furthermore, CH4 ef...

  12. Microbial diversity and dynamics during methane production from municipal solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Bareither, Christopher A., E-mail: christopher.bareither@colostate.edu [Civil and Environmental Engineering, Colorado State University, Ft. Collins, CO 80532 (United States); Geological Engineering, University of Wisconsin-Madison, Madison, WI 53706 (United States); Wolfe, Georgia L., E-mail: gwolfe@wisc.edu [Bacteriology, University of Wisconsin-Madison, Madison, WI 53706 (United States); McMahon, Katherine D., E-mail: tmcmahon@engr.wisc.edu [Bacteriology, Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI 53706 (United States); Benson, Craig H., E-mail: chbenson@wisc.edu [Civil and Environmental Engineering, Geological Engineering, University of Wisconsin-Madison, Madison, WI 53706 (United States)

    2013-10-15

    Highlights: ► Similar bacterial communities developed following different start-up operation. ► Total methanogens in leachate during the decelerated methane phase reflected overall methane yield. ► Created correlations between methanogens, methane yield, and available substrate. ► Predominant bacteria identified with syntrophic polysaccharide degraders. ► Hydrogenotrophic methanogens were dominant in the methane generation process. - Abstract: The objectives of this study were to characterize development of bacterial and archaeal populations during biodegradation of municipal solid waste (MSW) and to link specific methanogens to methane generation. Experiments were conducted in three 0.61-m-diameter by 0.90-m-tall laboratory reactors to simulate MSW bioreactor landfills. Pyrosequencing of 16S rRNA genes was used to characterize microbial communities in both leachate and solid waste. Microbial assemblages in effluent leachate were similar between reactors during peak methane generation. Specific groups within the Bacteroidetes and Thermatogae phyla were present in all samples and were particularly abundant during peak methane generation. Microbial communities were not similar in leachate and solid fractions assayed at the end of reactor operation; solid waste contained a more abundant bacterial community of cellulose-degrading organisms (e.g., Firmicutes). Specific methanogen populations were assessed using quantitative polymerase chain reaction. Methanomicrobiales, Methanosarcinaceae, and Methanobacteriales were the predominant methanogens in all reactors, with Methanomicrobiales consistently the most abundant. Methanogen growth phases coincided with accelerated methane production, and cumulative methane yield increased with increasing total methanogen abundance. The difference in methanogen populations and corresponding methane yield is attributed to different initial cellulose and hemicellulose contents of the MSW. Higher initial cellulose and

  13. Methane Detection for Oil and Gas Production Sites Using Portable Dual-Comb Spectrometry

    Science.gov (United States)

    Coburn, Sean; Wright, Robert; Cossel, Kevin C.; Truong, Gar-Wing; Baumann, Esther; Coddington, Ian; Newbury, Nathan R.; Alden, Caroline; Ghosh, Subhomoy; Prasad, Kuldeep; Rieker, Greg B.

    2016-06-01

    Considerable uncertainty exists regarding the contribution of oil and gas operations to anthropogenic emissions of atmospheric methane. Additionally, new proposed EPA regulations on volatile organic compound (VOC) emissions from oil and gas production facilities have been expanded to include methane, making this a topic of growing importance to the oil and gas industry as well as regulators. In order to gain a better understanding of emissions, reliable techniques that enable long-term monitoring of entire production facilities are needed. Recent advances in the development of compact and robust fiber frequency combs are enabling the use of this powerful spectroscopic tool outside of the laboratory. Here we characterize and demonstrate a dual comb spectrometer (DCS) system with the potential to locate and size methane leaks from oil and gas production sites over extended periods of time. The DCS operates over kilometer scale open paths, and the path integrated methane measurements will ultimately be coupled with an atmospheric inversion utilizing local meteorology and a high resolution fluid dynamics simulation to determine leak location and also derive a leak rate. High instrument precision is needed in order to accurately perform the measurement inversion on the highly varying methane background, thus the DCS system has been fully optimized for the detection of atmospheric methane in the methane absorption region around 180-184 THz.

  14. Sulfide and methane production in sewer sediments: Field survey and model evaluation.

    Science.gov (United States)

    Liu, Yiwen; Tugtas, A Evren; Sharma, Keshab R; Ni, Bing-Jie; Yuan, Zhiguo

    2016-02-01

    Sewer sediment processes have been reported to significantly contribute to overall sulfide and methane production in sewers, at a scale comparable to that of sewer biofilms. The physiochemical and biological characteristics of sewer sediments are heterogeneous; however, the variability of in-sediments sulfide and methane production rates among sewers has not been assessed to date. In this study, five sewer sediment samples were collected from two cities in Australia with different climatic conditions. Batch assays were conducted to determine the rates of sulfate reduction and methane production under different flow velocity (shear stress) conditions as well as under completely mixed conditions. The tests showed substantial and variable sulfate reduction and methane production activities among different sediments. Sulfate reduction and methane production from sewer sediments were confirmed to be areal processes, and were dependent on flow velocity/shear stress. Despite of the varying characteristics and reactions kinetics, the sulfate reduction and methane production processes in all sediments could be well described by a one-dimensional sewer sediment model recently developed based on results obtained from a laboratory sewer sediment reactor. Model simulations indicated that the in-situ contribution of sewer sediment emissions could be estimated without the requirement of measuring the specific sediment characteristics or the sediment depths.

  15. Comparison of Nonprecious Metal Cathode Materials for Methane Production by Electromethanogenesis.

    Science.gov (United States)

    Siegert, Michael; Yates, Matthew D; Call, Douglas F; Zhu, Xiuping; Spormann, Alfred; Logan, Bruce E

    2014-04-01

    In methanogenic microbial electrolysis cells (MMCs), CO2 is reduced to methane using a methanogenic biofilm on the cathode by either direct electron transfer or evolved hydrogen. To optimize methane generation, we examined several cathode materials: plain graphite blocks, graphite blocks coated with carbon black or carbon black containing metals (platinum, stainless steel or nickel) or insoluble minerals (ferrihydrite, magnetite, iron sulfide, or molybdenum disulfide), and carbon fiber brushes. Assuming a stoichiometric ratio of hydrogen (abiotic):methane (biotic) of 4:1, methane production with platinum could be explained solely by hydrogen production. For most other materials, however, abiotic hydrogen production rates were insufficient to explain methane production. At -600 mV, platinum on carbon black had the highest abiotic hydrogen gas formation rate (1600 ± 200 nmol cm(-3) d(-1)) and the highest biotic methane production rate (250 ± 90 nmol cm(-3) d(-1)). At -550 mV, plain graphite (76 nmol cm(-3) d(-1)) performed similarly to platinum (73 nmol cm(-3) d(-1)). Coulombic recoveries, based on the measured current and evolved gas, were initially greater than 100% for all materials except platinum, suggesting that cathodic corrosion also contributed to electromethanogenic gas production.

  16. Comparison of Nonprecious Metal Cathode Materials for Methane Production by Electromethanogenesis.

    KAUST Repository

    Siegert, Michael

    2014-02-18

    In methanogenic microbial electrolysis cells (MMCs), CO2 is reduced to methane using a methanogenic biofilm on the cathode by either direct electron transfer or evolved hydrogen. To optimize methane generation, we examined several cathode materials: plain graphite blocks, graphite blocks coated with carbon black or carbon black containing metals (platinum, stainless steel or nickel) or insoluble minerals (ferrihydrite, magnetite, iron sulfide, or molybdenum disulfide), and carbon fiber brushes. Assuming a stoichiometric ratio of hydrogen (abiotic):methane (biotic) of 4:1, methane production with platinum could be explained solely by hydrogen production. For most other materials, however, abiotic hydrogen production rates were insufficient to explain methane production. At -600 mV, platinum on carbon black had the highest abiotic hydrogen gas formation rate (1600 ± 200 nmol cm(-3) d(-1)) and the highest biotic methane production rate (250 ± 90 nmol cm(-3) d(-1)). At -550 mV, plain graphite (76 nmol cm(-3) d(-1)) performed similarly to platinum (73 nmol cm(-3) d(-1)). Coulombic recoveries, based on the measured current and evolved gas, were initially greater than 100% for all materials except platinum, suggesting that cathodic corrosion also contributed to electromethanogenic gas production.

  17. Methyl-coenzyme M reductase A as an indicator to estimate methane production from dairy cows.

    Science.gov (United States)

    Aguinaga Casañas, M A; Rangkasenee, N; Krattenmacher, N; Thaller, G; Metges, C C; Kuhla, B

    2015-06-01

    The evaluation of greenhouse gas mitigation strategies requires the quantitative assessment of individual methane production. Because methane measurement in respiration chambers is highly accurate, but also comprises various disadvantages such as limited capacity and high costs, the establishment of an indicator for estimating methane production of individual ruminants would provide an alternative to direct methane measurement. Methyl-coenzyme M reductase is involved in methanogenesis and the subunit α of methyl-coenzyme M reductase is encoded by the mcrA gene of rumen archaea. We therefore examined the relationship between methane emissions of Holstein dairy cows measured in respiration chambers with 2 different diets (high- and medium-concentrate diet) and the mcrA DNA and mcrA cDNA abundance determined from corresponding rumen fluid samples. Whole-body methane production per kilogram of dry matter intake and mcrA DNA normalized to the abundance of the rrs gene coding for 16S rRNA correlated significantly when using qmcrA primers. Use of qmcrA primers also revealed linear correlation between mcrA DNA copy number and methane yield. Regression analyses based on normalized mcrA cDNA abundances revealed no significant linear correlation with methane production per kilogram of dry matter intake. Furthermore, the correlations between normalized mcrA DNA abundance and the rumen fluid concentration of acetic and isobutyric acid were positive, whereas the correlations with propionic and lactic acid were negative. These data suggest that the mcrA DNA approach based on qmcrA primers could potentially be a molecular proxy for methane yield after further refinement.

  18. Experimental workflow for developing a feed forward strategy to control biomass growth and exploit maximum specific methane productivity of Methanothermobacter marburgensis in a biological methane production process (BMPP

    Directory of Open Access Journals (Sweden)

    Alexander Krajete

    2016-08-01

    Full Text Available Recently, interests for new biofuel generations allowing conversion of gaseous substrate(s to gaseous product(s arose for power to gas and waste to value applications. An example is biological methane production process (BMPP with Methanothermobacter marburgensis. The latter, can convert carbon dioxide (CO2 and hydrogen (H2, having different origins and purities, to methane (CH4, water and biomass. However, these gas converting bioprocesses are tendentiously gas limited processes and the specific methane productivity per biomass amount (qCH4 tends to be low. Therefore, this contribution proposes a workflow for the development of a feed forward strategy to control biomass, growth (rx and qCH4 in a continuous gas limited BMPP. The proposed workflow starts with a design of experiment (DoE to optimize media composition and search for a liquid based limitation to control selectively growth. From the DoE it came out that controlling biomass growth was possible independently of the dilution and gassing rate applied while not affecting methane evolution rates (MERs. This was done by shifting the process from a natural gas limited state to a controlled liquid limited growth. The latter allowed exploiting the maximum biocatalytic activity for methane formation of Methanothermobacter marburgensis. An increase of qCH4 from 42 to 129 mmolCH4 g−1 h−1 was achieved by applying a liquid limitation compare with the reference state. Finally, a verification experiment was done to verify the feeding strategy transferability to a different process configuration. This evidenced the ratio of the fed KH2PO4 to rx (R(FKH2PO4/rx has an appropriate parameter for scaling feeds in a continuous gas limited BMPP. In the verification experiment CH4 was produced in a single bioreactor step at a methane evolution rate (MER of   132 mmolCH4*L−1*h−1 at a CH4 purity of 93 [Vol.%].

  19. Production of hydrogen and methane from wastewater sludge using anaerobic fermentation.

    Science.gov (United States)

    Ting, C H; Lin, K R; Lee, D J; Tay, J H

    2004-01-01

    The hydrogen and methane were produced from wastewater sludge using a Clostridium strain. The original sludge and the pre-treated (acidified, sterilized, freeze/thawed, and sonicated) sludges were tested. Some pre-treatment could enhance hydrogen yield, and the other tests could enhance methane yield. Hydrogen yield followed freeze/thawed>acidified>sterilized>original sludge>sonicated; while methane yield followed sonicated>freeze/thawed>sterilized>acidified>original sludge. The production and consumption of acetate correlated closely with the trends in both yields.

  20. Semi-continuous methane production from undiluted brown algae using a halophilic marine microbial community.

    Science.gov (United States)

    Miura, Toyokazu; Kita, Akihisa; Okamura, Yoshiko; Aki, Tsunehiro; Matsumura, Yukihiko; Tajima, Takahisa; Kato, Junichi; Nakashimada, Yutaka

    2016-01-01

    Acclimated marine sediment-derived culture was used for semi-continuous methane production from materials equivalent to raw brown algae, without dilution of salinity and without nutrient supply, under 3 consecutive conditions of varying organic loading rates (OLRs) and hydraulic retention time (HRT). Methane production was stable at 2.0gVS/kg/day (39-day HRT); however, it became unstable at 2.9gVS/kg/day (28-day HRT) due to acetate and propionate accumulation. OLR subsequently decreased to 1.7gVS/kg/day (46-day HRT), stabilizing methane production beyond steady state. Methane yield was above 300mL/g VS at all OLRs. These results indicated that the acclimated marine sediment culture was able to produce methane semi-continuously from raw brown algae without dilution and nutrient supply under steady state. Microbial community analysis suggested that hydrogenotrophic methanogens predominated among archaea during unstable methane production, implying a partial shift of the methanogenic pathway from acetoclastic methanogenesis to acetate oxidation.

  1. Comparison between ensilage and fungal pretreatment for storage of giant reed and subsequent methane production.

    Science.gov (United States)

    Liu, Shan; Xu, Fuqing; Ge, Xumeng; Li, Yebo

    2016-06-01

    Ensilage and fungal pretreatment of giant reed harvested from August through December were compared based on their effects on feedstock preservation, glucose yield, and subsequent methane production via anaerobic digestion (AD). Compared to fungal pretreatment, ensilage obtained lower total solids (Ensilage increased glucose and methane yields by 7-15% and 4-14%, respectively, for giant reed harvested from August through December. Fungal pretreatment failed for giant reed harvested in August and October with reduced glucose yields, and was effective for that harvested in November and December, with about 20% increases in glucose yield. However, hydrocarbon losses during fungal pretreatment offset the increased glucose yield, resulting in decreased methane yields by AD. In summary, ensilage was found to be more suitable than fungal pretreatment for giant reed storage and its methane production via AD.

  2. Selective production of methane from aqueous biocarbohydrate streams over a mixture of platinum and ruthenium catalysts.

    Science.gov (United States)

    Neira D'Angelo, Maria Fernanda; Ordomsky, Vitaly; van der Schaaf, John; Schouten, Jaap C; Nijhuis, Tjeerd Alexander

    2014-02-01

    A one-step process for the selective production of methane from low-value aqueous carbohydrate streams is proposed. Sorbitol, used herein as a model compound, is fully converted to methane, CO2 , and a minor amount of H2 by using a physical mixture of Pt and Ru (1:5 in mass basis) at 220 °C and 35 bar. This conversion is the result of hydrogenolysis of part of the sorbitol over Ru and the in situ production of H2 through the aqueous-phase reforming of the remaining carbohydrate over Pt. A synergistic effect of the combination of these two catalysts results in the rapid and highly selective conversion of the carbohydrate to methane. This process offers the possibility of upgrading a low-value carbohydrate stream into a valuable fuel with no addition of H2. Exergy analysis reveals that nearly 80 % of the exergy of the reactant is recovered as methane.

  3. Evaluation of marine sediments as microbial sources for methane production from brown algae under high salinity.

    Science.gov (United States)

    Miura, Toyokazu; Kita, Akihisa; Okamura, Yoshiko; Aki, Tsunehiro; Matsumura, Yukihiko; Tajima, Takahisa; Kato, Junichi; Nakashimada, Yutaka

    2014-10-01

    Various marine sediments were evaluated as promising microbial sources for methane fermentation of Saccharina japonica, a brown alga, at seawater salinity. All marine sediments tested produced mainly acetate among volatile fatty acids. One marine sediment completely converted the produced volatile fatty acids to methane in a short period. Archaeal community analysis revealed that acetoclastic methanogens belonging to the Methanosarcina genus dominated after cultivation. Measurement of the specific conversion rate at each step of methane production under saline conditions demonstrated that the marine sediments had higher conversion rates of butyrate and acetate than mesophilic methanogenic granules. These results clearly show that marine sediments can be used as microbial sources for methane production from algae under high-salt conditions without dilution.

  4. Key factors influencing the potential of catch crops for methane production

    DEFF Research Database (Denmark)

    Molinuevo-Salces, Beatriz; Fernandez-Varela, Raquel; Uellendahl, Hinrich

    2014-01-01

    Catch crops are grown in crop rotation primarily for soil stabilization. The excess biomass of catch crops was investigated for its potential as feedstock for biogas production. Ten variables affecting catch crop growth and methane potential were evaluated. Field trials and methane potential were...... studied for 14 different catch crops species, with 19 samples harvested in 2010 and 36 harvested in 2011. Principal component analysis was applied to the data to identify the variables characterizing the potential for the different catch crops species for methane production. Two principal components...... explained up to 84.6% and 71.6% of the total variation for 2010 and 2011 samples, respectively. Specific methane yield, climate conditions (rainfall and temperature) and total nitrogen in the biomass were the variables classifying the different catch crops. Catch crops in the Brassicaceae and Graminaceae...

  5. The Potential Role of Seaweeds in the Natural Manipulation of Rumen Fermentation and Methane Production

    Science.gov (United States)

    Maia, Margarida R. G.; Fonseca, António J. M.; Oliveira, Hugo M.; Mendonça, Carla; Cabrita, Ana R. J.

    2016-08-01

    This study is the first to evaluate the effects of five seaweeds (Ulva sp., Laminaria ochroleuca, Saccharina latissima, Gigartina sp., and Gracilaria vermiculophylla) on gas and methane production and ruminal fermentation parameters when incubated in vitro with two substrates (meadow hay and corn silage) for 24 h. Seaweeds led to lower gas production, with Gigartina sp. presenting the lowest value. When incubated with meadow hay, Ulva sp., Gigartina sp. and G. vermiculophylla decreased methane production, but with corn silage, methane production was only decreased by G. vermiculophylla. With meadow hay, L. ochroleuca and S. latissima promoted similar methane production as the control, but with corn silage, L. ochroleuca increased it. With the exception of S. latissima, all seaweeds promoted similar levels of total volatile fatty acid production. The highest proportion of acetic acid was produced with Ulva sp., G. vermiculophylla, and S. latissima; the highest proportion of butyric acid with the control and L. ochroleuca; and the highest proportion of iso-valeric acid with Gigartina sp. These results reveal the potential of seaweeds to mitigate ruminal methane production and the importance of the basal diet. To efficiently use seaweeds as feed ingredients with nutritional and environmental benefits, more research is required to determine the mechanisms underlying seaweed and substrate interactions.

  6. The Potential Role of Seaweeds in the Natural Manipulation of Rumen Fermentation and Methane Production.

    Science.gov (United States)

    Maia, Margarida R G; Fonseca, António J M; Oliveira, Hugo M; Mendonça, Carla; Cabrita, Ana R J

    2016-08-30

    This study is the first to evaluate the effects of five seaweeds (Ulva sp., Laminaria ochroleuca, Saccharina latissima, Gigartina sp., and Gracilaria vermiculophylla) on gas and methane production and ruminal fermentation parameters when incubated in vitro with two substrates (meadow hay and corn silage) for 24 h. Seaweeds led to lower gas production, with Gigartina sp. presenting the lowest value. When incubated with meadow hay, Ulva sp., Gigartina sp. and G. vermiculophylla decreased methane production, but with corn silage, methane production was only decreased by G. vermiculophylla. With meadow hay, L. ochroleuca and S. latissima promoted similar methane production as the control, but with corn silage, L. ochroleuca increased it. With the exception of S. latissima, all seaweeds promoted similar levels of total volatile fatty acid production. The highest proportion of acetic acid was produced with Ulva sp., G. vermiculophylla, and S. latissima; the highest proportion of butyric acid with the control and L. ochroleuca; and the highest proportion of iso-valeric acid with Gigartina sp. These results reveal the potential of seaweeds to mitigate ruminal methane production and the importance of the basal diet. To efficiently use seaweeds as feed ingredients with nutritional and environmental benefits, more research is required to determine the mechanisms underlying seaweed and substrate interactions.

  7. The Potential Role of Seaweeds in the Natural Manipulation of Rumen Fermentation and Methane Production

    Science.gov (United States)

    Maia, Margarida R. G.; Fonseca, António J. M.; Oliveira, Hugo M.; Mendonça, Carla; Cabrita, Ana R. J.

    2016-01-01

    This study is the first to evaluate the effects of five seaweeds (Ulva sp., Laminaria ochroleuca, Saccharina latissima, Gigartina sp., and Gracilaria vermiculophylla) on gas and methane production and ruminal fermentation parameters when incubated in vitro with two substrates (meadow hay and corn silage) for 24 h. Seaweeds led to lower gas production, with Gigartina sp. presenting the lowest value. When incubated with meadow hay, Ulva sp., Gigartina sp. and G. vermiculophylla decreased methane production, but with corn silage, methane production was only decreased by G. vermiculophylla. With meadow hay, L. ochroleuca and S. latissima promoted similar methane production as the control, but with corn silage, L. ochroleuca increased it. With the exception of S. latissima, all seaweeds promoted similar levels of total volatile fatty acid production. The highest proportion of acetic acid was produced with Ulva sp., G. vermiculophylla, and S. latissima; the highest proportion of butyric acid with the control and L. ochroleuca; and the highest proportion of iso-valeric acid with Gigartina sp. These results reveal the potential of seaweeds to mitigate ruminal methane production and the importance of the basal diet. To efficiently use seaweeds as feed ingredients with nutritional and environmental benefits, more research is required to determine the mechanisms underlying seaweed and substrate interactions. PMID:27572486

  8. Role of Methane Capture for Sustainable Biodiesel Production from Palm Oil: A Life Cycle Assessment Approach

    OpenAIRE

    Hermawan Prasetya; Yandra Arkeman; Erliza Hambali

    2013-01-01

    Palm Oil Mill Effluent (POME) is one of the major wastes generated by palm oil milling which is a part of palm oil diesel production chain. POME contain of methane (about 60-70 %), which contribute to Greenhouse Gas (GHG) Emission. Due to reduction GHG emission is one of indicator bioenergy sustainability, some alternatives have been implementing to reduction it. One of the alternatives is implementing of methane capture technology which able to capture and/or utilize it for energy source. In...

  9. Production of uracil from methane by a newly isolated Methylomonas sp. SW1.

    Science.gov (United States)

    Kim, Sangwoo; Lee, Wangjun; Song, Insu; Kwon, Yuhyun; Yun, Seokhun; Park, Soohyun; Cho, Sukhyeong; Oh, Byung-Keun; Oh, Han Bin; Lee, Jinwon

    2016-12-20

    Methane is an abundant, inexpensive one-carbon feedstock and one of the most powerful greenhouse gases. Because it does not compete with food demand, it is considered a promising carbon feedstock for the production of valuable products using methanotrophic bacteria. Here, we isolated a novel methanotrophic bacterium, Methylomonas sp. SW1, from a sewage sample obtained from Wonju City Water Supply Drainage Center, Republic of Korea. The conditions for uracil production by Methylomonas sp. SW1, such as Cu(2+) concentration and temperature were investigated and optimized. As a result, Methylomonas sp. SW1 produced uracil from methane as a sole carbon source with a titer of 2.1mg/L in 84h without genetic engineering under the optimized condition. The results in this study demonstrate the feasibility of using Methylomonas sp. SW1 for the production of uracil from methane. This is the first report of uracil production from gas feedstock by methanotrophic bacteria.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    Hydrogen and methane production from desugared molasses by a two‐stage thermophilic anaerobic process was investigated in a series of two up‐flow anaerobic sludge blanket (UASB) reactors. The first reactor that was dominated with hydrogen‐producing bacteria of Thermoanaerobacterium...... thermosaccharolyticum and Thermoanaerobacterium aciditolerans could generate a high hydrogen production rate of 5600 mL H2/day/L, corresponding to a yield of 132 mL H2/g volatile solid (VS). The effluent from the hydrogen reactor was further converted to methane in the second reactor with the optimal production rate...... of 3380 mL CH4/day/L, corresponding to a yield of 239 mL CH4/g VS. Aceticlastic Methanosarcina mazei was the dominant methanogen in the methanogenesis stage. This work demonstrates that biohydrogen production can be very efficiently coupled with a subsequent step of methane production using desugared...

  11. Effect of temperature on methane production from field-scale anaerobic digesters treating dairy manure.

    Science.gov (United States)

    Arikan, Osman A; Mulbry, Walter; Lansing, Stephanie

    2015-09-01

    Temperature is a critical factor affecting anaerobic digestion because it influences both system heating requirements and methane production. Temperatures of 35-37°C are typically suggested for manure digestion. In temperate climates, digesters require a considerable amount of additional heat energy to maintain temperatures at these levels. In this study, the effects of lower digestion temperatures (22 and 28°C), on the methane production from dairy digesters were evaluated and compared with 35°C using duplicate replicates of field-scale (FS) digesters with a 17-day hydraulic retention time. After acclimation, the FS digesters were operated for 12weeks using solids-separated manure at an organic loading rate (OLR) of 1.4kgVSm(-3)d(-1) and then for 8weeks using separated manure amended with manure solids at an OLR of 2.6kgVSm(-3)d(-1). Methane production values of the FS digesters at 22 and 28°C were about 70% and 87%, respectively, of the values from FS digesters at 35°C. The results suggest that anaerobic digesters treating dairy manure at 28°C were nearly as efficient as digesters operated at 35°C, with 70% of total methane achievable at 22°C. These results are relevant to small farms interested in anaerobic digestion for methane reduction without heat recovery from generators or for methane recovery from covered lagoon digesters.

  12. Role of Methane Capture for Sustainable Biodiesel Production from Palm Oil: A Life Cycle Assessment Approach

    Directory of Open Access Journals (Sweden)

    Hermawan Prasetya

    2013-01-01

    Full Text Available Palm Oil Mill Effluent (POME is one of the major wastes generated by palm oil milling which is a part of palm oil diesel production chain. POME contain of methane (about 60-70 %, which contribute to Greenhouse Gas (GHG Emission. Due to reduction GHG emission is one of indicator bioenergy sustainability, some alternatives have been implementing to reduction it. One of the alternatives is implementing of methane capture technology which able to capture and/or utilize it for energy source. In this paper, Life Cycle Assessment (LCA was employed to identify role of methane capture technology in sustainability of palm oil biodiesel production. By employed cradle to gate LCA on biggest producer of palm oil biodiesel in Indonesia, GHG emission is 23.00 g CO2eq per Mega Joule (MJ biodiesel production with methane capture, and 40.79 g CO2eq per MJ biodiesel without methane capture. From this result, it was concluded that implementation of methane capture could reduce GHG emission significantly (more than 70 %.

  13. Biogenic amine production by the wine Lactobacillus brevis IOEB 9809 in systems that partially mimic the gastrointestinal tract stress

    Directory of Open Access Journals (Sweden)

    Russo Pasquale

    2012-10-01

    Full Text Available Abstract Background Ingestion of fermented foods containing high levels of biogenic amines (BA can be deleterious to human health. Less obvious is the threat posed by BA producing organisms contained within the food which, in principle, could form BA after ingestion even if the food product itself does not initially contain high BA levels. In this work we have investigated the production of tyramine and putrescine by Lactobacillus brevis IOEB 9809, of wine origin, under simulated gastrointestinal tract (GIT conditions. Results An in vitro model that simulates the normal physiological conditions in the human digestive tract, as well as Caco-2 epithelial human cell lines, was used to challenge L. brevis IOEB 9809, which produced both tyramine and putrescine under all conditions tested. In the presence of BA precursors and under mild gastric stress, a correlation between enhancement of bacterial survival and a synchronous transcriptional activation of the tyramine and putrescine biosynthetic pathways was detected. High levels of both BA were observed after exposure of the bacterium to Caco-2 cells. Conclusions L. brevis IOEB 9809 can produce tyramine and putrescine under simulated human digestive tract conditions. The results indicate that BA production may be a mechanism that increases bacterial survival under gastric stress.

  14. Enhancement of anaerobic biohydrogen/methane production from cellulose using heat-treated activated sludge.

    Science.gov (United States)

    Lay, C H; Chang, F Y; Chu, C Y; Chen, C C; Chi, Y C; Hsieh, T T; Huang, H H; Lin, C Y

    2011-01-01

    Anaerobic digestion is an effective technology to convert cellulosic wastes to methane and hydrogen. Heat-treatment is a well known method to inhibit hydrogen-consuming bacteria in using anaerobic mixed cultures for seeding. This study aims to investigate the effects of heat-treatment temperature and time on activated sludge for fermentative hydrogen production from alpha-cellulose by response surface methodology. Hydrogen and methane production was evaluated based on the production rate and yield (the ability of converting cellulose into hydrogen and methane) with heat-treated sludge as the seed at various temperatures (60-97 degrees C) and times (20-60 min). Batch experiments were conducted at 55 degrees C and initial pH of 8.0. The results indicate that hydrogen and methane production yields peaked at 4.3 mmol H2/g cellulose and 11.6 mmol CH4/g cellulose using the seed activated sludge that was thermally treated at 60 degrees C for 40 min. These parameter values are higher than those of no-treatment seed (HY 3.6 mmol H2/g cellulose and MY 10.4 mmol CH4/g cellulose). The maximum hydrogen production rate of 26.0 mmol H2/L/d and methane production rate of 23.2 mmol CH4/L/d were obtained for the seed activated sludge that was thermally treated at 70 degrees C for 50 min and 60 degrees C for 40 min, respectively.

  15. Analysis of methane potentials of steam-exploded wheat straw and estimation of energy yields of combined ethanol and methane production.

    Science.gov (United States)

    Bauer, Alexander; Bösch, Peter; Friedl, Anton; Amon, Thomas

    2009-06-01

    Agrarian biomass as a renewable energy source can contribute to a considerable CO(2) reduction. The overriding goal of the European Union is to cut energy consumption related greenhouse gas emission in the EU by 20% until the year 2020. This publication aims at optimising the methane production from steam-exploded wheat straw and presents a theoretical estimation of the ethanol and methane potential of straw. For this purpose, wheat straw was pretreated by steam explosion using different time/temperature combinations. Specific methane yields were analyzed according to VDI 4630. Pretreatment of wheat straw by steam explosion significantly increased the methane yield from anaerobic digestion by up to 20% or a maximum of 331 l(N)kg(-1) VS compared to untreated wheat straw. Furthermore, the residual anaerobic digestion potential of methane after ethanol fermentation was determined by enzymatic hydrolysis of pretreated wheat straw using cellulase. Based on the resulting glucose concentration the ethanol yield and the residual sugar available for methane production were calculated. The theoretical maximum ethanol yield of wheat straw was estimated to be 0.249 kg kg(-1) dry matter. The achievable maximum ethanol yield per kg wheat straw dry matter pretreated by steam explosion and enzymatic hydrolysis was estimated to be 0.200 kg under pretreatment conditions of 200 degrees C and 10 min corresponding to 80% of the theoretical maximum. The residual methane yield from straw stillage was estimated to be 183 l(N)kg(-1) wheat straw dry matter. Based on the presented experimental data, a concept is proposed that processes wheat straw for ethanol and methane production. The concept of an energy supply system that provides more than two forms of energy is met by (1) upgrading obtained ethanol to fuel-grade quality and providing methane to CHP plants for the production of (2) electric energy and (3) utility steam that in turn can be used to operate distillation columns in the

  16. Attributing Atmospheric Methane to Anthropogenic Emission Sources.

    Science.gov (United States)

    Allen, David

    2016-07-19

    Methane is a greenhouse gas, and increases in atmospheric methane concentration over the past 250 years have driven increased radiative forcing of the atmosphere. Increases in atmospheric methane concentration since 1750 account for approximately 17% of increases in radiative forcing of the atmosphere, and that percentage increases by approximately a factor of 2 if the effects of the greenhouse gases produced by the atmospheric reactions of methane are included in the assessment. Because of the role of methane emissions in radiative forcing of the atmosphere, the identification and quantification of sources of methane emissions is receiving increased scientific attention. Methane emission sources include biogenic, geogenic, and anthropogenic sources; the largest anthropogenic sources are natural gas and petroleum systems, enteric fermentation (livestock), landfills, coal mining, and manure management. While these source categories are well-known, there is significant uncertainty in the relative magnitudes of methane emissions from the various source categories. Further, the overall magnitude of methane emissions from all anthropogenic sources is actively debated, with estimates based on source sampling extrapolated to regional or national scale ("bottom-up analyses") differing from estimates that infer emissions based on ambient data ("top-down analyses") by 50% or more. To address the important problem of attribution of methane to specific sources, a variety of new analytical methods are being employed, including high time resolution and highly sensitive measurements of methane, methane isotopes, and other chemical species frequently associated with methane emissions, such as ethane. This Account describes the use of some of these emerging measurements, in both top-down and bottom-up methane emission studies. In addition, this Account describes how data from these new analytical methods can be used in conjunction with chemical mass balance (CMB) methods for source

  17. Redox controls on methane formation, migration and fate in shallow aquifers

    Science.gov (United States)

    Humez, Pauline; Mayer, Bernhard; Nightingale, Michael; Becker, Veith; Kingston, Andrew; Taylor, Stephen; Bayegnak, Guy; Millot, Romain; Kloppmann, Wolfram

    2016-07-01

    Development of unconventional energy resources such as shale gas and coalbed methane has generated some public concern with regard to the protection of groundwater and surface water resources from leakage of stray gas from the deep subsurface. In terms of environmental impact to and risk assessment of shallow groundwater resources, the ultimate challenge is to distinguish (a) natural in situ production of biogenic methane, (b) biogenic or thermogenic methane migration into shallow aquifers due to natural causes, and (c) thermogenic methane migration from deep sources due to human activities associated with the exploitation of conventional or unconventional oil and gas resources. This study combines aqueous and gas (dissolved and free) geochemical and isotope data from 372 groundwater samples obtained from 186 monitoring wells of the provincial Groundwater Observation Well Network (GOWN) in Alberta (Canada), a province with a long record of conventional and unconventional hydrocarbon exploration. We investigated whether methane occurring in shallow groundwater formed in situ, or whether it migrated into the shallow aquifers from elsewhere in the stratigraphic column. It was found that methane is ubiquitous in groundwater in Alberta and is predominantly of biogenic origin. The highest concentrations of biogenic methane (> 0.01 mM or > 0.2 mgL-1), characterized by δ13CCH4 values migration from deeper methanogenic aquifers. Of the samples, 14.1 % contained methane with δ13CCH4 values > -54 ‰, potentially suggesting a thermogenic origin, but aqueous and isotope geochemistry data revealed that the elevated δ13CCH4 values were caused by microbial oxidation of biogenic methane or post-sampling degradation of low CH4 content samples rather than migration of deep thermogenic gas. A significant number of samples (39.2 %) contained methane with predominantly biogenic C isotope ratios (δ13CCH4 migration into shallow aquifers either naturally or via anthropogenically

  18. Microbial and chemical factors influencing methane production in laboratory incubations of low-rank subsurface coals

    Science.gov (United States)

    Harris, Stephen H.; Smith, Richard L.; Barker, Charles E.

    2008-01-01

    Lignite and subbituminous coals were investigated for their ability to support microbial methane production in laboratory incubations. Results show that naturally-occurring microorganisms associated with the coals produced substantial quantities of methane, although the factors influencing this process were variable among different samples tested. Methanogenic microbes in two coals from the Powder River Basin, Wyoming, USA, produced 140.5-374.6 mL CH4/kg ((4.5-12.0 standard cubic feet (scf)/ton) in response to an amendment of H2/CO2. The addition of high concentrations (5-10 mM) of acetate did not support substantive methane production under the laboratory conditions. However, acetate accumulated in control incubations where methanogenesis was inhibited, indicating that acetate was produced and consumed during the course of methane production. Acetogenesis from H2/CO2 was evident in these incubations and may serve as a competing metabolic mode influencing the cumulative amount of methane produced in coal. Two low-rank (lignite A) coals from Fort Yukon, Alaska, USA, demonstrated a comparable level of methane production (131.1-284.0 mL CH4/kg (4.2-9.1 scf/ton)) in the presence of an inorganic nutrient amendment, indicating that the source of energy and organic carbon was derived from the coal. The concentration of chloroform-extractable organic matter varied by almost three orders of magnitude among all the coals tested, and appeared to be related to methane production potential. These results indicate that substrate availability within the coal matrix and competition between different groups of microorganisms are two factors that may exert a profound influence on methanogenesis in subsurface coal beds.

  19. Methane production potential (B0) of swine and cattle manures--a Canadian perspective.

    Science.gov (United States)

    Godbout, S; Verma, M; Larouche, J P; Potvin, L; Chapman, A M; Lemay, S P; Pelletier, F; Brar, S K

    2010-11-01

    Canada's agricultural emissions accounted for 60 Mt or 8% of national greenhouse gas (GHG) emissions in 2007. The estimation of CH4 emission factor (B0) from manure management systems in Canada is prone to uncertainty owing to lack of B0 values for Canadian conditions. Therefore, in this study, manure samples from six Canadian animal farms, two each of swine, beef and dairy cattle, were investigated in order to estimate their methane production potential (B0). The ultimate anaerobic biodegradability was measured with ISO standard batch fermentation. The extent of biodegradation of the manure samples with or without sodium benzoate was always greater than 60% and hence showed no inhibitory effect on methane production by the manure. The impact of use of antibiotics in the animal feed on methane production was also considered; however, no inhibitory effect on methane production could be observed. The plateau of methane production in all cases was achieved by 63 d of anaerobic digestion process and the final pH was within 6-8. The calculated B0 were in the range of 0.47-0.42, 0.21-0.19 and 0.35-0.30 for swine, beef cattle and dairy cattle, respectively. The uncertainties associated with B0 values were +/- 9% for swine, +/- 3% for beef cattle and, +/- 6 and +/- 2% for dairy cows.

  20. Thermophilic anaerobic fermentation of olive pulp for hydrogen and methane production: modelling of the anaerobic digestion process

    DEFF Research Database (Denmark)

    Gavala, Hariklia N.; Skiadas, Ioannis V.; Ahring, Birgitte Kiær;

    2006-01-01

    The present study investigates the thermophilic biohydrogen and methane production from olive pulp, which is the semi-solid. residue coming from the two-phase processing of olives. It focussed on: a) production of methane from the raw olive pulp; b) anaerobic bio-production of hydrogen from...... were performed. The hydrogen potential of the olive pulp amounted to 1.6 mmole H-2 per g TS. The methane potential of the raw olive pulp and hydrogen-effluent was as high as 19 mmole CH4 per g TS suggesting that: a) olive pulp is a suitable substrate for methane production; and b) biohydrogen...

  1. Evaluation of Dried Sweet Sorghum Stalks as Raw Material for Methane Production

    Science.gov (United States)

    Matsakas, Leonidas; Rova, Ulrika; Christakopoulos, Paul

    2014-01-01

    The potential of utilizing dried sweet sorghum stalks as raw material for anaerobic digestion has been evaluated. Two different treatments were tested, a mild thermal and an enzymatic, alone or in combination. Thermal pretreatment was found to decrease the methane yields, whereas one-step enzymatic treatment resulted in a significant increase of 15.1% comparing to the untreated sweet sorghum. Subsequently, in order to increase the total methane production, the combined effect of enzyme load and I/S on methane yields from sweet sorghum was evaluated by employing response surface methodology. The obtained model showed that the maximum methane yield that could be achieved is 296 mL CH4/g VS at I/S ratio of 0.35 with the addition of 11.12 FPU/g sweet sorghum. PMID:25210715

  2. Methane Production and Kinetic Modeling for Co-digestion of Manure with Lignocellulosic Residues

    DEFF Research Database (Denmark)

    Awais, Muhammad; Alvarado-Morales, Merlin; Tsapekos, Panagiotis;

    2016-01-01

    of 50% WS on an organic matter basis in the feedstock and substitution of the rest of the volatile solids (VS) component share between CM and MG (25:75, 50:50, and 75:25), the methane yield can be increased by 20-24% compared to WS mono-digestion, with a methane production rate of 27, 23, and 22 N m......L of CH4 g-1 of VS day-1, respectively. Moreover, the positive effects of coupled biological reactions in the reaction mixture of co-digestion were explained using the synergistic effect value (η). The η value was calculated using estimated and experimental methane yields. Furthermore, in MG co......-digestion results with the highest methane yield (up to 25%) and lowest lag phase (6-7 days) were achieved when 75% organic matter originated from CM. The combination presenting the above-mentioned increase in the methane yield also showed a methane production rate of 22 N mL of CH4 g-1 of VS day-1...

  3. Hydrothermal carbonisation of sewage sludge: effect of process conditions on product characteristics and methane production.

    Science.gov (United States)

    Danso-Boateng, E; Shama, G; Wheatley, A D; Martin, S J; Holdich, R G

    2015-02-01

    Hydrothermal carbonisation of primary sewage sludge was carried out using a batch reactor. The effect of temperature and reaction time on the characteristics of solid (hydrochar), liquid and gas products, and the conditions leading to optimal hydrochar characteristics were investigated. The amount of carbon retained in hydrochars decreased as temperature and time increased with carbon retentions of 64-77% at 140 and 160°C, and 50-62% at 180 and 200°C. Increasing temperature and treatment time increased the energy content of the hydrochar from 17 to 19 MJ/kg but reduced its energy yield from 88% to 68%. Maillard reaction products were identified in the liquid fractions following carbonisations at 180 and 200°C. Theoretical estimates of the methane yields resulting from the anaerobic digestion of the liquid by-products are also presented and optimal reaction conditions to maximise these identified.

  4. Methane and fertilizer production from seaweed biomass. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Betzer, P.R.; Humm, H.J.

    1984-01-01

    It was demonstrated that several varieties of abundant benthic algae indigenous to Tampa Bay (Gracilaria, Hypnea, and Ulva) were readily degradable via anaerobic digestion to methane. The energy yield per unit weight biomass degraded was higher than any previously reported. Given the large masses of readily degradable plants which are annually produced in and around Tampa Bay, the resource is estimated to be at least equivalent to several million gallons of gasoline.

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

    Directory of Open Access Journals (Sweden)

    Natália da Silva Sunada

    2012-11-01

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

  6. Seasonal Production and Emission of Methane from Rice Fields, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, M. Aslam K.; Rasmussen,Reinhold A.

    2002-12-03

    B 139 - Methane (CH4) is a greenhouse gas regarded second only to carbon dioxide in its ability to cause global warming. Methane is important because of its relatively fast increase, and also because it is, per molecule, some 60 times more effective than carbon dioxide in causing global warming. The largest present anthropogenic sources of methane are rice fields, cattle and biomass burning. The global emissions from these sources are still not well known. In the middle 1980s there were few available data on methane emissions from rice fields leading to estimates of a global source between 100-280 Tg/yr. Extensive worldwide research during the last decade has shown that the global emissions from rice fields are more likely to be in the range of 30-80Tg/yr. While this work has led to a substantial reduction in the estimated emissions, the uncertainty is still quite large, and seriously affects our ability to include methane in integrated assessments for future climate change and environmental management.China dominated estimates of methane emissions from rice fields because it was, and is, the largest producer of rice, and major increases in rice production had taken place in the country over the last several decades. This report summarizes the work in Sichuan Province, China, in each of the following areas: the design of the experiment; the main results on methane emissions from rice fields, delineating the factors controlling emissions; production of methane in the soil; a survey of water management practices in sample of counties in Sichuan province; and results of ambient measurements including data from the background continental site. B139

  7. High-time resolved measurements of biogenic and anthropogenic secondary organic aerosol precursors and products in urban air

    Science.gov (United States)

    Flores, Rosa M.; Doskey, Paul V.

    2016-04-01

    Volatile organic compounds (VOCs), which are present in the atmosphere entirely in the gas phase are directly emitted by biogenic (~1089 Tg yr-1) and anthropogenic sources (~185 Tg yr-1). However, the sources and molecular speciation of intermediate VOCs (IVOCs), which are for the most part also present almost entirely in the gas phase, are not well characterized. The VOCs and IVOCs participate in reactions that form ozone and semivolatile OC (SVOC) that partition into the aerosol phase. Formation and evolution of secondary organic aerosol (SOA) are part of a complex dynamic process that depends on the molecular speciation and concentration of VOCs, IVOCs, primary organic aerosol (POA), and the level of oxidants (NO3, OH, O3). The current lack of understanding of OA properties and their impact on radiative forcing, ecosystems, and human health is partly due to limitations of models to predict SOA production on local, regional, and global scales. More accurate forecasting of SOA production requires high-temporal resolution measurement and molecular characterization of SOA precursors and products. For the subject study, the IVOCs and aerosol-phase organic matter were collected using the high-volume sampling technique and were analyzed by multidimensional gas chromatography with time-of-flight mass spectrometry (GCxGC-ToFMS). The IVOCs included terpenes, terpenoids, n-alkanes, branched alkanes, isoprenoids, alkylbenzenes, cycloalkylbenzenes, PAH, alkyl PAH, and an unresolved complex mixture (UCM). Diurnal variations of OA species containing multiple oxygenated functionalities and selected SOA tracers of isorprene, α-pinene, toluene, cyclohexene, and n-dodecane oxidation were also quantified. The data for SOA precursor and oxidation products presented here will be useful for evaluating the ability of molecular-specific SOA models to forecast SOA production in and downwind of urban areas.

  8. Microbial Methane Production Associated with Carbon Steel Corrosion in a Nigerian Oil Field.

    Science.gov (United States)

    Mand, Jaspreet; Park, Hyung S; Okoro, Chuma; Lomans, Bart P; Smith, Seun; Chiejina, Leo; Voordouw, Gerrit

    2015-01-01

    Microbially influenced corrosion (MIC) in oil field pipeline systems can be attributed to many different types of hydrogenotrophic microorganisms including sulfate reducers, methanogens and acetogens. Samples from a low temperature oil reservoir in Nigeria were analyzed using DNA pyrotag sequencing. The microbial community compositions of these samples revealed an abundance of anaerobic methanogenic archaea. Activity of methanogens was demonstrated by incubating samples anaerobically in a basal salts medium, in the presence of carbon steel and carbon dioxide. Methane formation was measured in all enrichments and correlated with metal weight loss. Methanogens were prominently represented in pipeline solids samples, scraped from the inside of a pipeline, comprising over 85% of all pyrosequencing reads. Methane production was only witnessed when carbon steel beads were added to these pipeline solids samples, indicating that no methane was formed as a result of degradation of the oil organics present in these samples. These results were compared to those obtained for samples taken from a low temperature oil field in Canada, which had been incubated with oil, either in the presence or in the absence of carbon steel. Again, methanogens present in these samples catalyzed methane production only when carbon steel was present. Moreover, acetate production was also found in these enrichments only in the presence of carbon steel. From these studies it appears that carbon steel, not oil organics, was the predominant electron donor for acetate production and methane formation in these low temperature oil fields, indicating that the methanogens and acetogens found may contribute significantly to MIC.

  9. Microbial methane production associated with carbon steel corrosion in a Nigerian oil field

    Directory of Open Access Journals (Sweden)

    Jaspreet eMand

    2016-01-01

    Full Text Available Microbially influenced corrosion (MIC in oil field pipeline systems can be attributed to many different types of hydrogenotrophic microorganisms including sulfate reducers, methanogens and acetogens. Samples from a low temperature oil reservoir in Nigeria were analyzed using DNA pyrotag sequencing. The microbial community compositions of these samples revealed an abundance of anaerobic methanogenic archaea. Activity of methanogens was demonstrated by incubating samples anaerobically in a basal salts medium, in the presence of carbon steel and carbon dioxide. Methane formation was measured in all enrichments and correlated with metal weight loss. Methanogens were prominently represented in pipeline solids samples, scraped from the inside of a pipeline, comprising over 85% of all pyrosequencing reads. Methane production was only witnessed when carbon steel beads were added to these pipeline solids samples, indicating that no methane was formed as a result of degradation of the oil organics present in these samples. These results were compared to those obtained for samples taken from a low temperature oil field in Canada, which had been incubated with oil, either in the presence or in the absence of carbon steel. Again, methanogens present in these samples catalyzed methane production only when carbon steel was present. Moreover, acetate production was also found in these enrichments only in the presence of carbon steel. From these studies it appears that carbon steel, not oil organics, was the predominant electron donor for acetate production and methane formation in these low temperature oil fields, indicating that the methanogens and acetogens found may contribute significantly to MIC.

  10. Production of methane by co-digestion of cassava pulp with various concentrations of pig manure

    DEFF Research Database (Denmark)

    Panichnumsin, Pan; Nopharatana, Annop; Ahring, Birgitte Kiær

    2010-01-01

    Cassava pulp is a major by-product produced in a cassava starch factory, containing 50-60% of starch (dry basis). Therefore, in this study we are considering its potential as a raw material substrate for the production of methane. To ensure sufficient amounts of nutrients for the anaerobic digest...

  11. Natural carbon isotopes used to study methane consumption and production in soil

    DEFF Research Database (Denmark)

    Ambus, Per; Andersen, Bertel Lohmann; Kemner, Marianne;

    2002-01-01

    Changes in the isotopic composition of carbon can be used to reveal simultaneous occurrence of methane production and oxidation in soil. The method is conducted in laboratory jar experiments as well as in the field by using flux chambers. Simultaneous occurrence of production and oxidation...

  12. Improving methane production from digested manure biofibers by mechanical and thermal alkaline pretreatment

    DEFF Research Database (Denmark)

    Tsapekos, Panagiotis; Kougias, Panagiotis; Frison, A.

    2016-01-01

    Animal manure digestion is associated with limited methane production, due to the high content in fibers, which are hardly degradable lignocellulosic compounds. In this study, different mechanical and thermal alkaline pretreatment methods were applied to partially degradable fibers, separated from...... the effluent stream of biogas reactors. Batch and continuous experiments were conducted to evaluate the efficiency of these pretreatments. In batch experiments, the mechanical pretreatment improved the degradability up to 45%. Even higher efficiency was shown by applying thermal alkaline pretreatments......, enhancing fibers degradability by more than 4-fold. In continuous experiments, the thermal alkaline pretreatment, using 6% NaOH at 55 °C was proven to be the most efficient pretreatment method as the methane production was increased by 26%. The findings demonstrated that the methane production of the biogas...

  13. Enhancement of sludge reduction and methane production by removing extracellular polymeric substances from waste activated sludge.

    Science.gov (United States)

    Nguyen, Minh Tuan; Mohd Yasin, Nazlina Haiza; Miyazaki, Toshiki; Maeda, Toshinari

    2014-12-01

    The management of waste activated sludge (WAS) recycling is a concern that affects the development of the future low-carbon society, particularly sludge reduction and biomass utilization. In this study, we investigated the effect of removing extracellular polymeric substances (EPS), which play important roles in the adhesion and flocculation of WAS, on increased sludge disintegration, thereby enhancing sludge reduction and methane production by anaerobic digestion. EPS removal from WAS by ethylenediaminetetraacetic acid (EDTA) significantly enhanced sludge reduction, i.e., 49 ± 5% compared with 27 ± 1% of the control at the end the digestion process. Methane production was also improved in WAS without EPS by 8881 ± 109 CH4 μmol g(-1) dry-weight of sludge. Microbial activity was determined by denaturing gradient gel electrophoresis and real-time polymerase chain reaction, which showed that the hydrolysis and acetogenesis stages were enhanced by pretreatment with 2% EDTA, with a larger methanogenic community and better methane production.

  14. Improving methane production from digested manure biofibers by mechanical and thermal alkaline pretreatment.

    Science.gov (United States)

    Tsapekos, P; Kougias, Panagiotis G; Frison, A; Raga, R; Angelidaki, I

    2016-09-01

    Animal manure digestion is associated with limited methane production, due to the high content in fibers, which are hardly degradable lignocellulosic compounds. In this study, different mechanical and thermal alkaline pretreatment methods were applied to partially degradable fibers, separated from the effluent stream of biogas reactors. Batch and continuous experiments were conducted to evaluate the efficiency of these pretreatments. In batch experiments, the mechanical pretreatment improved the degradability up to 45%. Even higher efficiency was shown by applying thermal alkaline pretreatments, enhancing fibers degradability by more than 4-fold. In continuous experiments, the thermal alkaline pretreatment, using 6% NaOH at 55°C was proven to be the most efficient pretreatment method as the methane production was increased by 26%. The findings demonstrated that the methane production of the biogas plants can be increased by further exploiting the fraction of the digested manure fibers which are discarded in the post-storage tank.

  15. Protease cell wall degradation of Chlorella vulgaris: effect on methane production.

    Science.gov (United States)

    Mahdy, Ahmed; Mendez, Lara; Blanco, Saul; Ballesteros, Mercedes; González-Fernández, Cristina

    2014-11-01

    In order to optimize the enzymatic dosage and microalgae biomass loads subjected to enzymatic hydrolysis prior anaerobic digestion of Chlorella vulgaris, organic matter solubilisation and methane production were investigated. Experimental data using protease dosage of 0.585 AU g DW(-1) showed that increasing biomass loads up to 65 g L(-1) did not affect markedly the hydrolysis efficiency (51%). Enzymatically pretreated biomasses subjected to anaerobic digestion enhanced methane production by 50-70%. The attempt of decreasing the enzymatic dosages revealed diminished hydrolysis efficiency concomitantly with a decreased methane production enhancement. In agreement with the good results observed for organic matter conversion into biogas, total nitrogen mineralization was attained for enzymatically pretreated biomass. Despite the high protein content of the biomass and the biocatalyst used in the present study no ammonia inhibition was detected.

  16. Methane production in an UASB reactor operated under periodic mesophilic-thermophilic conditions.

    Science.gov (United States)

    Bourque, J-S; Guiot, S R; Tartakovsky, B

    2008-08-15

    Methane production was studied in a laboratory-scale 10 L anaerobic upflow sludge bed (UASB) reactor with periodic variations of the reactor temperature. On a daily basis the temperature was varied between 35 and 45 degrees C or 35 and 55 degrees C with a heating period of 6 h. Each temperature increase was accompanied by an increase in methane production and a decrease in the concentration of soluble organic matter in the effluent. In comparison to a reactor operated at 35 degrees C, a net increase in methane production of up to 22% was observed. Batch activity tests demonstrated a tolerance of mesophilic methanogenic populations to short-term, 2-6 h, temperature increases, although activity of acetoclastic methanogens decreased after 6 h exposure to a temperature of 55 degrees C. 16S sequencing of DGGE bands revealed proliferation of temperature-tolerant Methanospirillum hungatii sp. in the reactor.

  17. Pretreatment of food waste with high voltage pulse discharge towards methane production enhancement.

    Science.gov (United States)

    Zou, Lianpei; Ma, Chaonan; Liu, Jianyong; Li, Mingfei; Ye, Min; Qian, Guangren

    2016-12-01

    Anaerobic batch tests were performed to investigate the methane production enhancement and solid transformation rates from food waste (FW) by high voltage pulse discharge (HVPD) pretreatment. The total cumulative methane production with HVPD pretreatment was 134% higher than that of the control. The final volatile solids transformation rates of FW with and without HVPD pretreatment were 54.3% and 32.3%, respectively. Comparison study on HVPD pretreatment with acid, alkali and ultrasonic pretreatments showed that the methane production and COD removal rates of FW pretreated with HVPD were more than 100% higher than the control, but only about 50% higher can be obtained with other pretreatments. HVPD pretreatment could be a promising pretreatment method in the application of energy recovery from FW.

  18. Comparison of Methane Data Products from the TES and AIRS Infrared Sounders

    Science.gov (United States)

    Pagano, T. J.; Pagano, T. S.; Worden, J. R.

    2015-12-01

    Methane is the second most powerful greenhouse gas with a highly positive radiative forcing of 0.48 W/m2 (IPCC 2013). Global concentrations of methane have been steadily increasing since 2007 (Bruhwiler 2014), raising concerns about methane's impact on the future global climate. For about the last decade, the Tropospheric Emission Spectrometer (TES) on the Earth Observing System (EOS) Aura spacecraft has been detecting several trace gas species in the troposphere including methane. The goal of this study is to compare TES methane retrievals to that of the Atmospheric Infrared Sounder (AIRS) on the EOS Aqua spacecraft so that scientific investigations may be transferred from TES to AIRS. The two instruments fly in the afternoon constellation (A-Train), providing numerous coincident measurements for comparison. In addition, they also have a similar spectral range, (3.3 to 15.4 µm) for TES (Beer, 2006) and (3.7 to 15.4 µm) for AIRS (Chahine, 2006), making both instruments sensitive to the mid and upper troposphere. This makes them ideal candidates to compare methane data products. However, because AIRS spectral resolution is lower than that of the TES, there may be a difference in vertical sensitivity. In addition, the retrieval techniques and error characteristics are different for the two data sets. The current state of validation for these data products will be presented. To identify conditions in which the data sets agree and dis agree, we present global maps of methane concentrations from monthly level 3 (L3) data products. We also investigate the temporal stability between the two datasets by comparing global zonal averages derived from L3 over the last decade. Finally, we compare L2 retrieval profiles from representative granules in the tropical, mid-latitude and northern latitudes.

  19. A model for methane production in anaerobic digestion of swine wastewater.

    Science.gov (United States)

    Yang, Hongnan; Deng, Liangwei; Liu, Gangjin; Yang, Di; Liu, Yi; Chen, Ziai

    2016-10-01

    A study was conducted using a laboratory-scale anaerobic sequencing batch digester to investigate the quantitative influence of organic loading rates (OLRs) on the methane production rate during digestion of swine wastewater at temperatures between 15 °C and 35 °C. The volumetric production rate of methane (Rp) at different OLRs and temperatures was obtained. The maximum volumetric methane production rates (Rpmax) were 0.136, 0.796, 1.294, 1.527 and 1.952 LCH4 L(-1) d(-1) at corresponding organic loading rates of 1.2, 3.6, 5.6, 5.6 and 7.2 g volatile solids L(-1) d(-1), respectively, which occurred at 15, 20, 25, 30 and 35 °C, respectively. A new model was developed to describe the quantitative relationship between Rp and OLR. In addition to the maximum volumetric methane production rate (Rpmax) and the half-saturation constant (KLR) commonly used in previous models such as the modified Stover-Kincannon model and Deng model, the new model introduced a new index (KD) that denoted the speed of volumetric methane production rate approaching the maximum as a function of temperature. The new model more satisfactorily described the influence of OLR on the rate of methane production than other models as confirmed by higher determination coefficients (R(2)) (0.9717-0.9900) and lower bias between the experimental and predicted data in terms of the root mean square error and the Akaike Information Criterion. Data from other published research also validated the applicability and generality of the new kinetic model to different types of wastewater.

  20. Hydrogen and methane production from household solid waste in the two-stage fermentation process.

    Science.gov (United States)

    Liu, Dawei; Liu, Dapeng; Zeng, Raymond J; Angelidaki, Irini

    2006-06-01

    A two-stage process combined hydrogen and methane production from household solid waste was demonstrated working successfully. The yield of 43 mL H(2)/g volatile solid (VS) added was generated in the first hydrogen production stage and the methane production in the second stage was 500 mL CH(4)/g VS added. This figure was 21% higher than the methane yield from the one-stage process, which was run as control. Sparging of the hydrogen reactor with methane gas resulted in doubling of the hydrogen production. pH was observed as a key factor affecting fermentation pathway in hydrogen production stage. The optimum pH range for hydrogen production in this system was in the range from 5 to 5.5. The short hydraulic retention time (2 days) applied in the first stage was enough to separate acidogenesis from methanogenesis. No additional control for preventing methanogenesis in the first stage was necessary. Furthermore, this study also provided direct evidence in the dynamic fermentation process that, hydrogen production increase was reflected by acetate to butyrate ratio increase in liquid phase.

  1. Is the production of the biogenic amines tyramine and putrescine a species-level trait in enterococci?

    Science.gov (United States)

    Ladero, Victor; Fernández, María; Calles-Enríquez, Marina; Sánchez-Llana, Esther; Cañedo, Elena; Martín, M Cruz; Alvarez, Miguel A

    2012-05-01

    Biogenic amines (BA) are toxic nitrogenous compounds that can be accumulated in foods via the microbial decarboxylation of certain amino acids. Lactic acid bacteria (LAB) strains belonging to different species and genera have been described as BA producers and are mainly responsible for their synthesis in fermented foods. It is generally accepted that the capacity to produced BAs is strain-dependent. However, the large number of enterococci identified as BA producers suggests that the aminogenic trait may be a species-level characteristic. Enterococcus faecalis, Enterococcus faecium and Enterococcus durans strains of different origin were analysed to determine their capacity to produce tyramine and putrescine. The presence of the genes responsible for this and the identity of their flanking regions were checked by PCR. The results suggest that tyramine biosynthesis is a species-level characteristic in E. faecalis, E. faecium and E. durans. Putrescine synthesis was found to be a species-level trait of E. faecalis, with production occurring via the agmatine deamination pathway. Some E. faecium strains of human origin also produced putrescine; this trait was probably acquired via horizontal gene transfer.

  2. Experimental evaluation of methane dry reforming process on a membrane reactor to hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Fabiano S.A.; Benachour, Mohand; Abreu, Cesar A.M. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. of Chemical Engineering], Email: f.aruda@yahoo.com.br

    2010-07-01

    In a fixed bed membrane reactor evaluations of methane-carbon dioxide reforming over a Ni/{gamma}- Al{sub 2}O{sub 3} catalyst were performed at 773 K, 823 K and 873 K. A to convert natural gas into syngas a fixed-bed reactor associate with a selective membrane was employed, where the operating procedures allowed to shift the chemical equilibrium of the reaction in the direction of the products of the process. Operations under hydrogen permeation, at 873 K, promoted the increase of methane conversion, circa 83%, and doubled the yield of hydrogen production, when compared with operations where no hydrogen permeation occurred. (author)

  3. Enhanced methane productivity from swine manure fibers by aqueous ammonia soaking pretreatment

    DEFF Research Database (Denmark)

    Jurado, Esperanza; Skiadas, Ioannis; Gavala, Hariklia N.

    2011-01-01

    The necessity of increasing the methane productivity of manure based biogas plants has triggered the development of new separation technologies for being applied before anaerobic digestion of the manure. Thus, manure solid and liquid fractions could be used to centralized biogas plants for methane...... production and as fertilizer on the farm, respectively. One of the challenges of this approach is that the solid fraction of manure contains lignocellulosic fibers, which are difficult to digest and thus make anaerobic digestion process slow and economically unfavourable. In the present study, aqueous...

  4. Bovine Host Genetic Variation Influences Rumen Microbial Methane Production with Best Selection Criterion for Low Methane Emitting and Efficiently Feed Converting Hosts Based on Metagenomic Gene Abundance.

    Directory of Open Access Journals (Sweden)

    Rainer Roehe

    2016-02-01

    Full Text Available Methane produced by methanogenic archaea in ruminants contributes significantly to anthropogenic greenhouse gas emissions. The host genetic link controlling microbial methane production is unknown and appropriate genetic selection strategies are not developed. We used sire progeny group differences to estimate the host genetic influence on rumen microbial methane production in a factorial experiment consisting of crossbred breed types and diets. Rumen metagenomic profiling was undertaken to investigate links between microbial genes and methane emissions or feed conversion efficiency. Sire progeny groups differed significantly in their methane emissions measured in respiration chambers. Ranking of the sire progeny groups based on methane emissions or relative archaeal abundance was consistent overall and within diet, suggesting that archaeal abundance in ruminal digesta is under host genetic control and can be used to genetically select animals without measuring methane directly. In the metagenomic analysis of rumen contents, we identified 3970 microbial genes of which 20 and 49 genes were significantly associated with methane emissions and feed conversion efficiency respectively. These explained 81% and 86% of the respective variation and were clustered in distinct functional gene networks. Methanogenesis genes (e.g. mcrA and fmdB were associated with methane emissions, whilst host-microbiome cross talk genes (e.g. TSTA3 and FucI were associated with feed conversion efficiency. These results strengthen the idea that the host animal controls its own microbiota to a significant extent and open up the implementation of effective breeding strategies using rumen microbial gene abundance as a predictor for difficult-to-measure traits on a large number of hosts. Generally, the results provide a proof of principle to use the relative abundance of microbial genes in the gastrointestinal tract of different species to predict their influence on traits e

  5. Bovine Host Genetic Variation Influences Rumen Microbial Methane Production with Best Selection Criterion for Low Methane Emitting and Efficiently Feed Converting Hosts Based on Metagenomic Gene Abundance.

    Science.gov (United States)

    Roehe, Rainer; Dewhurst, Richard J; Duthie, Carol-Anne; Rooke, John A; McKain, Nest; Ross, Dave W; Hyslop, Jimmy J; Waterhouse, Anthony; Freeman, Tom C; Watson, Mick; Wallace, R John

    2016-02-01

    Methane produced by methanogenic archaea in ruminants contributes significantly to anthropogenic greenhouse gas emissions. The host genetic link controlling microbial methane production is unknown and appropriate genetic selection strategies are not developed. We used sire progeny group differences to estimate the host genetic influence on rumen microbial methane production in a factorial experiment consisting of crossbred breed types and diets. Rumen metagenomic profiling was undertaken to investigate links between microbial genes and methane emissions or feed conversion efficiency. Sire progeny groups differed significantly in their methane emissions measured in respiration chambers. Ranking of the sire progeny groups based on methane emissions or relative archaeal abundance was consistent overall and within diet, suggesting that archaeal abundance in ruminal digesta is under host genetic control and can be used to genetically select animals without measuring methane directly. In the metagenomic analysis of rumen contents, we identified 3970 microbial genes of which 20 and 49 genes were significantly associated with methane emissions and feed conversion efficiency respectively. These explained 81% and 86% of the respective variation and were clustered in distinct functional gene networks. Methanogenesis genes (e.g. mcrA and fmdB) were associated with methane emissions, whilst host-microbiome cross talk genes (e.g. TSTA3 and FucI) were associated with feed conversion efficiency. These results strengthen the idea that the host animal controls its own microbiota to a significant extent and open up the implementation of effective breeding strategies using rumen microbial gene abundance as a predictor for difficult-to-measure traits on a large number of hosts. Generally, the results provide a proof of principle to use the relative abundance of microbial genes in the gastrointestinal tract of different species to predict their influence on traits e.g. human metabolism

  6. Estimating daily methane production in individual cattle with irregular feed intake patterns from short-term methane emission measurements.

    Science.gov (United States)

    Cottle, D J; Velazco, J; Hegarty, R S; Mayer, D G

    2015-12-01

    Spot measurements of methane emission rate (n = 18 700) by 24 Angus steers fed mixed rations from GrowSafe feeders were made over 3- to 6-min periods by a GreenFeed emission monitoring (GEM) unit. The data were analysed to estimate daily methane production (DMP; g/day) and derived methane yield (MY; g/kg dry matter intake (DMI)). A one-compartment dose model of spot emission rate v. time since the preceding meal was compared with the models of Wood (1967) and Dijkstra et al. (1997) and the average of spot measures. Fitted values for DMP were calculated from the area under the curves. Two methods of relating methane and feed intakes were then studied: the classical calculation of MY as DMP/DMI (kg/day); and a novel method of estimating DMP from time and size of preceding meals using either the data for only the two meals preceding a spot measurement, or all meals for 3 days prior. Two approaches were also used to estimate DMP from spot measurements: fitting of splines on a 'per-animal per-day' basis and an alternate approach of modelling DMP after each feed event by least squares (using Solver), summing (for each animal) the contributions from each feed event by best-fitting a one-compartment model. Time since the preceding meal was of limited value in estimating DMP. Even when the meal sizes and time intervals between a spot measurement and all feeding events in the previous 72 h were assessed, only 16.9% of the variance in spot emission rate measured by GEM was explained by this feeding information. While using the preceding meal alone gave a biased (underestimate) of DMP, allowing for a longer feed history removed this bias. A power analysis taking into account the sources of variation in DMP indicated that to obtain an estimate of DMP with a 95% confidence interval within 5% of the observed 64 days mean of spot measures would require 40 animals measured over 45 days (two spot measurements per day) or 30 animals measured over 55 days. These numbers suggest that

  7. Production of Excess CO2 relative to methane in peatlands: a new H2 sink

    Science.gov (United States)

    Wilson, R.; Woodcroft, B. J.; Varner, R. K.; Tyson, G. W.; Tfaily, M. M.; Sebestyen, S.; Saleska, S. R.; Rogers, K.; Rich, V. I.; McFarlane, K. J.; Kostka, J. E.; Kolka, R. K.; Keller, J.; Iversen, C. M.; Hodgkins, S. B.; Hanson, P. J.; Guilderson, T. P.; Griffiths, N.; de La Cruz, F.; Crill, P. M.; Chanton, J.; Bridgham, S. D.; Barlaz, M.

    2015-12-01

    Methane is generated as the end product of anaerobic organic matter degradation following a series of reaction pathways including fermentation and syntrophy. Along with acetate and CO2, syntrophic reactions generate H2 and are only thermodynamically feasible when coupled to an exothermic reaction that consumes H2. The usual model of organic matter degradation in peatlands has assumed that methanogenesis is that exothermic H2-consuming reaction. If correct, this paradigm should ultimately result in equimolar production of CO2 and methane from the degradation of the model organic compound cellulose: i.e. C6H12O6 à 3CO2 + 3CH4. However, dissolved gas measurement and modeling results from field and incubation experiments spanning peatlands across the northern hemisphere have failed to demonstrate equimolar production of CO2 and methane. Instead, in a flagrant violation of thermodynamics, these studies show a large bias favoring CO2 production over methane generation. In this talk, we will use an array of complementary analytical techniques including FT-IR, cellulose and lignin measurements, 13C-NMR, fluorescence spectroscopy, and ultra-high resolution mass spectrometry to describe organic matter degradation within a peat column and identify the important degradation mechanisms. Hydrogenation was the most common transformation observed in the ultra-high resolution mass spectrometry data. From these results we propose a new mechanism for consuming H2 generated during CO2 production, without concomitant methane formation, consistent with observed high CO2/CH4 ratios. While homoacetogenesis is a known sink for H2 in these systems, this process also consumes CO2 and therefore does not explain the excess CO2 measured in field and incubation samples. Not only does the newly proposed mechanism consume H2 without generating methane, but it also yields enough energy to balance the coupled syntrophic reactions, thereby restoring thermodynamic order. Schematic of organic matter

  8. Effect of the chlortetracycline addition method on methane production from the anaerobic digestion of swine wastewater.

    Science.gov (United States)

    Huang, Lu; Wen, Xin; Wang, Yan; Zou, Yongde; Ma, Baohua; Liao, Xindi; Liang, Juanboo; Wu, Yinbao

    2014-10-01

    Effects of antibiotic residues on methane production in anaerobic digestion are commonly studied using the following two antibiotic addition methods: (1) adding manure from animals that consume a diet containing antibiotics, and (2) adding antibiotic-free animal manure spiked with antibiotics. This study used chlortetracycline (CTC) as a model antibiotic to examine the effects of the antibiotic addition method on methane production in anaerobic digestion under two different swine wastewater concentrations (0.55 and 0.22mg CTC/g dry manure). The results showed that CTC degradation rate in which manure was directly added at 0.55mg CTC/g (HSPIKE treatment) was lower than the control values and the rest of the treatment groups. Methane production from the HSPIKE treatment was reduced (pmethane production under different antibiotic addition methods might be explained by the microbial activity and the concentrations of antibiotic intermediate products and metabolites. Because the primary entry route of veterinary antibiotics into an anaerobic digester is by contaminated animal manure, the most appropriate method for studying antibiotic residue effects on methane production may be using manure from animals that are given a particular antibiotic, rather than adding the antibiotic directly to the anaerobic digester.

  9. Effects of lactone, ketone, and phenolic compounds on methane production and metabolic intermediates during anaerobic digestion.

    Science.gov (United States)

    Wikandari, Rachma; Sari, Noor Kartika; A'yun, Qurrotul; Millati, Ria; Cahyanto, Muhammad Nur; Niklasson, Claes; Taherzadeh, Mohammad J

    2015-02-01

    Fruit waste is a potential feedstock for biogas production. However, the presence of fruit flavors that have antimicrobial activity is a challenge for biogas production. Lactones, ketones, and phenolic compounds are among the several groups of fruit flavors that are present in many fruits. This work aimed to investigate the effects of two lactones, i.e., γ-hexalactone and γ-decalactone; two ketones, i.e., furaneol and mesifurane; and two phenolic compounds, i.e., quercetin and epicatechin on anaerobic digestion with a focus on methane production, biogas composition, and metabolic intermediates. Anaerobic digestion was performed in a batch glass digester incubated at 55 °C for 30 days. The flavor compounds were added at concentrations of 0.05, 0.5, and 5 g/L. The results show that the addition of γ-decalactone, quercetin, and epicathechin in the range of 0.5-5 g/L reduced the methane production by 50 % (MIC50). Methane content was reduced by 90 % with the addition of 5 g/L of γ-decalactone, quercetin, and epicathechin. Accumulation of acetic acid, together with an increase in carbon dioxide production, was observed. On the contrary, γ-hexalactone, furaneol, and mesifurane increased the methane production by 83-132 % at a concentration of 5 g/L.

  10. Fungal degradation of coal as a pretreatment for methane production

    Science.gov (United States)

    Haider, Rizwan; Ghauri, Muhammad A.; SanFilipo, John R.; Jones, Elizabeth J.; Orem, William H.; Tatu, Calin A.; Akhtar, Kalsoom; Akhtar, Nasrin

    2013-01-01

    Coal conversion technologies can help in taking advantage of huge low rank coal reserves by converting those into alternative fuels like methane. In this regard, fungal degradation of coal can serve as a pretreatment step in order to make coal a suitable substrate for biological beneficiation. A fungal isolate MW1, identified as Penicillium chrysogenum on the basis of fungal ITS sequences, was isolated from a core sample of coal, taken from a well drilled by the US. Geological Survey in Montana, USA. The low rank coal samples, from major coal fields of Pakistan, were treated with MW1 for 7 days in the presence of 0.1% ammonium sulfate as nitrogen source and 0.1% glucose as a supplemental carbon source. Liquid extracts were analyzed through Excitation–Emission Matrix Spectroscopy (EEMS) to obtain qualitative estimates of solubilized coal; these analyses indicated the release of complex organic functionalities. In addition, GC–MS analysis of these extracts confirmed the presence of single ring aromatics, polyaromatic hydrocarbons (PAHs), aromatic nitrogen compounds and aliphatics. Subsequently, the released organics were subjected to a bioassay for the generation of methane which conferred the potential application of fungal degradation as pretreatment. Additionally, fungal-mediated degradation was also prospected for extracting some other chemical entities like humic acids from brown coals with high huminite content especially from Thar, the largest lignite reserve of Pakistan.

  11. Methane production from hydrothermal transformation of siderite to magnetite

    Science.gov (United States)

    Muratbayev, T.; Schroeder, C.; Kappler, A.; Haderlein, S.

    2012-12-01

    Mumma et al. (2009) observed a methane (CH4) plume above the Nili Fossae region on Mars, a region rich in carbonate minerals. Morris et al. (2010) suggest this to be (Mg,Fe)-carbonate. McCollom (2003) demonstrated that the hydrothermal transformation of siderite (FeCO3), to magnetite (Fe3O4) produces CH4. This reaction may thus contribute to the formation of methane on Mars, but is also relevant in the context of such diverse topics as diagenesis of Precambrian banded iron formations, sources of prebiotic organic compounds on early Earth, oil and gas accumulations in Earth's crust, or geological sequestration and storage of CO2. However, neither the thermodynamics of this reaction nor the conditions of maximum CH4 yield have been investigated to date. In order to estimate how pressure and temperature influence CH4 yield we derived a thermodynamic model with a numerical solution implemented in MATLAB. We used the equation 12FeCO3 + 2H2O → 4Fe3O4 + 11CO2 + CH4 (Frost et al. 2007) and thermodynamic calculations of the stability field of FeCO3 by Thoms-Keprta et al. (2009) as a template. At 1 bar pressure, the Gibbs energy turns negative (favorable reaction conditions) at a temperature of 200°C. Increasing pressure to 1000 bar changes that temperature to 250°C. An increase in temperature has a larger effect on shifting the Gibbs energy to more negative values. We therefore chose ambient pressure and temperatures of 300°C, 400°C, and 500°C as experimental conditions. We added 100 mg of either natural or synthetic FeCO3 and 25 μL of MilliQ water into long tip Pasteur pipettes inside an anoxic glove box to avoid contamination by free oxygen. The Pasteur pipettes were sealed with butyl stoppers and then melted shut outside of the glove box. The glass capsules were heated for 48 hours in a muffle furnace at 300°C, 400 0C or 5000C. The composition of the gas phase and the formation of methane in particular were analyzed using gas chromatography with a flame

  12. Methane production potentials, pathways, and communities of methanogens in vertical sediment profiles of river Sitka.

    Science.gov (United States)

    Mach, Václav; Blaser, Martin B; Claus, Peter; Chaudhary, Prem P; Rulík, Martin

    2015-01-01

    Biological methanogenesis is linked to permanent water logged systems, e.g., rice field soils or lake sediments. In these systems the methanogenic community as well as the pathway of methane formation are well-described. By contrast, the methanogenic potential of river sediments is so far not well-investigated. Therefore, we analyzed (a) the methanogenic potential (incubation experiments), (b) the pathway of methane production (stable carbon isotopes and inhibitor studies), and (c) the methanogenic community composition (terminal restriction length polymorphism of mcrA) in depth profiles of sediment cores of River Sitka, Czech Republic. We found two depth-related distinct maxima for the methanogenic potentials (a) The pathway of methane production was dominated by hydrogenotrophic methanogenesis (b) The methanogenic community composition was similar in all depth layers (c) The main TRFs were representative for Methanosarcina, Methanosaeta, Methanobacterium, and Methanomicrobium species. The isotopic signals of acetate indicated a relative high contribution of chemolithotrophic acetogenesis to the acetate pool.

  13. Microalgae to biofuels: life cycle impacts of methane production of anaerobically digested lipid extracted algae.

    Science.gov (United States)

    Quinn, Jason C; Hanif, Asma; Sharvelle, Sybil; Bradley, Thomas H

    2014-11-01

    This study presents experimental measurements of the biochemical methane production for whole and lipid extracted Nannochloropsis salina. Results show whole microalgae produced 430 cm(3)-CH4 g-volatile solids(-1) (g-VS) (σ=60), 3 times more methane than was produced by the LEA, 140 cm(3)-CH4 g-VS(-1) (σ=30). Results illustrate current anaerobic modeling efforts in microalgae to biofuel assessments are not reflecting the impact of lipid removal. On a systems level, the overestimation of methane production is shown to positively skew the environmental impact of the microalgae to biofuels process. Discussion focuses on a comparison results to those of previous anaerobic digestion studies and quantifies the corresponding change in greenhouse gas emissions of the microalgae to biofuels process based on results from this study.

  14. ADM1-based modeling of methane production from acidified sweet sorghum extractin a two stage process

    DEFF Research Database (Denmark)

    Antonopoulou, Georgia; Gavala, Hariklia N.; Skiadas, Ioannis

    2012-01-01

    The present study focused on the application of the Anaerobic Digestion Model 1 οn the methane production from acidified sorghum extract generated from a hydrogen producing bioreactor in a two-stage anaerobic process. The kinetic parameters for hydrogen and volatile fatty acids consumption were...... estimated through fitting of the model equations to the data obtained from batch experiments. The simulation of the continuous reactor performance at all HRTs tested (20, 15 and 10d) was very satisfactory. Specifically, the largest deviation of the theoretical predictions against the experimental data...... was 12% for the methane production rate at the HRT of 20d while the deviation values for the 15 and 10 d HRT were 1.9% and 1.1%, respectively. The model predictions regarding pH, methane percentage in the gas phase and COD removal were in very good agreement with the experimental data with a deviation...

  15. Hydrogen and methane production from condensed molasses fermentation soluble by a two-stage anaerobic process

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chiu-Yue; Liang, You-Chyuan; Lay, Chyi-How [Feng Chia Univ., Taichung, Taiwan (China). Dept. of Environmental Engineering and Science; Chen, Chin-Chao [Chungchou Institute of Technology, Taiwan (China). Environmental Resources Lab.; Chang, Feng-Yuan [Feng Chia Univ., Taichung, Taiwan (China). Research Center for Energy and Resources

    2010-07-01

    The treatment of condensed molasses fermentation soluble (CMS) is a troublesome problem for glutamate manufacturing factory. However, CMS contains high carbohydrate and nutrient contents and is an attractive and commercially potential feedstock for bioenergy production. The aim of this paper is to produce hydrogen and methane by two-stage anaerobic fermentation process. The fermentative hydrogen production from CMS was conducted in a continuously-stirred tank bioreactor (working volume 4 L) which was operated at a hydraulic retention time (HRT) of 8 h, organic loading rate (OLR) of 120 kg COD/m{sup 3}-d, temperature of 35 C, pH 5.5 and sewage sludge as seed. The anaerobic methane production was conducted in an up-flow bioreactor (working volume 11 L) which was operated at a HRT of 24 -60 hrs, OLR of 4.0-10 kg COD/m{sup 3}-d, temperature of 35 C, pH 7.0 with using anaerobic granule sludge from fructose manufacturing factory as the seed and the effluent from hydrogen production process as the substrate. These two reactors have been operated successfully for more than 400 days. The steady-state hydrogen content, hydrogen production rate and hydrogen production yield in the hydrogen fermentation system were 37%, 169 mmol-H{sub 2}/L-d and 93 mmol-H{sub 2}/g carbohydrate{sub removed}, respectively. In the methane fermentation system, the peak methane content and methane production rate were 66.5 and 86.8 mmol-CH{sub 4}/L-d with methane production yield of 189.3 mmol-CH{sub 4}/g COD{sub removed} at an OLR 10 kg/m{sup 3}-d. The energy production rate was used to elucidate the energy efficiency for this two-stage process. The total energy production rate of 133.3 kJ/L/d was obtained with 5.5 kJ/L/d from hydrogen fermentation and 127.8 kJ/L/d from methane fermentation. (orig.)

  16. Assessment of metabolic properties and kinetic parameters of methanogenic sludge by on-line methane production rate measurements

    NARCIS (Netherlands)

    Gonzalez-Gil, G.; Kleerebezem, R.; Lettinga, G.

    2002-01-01

    This report presents a new approach to studying the metabolic and kinetic properties of anaerobic sludge from single batch experiments. The two main features of the method are that the methane production is measured on-line with a relatively cheap system, and that the methane production data can be

  17. Isotopic evidence for biogenic molecular hydrogen production in the Atlantic Ocean

    NARCIS (Netherlands)

    Walter, S.; Kock, A.; Steinhoff, T.; Fiedler, B.; Fietzek, P.; Kaiser, J.; Krol, M.; Popa, M. E.; Chen, Q.; Tanhua, T.; Röckmann, T.

    2016-01-01

    Oceans are a net source of molecular hydrogen (H2) to the atmosphere. The production of marine H2 is assumed to be mainly biological by N2 fixation, but photochemical pathways are also discussed. We present measurements of mole fraction and isotopic composition of dissolved and atmospheric H2 from t

  18. Effects of Plant Secondary Metabolites on Methane Production and Fermentation Parameters in In vitro Ruminal Cultures

    Directory of Open Access Journals (Sweden)

    Mihaela Giuburunca

    2014-11-01

    Full Text Available Enteric fermentation process is of concern worldwide for its contribution to global warming. It is known that ruminant animals, due to natural fermentation process contribute substantially to the increase in methane production. Methanogenesis process represents besides its contribution to greenhouse gases emissions an energy loss to the animal. To reduce ruminal methane productions in an ecologically and sustainable way, many attempts have been initiated, such as: uses of chemicals additives or ionophore antibiotics, defaunation process or immunization against ruminal methanogenesis. In the last years, a new strategy has been evaluated whether plant secondary metabolites can be used as natural additives to reduce ruminal methane emissions. The present study has been conducted to investigate the effects of trans-cinnamic, caffeic, p-coumaric acids and catechin hydrate, four plant secondary metabolites (PSMs on methane production and fermentation in in vitro ruminal cultures. The four PSMs were added anaerobically in a 6 mM concentration to 100 ml serum bottles containing 500 mg grass hay as a substrate, 10 ml rumen fluid collected from a fistulated sheep before morning feeding and 40 ml 141 DSM culture medium. The bottles were incubated at 39 ̊C. After 24 h, the following variables were measured: total gas volume, pH, methane and volatile fatty acids (VFAs production. The results showed that caffeic (p = 0.058 and p-coumaric (p = 0.052 acids tended to decrease methane production in comparison to control but the decrease was not statistic significantly at α= 0.05. The other two PSMs had no significant effect on methane production. Addition of PSMs did not affected the total gas volume, the pH and VFAs profile (P>0.05 in relation to the control (no PSM added. In conclusion, caffeic and p-coumaric acids in 6 mM concentration showed some promising effects for decreasing ruminal methane emissions without affecting ruminal fermentation parameters but

  19. Methane production by treating vinasses from hydrous ethanol using a modified UASB reactor

    Directory of Open Access Journals (Sweden)

    España-Gamboa Elda I

    2012-11-01

    Full Text Available Abstract Background A modified laboratory-scale upflow anaerobic sludge blanket (UASB reactor was used to obtain methane by treating hydrous ethanol vinasse. Vinasses or stillage are waste materials with high organic loads, and a complex composition resulting from the process of alcohol distillation. They must initially be treated with anaerobic processes due to their high organic loads. Vinasses can be considered multipurpose waste for energy recovery and once treated they can be used in agriculture without the risk of polluting soil, underground water or crops. In this sense, treatment of vinasse combines the elimination of organic waste with the formation of methane. Biogas is considered as a promising renewable energy source. The aim of this study was to determine the optimum organic loading rate for operating a modified UASB reactor to treat vinasse generated in the production of hydrous ethanol from sugar cane molasses. Results The study showed that chemical oxygen demand (COD removal efficiency was 69% at an optimum organic loading rate (OLR of 17.05 kg COD/m3-day, achieving a methane yield of 0.263 m3/kg CODadded and a biogas methane content of 84%. During this stage, effluent characterization presented lower values than the vinasse, except for potassium, sulfide and ammonia nitrogen. On the other hand, primers used to amplify the 16S-rDNA genes for the domains Archaea and Bacteria showed the presence of microorganisms which favor methane production at the optimum organic loading rate. Conclusions The modified UASB reactor proposed in this study provided a successful treatment of the vinasse obtained from hydrous ethanol production. Methanogen groups (Methanobacteriales and Methanosarcinales detected by PCR during operational optimum OLR of the modified UASB reactor, favored methane production.

  20. Optimization of process parameters for production of volatile fatty acid, biohydrogen and methane from anaerobic digestion.

    Science.gov (United States)

    Khan, M A; Ngo, H H; Guo, W S; Liu, Y; Nghiem, L D; Hai, F I; Deng, L J; Wang, J; Wu, Y

    2016-11-01

    The anaerobic digestion process has been primarily utilized for methane containing biogas production over the past few years. However, the digestion process could also be optimized for producing volatile fatty acids (VFAs) and biohydrogen. This is the first review article that combines the optimization approaches for all three possible products from the anaerobic digestion. In this review study, the types and configurations of the bioreactor are discussed for each type of product. This is followed by a review on optimization of common process parameters (e.g. temperature, pH, retention time and organic loading rate) separately for the production of VFA, biohydrogen and methane. This review also includes additional parameters, treatment methods or special additives that wield a significant and positive effect on production rate and these products' yield.

  1. Scale-up of the production of highly reactive biogenic magnetite nanoparticles using Geobacter sulfurreducens.

    Science.gov (United States)

    Byrne, J M; Muhamadali, H; Coker, V S; Cooper, J; Lloyd, J R

    2015-06-06

    Although there are numerous examples of large-scale commercial microbial synthesis routes for organic bioproducts, few studies have addressed the obvious potential for microbial systems to produce inorganic functional biomaterials at scale. Here we address this by focusing on the production of nanoscale biomagnetite particles by the Fe(III)-reducing bacterium Geobacter sulfurreducens, which was scaled up successfully from laboratory- to pilot plant-scale production, while maintaining the surface reactivity and magnetic properties which make this material well suited to commercial exploitation. At the largest scale tested, the bacterium was grown in a 50 l bioreactor, harvested and then inoculated into a buffer solution containing Fe(III)-oxyhydroxide and an electron donor and mediator, which promoted the formation of magnetite in under 24 h. This procedure was capable of producing up to 120 g of biomagnetite. The particle size distribution was maintained between 10 and 15 nm during scale-up of this second step from 10 ml to 10 l, with conserved magnetic properties and surface reactivity; the latter demonstrated by the reduction of Cr(VI). The process presented provides an environmentally benign route to magnetite production and serves as an alternative to harsher synthetic techniques, with the clear potential to be used to produce kilogram to tonne quantities.

  2. Role of Earthworms in Soil Fertility Maintenance through the Production of Biogenic Structures

    Directory of Open Access Journals (Sweden)

    Tunira Bhadauria

    2010-01-01

    Full Text Available The soil biota benefits soil productivity and contributes to the sustainable function of all ecosystems. The cycling of nutrients is a critical function that is essential to life on earth. Earthworms (EWs are a major component of soil fauna communities in most ecosystems and comprise a large proportion of macrofauna biomass. Their activity is beneficial because it can enhance soil nutrient cycling through the rapid incorporation of detritus into mineral soils. In addition to this mixing effect, mucus production associated with water excretion in earthworm guts also enhances the activity of other beneficial soil microorganisms. This is followed by the production of organic matter. So, in the short term, a more significant effect is the concentration of large quantities of nutrients (N, P, K, and Ca that are easily assimilable by plants in fresh cast depositions. In addition, earthworms seem to accelerate the mineralization as well as the turnover of soil organic matter. Earthworms are known also to increase nitrogen mineralization, through direct and indirect effects on the microbial community. The increased transfer of organic C and N into soil aggregates indicates the potential for earthworms to facilitate soil organic matter stabilization and accumulation in agricultural systems, and that their influence depends greatly on differences in land management practices. This paper summarises information on published data on the described subjects.

  3. Insights into biogenic and chemical production of inorganic nanomaterials and nanostructures.

    Science.gov (United States)

    Faramarzi, Mohammad Ali; Sadighi, Armin

    2013-03-01

    The synthesis of inorganic nanomaterials and nanostructures by the means of diverse physical, chemical, and biological principles has been developed in recent decades. The nanoscale materials and structures creation continue to be an active area of researches due to the exciting properties of the resulting nanomaterials and their innovative applications. Despite physical and chemical approaches which have been used for a long time to produce nanomaterials, biological resources as green candidates that can replace old production methods have been focused in recent years to generate various inorganic nanoparticles (NPs) or other nanoscale structures. Cost-effective, eco-friendly, energy efficient, and nontoxic produced nanomaterials using diverse biological entities have been received increasing attention in the last two decades in contrast to physical and chemical methods owe using toxic solvents, generate unwanted by-products, and high energy consumption which restrict the popularity of these ways employed in nanometric science and engineering. In this review, the biosynthesis of gold, silver, gold-silver alloy, magnetic, semiconductor nanocrystals, silica, zirconia, titania, palladium, bismuth, selenium, antimony sulfide, and platinum NPs, using bacteria, actinomycetes, fungi, yeasts, plant extracts and also informational bio-macromolecules including proteins, polypeptides, DNA, and RNA have been reported extensively to mention the current status of the biological inorganic nanomaterial production. In other hand, two well-known wet chemical techniques, namely chemical reduction and sol-gel methods, used to produce various types of nanocrystalline powders, metal oxides, and hybrid organic-inorganic nanomaterials have presented.

  4. Methane cracking over commercial carbons for hydrogen production

    Directory of Open Access Journals (Sweden)

    J. Sarada Prasad, Vivek Dhand, V. Himabindu Y. Anjaneyulu

    2010-07-01

    Full Text Available A bench scale unit has been designed and developed indigenously for producing hydrogen from methane in the presence of a catalyst. Five number carbon samples (two carbon blacks and three activated carbons of different origin procured from Indian market have been investigated in the bench scale unit with stainless steel continuous fixed bed reactor at a constant temperature of 850 0C and space velocity (VHSV of 1.62 Lit/hr.g. Among all the five samples, activated carbon produced from coconut shells with BET surface area of 1185 m2/g showed promising activity with a sustainability factor (R1/R0 of 0.33 and initial activity (R0 of 0.623 mmol/min.g of catalyst. Accumulated carbon yield (over a period of four hours of the above catalyst is 564 mg/g of catalyst.

  5. Quantification of Methane and VOC Emissions from Natural Gas Production in Two Basins with High Ozone Events

    Science.gov (United States)

    Edie, R.; Robertson, A.; Snare, D.; Soltis, J.; Field, R. A.; Murphy, S. M.

    2015-12-01

    Since 2005, the Uintah Basin of Utah and the Upper Green River Basin of Wyoming frequently exceeded the EPA 8-hour allowable ozone level of 75 ppb, spurring interest in volatile organic compounds (VOCs) emitted during oil and gas production. Debate continues over which stage of production (drilling, flowback, normal production, transmission, etc.) is the most prevalent VOC source. In this study, we quantify emissions from normal production on well pads by using the EPA-developed Other Test Method 33a. This methodology combines ground-based measurements of fugitive emissions with 3-D wind data to calculate the methane and VOC emission fluxes from a point source. VOC fluxes are traditionally estimated by gathering a canister of air during a methane flux measurement. The methane:VOC ratio of this canister is determined at a later time in the laboratory, and applied to the known methane flux. The University of Wyoming Mobile Laboratory platform is equipped with a Picarro methane analyzer and an Ionicon Proton Transfer Reaction-Time of Flight-Mass Spectrometer, which provide real-time methane and VOC data for each well pad. This independent measurement of methane and VOCs in situ reveals multiple emission sources on one well pad, with varying methane:VOC ratios. Well pad emission estimates of methane, benzene, toluene and xylene for the two basins will be presented. The different emission source VOC profiles and the limitations of real-time and traditional VOC measurement methods will also be discussed.

  6. Effects of Fe and Mn in Paddy Soils Derived from Different Parent Materials on Methane Production and Emission

    Institute of Scientific and Technical Information of China (English)

    LIU Ke-Xing; LIAO Zong-Wen; WANG Sheng-Chun; YOU Zhi-Lin

    2003-01-01

    Three types of paddy soils, derived from granite, Quaternary red clay and basalt, respectively, were selected to study the effects of Fe and Mn in paddy soils on methane production and emission through pot and incubation experiments. The results indicated that the difference of Fe and Mn in paddy soils was one of the important factors causing obvious differences in methane emission from different soil types. Soil Fe and Mn affecting methane emission from the paddy soils was likely through affecting soil Eh and forming Fe and Mn plaques on rice roots. Different rates and valences of added Fe and Mn significantly affected methane production from paddy soils. Therefore, this study enhanced understanding of processes controlling methane emission from paddy soils and may help to improve modeling and estimating regional and global methane emission from paddy soils.

  7. Monitoring the Methane Hydrate Dissociation by the Offshore Methane Hydrate Production Tests using Multi-component Seismic

    Science.gov (United States)

    Asakawa, Eiichi; Hayashi, Tsutomu; Tsukahara, Hitoshi; Takahashi, Hiroo; Saeki, Tatsuo

    2013-04-01

    We developed a new OBC (Ocean Bottom Cable), named as 'DSS' (Deep-sea Seismic System). The sensor has 3-component accelerometer and a hydrophone applicable for four-component (4C) seismic survey. Using the DSS, the methane hydrate dissociation zone will be tried to be monitored at the water depth of around 1000m during JOGMEC offshore methane hydrate production test in early 2013. Before the DSS, we had developed the RSCS (Real-time Seismic Cable System) with 3-component gimbaled geophones, and carried out a reflection seismic survey in the Nankai Trough in 2006. Referring this successful survey, we improved the RSCS to the DSS. The receiver size is reduced to 2/3 and the receiver case has a protective metallic exterior and the cable is protected with steel-screened armouring, allowing burial usage using ROV for sub-seabed deployment at the water depth up to 2000m. It will realize a unique survey style that leaves the system on the seabed between pre-test baseline survey and post-test repeated surveys, which might be up to 6 months. The fixed location of the receiver is very important for time-lapse monitoring survey. The DSS has totally 36 sensors and the sensor spacing is 26.5m. The total length is about 1km. We carried out the pre-test baseline survey between off Atsumi and Shima-peninsula in August, 2012.We located the DSS close to the production test well. The nearest sensor is 63m apart from the well. A newly developed real-time 3-D laying simulation system consisting of ADCP (Acoustic Doppler Current Profiler), transponders attached to the DSS, and real-time 3-D plotting system for transponder locations have been adopted. After we laid the cable, we buried the DSS using ROV (Remotely Operated Vehicle). The baseline survey included 2D/3D seismic surveys with shooting vessel and cable laying/observation ship. The resultant 2D section and 3D volume shows the good quality to delineate the methane hydrate concentrated zone. After the baseline survey, we have left

  8. Methane production by fermentation cultures acclimated to waste from cattle fed monensin, lasalocid, salinomycin, or avoparcin

    Energy Technology Data Exchange (ETDEWEB)

    Varel, V.H.; Hashimoto, A.G.

    1982-12-01

    The ability of microorganisms to ferment waste from cattle fed monensin, lasalocid, or salinomycin to methane was determined. Continuously mixed anaerobic fermentors with 3-liter working volumes at 55 degrees C were used; fermentors were fed once per day. Initially, all fermentors were fed waste without antibiotics at 6% volatile solids (VSs, organic matter) and a 20-day retention time (RT) for 60 days. Waste from animals fed monensin, lasalocid, or salinomycin at 29, 20, and 16.5 mg per kg of feed, respectively, was added to duplicate fermentors at the above VSs, and RT. Avoparcin (5 to 45 mg/liter) was not fed to animals but was added directly to duplicate fermentors. Lasalocid and salinomycin had minimal effects of the rate of methane production at RTs of 20 days and later at 6.5 days. Avoparcin caused an increaes in organic acids from 599 to 1,672 mg/liter (as acetate) after 4 weeks, but by 6 weeks, acid concentrations declined and the rate of methane production was similar to controls at 6.5 day RT. The monensin fermentors stopped producing methane 3 weeks after antibiotic addition. However, after a 6-month acclimation period, the microorganisms apparently adapted, and methane production rates of 1.65 and 2.51 liters per liter of fermentor volume per day were obtained with 6% VSs, and RTs of 10 and 6.5 days, respectively. All fermentors that were fed waste containing antibiotics had lower pH values and ammonia and alkalinity concentrations, suggesting less buffering capacity and protein catabolism than in controls. Acclimation results obtained with fermentors at 35 degrees C were similar to those for fermentors at 55 degrees C. These studies indicate that waste from cattle fed these selected growth-promoting antibiotics can be thermophilically fermented to methane at RTs of 6.5 days or longer and VS concentrations of 6%, at rates comparable to waste without antibiotics. (Refs. 21).

  9. Evidence for methane production by marine algae (Emiliana huxleyi) and its implication for the methane paradox in oxic waters

    Science.gov (United States)

    Lenhart, K.; Klintzsch, T.; Langer, G.; Nehrke, G.; Bunge, M.; Schnell, S.; Keppler, F.

    2015-12-01

    Methane (CH4), an important greenhouse gas that affects radiation balance and consequently the earth's climate, still has uncertainties in its sinks and sources. The world's oceans are considered to be a source of CH4 to the atmosphere, although the biogeochemical processes involved in its formation are not fully understood. Several recent studies provided strong evidence of CH4 production in oxic marine and freshwaters but its source is still a topic of debate. Studies of CH4 dynamics in surface waters of oceans and large lakes have concluded that pelagic CH4 supersaturation cannot be sustained either by lateral inputs from littoral or benthic inputs alone. However, frequently regional and temporal oversaturation of surface waters occurs. This comprises the observation of a CH4 oversaturating state within the surface mixed layer, sometimes also termed the "oceanic methane paradox". In this study we considered marine algae as a possible direct source of CH4. Therefore, the coccolithophore Emiliania huxleyi was grown under controlled laboratory conditions and supplemented with two 13C-labelled carbon substrates, namely bicarbonate and a position-specific 13C-labelled methionine (R-S-13CH3). The CH4 production was 0.7 μg POC g-1 d-1, or 30 ng g-1 POC h-1. After supplementation of the cultures with the 13C labelled substrate, the isotope label was observed in headspace-CH4. Moreover, the absence of methanogenic archaea within the algal culture and the oxic conditions during CH4 formation suggest that marine algae such as Emiliania huxleyi contribute to the observed spatial and temporal restricted CH4 oversaturation in ocean surface waters.

  10. Assessment of methane production from shredder waste in landfills: The influence of temperature, moisture and metals

    DEFF Research Database (Denmark)

    Fathi Aghdam, Ehsan; Scheutz, Charlotte; Kjeldsen, Peter

    2017-01-01

    In this study, methane (CH4) production rates from shredder waste (SW) were determined by incubation of waste samples over a period of 230days under different operating conditions, and first-order decay kinetic constants (k-values) were calculated. SW and sterilized SW were incubated under...

  11. Methane production by Methanothermobacter thermautotrophicus to recover energy from carbon dioxide sequestered in geological reservoirs.

    Science.gov (United States)

    Kawaguchi, Hideo; Sakuma, Takahiro; Nakata, Yuiko; Kobayashi, Hajime; Endo, Keita; Sato, Kozo

    2010-07-01

    To recover energy from carbon dioxide sequestered in geological reservoirs, the geochemical effects of acidic and substrate- and nutrient-limiting conditions on methane production by the hydrogenotrophic methanogen Methanothermobacter thermautotrophicus were investigated in a simulated deep saline aquifer environment using formation water media retrieved from petroleum reservoirs.

  12. Diversity of condensed tannin structures affects rumen in vitro methane production in sainfoin (Onobrychis viciifolia) accessions

    NARCIS (Netherlands)

    Hatew, B.; Hayot Carbonero, C.; Stringano, E.; Sales, L.F.; Smith, L.M.J.; Mueller-Harvey, I.; Hendriks, W.H.; Pellikaan, W.F.

    2015-01-01

    Sainfoin is a non-bloating temperate forage legume with a moderate-to-high condensed tannin (CT) content. This study investigated whether the diversity of sainfoin accessions in terms of CT structures and contents could be related to rumen in vitro gas and methane (CH4) production and fermentation c

  13. Structural features of condensed tannins affect in vitro ruminal methane production and fermentation characteristics

    NARCIS (Netherlands)

    Huyen, N.T.; Fryganas, C.; Uittenbogaard, G.; Mueller-Harvey, I.; Verstegen, M.W.A.; Hendriks, W.H.; Pellikaan, W.F.

    2016-01-01

    An in vitro study was conducted to investigate the effects of condensed tannin (CT) structural properties, i.e. average polymer size (or mean degree of polymerization), percentage of cis flavan-3-ols and percentage of prodelphinidins in CT extracts on methane (CH4) production and ferme

  14. Anaerobic digestion of poplar processing residues for methane production after alkaline treatment.

    Science.gov (United States)

    Yao, Yiqing; He, Mulan; Ren, Yubing; Ma, Liying; Luo, Yang; Sheng, Hongmei; Xiang, Yun; Zhang, Hua; Li, Qien; An, Lizhe

    2013-04-01

    Poplar processing residues were used for methane production by anaerobic digestion after alkaline treatment and methane production was measured. The highest methane production of 271.9 L/kg volatile solid (VS) was obtained at conditions of 35 g/L and 5.0% NaOH, which was 113.8% higher than non-alkaline treated samples, and 28.9% higher than that of corn straw, which is the conventional anaerobic digestion material in China. The maximal enhancement of 275.5% obtained at conditions of 50 g/L and 7.0% NaOH. Degradation of cellulose, hemicellulose and lignin after treatment increased by 4.0-9.0%, 3.3-6.2%, and 11.1-20.5%, respectively, with NaOH dose ranged from 3.0% to 7.0%. Scanning electron microscopy (SEM), FTIR spectra and Crystallinity measurements showed that the lignocellulosic structures were disrupted by NaOH. The results indicate poplar processing residues might be an efficient substrate for methane production after alkaline treatment.

  15. Zero valent iron simultaneously enhances methane production and sulfate reduction in anaerobic granular sludge reactors.

    Science.gov (United States)

    Liu, Yiwen; Zhang, Yaobin; Ni, Bing-Jie

    2015-05-15

    Zero valent iron (ZVI) packed anaerobic granular sludge reactors have been developed for improved anaerobic wastewater treatment. In this work, a mathematical model is developed to describe the enhanced methane production and sulfate reduction in anaerobic granular sludge reactors with the addition of ZVI. The model is successfully calibrated and validated using long-term experimental data sets from two independent ZVI-enhanced anaerobic granular sludge reactors with different operational conditions. The model satisfactorily describes the chemical oxygen demand (COD) removal, sulfate reduction and methane production data from both systems. Results show ZVI directly promotes propionate degradation and methanogenesis to enhance methane production. Simultaneously, ZVI alleviates the inhibition of un-dissociated H2S on acetogens, methanogens and sulfate reducing bacteria (SRB) through buffering pH (Fe(0) + 2H(+) = Fe(2+) + H2) and iron sulfide precipitation, which improve the sulfate reduction capacity, especially under deterioration conditions. In addition, the enhancement of ZVI on methane production and sulfate reduction occurs mainly at relatively low COD/ [Formula: see text] ratio (e.g., 2-4.5) rather than high COD/ [Formula: see text] ratio (e.g., 16.7) compared to the reactor without ZVI addition. The model proposed in this work is expected to provide support for further development of a more efficient ZVI-based anaerobic granular system.

  16. Enhancement of methane production from co-digestion of chicken manure with agricultural wastes.

    Science.gov (United States)

    Abouelenien, Fatma; Namba, Yuzaburo; Kosseva, Maria R; Nishio, Naomichi; Nakashimada, Yutaka

    2014-05-01

    The potential for methane production from semi-solid chicken manure (CM) and mixture of agricultural wastes (AWS) in a co-digestion process has been experimentally evaluated at thermophilic and mesophilic temperatures. To the best of author(')s knowledge, it is the first time that CM is co-digested with mixture of AWS consisting of coconut waste, cassava waste, and coffee grounds. Two types of anaerobic digestion processes (AD process) were used, process 1 (P1) using fresh CM (FCM) and process 2 (P2) using treated CM (TCM), ammonia stripped CM, were conducted. Methane production in P1 was increased by 93% and 50% compared to control (no AWS added) with maximum methane production of 502 and 506 mL g(-1)VS obtained at 55°C and 35°C, respectively. Additionally, 42% increase in methane production was observed with maximum volume of 695 mL g(-1)VS comparing P2 test with P2 control under 55°C. Ammonia accumulation was reduced by 39% and 32% in P1 and P2 tests.

  17. Hourly methane production in finishing steers fed at different levels of dry matter intake

    Science.gov (United States)

    Methane (CH4) loss from finishing cattle is important as it represents an energy loss that could be used for maintenance and growth, and CH4 is a greenhouse gas with a global warming potential 21 to 25 times that of CO2. Our objectives were to determine hourly CH4 production from growing cattle fed...

  18. Effects of dietary starch content and rate of fermentation on methane production in lactating dairy cows

    NARCIS (Netherlands)

    Hatew, B.; Podesta, S.C.; Laar, van H.; Pellikaan, W.F.; St-Pierre, J.L.; Dijkstra, J.; Bannink, A.

    2015-01-01

    The objective of this study was to investigate the effects of starch varying in rate of fermentation and level of inclusion in the diet in exchange for fiber on methane (CH4) production of dairy cows. Forty Holstein-Friesian lactating dairy cows of which 16 were rumen cannulated were grouped in 10 b

  19. Methane Production and Consumption in Loess Soil at Different Slope Position

    Directory of Open Access Journals (Sweden)

    Małgorzata Brzezińska

    2012-01-01

    Full Text Available Methane (CH4 production and consumption and soil respiration in loess soils collected from summit (Top, back slope (Middle, and slope bottom (Bottom positions were assessed in laboratory incubations. The CH4 production potential was determined under conditions which can occur in the field (relatively short-term flooding periods with initially ambient O2 concentrations, and the CH4 oxidation potential was estimated in wet soils enriched with CH4. None of the soils tested in this study emitted a significant amount of CH4. In fact, the Middle and Bottom soils, especially at the depth of 20–40 cm, were a consistent sink of methane. Soils collected at different slope positions significantly differed in their methanogenic, methanotrophic, and respiration activities. In comparison with the Top position (as reference soil, methane production and both CO2 production and O2 consumption under flooding were significantly stimulated in the soil from the Middle slope position (P<0.001, while they were reduced in the Bottom soil (not significantly, by 6 to 57%. All upper soils (0–20 cm completely oxidized the added methane (5 kPa during 9–11 days of incubation. Soils collected from the 20–40 cm at the Middle and Bottom slope positions, however, consumed significantly more CH4 than the Top soil (P<0.001.

  20. Effects of probiotics on the faecal production of hydrogen and methane in patients with meteorism

    DEFF Research Database (Denmark)

    Schrøder, Julie Bernstorf; Jespersen, Lene; Westermann, Peter;

    Meteorism is a dominating problem in the western world, especially in women. The condition is very difficult to quantify, and effective and documented therapies are not avaiable. We wanted to develop a method for measuring anaerobic production of hydrogen and methane in faeces, and to correlate t...

  1. Modelling Methane Production and Sulfate Reduction in Anaerobic Granular Sludge Reactor with Ethanol as Electron Donor

    Science.gov (United States)

    Sun, Jing; Dai, Xiaohu; Wang, Qilin; Pan, Yuting; Ni, Bing-Jie

    2016-10-01

    In this work, a mathematical model based on growth kinetics of microorganisms and substrates transportation through biofilms was developed to describe methane production and sulfate reduction with ethanol being a key electron donor. The model was calibrated and validated using experimental data from two case studies conducted in granule-based Upflow Anaerobic Sludge Blanket reactors. The results suggest that the developed model could satisfactorily describe methane and sulfide productions as well as ethanol and sulfate removals in both systems. The modeling results reveal a stratified distribution of methanogenic archaea, sulfate-reducing bacteria and fermentative bacteria in the anaerobic granular sludge and the relative abundances of these microorganisms vary with substrate concentrations. It also indicates sulfate-reducing bacteria can successfully outcompete fermentative bacteria for ethanol utilization when COD/SO42‑ ratio reaches 0.5. Model simulation suggests that an optimal granule diameter for the maximum methane production efficiency can be achieved while the sulfate reduction efficiency is not significantly affected by variation in granule size. It also indicates that the methane production and sulfate reduction can be affected by ethanol and sulfate loading rates, and the microbial community development stage in the reactor, which provided comprehensive insights into the system for its practical operation.

  2. The presence of hydrogenotrophic methanogens in the inoculum improves methane gas production in microbial electrolysis cells.

    KAUST Repository

    Siegert, Michael

    2014-01-01

    High current densities in microbial electrolysis cells (MECs) result from the predominance of various Geobacter species on the anode, but it is not known if archaeal communities similarly converge to one specific genus. MECs were examined here on the basis of maximum methane production and current density relative to the inoculum community structure. We used anaerobic digester (AD) sludge dominated by acetoclastic Methanosaeta, and an anaerobic bog sediment where hydrogenotrophic methanogens were detected. Inoculation using solids to medium ratio of 25% (w/v) resulted in the highest methane production rates (0.27 mL mL(-1) cm(-2), gas volume normalized by liquid volume and cathode projected area) and highest peak current densities (0.5 mA cm(-2)) for the bog sample. Methane production was independent of solid to medium ratio when AD sludge was used as the inoculum. 16S rRNA gene community analysis using pyrosequencing and quantitative PCR confirmed the convergence of Archaea to Methanobacterium and Methanobrevibacter, and of Bacteria to Geobacter, despite their absence in AD sludge. Combined with other studies, these findings suggest that Archaea of the hydrogenotrophic genera Methanobacterium and Methanobrevibacter are the most important microorganisms for methane production in MECs and that their presence in the inoculum improves the performance.

  3. Effect of temperature on methane production from field-scale anaerobic digesters treating dairy manure

    Science.gov (United States)

    Temperature is a critical factor affecting anaerobic digestion because it influences both system heating requirements and methane production. Temperatures of 35-37°C are typically suggested for manure digestion, yet in temperate climate digesters, require a considerable amount of additional heat en...

  4. Fungal secondary metabolites from Monascus spp. reduce rumen methane production in vitro and in vivo.

    Science.gov (United States)

    Morgavi, D P; Martin, C; Boudra, H

    2013-02-01

    Decreasing methanogenesis without affecting fermentation and digestion of feeds in the rumen can reduce the environmental impact of ruminant production and have a beneficial effect on feed conversion efficiency. In this work, metabolites produced by Monascus spp. molds were assayed for their antimethanogenic activity in vitro and in vivo. The capacity of 7 strains of Monascus to produce secondary metabolites was assessed in solid media. Monitored metabolites included the statins monacolin K, pravastatin, and mevastatin, and the mycotoxin citrinin. Ethanolic extracts from 5 different solid media from 2 selected strains were tested in vitro. Fermentation was not negatively affected by any treatment, but one extract decreased methane production (P 0.05). Rice on which the selected Monascus sp. was grown also decreased methane production when used as substrate for in vitro incubations (P Monascus-fermented rice on methane production was then assayed in vivo. Six wethers were adapted to a diet containing rice grain and hay (1:1 ratio). Rice was then replaced by fermented rice and given to animals for nearly 2 wk. Animals were monitored for a further 2 wk after the treatment. Daily methane emissions decreased (P Monascus appear to have an inhibitory effect on methanogens and decreased methanogenesis in vitro and in short-term in vivo without any apparent negative effect on rumen fermentation. This strategy deserves to be further explored and could be an abatement option under certain feeding situations.

  5. Gas Production Potential in the Landfill of Tehran by Landfill Methane Outreach Program

    Directory of Open Access Journals (Sweden)

    Pazoki

    2015-10-01

    Full Text Available Background Landfilling is the most common way of municipal solid waste (MSW disposal in Iran. Many countries have targeted landfill methane recovery among greenhouse gas mitigation strategies, since methane is the second most important greenhouse gas after carbon dioxide. Major questions remain with respect to actual methane production rates in field settings as well as the relative mass of methane that is recovered, emitted, oxidized by methanotrophic bacteria, laterally migrated, or temporarily stored within the landfill volume. Landfill gas (LFG consists of 50% - 60 vol% methane and 30% - 40 vol% carbon dioxide as well as trace amounts of numerous chemical compounds such as aromatics, chlorinated organic compounds and sulfur compounds. Landfill methane outreach program (LMOP is a voluntary assistance program which helps reduce methane emissions from landfills by encouraging the recovery and the beneficial use of LFG as an energy resource. Objectives In this study, the volume of LFG of Tehran by landfill methane outreach program (LMOP software was calculated. In addition, the relationship between the time of gas collection system operation and the volume of LFG production was evaluated. Materials and Methods The LMOP software was used. The available information and some presumptions were used to operate the software. The composition of the solid waste collected from the landfill of Tehran had specific details. A large amount of it was organic materials, which was about 67.8%. These materials have a good potential to produce gas. In addition, LMOP Colombia model uses the first-order equations in all the analytical equations. Furthermore, it is assumed that the landfill operation time is 30 years and the process is considered in two conditions; first, the gas was recovered in 2000, and second, the process started in 2015. Results The modeling results showed that for the gas recovery starting in 2000 and 2015, the power generation would be 2

  6. The presence of hydrogenotrophic methanogens in the inoculum improves methane gas production in microbial electrolysis cells

    Directory of Open Access Journals (Sweden)

    Michael eSiegert

    2015-01-01

    Full Text Available High current densities in microbial electrolysis cells (MECs result from the predominance of various Geobacter species on the anode. MECs inoculated from different sources often converge in terms of current production and predominance of Geobacter species despite variability in the inoculum community. Relatively less is known about the effects of inoculum source on methane gas production in MECs, and specifically whether archaeal communities similarly converge to one specific genus. MECs were examined here on the basis of maximum methane production and current density relative to the inoculum community structure. We used anaerobic digester (AD sludge dominated by acetoclastic Methanosaeta species, and an anaerobic bog sediment where hydrogenotrophic methanogens were detected. Inoculation using solids to medium ratio of 25% w/v resulted in the highest methane production rates (0.27 mL mL–1 cm–2, gas volume normalized by liquid volume and cathode projected area and highest peak current densities (0.5 mA cm–2 for the bog sample. Methane production was independent of solid to medium ratio when AD sludge was used as the inoculum. 16S rRNA gene community analysis using pyrosequencing and qPCR confirmed the convergence of Archaea to Methanobacterium and Methanobrevibacter, and of Bacteria to Geobacter, despite their absence in AD sludge. Combined with other studies, these findings suggest that Archaea of the hydrogenotrophic genera Methanobacterium and Methanobrevibacter are the most important microorganisms for methane production in MECs and that their presence in the inoculum improves the performance.

  7. Bioenergy potential of Ulva lactuca: Biomass yield, methane production and combustion

    DEFF Research Database (Denmark)

    Bruhn, Annette; Dahl, Jonas; Bangsø Nielsen, Henrik;

    2011-01-01

    a production potential of 45 T (TS) ha−1 y−1. Biogas production from fresh and macerated U. lactuca yielded up to 271 ml CH4 g−1 VS, which is in the range of the methane production from cattle manure and land based energy crops, such as grass-clover. Drying of the biomass resulted in a 5–9-fold increase...... in weight specific methane production compared to wet biomass. Ash and alkali contents are the main challenges in the use of U. lactuca for direct combustion. Application of a bio-refinery concept could increase the economical value of the U. lactuca biomass as well as improve its suitability for production...

  8. Experimental characterization of production behavior accompanying the hydrate reformation in methane hydrate bearing sediments

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, T.; Kang, J.M.; Nguyen, H.T. [Seoul National Univ., Seoul (Korea, Republic of); Park, C. [Kangwon National Univ., (Korea, Republic of); Lee, J. [Korea Inst., of Geoscience and Mineral Resources (Korea, Republic of)

    2010-07-01

    This study investigated the production behaviour associated with gas hydrate reformation in methane hydrate-bearing sediment by hot-brine injection. A range of different temperature and brine injection rates were used to analyze the pressure and temperature distribution, the gas production behaviour and the movement of the dissociation front. The study showed that hydrate reformation reduces the production rate considerably at an early time. However, gas production increases during the dissociation, near the outlet because the dissociated methane around the inlet is consumed in reforming the hydrate and increases the hydrate saturation around the outlet. Higher temperature also increases the gas production rate and the speed of the dissociation front. 12 refs., 2 tabs., 4 figs.

  9. Effect of thermal, chemical and thermo-chemical pre-treatments to enhance methane production

    Energy Technology Data Exchange (ETDEWEB)

    Rafique, Rashad; Nizami, Abdul-Sattar; Murphy, Jerry D.; Kiely, Gerard [Department of Civil and Environmental Engineering, University College Cork (Ireland); Poulsen, Tjalfe Gorm [Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University (Denmark); Asam, Zaki-ul-Zaman [Department of Civil Engineering, National University of Ireland Galway (Ireland)

    2010-12-15

    The rise in oil price triggered the exploration and enhancement of various renewable energy sources. Producing biogas from organic waste is not only providing a clean sustainable indigenous fuel to the number of on-farm digesters in Europe, but also reducing the ecological and environmental deterioration. The lignocellulosic substrates are not completely biodegraded in anaerobic digesters operating at commercial scale due to their complex physical and chemical structure, which result in meager energy recovery in terms of methane yield. The focus of this study is to investigate the effect of pre-treatments: thermal, thermo-chemical and chemical pre-treatments on the biogas and methane potential of dewatered pig manure. A laboratory scale batch digester is used for these pre-treatments at different temperature range (25 C-150 C). Results showed that thermo-chemical pretreatment has high effect on biogas and methane potential in the temperature range (25-100 C). Maximum enhancement is observed at 70 C with increase of 78% biogas and 60% methane production. Thermal pretreatment also showed enhancement in the temperature range (50-10 C), with maximum enhancement at 100 C having 28% biogas and 25% methane increase. (author)

  10. Optimization of a Pd-based membrane reactor for hydrogen production from methane steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Assis, A.J.; Hori, C.E.; Silva, L.C.; Murata, V.V. [Universidade Federal de Uberlandia (UFU), MG (Brazil). School of Chemical Engineering]. E-mail: adilsonjassis@gmail.com

    2008-07-01

    In this work, it is proposed a phenomenological model in steady state to describe the performance of a membrane reactor for hydrogen production through methane steam reform as well as it is performed an optimization of operating conditions. The model is composed by a set of ordinary differential equations from mass, energy and momentum balances and constitutive relations. They were used two different intrinsic kinetic expressions from literature. The results predicted by the model were validated using experimental data. They were investigated the effect of five important process parameters, inlet reactor pressure (PR0), methane feed flow rate (FCH40), sweep gas flow rate (FI), external reactor temperature (TW) and steam to methane feed flow ratio (M), both on methane conversion (XCH{sub 4} ) and hydrogen recovery (YH{sub 2}). The best operating conditions were obtained through simple parametric optimization and by a method based on gradient, which uses the computer code DIRCOL in FORTRAN. It is shown that high methane conversion (96%) as well as hydrogen recovery (91%) can be obtained, using the optimized conditions. (author)

  11. Stimulation of methane generation from nonproductive coal by addition of nutrients or a microbial consortium

    Science.gov (United States)

    Jones, Elizabeth J.P.; Voytek, Mary A.; Corum, Margo D.; Orem, William H.

    2010-01-01

    Biogenic formation of methane from coal is of great interest as an underexploited source of clean energy. The goal of some coal bed producers is to extend coal bed methane productivity and to utilize hydrocarbon wastes such as coal slurry to generate new methane. However, the process and factors controlling the process, and thus ways to stimulate it, are poorly understood. Subbituminous coal from a nonproductive well in south Texas was stimulated to produce methane in microcosms when the native population was supplemented with nutrients (biostimulation) or when nutrients and a consortium of bacteria and methanogens enriched from wetland sediment were added (bioaugmentation). The native population enriched by nutrient addition included Pseudomonas spp., Veillonellaceae, and Methanosarcina barkeri. The bioaugmented microcosm generated methane more rapidly and to a higher concentration than the biostimulated microcosm. Dissolved organics, including long-chain fatty acids, single-ring aromatics, and long-chain alkanes accumulated in the first 39 days of the bioaugmented microcosm and were then degraded, accompanied by generation of methane. The bioaugmented microcosm was dominated by Geobacter sp., and most of the methane generation was associated with growth of Methanosaeta concilii. The ability of the bioaugmentation culture to produce methane from coal intermediates was confirmed in incubations of culture with representative organic compounds. This study indicates that methane production could be stimulated at the nonproductive field site and that low microbial biomass may be limiting in situ methane generation. In addition, the microcosm study suggests that the pathway for generating methane from coal involves complex microbial partnerships.

  12. Marine methane paradox explained by bacterial degradation of dissolved organic matter

    Science.gov (United States)

    Repeta, Daniel J.; Ferrón, Sara; Sosa, Oscar A.; Johnson, Carl G.; Repeta, Lucas D.; Acker, Marianne; Delong, Edward F.; Karl, David M.

    2016-12-01

    Biogenic methane is widely thought to be a product of archaeal methanogenesis, an anaerobic process that is inhibited or outcompeted by the presence of oxygen and sulfate. Yet a large fraction of marine methane delivered to the atmosphere is produced in high-sulfate, fully oxygenated surface waters that have methane concentrations above atmospheric equilibrium values, an unexplained phenomenon referred to as the marine methane paradox. Here we use nuclear magnetic resonance spectroscopy to show that polysaccharide esters of three phosphonic acids are important constituents of dissolved organic matter in seawater from the North Pacific. In seawater and pure culture incubations, bacterial degradation of these dissolved organic matter phosphonates in the presence of oxygen releases methane, ethylene and propylene gas. Moreover, we found that in mutants of a methane-producing marine bacterium, Pseudomonas stutzeri, disrupted in the C-P lyase phosphonate degradation pathway, methanogenesis was also disabled, indicating that the C-P lyase pathway can catalyse methane production from marine dissolved organic matter. Finally, the carbon stable isotope ratio of methane emitted during our incubations agrees well with anomalous isotopic characteristics of seawater methane. We estimate that daily cycling of only about 0.25% of the organic matter phosphonate inventory would support the entire atmospheric methane flux at our study site. We conclude that aerobic bacterial degradation of phosphonate esters in dissolved organic matter may explain the marine methane paradox.

  13. Stimulation of methane generation from nonproductive coal by addition of nutrients or a microbial consortium.

    Science.gov (United States)

    Jones, Elizabeth J P; Voytek, Mary A; Corum, Margo D; Orem, William H

    2010-11-01

    Biogenic formation of methane from coal is of great interest as an underexploited source of clean energy. The goal of some coal bed producers is to extend coal bed methane productivity and to utilize hydrocarbon wastes such as coal slurry to generate new methane. However, the process and factors controlling the process, and thus ways to stimulate it, are poorly understood. Subbituminous coal from a nonproductive well in south Texas was stimulated to produce methane in microcosms when the native population was supplemented with nutrients (biostimulation) or when nutrients and a consortium of bacteria and methanogens enriched from wetland sediment were added (bioaugmentation). The native population enriched by nutrient addition included Pseudomonas spp., Veillonellaceae, and Methanosarcina barkeri. The bioaugmented microcosm generated methane more rapidly and to a higher concentration than the biostimulated microcosm. Dissolved organics, including long-chain fatty acids, single-ring aromatics, and long-chain alkanes accumulated in the first 39 days of the bioaugmented microcosm and were then degraded, accompanied by generation of methane. The bioaugmented microcosm was dominated by Geobacter sp., and most of the methane generation was associated with growth of Methanosaeta concilii. The ability of the bioaugmentation culture to produce methane from coal intermediates was confirmed in incubations of culture with representative organic compounds. This study indicates that methane production could be stimulated at the nonproductive field site and that low microbial biomass may be limiting in situ methane generation. In addition, the microcosm study suggests that the pathway for generating methane from coal involves complex microbial partnerships.

  14. Effects of rutin and buckwheat seeds on energy metabolism and methane production in dairy cows.

    Science.gov (United States)

    Stoldt, Ann-Kathrin; Derno, Michael; Das, Gürbüz; Weitzel, Joachim M; Wolffram, Siegfried; Metges, Cornelia C

    2016-03-01

    Flavonoids are secondary plant metabolites with several health promoting effects. As dairy cows often suffer from metabolic imbalance and health problems, interest is growing in health improvements by plant substances such as flavonoids. Our group has recently shown that the flavonoids quercetin and rutin (a glucorhamnoside of quercetin) are bioavailable in cows when given via a duodenal fistula or orally, respectively, affect glucose metabolism, and have beneficial effects on liver health. Furthermore, flavonoids may reduce rumen methane production in vitro through their antibacterial properties. To test the hypothesis that rutin has effects on energy metabolism, methane production, and production performance in dairy cows, we fed rutin trihydrate at a dose of 100mg/kg of body weight to a group of 7 lactating dairy cows for 2 wk in a crossover design. In a second experiment, 2 cows were fed the same ration but were supplemented with buckwheat seeds (Fagopyrum tartaricum), providing rutin at a dose comparable to the first experiment. Two other cows receiving barley supplements were used as controls in a change-over mode. Blood samples were taken weekly and respiration measurements were performed at the end of each treatment. Supplementation of pure rutin, but not of rutin contained in buckwheat seeds, increased the plasma quercetin content. Methane production and milk yield and composition were not affected by rutin treatment in either form. Plasma glucose, β-hydroxybutyrate, and albumin were increased by pure rutin treatment, indicating a possible metabolic effect of rutin on energy metabolism of dairy cows. In addition, we did not show that in vivo ruminal methane production was reduced by rutin. In conclusion, we could not confirm earlier reports on in vitro methane reduction by rutin supplementation in dairy cows in established lactation.

  15. Mitigation of methane production from cattle by feeding cashew nut shell liquid.

    Science.gov (United States)

    Shinkai, T; Enishi, O; Mitsumori, M; Higuchi, K; Kobayashi, Y; Takenaka, A; Nagashima, K; Mochizuki, M; Kobayashi, Y

    2012-09-01

    The effects of cashew nut shell liquid (CNSL) feeding on methane production and rumen fermentation were investigated by repeatedly using 3 Holstein nonlactating cows with rumen fistulas. The cows were fed a concentrate and hay diet (6:4 ratio) for 4 wk (control period) followed by the same diet with a CNSL-containing pellet for the next 3 wk (CNSL period). Two trials were conducted using CNSL pellets blended with only silica (trial 1) or with several other ingredients (trial 2). Each pellet type was fed to cows to allow CNSL intake at 4 g/100 kg of body weight per day. Methane production was measured in a respiration chamber system, and energy balance, nutrient digestibility, and rumen microbial changes were monitored. Methane production per unit of dry matter intake decreased by 38.3 and 19.3% in CNSL feeding trials 1 and 2, respectively. Energy loss as methane emission decreased from 9.7 to 6.1% (trial 1) and from 8.4 to 7.0% (trial 2) with CNSL feeding, whereas the loss to feces (trial 1) and heat production (trial 2) increased. Retained energy did not differ between the control and CNSL periods. Digestibility of dry matter and gross energy decreased with CNSL feeding in trial 1, but did not differ in trial 2. Feeding CNSL caused a decrease in acetate and total short-chain fatty acid levels and an increase in propionate proportion in both trials. Relative copy number of methyl coenzyme-M reductase subunit A gene and its expression decreased with CNSL feeding. The relative abundance of fibrolytic or formate-producing species such as Ruminococcus flavefaciens, Butyrivibrio fibrisolvens, and Treponema bryantii decreased, but species related to propionate production, including Prevotella ruminicolla, Selenomonas ruminantium, Anaerovibrio lipolytica, and Succinivibrio dextrinosolvens, increased. If used in a suitable formulation, CNSL acts as a potent methane-inhibiting and propionate-enhancing agent through the alteration of rumen microbiota without adversely

  16. Methane Production in Microbial Reverse-Electrodialysis Methanogenesis Cells (MRMCs) Using Thermolytic Solutions

    KAUST Repository

    Luo, Xi

    2014-08-05

    The utilization of bioelectrochemical systems for methane production has attracted increasing attention, but producing methane in these systems requires additional voltage to overcome large cathode overpotentials. To eliminate the need for electrical grid energy, we constructed a microbial reverse- electrodialysis methanogenesis cell (MRMC) by placing a reverse electrodialysis (RED) stack between an anode with exoelectrogenic microorganisms and a methanogenic biocathode. In the MRMC, renewable salinity gradient energy was converted to electrical energy, thus providing the added potential needed for methane evolution from the cathode. The feasibility of the MRMC was examined using three different cathode materials (stainless steel mesh coated with platinum, SS/Pt; carbon cloth coated with carbon black, CC/CB; or a plain graphite fiber brush, GFB) and a thermolytic solution (ammonium bicarbonate) in the RED stack. A maximum methane yield of 0.60 ± 0.01 mol-CH 4/mol-acetate was obtained using the SS/Pt biocathode, with a Coulombic recovery of 75 ± 2% and energy efficiency of 7.0 ± 0.3%. The CC/CB biocathode MRMC had a lower methane yield of 0.55 ± 0.02 mol-CH4/mol-acetate, which was twice that of the GFB biocathode MRMC. COD removals (89-91%) and Coulombic efficiencies (74-81%) were similar for all cathode materials. Linear sweep voltammetry and electrochemical impedance spectroscopy tests demonstrated that cathodic microorganisms enhanced electron transfer from the cathode compared to abiotic controls. These results show that the MRMC has significant potential for production of nearly pure methane using low-grade waste heat and a source of waste organic matter at the anode. © 2014 American Chemical Society.

  17. Evidence for methane-subsidised secondary production in a groundwater-fed lowland river.

    Science.gov (United States)

    Trimmer, M.; Grey, J.; Hildrew, A.; Jackson, M.

    2009-04-01

    We are probably familiar with the chemosynthetic ecosystems of the deep Pacific, where life in the dark is coupled to the oxidation of sulphur from ‘black smokers' rather than the sun, but few, if any, would suspect such a mode of life in the classic chalk rivers of southern England. We measured the delta13C values of dominant primary consumers and their potential food sources in a groundwater-fed lowland river. The delta13C of most consumers, such as Gammarus and Simulium, reflected that of the dominant forms of photosynthetic production, whereas the cased larvae of two caddis flies (Agapetus and Silo) were consistently 13C-depleted throughout the year. The river water was supersaturated (50-60 times atmospheric) with methane, reflecting both supersaturation in the groundwater and local production in fine sediments. We measured significant rates of methane oxidation, which generates 13C-depleted organic carbon, in the biofilms on gravel, on the caddis fly cases, and on the bottom of larger rocks. In addition, there was a marked difference in the ratio of methane oxidising potential to chlorophyll a across those substrata. This ratio was below detection in the biofilm (i.e. no methane oxidation) on the tops of rocks, greater on the bottom of rocks, and maximal for the gravels and the caddis cases. If the caddis larvae acquire most of their carbon by grazing the tops of such rocks (where they are normally found), then they must acquire their depleted delta13C values by occasionally grazing biofilm where the ratio of methane oxidation to chlorophyll was much greater, and the most likely candidate is from their own cases. Grazing methane oxidising bacteria could provide the caddis larvae with up to 30 % of their carbon, which could represent a true subsidy from an ancient groundwater source.

  18. Methane production in microbial reverse-electrodialysis methanogenesis cells (MRMCs) using thermolytic solutions.

    Science.gov (United States)

    Luo, Xi; Zhang, Fang; Liu, Jia; Zhang, Xiaoyuan; Huang, Xia; Logan, Bruce E

    2014-01-01

    The utilization of bioelectrochemical systems for methane production has attracted increasing attention, but producing methane in these systems requires additional voltage to overcome large cathode overpotentials. To eliminate the need for electrical grid energy, we constructed a microbial reverse-electrodialysis methanogenesis cell (MRMC) by placing a reverse electrodialysis (RED) stack between an anode with exoelectrogenic microorganisms and a methanogenic biocathode. In the MRMC, renewable salinity gradient energy was converted to electrical energy, thus providing the added potential needed for methane evolution from the cathode. The feasibility of the MRMC was examined using three different cathode materials (stainless steel mesh coated with platinum, SS/Pt; carbon cloth coated with carbon black, CC/CB; or a plain graphite fiber brush, GFB) and a thermolytic solution (ammonium bicarbonate) in the RED stack. A maximum methane yield of 0.60 ± 0.01 mol-CH4/mol-acetate was obtained using the SS/Pt biocathode, with a Coulombic recovery of 75 ± 2% and energy efficiency of 7.0 ± 0.3%. The CC/CB biocathode MRMC had a lower methane yield of 0.55 ± 0.02 mol-CH4/mol-acetate, which was twice that of the GFB biocathode MRMC. COD removals (89-91%) and Coulombic efficiencies (74-81%) were similar for all cathode materials. Linear sweep voltammetry and electrochemical impedance spectroscopy tests demonstrated that cathodic microorganisms enhanced electron transfer from the cathode compared to abiotic controls. These results show that the MRMC has significant potential for production of nearly pure methane using low-grade waste heat and a source of waste organic matter at the anode.

  19. Genetic parameters for predicted methane production and potential for reducing enteric emissions through genomic selection.

    Science.gov (United States)

    Haas, Y de; Windig, J J; Calus, M P L; Dijkstra, J; Haan, M de; Bannink, A; Veerkamp, R F

    2011-12-01

    Mitigation of enteric methane (CH₄) emission in ruminants has become an important area of research because accumulation of CH₄ is linked to global warming. Nutritional and microbial opportunities to reduce CH₄ emissions have been extensively researched, but little is known about using natural variation to breed animals with lower CH₄ yield. Measuring CH₄ emission rates directly from animals is difficult and hinders direct selection on reduced CH₄ emission. However, improvements can be made through selection on associated traits (e.g., residual feed intake, RFI) or through selection on CH₄ predicted from feed intake and diet composition. The objective was to establish phenotypic and genetic variation in predicted CH₄ output, and to determine the potential of genetics to reduce methane emissions in dairy cattle. Experimental data were used and records on daily feed intake, weekly body weights, and weekly milk production were available from 548 heifers. Residual feed intake (MJ/d) is the difference between net energy intake and calculated net energy requirements for maintenance as a function of body weight and for fat- and protein-corrected milk production. Predicted methane emission (PME; g/d) is 6% of gross energy intake (Intergovernmental Panel on Climate Change methodology) corrected for energy content of methane (55.65 kJ/g). The estimated heritabilities for PME and RFI were 0.35 and 0.40, respectively. The positive genetic correlation between RFI and PME indicated that cows with lower RFI have lower PME (estimates ranging from 0.18 to 0.84). Hence, it is possible to decrease the methane production of a cow by selecting more-efficient cows, and the genetic variation suggests that reductions in the order of 11 to 26% in 10 yr are theoretically possible, and could be even higher in a genomic selection program. However, several uncertainties are discussed; for example, the lack of true methane measurements (and the key assumption that methane

  20. Waste lipids to energy: how to optimize methane production from long-chain fatty acids (LCFA).

    Science.gov (United States)

    Alves, M Madalena; Pereira, M Alcina; Sousa, Diana Z; Cavaleiro, Ana J; Picavet, Merijn; Smidt, Hauke; Stams, Alfons J M

    2009-09-01

    The position of high-rate anaerobic technology (HR-AnWT) in the wastewater treatment and bioenergy market can be enhanced if the range of suitable substrates is expanded. Analyzing existing technologies, applications and problems, it is clear that, until now, wastewaters with high lipids content are not effectively treated by HR-AnWT. Nevertheless, waste lipids are ideal potential substrates for biogas production, since theoretically more methane can be produced, when compared with proteins or carbohydrates. In this minireview, the classical problems of lipids methanization in anaerobic processes are discussed and new concepts to enhance lipids degradation are presented. Reactors operation, feeding strategies and prospects of technological developments for wastewater treatment are discussed. Long-chain fatty acids (LCFA) degradation is accomplished by syntrophic communities of anaerobic bacteria and methanogenic archaea. For optimal performance these syntrophic communities need to be clustered in compact aggregates, which is often difficult to achieve with wastewaters that contain fats and lipids. Driving the methane production from lipids/LCFA at industrial scale without risk of overloading and inhibition is still a challenge that has the potential for filling a gap in the existing processes and technologies for biological methane production associated to waste and wastewater treatment.

  1. Waste lipids to energy: how to optimize methane production from long‐chain fatty acids (LCFA)

    Science.gov (United States)

    Alves, M. Madalena; Pereira, M. Alcina; Sousa, Diana Z.; Cavaleiro, Ana J.; Picavet, Merijn; Smidt, Hauke; Stams, Alfons J. M.

    2009-01-01

    Summary The position of high‐rate anaerobic technology (HR‐AnWT) in the wastewater treatment and bioenergy market can be enhanced if the range of suitable substrates is expanded. Analyzing existing technologies, applications and problems, it is clear that, until now, wastewaters with high lipids content are not effectively treated by HR‐AnWT. Nevertheless, waste lipids are ideal potential substrates for biogas production, since theoretically more methane can be produced, when compared with proteins or carbohydrates. In this minireview, the classical problems of lipids methanization in anaerobic processes are discussed and new concepts to enhance lipids degradation are presented. Reactors operation, feeding strategies and prospects of technological developments for wastewater treatment are discussed. Long‐chain fatty acids (LCFA) degradation is accomplished by syntrophic communities of anaerobic bacteria and methanogenic archaea. For optimal performance these syntrophic communities need to be clustered in compact aggregates, which is often difficult to achieve with wastewaters that contain fats and lipids. Driving the methane production from lipids/LCFA at industrial scale without risk of overloading and inhibition is still a challenge that has the potential for filling a gap in the existing processes and technologies for biological methane production associated to waste and wastewater treatment. PMID:21255287

  2. Low temperature calcium hydroxide treatment enhances anaerobic methane production from (extruded) biomass.

    Science.gov (United States)

    Khor, Way Cern; Rabaey, Korneel; Vervaeren, Han

    2015-01-01

    Ca(OH)2 treatment was applied to enhance methane yield. Different alkali concentration, incubation temperature and duration were evaluated for their effect on methane production and COD conversion efficiency from (non-)extruded biomass during mesophilic anaerobic digestion at lab-scale. An optimum Ca(OH)2 pretreatment for grass is found at 7.5% lime loading at 10°C for 20h (37.3% surplus), while mild (50°C) and high temperatures perform sub-optimal. Ca(OH)2 post-treatment after fast extrusion gives an additional surplus compared to extruded material of 15.2% (grass), 11.2% (maize straw) and 8.2% (sprout stem) regarding methane production. COD conversion improves accordingly, with additional improvements of 10.3% (grass), 9.0% (maize straw) and 6.8% (sprout stem) by Ca(OH)2 post-treatment. Therefore, Ca(OH)2 pretreatment and post-treatment at low temperature generate an additional effect regarding methane production and COD conversion efficiency. Fast extrusion gives a higher energy efficiency ratio compared to slow extrusion.

  3. Methane production and methanogenic Archaea in the digestive tracts of millipedes (Diplopoda.

    Directory of Open Access Journals (Sweden)

    Vladimír Šustr

    Full Text Available Methane production by intestinal methanogenic Archaea and their community structure were compared among phylogenetic lineages of millipedes. Tropical and temperate millipedes of 35 species and 17 families were investigated. Species that emitted methane were mostly in the juliform orders Julida, Spirobolida, and Spirostreptida. The irregular phylogenetic distribution of methane production correlated with the presence of the methanogen-specific mcrA gene. The study brings the first detailed survey of methanogens' diversity in the digestive tract of millipedes. Sequences related to Methanosarcinales, Methanobacteriales, Methanomicrobiales and some unclassified Archaea were detected using molecular profiling (DGGE. The differences in substrate preferences of the main lineages of methanogenic Archaea found in different millipede orders indicate that the composition of methanogen communities may reflect the differences in available substrates for methanogenesis or the presence of symbiotic protozoa in the digestive tract. We conclude that differences in methane production in the millipede gut reflect differences in the activity and proliferation of intestinal methanogens rather than an absolute inability of some millipede taxa to host methanogens. This inference was supported by the general presence of methanogenic activity in millipede faecal pellets and the presence of the 16S rRNA gene of methanogens in all tested taxa in the two main groups of millipedes, the Helminthophora and the Pentazonia.

  4. Methane production and methanogenic Archaea in the digestive tracts of millipedes (Diplopoda).

    Science.gov (United States)

    Šustr, Vladimír; Chroňáková, Alica; Semanová, Stanislava; Tajovský, Karel; Šimek, Miloslav

    2014-01-01

    Methane production by intestinal methanogenic Archaea and their community structure were compared among phylogenetic lineages of millipedes. Tropical and temperate millipedes of 35 species and 17 families were investigated. Species that emitted methane were mostly in the juliform orders Julida, Spirobolida, and Spirostreptida. The irregular phylogenetic distribution of methane production correlated with the presence of the methanogen-specific mcrA gene. The study brings the first detailed survey of methanogens' diversity in the digestive tract of millipedes. Sequences related to Methanosarcinales, Methanobacteriales, Methanomicrobiales and some unclassified Archaea were detected using molecular profiling (DGGE). The differences in substrate preferences of the main lineages of methanogenic Archaea found in different millipede orders indicate that the composition of methanogen communities may reflect the differences in available substrates for methanogenesis or the presence of symbiotic protozoa in the digestive tract. We conclude that differences in methane production in the millipede gut reflect differences in the activity and proliferation of intestinal methanogens rather than an absolute inability of some millipede taxa to host methanogens. This inference was supported by the general presence of methanogenic activity in millipede faecal pellets and the presence of the 16S rRNA gene of methanogens in all tested taxa in the two main groups of millipedes, the Helminthophora and the Pentazonia.

  5. Comparison of ultrasound and thermal pretreatment of Scenedesmus biomass on methane production.

    Science.gov (United States)

    González-Fernández, C; Sialve, B; Bernet, N; Steyer, J P

    2012-04-01

    Ultrasound at 20Hz was applied at different energy levels (Es) to treat Scenedesmus biomass, and organic matter solubilization, particle size distribution, cell disruption and biochemical methane potential were evaluated. An Es of 35.5 and 47.2MJ/kg resulted in floc deagglomeration but no improvement in methane production compared to untreated biomass. At an Es of 128.9, cell wall disruption was observed together with a 3.1-fold organic matter solubilization and an approximately 2-fold methane production in comparison with untreated biomass. Thermal pretreatment at 80°C caused cell wall disruption and improved anaerobic biodegradability 1.6-fold compared to untreated biomass. Since sonication caused a temperature increase in samples to as high as 85°C, it is likely that thermal effects accounted for much of the observed changes in the biomass. Given that ultrasound treatment at the highest Es studied only increased methane production by 1.2-fold over thermal treatment at 80°C, the higher energy requirement of sonication might not justify the use of this approach over thermal treatment.

  6. Methane production enhancement by an independent cathode in integrated anaerobic reactor with microbial electrolysis.

    Science.gov (United States)

    Cai, Weiwei; Han, Tingting; Guo, Zechong; Varrone, Cristiano; Wang, Aijie; Liu, Wenzong

    2016-05-01

    Anaerobic digestion (AD) represents a potential way to achieve energy recovery from waste organics. In this study, a novel bioelectrochemically-assisted anaerobic reactor is assembled by two AD systems separated by anion exchange membrane, with the cathode placing in the inside cylinder (cathodic AD) and the anode on the outside cylinder (anodic AD). In cathodic AD, average methane production rate goes up to 0.070 mL CH4/mL reactor/day, which is 2.59 times higher than AD control reactor (0.027 m(3) CH4/m(3)/d). And COD removal is increased ∼15% over AD control. When changing to sludge fermentation liquid, methane production rate has been further increased to 0.247 mL CH4/mL reactor/day (increased by 51.53% comparing with AD control). Energy recovery efficiency presents profitable gains, and economic revenue from increased methane totally self-cover the cost of input electricity. The study indicates that cathodic AD could cost-effectively enhance methane production rate and degradation of glucose and fermentative liquid.

  7. CYANOBACTERIA FOR MITIGATING METHANE EMISSION FROM SUBMERGED PADDY FIELDS

    Energy Technology Data Exchange (ETDEWEB)

    Upasana Mishra; Shalini Anand [Department of Environmental Studies, Inderprastha Engineering College, Sahibabad, Ghaziabad (India)

    2008-09-30

    Atmospheric methane, a potent greenhouse gas with high absorption potential for infrared radiation, is responsible for one forth of the total anticipated warming. It is forming a major part of green house gases, next after carbon dioxide. Its concentration has been increasing alarmingly on an average at the rate of one percent per year. Atmospheric methane, originating mainly from biogenic sources such as paddy fields, natural wetlands and landfills, accounts for 15-20% of the world's total anthropogenic methane emission. With intensification of rice cultivation in coming future, methane emissions from paddy fields are anticipated to increase. India's share in world's rice production is next after to China and likewise total methane emission from paddy fields also. Methane oxidation through planktophytes, particularly microalgae which are autotrophic and abundant in rice rhizospheres, hold promise in controlling methane emission from submerged paddy fields. The present study is focused on the role of nitrogen fixing, heterocystous cyanobacteria and Azolla (a water fern harboring a cyanobacterium Anabaena azollae) as biological sink for headspace concentration of methane in flooded soils. In this laboratory study, soil samples containing five potent nitrogen fixer cyanobacterial strains from paddy fields, were examined for their methane reducing potential. Soil sample without cyanobacterial strain was tested and taken as control. Anabaena sp. was found most effective in inhibiting methane concentration by 5-6 folds over the control. Moist soil cores treated with chemical nitrogen, urea, in combination with cyanobacteria mixture, Azolla microphylla or cyanobacteria mixture plus Azolla microphylla exhibited significance reduction in the headspace concentration of methane than the soil cores treated with urea alone. Contrary to other reports, this study also demonstrates that methane oxidation in soil core samples from paddy fields was stimulated by

  8. Sulfidogenesis interference on methane production from carbohydrate-rich wastewater.

    Science.gov (United States)

    Godoi, L A G; Damianovic, M H R Z; Foresti, E

    2015-01-01

    Two anaerobic fixed-structured bed reactors were fed with synthetic wastewater simulating the soluble fraction of sugarcane vinasse to evaluate the interference of sulfidogenesis on methanogenesis. The reactors running in parallel were subjected to the same operating conditions. The influent organic matter concentration (in term of chemical oxygen demand (COD)) remained close to 4,000 mgCOD L(-1) and the hydraulic retention time was 24 hours. One reactor, the methanogenic (control reactor), received sulfate only to provide the sulfur required as a nutrient to the methanogenic biomass. The other one, the sulfidogenic/methanogenic reactor (SMR), received sulfate concentration corresponding to COD/sulfate ratios of 4, 5 and 3. In the last phase, the COD removal efficiencies were higher than 96% in both reactors and the SMR achieved 97% of sulfate removal efficiency (COD/sulfate ratio of 3 and influent sulfate concentration close to 1,300 mgSO4(2-) L(-1)). Both reactors also had similar methane yields in this phase, close to 350 mLCH4 gCODremoved(-1) at standard temperature and pressure. These results indicated no significant inhibition of methanogenic activity under the sulfidogenic conditions assessed.

  9. Methane production and energy evaluation of a farm scaled biogas plant in cold climate area.

    Science.gov (United States)

    Fjørtoft, Kristian; Morken, John; Hanssen, Jon Fredrik; Briseid, Tormod

    2014-10-01

    The aim of this study was to investigate the specific methane production and the energy balance at a small farm scaled mesophilic biogas plant in a cold climate area. The main substrate was dairy cow slurry. Fish silage was used as co-substrate for two of the three test periods. Energy production, substrate volumes and thermal and electric energy consumption was monitored. Methane production depended mainly on type and amount of substrates, while energy consumption depended mainly on the ambient temperature. During summer the main thermal energy consumption was caused by heating of new substrates, while covering for thermal energy losses from digester and pipes required most thermal energy during winter. Fish silage gave a total energy production of 1623 k Wh/m(3), while the dairy cow slurry produced 79 k Wh/m(3) slurry. Total energy demand at the plant varied between 26.9% and 88.2% of the energy produced.

  10. Enhancement of bioenergy production from organic wastes by two-stage anaerobic hydrogen and methane production process.

    Science.gov (United States)

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

    2011-09-01

    The present study investigated a two-stage anaerobic hydrogen and methane process for increasing bioenergy production from organic wastes. A two-stage process with hydraulic retention time (HRT) 3d for hydrogen reactor and 12d for methane reactor, obtained 11% higher energy compared to a single-stage methanogenic process (HRT 15 d) under organic loading rate (OLR) 3 gVS/(L d). The two-stage process was still stable when the OLR was increased to 4.5 gVS/(Ld), while the single-stage process failed. The study further revealed that by changing the HRT(hydrogen):HRT(methane) ratio of the two-stage process from 3:12 to 1:14, 6.7%, more energy could be obtained. Microbial community analysis indicated that the dominant bacterial species were different in the hydrogen reactors (Thermoanaerobacterium thermosaccharolyticum-like species) and methane reactors (Clostridium thermocellum-like species). The changes of substrates and HRT did not change the dominant species. The archaeal community structures in methane reactors were similar both in single- and two- stage reactors, with acetoclastic methanogens Methanosarcina acetivorans-like organisms as the dominant species.

  11. Effects of composition of labile organic matter on biogenic production of methane in the coastal sediments of the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Gonsalves, M.J.B.D.; Fernandes, C.E.G.; Fernandes, S.O.; Kirchman, D.L.; LokaBharathi, P.A.

    , University of Texas Publication, p 170 Graf, G. (1989). Benthic-pelagic coupling in a deep-sea benthic community. Nature, 341, 437-439. Gremare, A., Medernach, L., DeBovee, F., Amouroux, J. M., Charles, F., Dinet, A., Vetion, G., Albert, P., & Colomines, J...

  12. Assessment of wet explosion as a pretreatment method to enhance methane production from agricultural residues and energy crops

    DEFF Research Database (Denmark)

    Wang, Guangtao; Gavala, Hariklia N.; Skiadas, Ioannis

    2011-01-01

    In the present study, wet explosion has been studied as a pretreatment method for increasing the methane yield from wheat straw, miscantus and willow. Among the three biomasses tested, wheat straw and miscanthus were the most promising in terms of methane production, yielding around 265 mL of met...

  13. Effect of biochar addition on hydrogen and methane production in two-phase anaerobic digestion of aqueous carbohydrates food waste.

    Science.gov (United States)

    Sunyoto, Nimas M S; Zhu, Mingming; Zhang, Zhezi; Zhang, Dongke

    2016-11-01

    Effect of biochar addition on hydrogen and methane production in two-phase anaerobic digestion of aqueous carbohydrates was studied using bench-scale bioreactors. The cultures with biochar additions were placed in 100ml reactors and incubated at 35°C and pH 5 for hydrogen production. The residual cultures were then used for methane production, incubated at 35°C and pH 7. Daily yields of hydrogen and methane and weekly yield of volatile fatty acids (VFA) were measured. The hydrogen and methane production potentials, rate and lag phases of the two phases were analysed using the Gompertz model. The results showed that biochar addition increased the maximum production rates of hydrogen by 32.5% and methane 41.6%, improved hydrogen yield by 31.0% and methane 10.0%, and shortened the lag phases in the two phases by 36.0% and 41.0%, respectively. Biochar addition also enhanced VFA generation during hydrogen production and VFA degradation in methane production.

  14. Methane-rich syngas production from hydrocarbon fuels using multi-functional catalyst/capture agent

    Energy Technology Data Exchange (ETDEWEB)

    Siefert, Nicholas S.; Shekhawat, Dushyant; Berry, David A.; Surdoval, Wayne A.

    2017-02-07

    The disclosure provides a gasification process for the production of a methane-rich syngas at temperatures exceeding 400.degree. C. through the use of an alkali hydroxide MOH, using a gasification mixture comprised of at least 0.25 moles and less than 2 moles of water for each mole of carbon, and at least 0.15 moles and less than 2 moles of alkali hydroxide MOH for each mole of carbon. These relative amounts allow the production of a methane-rich syngas at temperatures exceeding 400.degree. C. by enabling a series of reactions which generate H.sub.2 and CH.sub.4, and mitigate the reforming of methane. The process provides a methane-rich syngas comprised of roughly 20% (dry molar percentage) CH.sub.4 at temperatures above 400.degree. C., and may effectively operate within an IGFC cycle at reactor temperatures between 400-900.degree. C. and pressures in excess of 10 atmospheres.

  15. Ammonia, a selective agent for methane production by syntrophic acetate oxidation at mesophilic temperature.

    Science.gov (United States)

    Schnürer, A; Nordberg, A

    2008-01-01

    In biogas processes, methane production from acetate proceeds by either aceticlastic methanogenesis or through syntrophic acetate oxidation (SAO). In the present study, the pathway for methane production from acetate was analysed; i) during a gradual increase of the ammonia concentration (final concentration 7 g NH(4)(+) -N/L) in a semi-continuous lab-scale anaerobic digester (4.3 L), operating at mesophilic temperature (37 degrees C) or ii) in diluted enrichment cultures (100 ml) experiencing a gradual increase in ammonia, sodium, potassium and propionic acid. The pathway for methane formation was determined by calculating the (14)CO(2)/(14)CH(4) ratio after incubating samples with (14)C-2-acetate. In the anaerobic digester, as well as in the enrichment cultures, the (14)CO(2)/(14)CH4 ratio clearly increased with increasing ammonium-nitrogen concentration, i.e. as the ammonia concentration increased, a shift from the aceticlastic mechanism to the syntrophic pathway occurred. The shift was very distinct and occurred as the NH(4)(+) -N concentration rose above 3 g/l. No shift in pathway was seen during increasing concentrations of sodium, potassium or propionic acid. The shift to SAO in the biogas digester resulted in a twofold decrease in the specific gas and methane yield.

  16. Methane production and small intestinal bacterial overgrowth in children living in a slum

    Institute of Scientific and Technical Information of China (English)

    Carolina Santos Mello; Soraia Tahan; Lígia Cristina FL Melli; Mirian Silva do Carmo Rodrigues; Ricardo Martin Pereira de Mello; Isabel Cristina Affonso Scaletsky; Mauro Batista de Morais

    2012-01-01

    AIM:To analyze small intestinal bacterial overgrowth in school-aged children and the relationship between hydrogen and methane production in breath tests.METHODS:This transversal study included 85 children residing in a slum and 43 children from a private school,all aged between 6 and 10 years,in Osasco,Brazil.For characterization of the groups,data regarding the socioeconomic status and basic housing sanitary conditions were collected.Anthropometric data was obtained in children from both groups.All children completed the hydrogen (H2) and methane (CH4) breath test in order to assess small intestinal bacterial overgrowth (SIBO).SIBO was diagnosed when there was an increase in H2 ≥ 20 ppm or CH4 ≥ 10 ppm with regard to the fasting value until 60 min after lactulose ingestion.RESULTS:Children from the slum group had worse living conditions and lower nutritional indices than children from the private school.SIBO was found in 30.9% (26/84) of the children from the slum group and in 2.4% (1/41) from the private school group (P =0.0007).Greater hydrogen production in the small intestine was observed in children from the slum group when compared to children from the private school (P =0.007).A higher concentration of hydrogen in the small intestine (P < 0.001) and in the colon (P < 0.001) was observed among the children from the slum group with SIBO when compared to children from the slum group without SIBO.Methane production was observed in 63.1% (53/84) of the children from the slum group and in 19.5% (8/41) of the children from the private school group (P < 0.0001).Methane production was observed in 38/58 (65.5%) of the children without SIBO and in 15/26 (57.7%) of the children with SIBO from the slum.Colonic production of hydrogen was lower in methaneproducing children (P =0.017).CONCLUSION:Children who live in inadequate environmental conditions are at risk of bacterial overgrowth and methane production.Hydrogen is a substrate for methane

  17. Conversion of Crude Oil to Methane by a Microbial Consortium Enriched From Oil Reservoir Production Waters

    Directory of Open Access Journals (Sweden)

    Carolina eBerdugo-Clavijo

    2014-05-01

    Full Text Available The methanogenic biodegradation of crude oil is an important process occurring in petroleum reservoirs and other oil-containing environments such as contaminated aquifers. In this process, syntrophic bacteria degrade hydrocarbon substrates to products such as acetate, and/or H2 and CO2 that are then used by methanogens to produce methane in a thermodynamically dependent manner. We enriched a methanogenic crude oil-degrading consortium from production waters sampled from a low temperature heavy oil reservoir. Alkylsuccinates indicative of fumarate addition to C5 and C6 n-alkanes were identified in the culture (above levels found in controls, corresponding to the detection of an alkyl succinate synthase gene (assA in the culture. In addition, the enrichment culture was tested for its ability to produce methane from residual oil in a sandstone-packed column system simulating a mature field. Methane production rates of up 5.8 μmol CH4/g of oil/day were measured in the column system. Amounts of produced methane were in relatively good agreement with hydrocarbon loss showing depletion of more than 50% of saturate and aromatic hydrocarbons. Microbial community analysis revealed that the enrichment culture was dominated by members of the genus Smithella, Methanosaeta, and Methanoculleus. However, a shift in microbial community occurred following incubation of the enrichment in the sandstone columns. Here, Methanobacterium sp. were most abundant, as were bacterial members of the genus Pseudomonas and other known biofilm forming organisms. Our findings show that microorganisms enriched from petroleum reservoir waters can bioconvert crude oil components to methane both planktonically and in sandstone-packed columns as test systems. Further, the results suggest that different organisms may contribute to oil biodegradation within different phases (e.g., planktonic versus sessile within a subsurface crude oil reservoir.

  18. Production of methane by co-digestion of cassava pulp with various concentrations of pig manure

    Energy Technology Data Exchange (ETDEWEB)

    Panichnumsin, Pornpan [The Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology Thonburi, Thungkru, Bangkok 10140 (Thailand); Excellent Center of Waste Utilization and Management, National Center for Genetic Engineering and Biotechnology, Bangkhuntien, Bangkok 10150 (Thailand); Nopharatana, Annop [Pilot Plant Development and Training Institute, King Mongkut' s University of Technology Thonburi, Bangkhuntien, Bangkok 10150 (Thailand); Ahring, Birgitte [AAU, Copenhagen Institute of Technology, Lautrupvang 15, 2750 Ballerup (Denmark); Chaiprasert, Pawinee [School of Bioresources and Technology, King Mongkut' s University of Technology Thonburi, Bangkhuntien, Bangkok 10150 (Thailand)

    2010-08-15

    Cassava pulp is a major by-product produced in a cassava starch factory, containing 50-60% of starch (dry basis). Therefore, in this study we are considering its potential as a raw material substrate for the production of methane. To ensure sufficient amounts of nutrients for the anaerobic digestion process, the potential of co-digestion of cassava pulp (CP) with pig manure (PM) was further examined. The effect of the co-substrate mixture ratio was carried out in a semi-continuously fed stirred tank reactor (CSTR) operated under mesophilic condition (37 C) and at a constant OLR of 3.5 kg VS m{sup -3} d{sup -1} and a HRT of 15 days. The results showed that co-digestion resulted in higher methane production and reduction of volatile solids (VS) but lower buffering capacity. Compared to the digestion of PM alone, the specific methane yield increased 41% higher when co-digested with CP in concentrations up to 60% of the incoming VS. This was probably due to an increase in available easily degradable carbohydrates as the CP ratio in feedstock increased. The highest methane yield and VS removal of 306 mL g{sup -1} VS{sub added} and 61%, respectively, were achieved with good process stability (VFA:Alkalinity ratio < 0.1) when CP accounted for 60% of the feedstock VS. A further increase of CP of the feedstock led to a decrease in methane yield and solid reductions. This appeared to be caused by an extremely high C:N ratio of the feedstock resulting in a deficiency of ammonium nitrogen for microbial growth and buffering capacity. (author)

  19. Effect of urea addition on giant reed ensilage and subsequent methane production by anaerobic digestion.

    Science.gov (United States)

    Liu, Shan; Ge, Xumeng; Liew, Lo Niee; Liu, Zhe; Li, Yebo

    2015-09-01

    The effect of urea addition on giant reed ensilage and sequential anaerobic digestion (AD) of the ensiled giant reed was evaluated. The dry matter loss during ensilage (up to 90 days) with or without urea addition was about 1%. Addition of 2% urea enhanced production of lactic acid by about 4 times, and reduced production of propionic acid by 2-8 times. Besides, urea addition reduced degradation of cellulose and hemicellulose, and increased degradation of lignin in giant reed during ensilage. Ensilage with or without urea addition had no significant effects on the enzymatic digestibility of giant reed, but ensilage with urea addition achieved a cumulative methane yield of 173 L/kg VS, which was 18% higher than that of fresh giant reed. The improved methane yield of giant reed could be attributed to the production of organic acids and ethanol during ensilage.

  20. Effect of nitrogen content on methane production by the marine algae Gracilaria tikvahiae and Ulva sp

    Energy Technology Data Exchange (ETDEWEB)

    Habig, C.; DeBusk, T.A.; Ryther, J.H.

    1984-01-01

    The rhodophyte Gracilaria tikvahiae and the chlorophyte Ulva sp. were grown under three different concentrations of tissue nitrogen. Each was then digested in batch-mode fermentation experiments. Both biogas and methane production were initially greater in Ulva but persisted longer in Gracilaria, resulting in similar performances for the two species over the entire time course of the experiment. Low-nitrogen Gracilaria contained more volatile solids and produced more biogas and methane per unit dry weight than did higher nitrogen plants, but about the same gas production per unit volatile solids. However, low nitrogen Ulva consistently out-performed the high nitrogen plants in gas production per unit volatile solids, total volatile solids, total volatile solids reduction, and bioconversion efficiency. These results, in contrast with those found in higher plants, probably reflect the low fiber, high soluble carbohydrate levels of nitrogen-deficient seaweeds in general and of Ulva in particular. 18 references, 2 figures, 4 tables.

  1. Effect of nitrogen content on methane production by the marine algae gracilaria tikvahiae and ulva species

    Energy Technology Data Exchange (ETDEWEB)

    Habig, C.; De Busk, T.A.; Ryther, J.H.

    1984-01-01

    The rhodophyte Gracilaria tikvahiae and the chlorophyte Ulva species were grown under three different nitrogen enrichment regimes producing plants of each species with three different concentrations of tissue nitrogen. Each was then digested in batch-mode fermentation experiments. Both biogas and methane production were initially greater in Ulva but persisted longer in Gracilaria, resulting in similar performances for the two species over the entire time course of the experiment. Low-nitrogen Gracilaria contained more volatile solids and produced more biogas and methane per unit dry weight than did higher nitrogen plants, but about the same gas production per unit volatile solids. However, low nitrogen Ulva consistently out-performed the high nitrogen plants in gas production per unit volatile solids, total volatile solids reduction, and bioconversion efficiency. These results, in contrast with those found in higher plants, probably reflect the low fiber, high soluble carbohydrate levels of nitrogen-deficient seaweeds in general and of Ulva in particular.

  2. Study on methane fermentation and production of vitamin B12 from alcohol waste slurry.

    Science.gov (United States)

    Zhang, Zhenya; Quan, Taisheng; Li, Pomin; Zhang, Yansheng; Sugiura, Norio; Maekawa, Takaaki

    2004-01-01

    We studied biogas fermentation from alcohol waste fluid to evaluate the anaerobic digestion process and the production of vitamin B12 as a byproduct. Anaerobic digestion using acclimated methanogens was performed using the continuously stirred tank reactor (CSTR) and fixed-bed reactor packed with rock wool as carrier material at 55 degrees C. We also studied the effects of metal ions added to the culture broth on methane and vitamin B12 formation. Vitamin B12 production was 2.92 mg/L in the broth of the fixed-bed reactor, twice that of the CSTR. The optimum concentrations of trace metal ions added to the culture liquid for methane and vitamin B12 production were 1.0 and 8 mL/L for the CSTR and fixed-bed reactor, respectively. Furthermore, an effective method for extracting and purifying vitamin B12 from digested fluid was developed.

  3. Primary production control of methane emission from wetlands

    Science.gov (United States)

    Whiting, G. J.; Chanton, J. P.

    1993-01-01

    Based on simultaneous measurements of CO2 and CH4 exchange in wetlands extending from subarctic peatlands to subtropical marshes, a positive correlation between CH4 emission and net ecosystem production is reported. It is suggested that net ecosystem production is a master variable integrating many factors which control CH4 emission in vegetated wetlands. It is found that about 3 percent of the daily net ecosystem production is emitted back to the atmosphere as CH4. With projected stimulation of primary production and soil microbial activity in wetlands associated with elevated atmospheric CO2 concentration, the potential for increasing CH4 emission from inundated wetlands, further enhancing the greenhouse effect, is examined.

  4. Kinetics of methane fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y. R.; Hashimoto, A. G.

    1978-01-01

    The kinetics on methane fermentation are described using published data for livestock residue, sewage sludge, and municipal refuse. Methods are presented to determine the kinetic constants and the finally attainable methane production using steady-state methane production data. The effects of temperature, loading rate, and influent substrate concentration on methane fermentation kinetics are discussed. These relationships were used to predict the rate of methane production of a pilot-scale fermentor with excellent results.

  5. Wet explosion of wheat straw and codigestion with swine manure: effect on the methane productivity.

    Science.gov (United States)

    Wang, G; Gavala, H N; Skiadas, I V; Ahring, B K

    2009-11-01

    The continuously increasing demand for renewable energy sources renders anaerobic digestion to one of the most promising technologies for renewable energy production. Twenty-two (22) large-scale biogas plants are currently under operation in Denmark. Most of these plants use manure as the primary feedstock but their economical profitable operation relies on the addition of other biomass products with a high biogas yield. Wheat straw is the major crop residue in Europe and the second largest agricultural residue in the world. So far it has been used in several applications, i.e. pulp and paper making, production of regenerated cellulose fibers as an alternative to wood for cellulose-based materials and ethanol production. The advantage of exploiting wheat straw for various applications is that it is available in considerable quantity and at low-cost. In the present study, the codigestion of swine manure with wheat straw in a continuous operated system was investigated, as a method to increase the efficiency of biogas plants that are based on anaerobic digestion of swine manure. Also, the pretreatment of wheat straw with the wet explosion method was studied and the efficiency of the wet explosion process was evaluated based on (a) the sugars release and (b) the methane potential of the pretreated wheat straw compared to that of the raw biomass. It was found that, although a high release of soluble sugars was observed after wet explosion, the methane obtained from the wet-exploded wheat straw was slightly lower compared to that from the raw biomas s. On the other hand, the results from the codigestion of raw (non-pretreated) wheat straw with swine manure were very promising, suggesting that 4.6 kg of straw added to 1t of manure increase the methane production by 10%. Thus, wheat straw can be considered as a promising, low-cost biomass for increasing the methane productivity of biogas plants that are based mainly on swine manure.

  6. Laboratory-scale bioaugmentation relieves acetate accumulation and stimulates methane production in stalled anaerobic digesters.

    Science.gov (United States)

    Town, Jennifer R; Dumonceaux, Tim J

    2016-01-01

    An imbalance between acidogenic and methanogenic organisms during anaerobic digestion can result in increased accumulation of volatile fatty acids, decreased reactor pH, and inhibition of methane-producing Archaea. Most commonly the result of organic input overload or poor inoculum selection, these microbiological and biochemical changes severely hamper reactor performance, and there are a few tools available to facilitate reactor recovery. A small, stable consortium capable of catabolizing acetate and producing methane was propagated in vitro and evaluated as a potential bioaugmentation tool for stimulating methanogenesis in acidified reactors. Replicate laboratory-scale batch digesters were seeded with a combination of bioethanol stillage waste and a dairy manure inoculum previously observed to result in high volatile fatty acid accumulation and reactor failure. Experimental reactors were then amended with the acetoclastic consortium, and control reactors were amended with sterile culture media. Within 7 days, bioaugmented reactors had significantly reduced acetate accumulation and the proportion of methane in the biogas increased from 0.2 ± 0 to 74.4 ± 9.9 % while control reactors showed no significant reduction in acetate accumulation or increase in methane production. Organisms from the consortium were enumerated using specific quantitative PCR assays to evaluate their growth in the experimental reactors. While the abundance of hydrogenotrophic microorganisms remained stable during the recovery period, an acetoclastic methanogen phylogenetically similar to Methanosarcina sp. increased more than 100-fold and is hypothesized to be the primary contributor to reactor recovery. Genomic sequencing of this organism revealed genes related to the production of methane from acetate, hydrogen, and methanol.

  7. [Influence of substrate COD on methane production in single-chambered microbial electrolysis cell].

    Science.gov (United States)

    Teng, Wen-Kai; Liu, Guang-Li; Luo, Hai-Ping; Zhang, Ren-Duo; Fu, Shi-Yu

    2015-03-01

    The chemical oxygen demand (COD) of substrate can affect the microbial activity of both anode and cathode biofilm in the single-chamber methanogenic microbial electrolysis cell (MEC). In order to investigate the effect of COD on the performance of MEC, a single chamber MEC was constructed with biocathode. With the change of initial concentration of COD (700, 1 000 and 1 350 mg x L(-1)), the methane production rate, COD removal and energy efficiency in the MEC were examined under different applied voltages. The results showed that the methane production rate and COD removal increased with the increasing COD. With the applied voltage changing from 0.3 to 0.7 V, the methane production rate increased at the COD of 700 mg x L(-1), while it increased at first and then decreased at the COD of 1000 mg x L(-1) and 1350 mg x L(-1). A similar trend was observed for the COD removal. The cathode potential reached the minimum (- 0.694 ± 0.001) V as the applied voltage was 0.5 V, which therefore facilitated the growth of methanogenic bacteria and improved the methane production rate and energy efficiency of the MEC. The maximum energy income was 0.44 kJ ± 0.09 kJ (1450 kJ x m(-3)) in the MEC, which was obtained at the initial COD of 1000 mg x L(-1) and the applied voltage of 0.5 V. Methanogenic MECs could be used for the treatment of wastewaters containing low organic concentrations to achieve positive energy production, which might provide a new method to recover energy from low-strength domestic wastewater.

  8. Anaerobic digestion of grape pomace: Biochemical characterization of the fractions and methane production in batch and continuous digesters.

    Science.gov (United States)

    El Achkar, Jean H; Lendormi, Thomas; Hobaika, Zeina; Salameh, Dominique; Louka, Nicolas; Maroun, Richard G; Lanoisellé, Jean-Louis

    2016-04-01

    In this study, we have estimated the biogas and methane production from grape pomace (variety Cabernet Franc). The physical and chemical characteristics of the raw material were determined, and the structural polysaccharides were identified and analyzed by the Van Soest method. Batch anaerobic digestions were carried out to assess the methane production of the grape pomace, pulp and seeds. The obtained cumulative methane productions are 0.125, 0.165 and 0.052 Nm(3) kg COD(-1) for grape pomace, pulps and seeds, respectively. The effect of grinding on the methane potential of the substrates, as a mechanical pretreatment, was evaluated. We found that it increased the anaerobic biodegradability for grape pomace, pulp and seeds by 13.1%, 4.8% and 22.2%, respectively. On the other hand, the methane potential of the grape pomace was determined in a laboratory pilot plant (12L) continuously mixed with an organic loading rate of 2.5 kg COD m(3) d(-1) and a hydraulic retention time of 30 days. The corresponding biogas production was 6.43 × 10(-3) Nm(3) d(-1), with a methane content of 62.3%. Thus, the pilot plant's efficiency compared to that achieved in the batch process was 81.2%. Finally, a significant correlation was found between the biochemical content and methane production.

  9. Hydrogen production by catalytic processing of renewable methane-rich gases

    Energy Technology Data Exchange (ETDEWEB)

    Muradov, Nazim; Smith, Franklyn; T-Raissi, Ali [Florida Solar Energy Center, University of Central Florida, Cocoa, FL 32922-5703 (United States)

    2008-04-15

    Biomass-derived methane-rich gases such as landfill gas (LFG), biogas and digester gas are promising renewable resources for near-future production of hydrogen. The technical and economical feasibility of hydrogen production via catalytic reforming of LFG and other methane-rich gases is evaluated in this paper. The thermodynamic equilibrium calculations and experimental measurements of reformation of methane-rich CH{sub 4}-CO{sub 2} mixtures over Ni-based catalyst were conducted. The problems associated with the catalyst deactivation due to carbon lay down and effects of steam and oxygen on the process sustainability were explored. Two technological approaches distinguished by the mode of heat input to the endothermic process (i.e., external vs autothermal) were modeled using AspenPlus trademark chemical process simulator and validated experimentally. A 5 kW{sub th} pilot unit for hydrogen production from LFG-mimicking CH{sub 4}-CO{sub 2} mixture was fabricated and operated. A preliminary techno-economic assessment indicates that the liquid hydrogen production costs are in the range of 3.00-7.00 per kilogram depending upon the plant capacity, the process heat input option and whether or not carbon sequestration is included in the process. (author)

  10. Cattle selected for lower residual feed intake have reduced daily methane production.

    Science.gov (United States)

    Hegarty, R S; Goopy, J P; Herd, R M; McCorkell, B

    2007-06-01

    Seventy-six Angus steers chosen from breeding lines divergently selected for residual feed intake (RFI) were studied to quantify the relationship between RFI and the daily rate of methane production (MPR). A 70-d feeding test using a barley-based ration was conducted in which the voluntary DMI, feeding characteristics, and BW of steers were monitored. The estimated breeding value (EBV) for RFI (RFI(EBV)) for each steer had been calculated from 70-d RFI tests conducted on its parents. Methane production rate (g/d) was measured on each steer using SF(6) as a tracer gas in a series of 10-d measurement periods. Daily DMI of steers was lower during the methane measurement period than when methane was not being measured (11.18 vs. 11.88 kg; P = 0.001). A significant relationship existed between MPR and RFI when RFI (RFI(15d)) was estimated over the 15 d when steers were harnessed for methane collection (MPR = 13.3 x RFI(15d) + 179; r(2) = 0.12; P = 0.01). Animals expressing lower RFI had lower daily MPR. The relationship established between MPR and RFI(15d) was used to calculate a reduction in daily methane emission of 13.38 g accompanied a 1 kg/d reduction in RFI(EBV) in cattle consuming ad libitum a diet of 12.1 MJ of ME/kg. The magnitude of this emission reduction was between that predicted on the basis of intake reduction alone (18 g x d(-1) x kg of DMI(-1)) and that predicted by a model incorporating steer midtest BW and level of intake relative to maintenance (5 g x d(-1) x kg of DMI(-1)). Comparison of data from steers exhibiting the greatest (n = 10) and lowest (n = 10) RFI(15d) showed the low RFI(15d) group to not only have lower MPR (P = 0.017) but also reduced methane cost of growth (by 41.2 g of CH(4)/kg of ADG; P = 0.09). Although the opportunity to abate livestock MPR by selection against RFI seems great, RFI explained only a small proportion of the observed variation in MPR. A genotype x nutrition interaction can be anticipated, and the MPR

  11. H{sub 2} production from methane pyrolysis over commercial carbon catalysts: Kinetic and deactivation study

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, D.P.; Botas, J.A. [Chemical and Environmental Technology Department, ESCET, Rey Juan Carlos University, C/Tulipan s/n, 28933 Mostoles (Spain); IMDEA Energia, C/Tulipan s/n, 28933 Mostoles (Spain); Guil-Lopez, R. [Chemical and Environmental Technology Department, ESCET, Rey Juan Carlos University, C/Tulipan s/n, 28933 Mostoles (Spain)

    2009-05-15

    Hydrogen production from catalytic methane decomposition (DeCH{sub 4}) is a simple process to produce high purity hydrogen with no formation of carbon oxides (CO or CO{sub 2}). However, to completely avoid those emissions, the catalyst must not be regenerated. Therefore, it is necessary to use inexpensive catalysts, which show low deactivation during the process. Use of carbon materials as catalysts fulfils these requirements. Methane decomposition catalysed by a number of commercial carbons has been studied in this work using both constant and variable temperature experiments. The results obtained showed that the most active catalyst at short reaction times was activated carbon, but it underwent a fast deactivation due to the deposition of the carbon formed from methane cracking. On the contrary, carbon blacks, and especially the CB-bp sample, present high reaction rates for methane decomposition at both short and long reaction times. Carbon nanotubes exhibit a relatively low activity in spite of containing significant amounts of metals. The initial loss of activity observed with the different catalysts is attributed mainly to the blockage of their micropores due to the deposition of the carbon formed during the reaction. (author)

  12. Optimization of thermal-dilute sulfuric acid pretreatment for enhancement of methane production from cassava residues.

    Science.gov (United States)

    Zhang, Qinghua; Tang, Lei; Zhang, Jianhua; Mao, Zhonggui; Jiang, Li

    2011-02-01

    In this study, the pretreatment of cassava residues by thermal-dilute sulfuric acid (TDSA) hydrolysis was investigated by means of a statistically designed set of experiments. A three-factor central composite design (CCD) was employed to identify the optimum pretreatment condition of cassava residues for methane production. The individual and interactive effects of temperature, H(2)SO(4) concentration and reaction time on increase of methane yield (IMY) were evaluated by applying response surface methodology (RSM). After optimization, the resulting optimum pretreatment condition was 157.84°C, utilizing 2.99% (w/w TS) H(2)SO(4) for 20.15 min, where the maximum methane yield (248 mL/g VS) was 56.96% higher than the control (158 mL/g VS), which was very close to the predict value 56.53%. These results indicate the model obtained through RSM analysis is suit to predict the optimum pretreatment condition and there is great potential of using TDSA pretreatment of cassava residues to enhance methane yield.

  13. Synthesis gas production through redox cycles of bimetallic oxides and methane

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, M.I.S.; Vigil, M.D.D.; Gutierrez, J.S.; Collins-Martinez, V.; Ortiz, A.L. [Centro de Investigacion en Materiales Avanzados, Chihuahua, Chih (Mexico). Dept. de Quimica de Materiales

    2009-01-15

    High-purity hydrogen is required by fuel cells to produce electricity with high efficiency and reduced emissions. Therefore, new and cost effective technologies must be developed that can produce hydrogen to supply the increased demand of the current world market. These new technologies have to overcome several challenges such as large size, weight and cost, high temperature requirements for the process and other associated obstacles such as slow start-ups, storage and transportation issues. Hydrogen production through the partial oxidation of methane (POX) is a well known technology at industrial scale. This paper examined the synthesis, characterization and evaluation of iron (Fe) cerium (Ce) zirconium (Zr) with different Fe to CeZr ratios as oxygen carrier to produce syngas through the partial oxidation of methane. The paper also examined the effect of adding nickel (Ni) to FeCeZr as a catalyst to promote the partial oxidation and the proper assessment of the carbon formation within the reaction system. The paper described the experiment with particular reference to synthesis, characterization and reaction evaluation. The results were presented using X-ray diffraction; crystallite size and BET surface area; reaction evaluation by TGA; and evaluation of the partial oxidation of methane. Experimental values showed a clear trend towards the partial oxidation of methane reaction with samples containing Ni. 28 tabs., 4 tabs., 2 figs.

  14. Evaluation of feeds from tropical origin for in vitro methane production potential and rumen fermentation in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Pal, K.; Patra, A. K.; Sahoo, K.

    2015-07-01

    Enteric methane arising due to fermentation of feeds in the rumen contributes substantially to the greenhouse gas emissions. Thus, like evaluation of chemical composition and nutritive values of feeds, methane production potential of each feed should be determined. This experiment was conducted to evaluate several feeds for methane production potential and rumen fermentation using in vitro gas production technique so that low methane producing feeds could be utilized to feed ruminants. Protein- and energy-rich concentrates (n=11), cereal and grass forages (n=11), and different straws and shrubs (n=12), which are commonly fed to ruminants in India, were collected from a number of locations. Gas production kinetics, methane production, degradability and rumen fermentation greatly varied (p<0.01) among feeds depending upon the chemical composition. Methane production (mL/g of degraded organic matter) was lower (p<0.01) for concentrate than forages, and straws and shrubs. Among shrubs and straws, methane production was lower (p<0.01) for shrubs than straws. Methane production was correlated (p<0.05) with concentrations of crude protein (CP), ether extract and non-fibrous carbohydrate (NFC) negatively, and with neutral detergent (NDF) and acid detergent fiber (ADF) positively. Potential gas production was negatively correlated (p=0.04) with ADF, but positively (p<0.01) with NFC content. Rate of gas production and ammonia concentration were influenced by CP content positively (p<0.05), but by NDF and ADF negatively (p<0.05). Total volatile fatty acid concentration and organic matter degradability were correlated (p<0.05) positively with CP and NFC content, but negatively with NDF and ADF content. The results suggest that incorporation of concentrates and shrubs replacing straws and forages in the diets of ruminants may decrease. (Author)

  15. Microbial electrolysis contribution to anaerobic digestion of waste activated sludge, leading to accelerated methane production

    DEFF Research Database (Denmark)

    Liu, Wenzong; Cai, Weiwei; Guo, Zechong;

    2016-01-01

    Methane production rate (MPR) in waste activated sludge (WAS) digestion processes is typically limitedby the initial steps of complex organic matter degradation, leading to a limited MPR due to sludgefermentation speed of solid particles. In this study, a novel microbial electrolysis AD reactor (ME......-AD) wasused to accelerate methane production for energy recovery from WAS. Carbon bioconversion wasaccelerated by ME producing H2 at the cathode. MPR was enhanced to 91.8 gCH4/m3 reactor/d in themicrobial electrolysis ME-AD reactor, thus improving the rate by 3 times compared to control conditions (30.6 gCH4......-AD reactor allowed to significantly enhance carbon degradation and methaneproduction from WAS....

  16. Effect of fat supplementation and stage of lactation on methane production in dairy cows

    DEFF Research Database (Denmark)

    Alstrup, Lene; Hellwing, Anne Louise Frydendahl; Lund, Peter

    2015-01-01

    decreased milk yield, both measured as kg milk and kg energy corrected milk (ECM). Fat supplementation increased milk yield compared to CON, however ECM yield was not affected. Milk protein concentration decreased with fat supplementation. Methane production increased with DIM when measured in L/d, L/kg DMI......The aim was to determine the effect of fat supplementation on methane (CH4) production and to study if the effect persists over time as lactation progresses. Rumen microbial protein synthesis and thereby milk yield may be reduced when fermentable organic matter (OM) is replaced by nonfermentable...... treatments: Control (CON), CON supplemented with whole cracked rapeseed (WCR), CON supplemented with vegetable rumen protected fat (Lipmix 40/60, Lipitec, NLM Vantinge Aps, Ringe, Denmark) (RPF), and RPF supplemented with HMBi (MetaSmart, Adisseo, France) (RPFA). All diets contained maize silage (230 g...

  17. Methane production enhancement by an independent cathode in integrated anaerobic reactor with microbial electrolysis

    DEFF Research Database (Denmark)

    Cai, Weiwei; Han, Tingting; Guo, Zechong

    2016-01-01

    Anaerobic digestion (AD) represents a potential way to achieve energy recovery from waste organics. In this study, a novel bioelectrochemically-assisted anaerobic reactor is assembled by two AD systems separated by anion exchange membrane, with the cathode placing in the inside cylinder (cathodic...... AD) and the anode on the outside cylinder (anodic AD). In cathodic AD, average methane production rate goes up to 0.070 mL CH4/mL reactor/day, which is 2.59 times higher than AD control reactor (0.027 m3 CH4/m3/d). And COD removal is increased ~15% over AD control. When changing to sludge...... indicates that cathodic AD could cost-effectively enhance methane production rate and degradation of glucose and fermentative liquid....

  18. Effects of Oxytetracycline on Methane Production and the Microbial Communities During Anaerobic Digestion of Cow Manure

    Institute of Scientific and Technical Information of China (English)

    KE Xin; WANG Chun-yong; LI Run-dong; ZHANG Yun

    2014-01-01

    The effects of different concentrations of oxytetracycline (OTC) on the dynamics of bacterial and archaeal communities during the mesophilic anaerobic digestion (37°C) of cow manure were investigated. Before anaerobic digestion, OTC was added to digesters at concentrations of 20, 50, and 80 mg L-1, respectively. Compared with no-antibiotic control, all methane productions underwent different levels of inhibition at different concentrations of OTC. Changes in the bacterial and archaeal communities were discussed by using PCR-denaturing gradient gel electrophoresis (DGGE). Results showed that OTC affected the richness and diversity of bacterial and archaeal communities. The bacterial genus Flavobacterium and an uncultured bacterium (JN256083.1) were detected throughout the entire process of anaerobic digestion and seemed to be the functional bacteria. Methanobrevibacter boviskoreani and an uncultured archaeon (FJ230982.1) dominated the archaeal communities during anaerobic digestion. These microorganisms may have high resistance to OTC and may play vital roles in methane production.

  19. Methane production from the red seaweed gracilaria tikvahiae

    Energy Technology Data Exchange (ETDEWEB)

    Hanisak, M.D.

    1981-01-01

    Stable continuous anaerobic digestion of the title seaweed was maintained in large (120 L) digesters for more than 20 months, with an average gas (60% CH4) production of 0.4 L/g volatile solids. The average bioconversion efficiency was approximately 48%. When the retention time, t, was increased (i.e., loading rate decreased) from 10 to 60 days the total production of biogas and CH4 (as well as the percent CH4 and the reduction of total volatile solids) increased to maximum at t = 30 days and decreased at t = 60 days. Biogas and CH4 production on the basis of volatile solids added increased to less than or equal to 60 days, as did the percent volatile solids reduction. The pH in the digesters increased with increasing t.

  20. Effect of nickel ions on anaerobic methane production from water hyacinth.

    Science.gov (United States)

    Cai, Xuan; Hong, Zi-Jian; Dai, Rui-Hua; Liu, Yan; Liu, Xiang

    2012-01-01

    The effect of different concentrations of nickel ions (Ni(2+), 0, 10, 40 and 80 mg/L) on the anaerobic methane production of water hyacinth were investigated. Under these four concentrations, the methane production in 40 d was 2,275, 2,703, 3,210 and 2,481 mL, respectively. This situation illustrated that the Ni(2+) promoted the growth of hydrogen-producing acetic acid bacteria and methanogenic bacteria, even at high concentrations (i.e. 40-80 mg/L). The highest methane production per unit weight water hyacinth reached 206 mL/gTS with 40 mg/L Ni(2+). Meanwhile, the modified Gompertz and Logistic equations were applied to describe the effect on anaerobic culture of Ni(2+). According to these models, the values of methane production potential (mL) for four concentrations were in the following order: 40 mg/L (3,123.42 ± 60.08) > 10 mg/L (2,541.16 ± 46.94) > 80 mg/L (2,432.36 ± 40.18) > 0 mg/L (2,238.10 ± 31.90). According to the analysis of the digestate, the residual concentration of Ni(2+) was approximately 1.05-4.9 mg/L, which was relatively low compared with the Ni(2+) concentrations in the raw feedstock. The results would provide academic guidance and technical support for treatment of water hyacinth with an accumulation of heavy metals.

  1. Temperature response of methane oxidation and production potentials in peatland ecosystems across Finland

    Science.gov (United States)

    Welti, Nina; Korrensalo, Aino; Kerttula, Johanna; Maljanen, Marja; Uljas, Salli; Lohila, Annalea; Laine, Anna; Vesala, Timo; Elliott, David; Tuittila, Eeva-Stiina

    2016-04-01

    It has been suggested that the ecosystems located in the high latitudes are especially sensitive to warming. Therefore, we compared 14 peatland systems throughout Finland along a latitudinal gradient from 69°N to 61°N to examine the response of methane production and methane oxidation with warming climate. Peat samples were taken at the height of the growing season in 2015 from 0 - 10cm below the water table depth. The plant communities in sampling locations were described by estimating cover of each plant species and pH of water was measured. Upon return to the lab, we made two parallel treatments, under anoxic and oxic conditions in order to calculate the CH4 production and consumption potentials of the peat and used three temperatures, 4°C, 17.5°C, and 30°C to examine the temperature effect on the potentials. We hypothesized that there will be an observable response curve in CH4 production and oxidation relative to temperature with a greater response with increasing latitude. In general, increasing temperature increased the potential for CH4 production and oxidation, at some sites, the potential was highest at 17.5°C, indicating that there is an optimum temperature threshold for the in situ methane producing and oxidizing microbial communities. Above this threshold, the peat microbial communities are not able to cope with increasing temperature. This is especially noticeable for methane oxidation at sites above 62°N. As countries are being expected to adequately account for their greenhouse gas budgets with increasing temperature models, knowing where the temperature threshold exists is of critical importance.

  2. Bioelectrochemical enhancement of methane production in low temperature anaerobic digestion at 10 °C.

    Science.gov (United States)

    Liu, Dandan; Zhang, Lei; Chen, Si; Buisman, Cees; Ter Heijne, Annemiek

    2016-08-01

    Anaerobic digestion at low temperature is an attractive technology especially in moderate climates, however, low temperature results in low microbial activity and low rates of methane formation. This study investigated if bioelectrochemical systems (BESs) can enhance methane production from organic matter in low-temperature anaerobic digestion (AD). A bioelectrochemical reactor was operated with granular activated carbon as electrodes at 10 °C. Our results showed that bioelectrochemical systems can enhance CH4 yield, accelerate CH4 production rate and increase acetate removal efficiency at 10 °C. The highest CH4 yield of 31 mg CH4-COD/g VSS was achieved in the combined BES-AD system at a cathode potential of -0.90 V (Ag/AgCl), which was 5.3-6.6 times higher than that in the AD reactor at 10 °C. CH4 production rate achieved in the combined BES-AD system at 10 °C was only slightly lower than that in the AD reactor at 30 °C. The presence of an external circuit between the acetate-oxidizing bioanode and methane-producing cathode provided an alternative pathway from acetate via electrons to methane, potentially via hydrogen. This alternative pathway seems to result in higher CH4 production rates at low temperature compared with traditional methanogenesis from acetate. Integration of BES with AD could therefore be an attractive alternative strategy to enhance the performance of anaerobic digestion in cold areas.

  3. Magnetite nanoparticles facilitate methane production from ethanol via acting as electron acceptors.

    Science.gov (United States)

    Yang, Zhiman; Shi, Xiaoshuang; Wang, Chuanshui; Wang, Lin; Guo, Rongbo

    2015-11-12

    Potential for interspecies hydrogen transfer within paddy soil enrichments obtained via addition of magnetite nanoparticles and ethanol (named as PEM) was investigated. To do this, PEM derived from rice field of Hangzhou (named as PEM-HZ) was employed, because it offered the best methane production performance. Methane production and Fe (III) reduction proceeded in parallel in the presence of magnetite. Inhibition experiments with 2-bromoethane sulfonate (BES) or phosphate showed that interspecies hydrogen transfer and Fe (III) reduction also occurred in methane production from ethanol. 16S rRNA-based Illumina sequencing results showed that Dechloromonas, Thauera, Desulfovibrio and Clostridium were the dominant putative Fe (III) -reducers, and that hydrogenotrophic Methanobacterium accounted for about 88% of the total archaeal community. These results indicated that magnetite nanoparticles that acted as electron acceptor could facilitate rapid oxidation of ethanol by members of the Fe (III) -reducers in PEM-HZ and establishment of the syntrophic relationship of Fe (III) -reducers with Methanobacterium via interspecies hydrogen transfer. Our results could offer a model to understand the microbial interaction with magnetite from a novel angle during methanogenesis.

  4. Toward a Functional Definition of Methane Super-Emitters: Application to Natural Gas Production Sites.

    Science.gov (United States)

    Zavala-Araiza, Daniel; Lyon, David; Alvarez, Ramón A; Palacios, Virginia; Harriss, Robert; Lan, Xin; Talbot, Robert; Hamburg, Steven P

    2015-07-07

    Emissions from natural gas production sites are characterized by skewed distributions, where a small percentage of sites-commonly labeled super-emitters-account for a majority of emissions. A better characterization of super-emitters is needed to operationalize ways to identify them and reduce emissions. We designed a conceptual framework that functionally defines superemitting sites as those with the highest proportional loss rates (methane emitted relative to methane produced). Using this concept, we estimated total methane emissions from natural gas production sites in the Barnett Shale; functionally superemitting sites accounted for roughly three-fourths of total emissions. We discuss the potential to reduce emissions from these sites, under the assumption that sites with high proportional loss rates have excess emissions resulting from abnormal or otherwise avoidable operating conditions, such as malfunctioning equipment. Because the population of functionally superemitting sites is not expected to be static over time, continuous monitoring will likely be necessary to identify them and improve their operation. This work suggests that achieving and maintaining uniformly low emissions across the entire population of production sites will require mitigation steps at a large fraction of sites.

  5. Intake, performance and estimated methane production of Nellore steers fed soybean grain

    Directory of Open Access Journals (Sweden)

    Juliana Duarte Messana

    2014-12-01

    Full Text Available The objective of this study was to evaluate nutrient intake, performance, estimated methane production and carcass characteristics of steers fed diets containing three different levels of soybean grain: 0, 120 and 230 g/kg on the dry matter (DM. The study was conducted on eighteen castrated Nellore males with an average initial body weight (BW of 370±12 kg in a completely randomized design, with three treatments and six repetitions. Intake of dry matter (DMI, kg/day and crude protein tended to decrease linearly, and the intake of ether extract increased linearly in response to the soybean grain levels in the diet. Levels of soybean grain in the diet did not affect DMI (g/kg of BW, final average weight, average daily weight gain, feed efficiency and estimated methane production. Animals fed diets with different levels of soybean grain were not different with respect to carcass yield, loin eye area, subcutaneous fat thickness, or bone, muscle and fat ratios. Carcass characteristics and meat quality were also not significantly different. Replacement of soybean meal by soybean grain in the diet alters the intake of crude protein and ether extract but does not affect performance, estimates of methane production, or carcass characteristics of feedlot Nellore.

  6. The distribution of methane in groundwater in Alberta (Canada) and associated aqueous geochemistry conditions

    Science.gov (United States)

    Humez, Pauline; Mayer, Bernhard; Nightingale, Michael; Becker, Veith; Kingston, Andrew; Taylor, Stephen; Millot, Romain; Kloppmann, Wolfram

    2016-04-01

    Development of unconventional energy resources such as shale gas and coalbed methane has generated some public concern with regard to the protection of groundwater and surface water resources from leakage of stray gas from the deep subsurface. In terms of environmental impact to and risk assessment of shallow groundwater resources, the ultimate challenge is to distinguish: (a) natural in-situ production of biogenic methane, (b) biogenic or thermogenic methane migration into shallow aquifers due to natural causes, and (c) thermogenic methane migration from deep sources due to human activities associated with the exploitation of conventional or unconventional oil and gas resources. We have conducted a NSERC-ANR co-funded baseline study investigating the occurrence of methane in shallow groundwater of Alberta (Canada), a province with a long record of conventional and unconventional hydrocarbon exploration. Our objective was to assess the occurrence and sources of methane in shallow groundwaters and to also characterize the hydrochemical environment in which the methane was formed or transformed through redox processes. Ultimately our aim was to determine whether methane was formed in-situ or whether it migrated from deeper formations into shallow aquifers. Combining hydrochemical and dissolved and free geochemical gas data from 372 groundwater samples obtained from 186 monitoring wells of the provincial groundwater observation well network (GOWN) in Alberta, it was found that methane is ubiquitous in groundwater in Alberta and is predominantly of biogenic origin. The highest concentrations of dissolved biogenic methane (> 0.01 mM or > 0.2 mg/L), characterized by δ13CCH4 values migrated in significant amounts into shallow aquifers either naturally or via anthropogenically induced pathways. This study shows that the combined interpretation of aqueous geochemistry data in concert with the chemical and isotopic composition of dissolved and/or free gas can yield

  7. Saccharomyces cerevisiae Live Cells Decreased In vitro Methane Production in Intestinal Content of Pigs.

    Science.gov (United States)

    Gong, Y L; Liao, X D; Liang, J B; Jahromi, M F; Wang, H; Cao, Z; Wu, Y B

    2013-06-01

    An in vitro gas production technique was used in this study to elucidate the effect of two strains of active live yeast on methane (CH4) production in the large intestinal content of pigs to provide an insight to whether active live yeast could suppress CH4 production in the hindgut of pigs. Treatments used in this study include blank (no substrate and no live yeast cells), control (no live yeast cells) and yeast (YST) supplementation groups (supplemented with live yeast cells, YST1 or YST2). The yeast cultures contained 1.8×10(10) cells per g, which were added at the rates of 0.2 mg and 0.4 mg per ml of the fermented inoculum. Large intestinal contents were collected from 2 Duroc×Landrace×Yorkshire pigs, mixed with a phosphate buffer (1:2), and incubated anaerobically at 39°C for 24 h using 500 mg substrate (dry matter (DM) basis). Total gas and CH4 production decreased (pyeast. The methane production reduction potential (MRP) was calculated by assuming net methane concentration for the control as 100%. The MRP of yeast 2 was more than 25%. Compared with the control group, in vitro DM digestibility (IVDMD) and total volatile fatty acids (VFA) concentration increased (pyeast supplementation. Quantity of methanogenic archaea per milliliter of inoculum decreased (pyeast supplementation after 24 h of incubation. Our results suggest that live yeast cells suppressed in vitro CH4 production when inoculated into the large intestinal contents of pigs and shifted the fermentation pattern to favor propionate production together with an increased population of acetogenic bacteria, both of which serve as a competitive pathway for the available H2 resulting in the reduction of methanogenic archaea.

  8. Diamond dissolution and the production of methane and other carbon-bearing species in hydrothermal diamond-anvil cells

    Science.gov (United States)

    Chou, I.-Ming; Anderson, Alan J.

    2009-01-01

    Raman analysis of the vapor phase formed after heating pure water to near critical (355-374 ??C) temperatures in a hydrothermal diamond-anvil cell (HDAC) reveals the synthesis of abiogenic methane. This unexpected result demonstrates the chemical reactivity of diamond at relatively low temperatures. The rate of methane production from the reaction between water and diamond increases with increasing temperature and is enhanced by the presence of a metal gasket (Re, Ir, or Inconel) which is compressed between the diamond anvils to seal the aqueous sample. The minimum detection limit for methane using Raman spectroscopy was determined to be ca. 0.047 MPa, indicating that more than 1.4 nanograms (or 8.6 ?? 10-11 mol) of methane were produced in the HDAC at 355 ??C and 30 MPa over a period of ten minutes. At temperatures of 650 ??C and greater, hydrogen and carbon dioxide were detected in addition to methane. The production of abiogenic methane, observed in all HDAC experiments where a gasket was used, necessitates a reexamination of the assumed chemical systems and intensive parameters reported in previous hydrothermal investigations employing diamonds. The results also demonstrate the need to minimize or eliminate the production of methane and other carbonic species in experiments by containing the sample within a HDAC without using a metal gasket.

  9. Methane production from the Anaerobic digestion of some Marine Macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Habig, C.; Ryther, J.H.

    1983-01-01

    Recently, considerable interest has developed concerning the use of biomass as an alternative fuel source. Among the possible substrates, marine plant biomass has frequently been mentioned, primarily due to the fact that such plants do not have competing, more valuable uses for food or fiber and their cultivation does not compete for valuable agricultural lands (1,2). Also, recent research has demonstrated that at least one potential marine energy crop, the red alga Gracilaria tikvahiae, is capable of extremely high production rates that equal or exceed those of terrestrial plants, and are rivaled by the productivity of another possible aquatic energy crop, the water hyacinth. To date, seaweed energy research has emphasized cultivation, while a marked paucity of information exists regarding the comparative performance of these algae as a methanogenic substrate. Only two species, the giant kelp, Macrocystic pyrifera and Gracilaria tikvahiae, have been tested in fermentation trials. The relative merits of a red, a green, and a brown alga, run vis a vis at four different loading rates are discussed in this report. In addition, two loading procedures were utilized to assess what if any, effect they might have on digester performance.

  10. Methane production from the anaerobic digestion of some marine macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Habig, C.; Ryther, J.H.

    1983-01-01

    Recently, considerable interest has developed concerning the use of biomass as an alternative fuel source. Among the possible substrates, marine plant biomass has frequently been mentioned, primarily due to the fact that such plants do not have competing, more valuable uses for food or fiber and their cultivation does not compete for valuable agricultural lands. Also, recent research has demonstrated that at least one potential marine energy crop, the red alga Graciliaria tikvahiae, is capable of extremely high production rates that equal or exceed those of terrestrial plants, and are rivaled by the productivity of another possible aquatic energy crop, the water hyacinth. To date, seaweed energy research has emphasized cultivation, while a marked paucity of information exists regarding the comparative performance of these algae as a methanogenic substrate. Only two species, the giant kelp, Macrocystic pyrifera and Gracilaria tikvahiae, have been tested in fermentation trials. The relative merits of a red, a green, and a brown alga, run vis a vis at four different loading rates, are discussed in this report. In addition, two loading procedures were utilized to assess what if any, effect they might have on digester performance. (Refs. 14).

  11. Simultaneous enhancement of methane production and methane content in biogas from waste activated sludge and perennial ryegrass anaerobic co-digestion: The effects of pH and C/N ratio.

    Science.gov (United States)

    Dai, Xiaohu; Li, Xiaoshuai; Zhang, Dong; Chen, Yinguang; Dai, Lingling

    2016-09-01

    It is necessary to find an appropriate strategy to simultaneously enhance the methane production and methane content in biogas from waste activated sludge (WAS) and grass co-digestion. In this study an efficient strategy, i.e., adjusting the initial pH 12 and C/N ratio 17/1, for simultaneous enhancement of methane production and methane content in biogas from WAS and perennial ryegrass co-digestion was reported. Experimental results indicated that the maximal methane production was 310mL/gVSadd at the optimum conditions after 30-d anaerobic digestion, which was, respectively, about 1.5- and 3.8-fold of the sole WAS and sole perennial ryegrass anaerobic digestion. Meanwhile, the methane content in biogas was about 74%, which was much higher than that of sole WAS (64%) or sole perennial ryegrass (54%) anaerobic digestion.

  12. Production of biogenic amines by lactic acid bacteria and enterobacteria isolated from fresh pork sausages packaged in different atmospheres and kept under refrigeration.

    Science.gov (United States)

    Curiel, J A; Ruiz-Capillas, C; de Las Rivas, B; Carrascosa, A V; Jiménez-Colmenero, F; Muñoz, R

    2011-07-01

    The occurrence of in vitro amino acid activity in bacterial strains associated with fresh pork sausages packaged in different atmospheres and kept in refrigeration was studied. The presence of biogenic amines in decarboxylase broth was confirmed by ion-exchange chromatography and by the presence of the corresponding decarboxylase genes by PCR. From the 93 lactic acid bacteria and 100 enterobacteria strains analysed, the decarboxylase medium underestimates the number of biogenic amine-producer strains. 28% of the lactic acid bacteria produced tyramine and presented the tdc gene. All the tyramine-producer strains were molecularly identified as Carnobacterium divergens. Differences on the relative abundance of C. divergens were observed among the different packaging atmospheres assayed. After 28 days of storage, the presence of argon seems to inhibit C. divergens growth, while packing under vacuum seems to favour it. Among enterobacteria, putrescine was the amine more frequently produced (87%), followed by cadaverine (85%); agmatine and tyramine were only produced by 13 and 1%, respectively, of the strains analysed. Packing under vacuum or in an atmosphere containing nitrogen seems to inhibit the growth of enterobacteria which produce simultaneously putrescine, cadaverine, and agmatine. Contrarily, over-wrapping or packing in an atmosphere containing argon seems to favour the growth of agmatine producer-enterobacteria. The production of putrescine and cadaverine was associated with the presence of the corresponding amino acid decarboxylase genes. The biogenic amine-producer strains were included in a wide range of enterobacterial species, including Kluyvera intermedia, Enterobacter aerogenes, Yersinia kristensenii, Serratia grimesii, Serratia ficaria, Yersinia rodhei, Providencia vermicola and Obesumbacterium proteus.

  13. Methane emissions from process equipment at natural gas production sites in the United States: liquid unloadings.

    Science.gov (United States)

    Allen, David T; Sullivan, David W; Zavala-Araiza, Daniel; Pacsi, Adam P; Harrison, Matthew; Keen, Kindal; Fraser, Matthew P; Daniel Hill, A; Lamb, Brian K; Sawyer, Robert F; Seinfeld, John H

    2015-01-01

    Methane emissions from liquid unloadings were measured at 107 wells in natural gas production regions throughout the United States. Liquid unloadings clear wells of accumulated liquids to increase production, employing a variety of liquid lifting mechanisms. In this work, wells with and without plunger lifts were sampled. Most wells without plunger lifts unload less than 10 times per year with emissions averaging 21,000-35,000 scf methane (0.4-0.7 Mg) per event (95% confidence limits of 10,000-50,000 scf/event). For wells with plunger lifts, emissions averaged 1000-10,000 scf methane (0.02-0.2 Mg) per event (95% confidence limits of 500-12,000 scf/event). Some wells with plunger lifts are automatically triggered and unload thousands of times per year and these wells account for the majority of the emissions from all wells with liquid unloadings. If the data collected in this work are assumed to be representative of national populations, the data suggest that the central estimate of emissions from unloadings (270 Gg/yr, 95% confidence range of 190-400 Gg) are within a few percent of the emissions estimated in the EPA 2012 Greenhouse Gas National Emission Inventory (released in 2014), with emissions dominated by wells with high frequencies of unloadings.

  14. Methane production and microbial community structure for alkaline pretreated waste activated sludge.

    Science.gov (United States)

    Sun, Rui; Xing, Defeng; Jia, Jianna; Zhou, Aijuan; Zhang, Lu; Ren, Nanqi

    2014-10-01

    Alkaline pretreatment was studied to analyze the influence on waste activated sludge (WAS) reduction, methane production and microbial community structure during anaerobic digestion. Methane production from alkaline pretreated sludge (A-WAS) (pH = 12) increased from 251.2 mL/Ld to 362.2 mL/Ld with the methane content of 68.7% compared to raw sludge (R-WAS). Sludge reduction had been improved, and volatile suspended solids (VSS) removal rate and protein reduction had increased by ∼ 10% and ∼ 35%, respectively. The bacterial and methanogenic communities were analyzed using 454 pyrosequencing and clone libraries of 16S rRNA gene. Remarkable shifts were observed in microbial community structures after alkaline pretreatment, especially for Archaea. The dominant methanogenic population changed from Methanosaeta for R-WAS to Methanosarcina for A-WAS. In addition to the enhancement of solubilization and hydrolysis of anaerobic digestion of WAS, alkaline pretreatment showed significant impacts on the enrichment and syntrophic interactions between microbial communities.

  15. Methane production from rice straw with acclimated anaerobic sludge: effect of phosphate supplementation.

    Science.gov (United States)

    Lei, Zhongfang; Chen, Jiayi; Zhang, Zhenya; Sugiura, Norio

    2010-06-01

    Rice straw particles were directly used as substrate for anaerobic digestion with acclimated sludge under room temperature and different levels of phosphate. Two obvious biogas production peaks were observed for all reactors, with biogas or methane yields of (0.33-0.35)m(3)/kg-VS loaded or (0.27-0.29)m(3) CH(4)/kg-VS loaded and average methane contents of 75.9-78.2%. A separated two-stage first-order kinetic model was developed in this study and showed a good fit to the experimental data when this complicated process was divided into two stages. The average biogas and methane production rate constants were (0.027-0.031)d(-1) and (0.028-0.033)d(-1), respectively, increased by 2-3 times in the second stages than those in the first. The results indicated that an adequate level of phosphate addition (465 mg-P/L) could accelerate the biogasification process: 7-13 days earlier appearance of the two peaks and shorter time needed for complete biogasification of rice straw.

  16. Massive production of abiotic methane during subduction evidenced in metamorphosed ophicarbonates from the Italian Alps

    Science.gov (United States)

    Vitale Brovarone, Alberto; Martinez, Isabelle; Elmaleh, Agnès; Compagnoni, Roberto; Chaduteau, Carine; Ferraris, Cristiano; Esteve, Imène

    2017-01-01

    Alteration of ultramafic rocks plays a major role in the production of hydrocarbons and organic compounds via abiotic processes on Earth and beyond and contributes to the redistribution of C between solid and fluid reservoirs over geological cycles. Abiotic methanogenesis in ultramafic rocks is well documented at shallow conditions, whereas natural evidence at greater depths is scarce. Here we provide evidence for intense high-pressure abiotic methanogenesis by reduction of subducted ophicarbonates. Protracted (≥0.5–1 Ma), probably episodic infiltration of reduced fluids in the ophicarbonates and methanogenesis occurred from at least ∼40 km depth to ∼15–20 km depth. Textural, petrological and isotopic data indicate that methane reached saturation triggering the precipitation of graphitic C accompanied by dissolution of the precursor antigorite. Continuous infiltration of external reducing fluids caused additional methane production by interaction with the newly formed graphite. Alteration of high-pressure carbonate-bearing ultramafic rocks may represent an important source of abiotic methane, with strong implications for the mobility of deep C reservoirs. PMID:28223715

  17. Nitrogen recycling and methane production using Gracilaria tikvahiae: a closed system approach

    Energy Technology Data Exchange (ETDEWEB)

    Habig, C.; Andrews, D.A.; Ryther, J.H.

    1984-01-01

    The macroalga Gracilaria tikvahiae (Rhodophyta) was used in a closed system of materials to study methane production and nitrogen recycling. Twenty liter carboys served as digesters. The performance of these digesters mirrors results obtained with two- and four litre Gracilaria digesters with respect to optimal retention times for biogas production, methane content, and bioconversion efficiency to methane. Three groups of Gracilaria were cultivated in 850-L vaults to compare growth performance under three different enrichment treatments. These treatments consisted of an unfertilized group, a group raised on a typical commercial enrichment regime, and a group raised on the residues removed from the digester when additional substrate was loaded into the digester. The results indicate that growth of Gracilaria on the digester residue enrichment scheme is statistically similar to growth using a commercial enrichment mixture. In addition, the nitrogen content of the digester residue is described, along with nitrogen assimilation by Gracilaria and nitrogen recycling efficiencies. Both nitrogen assimilation and recycling efficiency closely parallel the ammonium content of the residue enrichment media. (Refs. 18).

  18. Combustible gas production (methane) and biodegradation of solid and liquid mixtures of meat industry wastes

    Energy Technology Data Exchange (ETDEWEB)

    Marcos, A.; Al-Kassir, A.; Cuadros, F.; Lopez-Rodriguez, F. [School of Engineering, University of Extremadura, Avda. De Elva, s/n, 06071, Badajoz (Spain); Mohamad, A.A. [Department of Mechanical and Manufacturing Engineering, University of Calgary, 2500 University Dr. N.W., Calgary, Alberta (Canada)

    2010-05-15

    This work is devoted to determine the optimal operational conditions on the methane production as well as on the biodegradation obtained from the anaerobic codigestion of solid (fat, intestines, rumen, bowels, whiskers, etc.) and liquid (blood, washing water, manure, etc.) wastes of meat industry, particularly the ones rising from the municipal slaughterhouse of Badajoz (Spain). The experiments were performed using a 2 l capacity discontinuous digester at 38 C. The loading rate were 0.5, 1, 2, 3, and 4.5 g COD for wastewater (washing water and blood; Mixture 1), and 0.5, 1, 2, 3, and 4 g COD for the co-digestion of a mixture of 97% liquid effluent and 3% solid wastes v/v (Mixture 2) which represents the annual mean composition of the waste generated by the slaughterhouse. The maximal biodegradation rates obtained were: Mixture 1, 56.9% for a COD load of 1 g; and Mixture 2, 19.1% for a COD load of 2 g. For both mixtures, the greatest methane production was for the maximum COD load (4.5 g for Mixture 1, and 4 g for Mixture 2), at which values the amounts of methane obtained during and at the end of the co-digestion were practically indistinguishable between the two mixtures. The results will be used to design, construct, and establish the optimal operating conditions of a continuous complete-mixture biodigester. (author)

  19. Gravimetric analysis of the solubility of methane in high boiling hydrocarbons and petroleum products; Gravimetrische Bestimmung der Loeslichkeit von Methan in hoeher siedenden Kohlenwasserstoffen und Erdoelprodukten

    Energy Technology Data Exchange (ETDEWEB)

    Laux, H.; Rahimian, I. [Institut fuer Erdoel- und Erdgasforschung, Clausthal-Zellerfeld (Germany)

    2001-05-01

    The solubility of methane has a great influence on the colloid stability of crude oils at the conditions of production. Adequate data are needed for the modelling of the beginning of asphaltene precipitation as the result of the destabilization. Because such data are limited in the literature a magnetic suspension balance was used. By means of the magnetic suspension balance the solubility of gases in high boiling products can be determined by the weight difference resulting from the steped pressure reduction. The solubility of methane was investigated in different n-alkanes and squalane as well as a wax, a slack wax, a extract from the solvent raffination and a atmospheric crude oil residue. The aim was to investigate the influence of the molare weight, the structure and the composition of mixture on the solubility of methane. The pressure was varied in the region to 120 bar, the temperature was predominantly 75 C. The influence of the temperature on the solubility of methane was studied in the slack wax and the atmospheric residue. The results and the advantage as well as the disadvantage of the using of the magnetic suspension balance will be discussed. (orig.)

  20. Discrimination of abiogenic and biogenic alkane gases

    Institute of Scientific and Technical Information of China (English)

    DAI JinXing; MI JingKui; LI ZhiSheng; HU AnPing; YANG Chun; ZHOU QingHua; SHUAI YanHua; ZHANG Ying; MA ChengHua; ZOU CaiNeng; ZHANG ShuiChang; LI Jian; NI YunYan; HU GuoYi; LUO Xia; TAO ShiZhen; ZHU GuangYou

    2008-01-01

    We have combined the analytical data of the carbon isotope distribution pattern, R/Ra and cliche values of abiogenic and biogenic (referring to the therrnogenic and bacterial or microbial) alkane gases in China with those of alkane gases from USA, Russia, Germany, Australia and other countries. Four discrimination criteria are derived from this comparative study: 1) Carbon isotopic composition is generally greater than -30‰ for abiogenic methane and less than -30‰ for biogenic methane; 2)Abiogenic alkane gases have a carbon isotopic reversal trend (Δ13c1>Δ13c2>Δ13c3>Δ13c4) with Δ13c1>-30‰ in general; 3) Gases with R/Ra>0.5 and Δ13c1- Δ13c2>0 are of abiogenic origin; 4) Gases (methane) with CH4/3He≤106 are of abiogenic origin, whereas gases with CH4/3He≥1011 are of biogenic origin.

  1. Carbon and nitrogen removal and enhanced methane production in a microbial electrolysis cell.

    Science.gov (United States)

    Villano, Marianna; Scardala, Stefano; Aulenta, Federico; Majone, Mauro

    2013-02-01

    The anode of a two-chamber methane-producing microbial electrolysis cell (MEC) was poised at +0.200V vs. the standard hydrogen electrode (SHE) and continuously fed (1.08gCOD/Ld) with acetate in anaerobic mineral medium. A gas mixture (carbon dioxide 30vol.% in N(2)) was continuously added to the cathode for both pH control and carbonate supply. At the anode, 94% of the influent acetate was removed, mostly through anaerobic oxidation (91% coulombic efficiency); the resulting electric current was mainly recovered as methane (79% cathode capture efficiency). Low biomass growth was observed at the anode and ammonium was transferred through the cationic membrane and concentrated at the cathode. These findings suggest that the MEC can be used for the treatment of low-strength wastewater, with good energy efficiency and low sludge production.

  2. Effect of Catalytic Cylinders on Autothermal Reforming of Methane for Hydrogen Production in a Microchamber Reactor

    Directory of Open Access Journals (Sweden)

    Yunfei Yan

    2014-01-01

    Full Text Available A new multicylinder microchamber reactor is designed on autothermal reforming of methane for hydrogen production, and its performance and thermal behavior, that is, based on the reaction mechanism, is numerically investigated by varying the cylinder radius, cylinder spacing, and cylinder layout. The results show that larger cylinder radius can promote reforming reaction; the mass fraction of methane decreased from 26% to 21% with cylinder radius from 0.25 mm to 0.75 mm; compact cylinder spacing corresponds to more catalytic surface and the time to steady state is decreased from 40 s to 20 s; alteration of staggered and aligned cylinder layout at constant inlet flow rates does not result in significant difference in reactor performance and it can be neglected. The results provide an indication and optimize performance of reactor; it achieves higher conversion compared with other reforming reactors.

  3. Effect of catalytic cylinders on autothermal reforming of methane for hydrogen production in a microchamber reactor.

    Science.gov (United States)

    Yan, Yunfei; Guo, Hongliang; Zhang, Li; Zhu, Junchen; Yang, Zhongqing; Tang, Qiang; Ji, Xin

    2014-01-01

    A new multicylinder microchamber reactor is designed on autothermal reforming of methane for hydrogen production, and its performance and thermal behavior, that is, based on the reaction mechanism, is numerically investigated by varying the cylinder radius, cylinder spacing, and cylinder layout. The results show that larger cylinder radius can promote reforming reaction; the mass fraction of methane decreased from 26% to 21% with cylinder radius from 0.25 mm to 0.75 mm; compact cylinder spacing corresponds to more catalytic surface and the time to steady state is decreased from 40 s to 20 s; alteration of staggered and aligned cylinder layout at constant inlet flow rates does not result in significant difference in reactor performance and it can be neglected. The results provide an indication and optimize performance of reactor; it achieves higher conversion compared with other reforming reactors.

  4. Solid-state co-digestion of expired dog food and corn stover for methane production.

    Science.gov (United States)

    Xu, Fuqing; Li, Yebo

    2012-08-01

    Expired dog food was co-digested with corn stover for biogas production via solid-state anaerobic digestion (SS-AD) at feedstock-to-effluent (F/E) ratios of 2, 4, and 6 using effluent from a sewage sludge digester as inoculum. Degradation of the main components in dog food and corn stover was measured. Higher methane yields were obtained at lower F/E ratios and at higher percentages of dog food in the substrate. The highest methane yield of 304.4 L/kg VS(feed) was obtained for the substrate containing 50% corn stover and 50% dog food, which was an increase of 229% and 109% compared to digesting corn stover and dog food alone, respectively. Co-digestion of corn stover with dog food reduced the start-up time and volatile fatty acid (VFA) accumulation, but decreased the cellulose and xylan degradation of corn stover.

  5. Optimisation of a microwave pretreatment of wheat straw for methane production.

    Science.gov (United States)

    Jackowiak, D; Bassard, D; Pauss, A; Ribeiro, T

    2011-06-01

    This study aims at the optimisation of a microwave pretreatment for wheat straw solubilisation and anaerobic biodegradability. The maximum yield of methane production was obtained at 150°C with an improvement of 28% compared to an untreated sample. In addition, at this temperature, the time to reach 80% of the methane volume obtained from untreated straw was about 35%. The study of ramp time and holding time at targeted temperature showed that they had no improvement effect. Thus, the best conditions are the highest heating rate for a final temperature 150°C without any holding time. The reading of energy consumed by pretreatment and energy overproduced by pretreated samples showed that increasing tVS amount and heating rate led to a saving of energy consumption. Nevertheless, to obtain a positive energy balance, a microwave device should consume less than 2.65 kJ/g(tVS).

  6. Ancient and methane-derived carbon subsidizes contemporary food webs

    Science.gov (United States)

    Delvecchia, Amanda G.; Stanford, Jack A.; Xu, Xiaomei

    2016-11-01

    While most global productivity is driven by modern photosynthesis, river ecosystems are supplied by locally fixed and imported carbon that spans a range of ages. Alluvial aquifers of gravel-bedded river floodplains present a conundrum: despite no possibility for photosynthesis in groundwater and extreme paucity of labile organic carbon, they support diverse and abundant large-bodied consumers (stoneflies, Insecta: Plecoptera). Here we show that up to a majority of the biomass carbon composition of these top consumers in four floodplain aquifers of Montana and Washington is methane-derived. The methane carbon ranges in age from modern to up to >50,000 years old and is mostly derived from biogenic sources, although a thermogenic contribution could not be excluded. We document one of the most expansive ecosystems to contain site-wide macroinvertebrate biomass comprised of methane-derived carbon and thereby advance contemporary understanding of basal resources supporting riverine productivity.

  7. Methane catalytic decomposition over ordered mesoporous carbons: A promising route for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Botas, J.A.; Serrano, D.P. [Department of Chemical and Environmental Technology, ESCET, Rey Juan Carlos University, c/ Tulipan s/n, 28933 Mostoles, Madrid (Spain); IMDEA Energia, c/Tulipan s/n, 28933 Mostoles, Madrid (Spain); Guil-Lopez, R.; Pizarro, P.; Gomez, G. [Department of Chemical and Environmental Technology, ESCET, Rey Juan Carlos University, c/ Tulipan s/n, 28933 Mostoles, Madrid (Spain)

    2010-09-15

    Methane decomposition offers an interesting route for the CO{sub 2}-free hydrogen production. The use of carbon catalysts, in addition to lowering the reaction temperature, presents a number of advantages, such as low cost, possibility of operating under autocatalytic conditions and feasibility of using the produced carbons in non-energy applications. In this work, a novel class of carbonaceous materials, having an ordered mesoporous structure (CMK-3 and CMK-5), has been checked as catalysts for methane decomposition, the results obtained being compared to those corresponding to a carbon black sample (CB-bp) and two activated carbons, presenting micro- (AC-mic) and mesoporosity (AC-mes), respectively. Ordered mesoporous carbons, and especially CMK-5, possess a remarkable activity and stability for the hydrogen production through that reaction. Under both temperature programmed and isothermal experiments, CMK-5 has shown to be a superior catalyst for methane decomposition than the AC-mic and CB-bp materials. Likewise, the catalytic activity of CMK-5 is superior to that of AC-mes in spite of the presence of mesoporosity and a high surface area in the latter. The remarkable stability of the CMK-5 catalyst is demonstrated by the high amount of carbon deposits that can be formed on this sample. This result has been assigned to the growth of the carbon deposits from methane decomposition towards the outer part of the catalyst particles, avoiding the blockage of the uniform mesopores present in CMK-5. Thus, up to 25 g of carbon deposits have been formed per gram of CMK-5, while the latter still retains a significant catalytic activity. (author)

  8. Straw application in paddy soil enhances methane production also from other carbon sources

    Science.gov (United States)

    Yuan, Q.; Pump, J.; Conrad, R.

    2013-08-01

    Flooded rice fields are an important source of the greenhouse gas methane. Methane is produced from rice straw (RS), soil organic matter (SOM), and rice root organic carbon (ROC). Addition of RS is widely used for ameliorating soil fertility. However, this practice provides additional substrate for CH4 production and results in increased CH4 emission. Here, we found that decomposing RS is not only a substrate of CH4 production, but in addition stimulates CH4 production from SOM and ROC. Apart from accelerating the creation of reduced conditions in the soil environment, RS decomposition exerted a positive priming effect on SOM-derived CH4 production. In particular, hydrogenotrophic methanogenesis from SOM-derived CO2 was stimulated, presumably by H2 released from RS decomposition. On the other hand, the positive priming effect of RS on ROC-derived CH4 production was probably caused by the significant increase of the abundance of methanogenic archaea in the RS treatment compared with the untreated control. Our results show that traditional management of rice residues exerts a positive feedback on CH4 production from rice fields, thus exacerbating its effect on the global CH4 budget.

  9. Straw application in paddy soil enhances methane production also from other carbon sources

    Directory of Open Access Journals (Sweden)

    Q. Yuan

    2013-08-01

    Full Text Available Flooded rice fields are an important source of the greenhouse gas methane. Methane is produced from rice straw (RS, soil organic matter (SOM, and rice root organic carbon (ROC. Addition of RS is widely used for ameliorating soil fertility. However, this practice provides additional substrate for CH4 production and results in increased CH4 emission. Here, we found that decomposing RS is not only a substrate of CH4 production, but in addition stimulates CH4 production from SOM and ROC. Apart from accelerating the creation of reduced conditions in the soil environment, RS decomposition exerted a positive priming effect on SOM-derived CH4 production. In particular, hydrogenotrophic methanogenesis from SOM-derived CO2 was stimulated, presumably by H2 released from RS decomposition. On the other hand, the positive priming effect of RS on ROC-derived CH4 production was probably caused by the significant increase of the abundance of methanogenic archaea in the RS treatment compared with the untreated control. Our results show that traditional management of rice residues exerts a positive feedback on CH4 production from rice fields, thus exacerbating its effect on the global CH4 budget.

  10. Utilization of coal mine methane for methanol and SCP production. Topical report, May 5, 1995--March 4, 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    The feasibility of utilizing a biological process to reduce methane emissions from coal mines and to produce valuable single cell protein (SCP) and/or methanol as a product has been demonstrated. The quantities of coal mine methane from vent gas, gob wells, premining wells and abandoned mines have been determined in order to define the potential for utilizing mine gases as a resource. It is estimated that 300 MMCFD of methane is produced in the United States at a typical concentration of 0.2-0.6 percent in ventilation air. Of this total, almost 20 percent is produced from the four Jim Walter Resources (JWR) mines, which are located in very gassy coal seams. Worldwide vent gas production is estimated at 1 BCFD. Gob gas methane production in the U.S. is estimated to be 38 MMCFD. Very little gob gas is produced outside the U.S. In addition, it is estimated that abandoned mines may generate as much as 90 MMCFD of methane. In order to make a significant impact on coal mine methane emissions, technology which is able to utilize dilute vent gases as a resource must be developed. Purification of the methane from the vent gases would be very expensive and impractical. Therefore, the process application must be able to use a dilute methane stream. Biological conversion of this dilute methane (as well as the more concentrated gob gases) to produce single cell protein (SCP) and/or methanol has been demonstrated in the Bioengineering Resources, Inc. (BRI) laboratories. SCP is used as an animal feed supplement, which commands a high price, about $0.11 per pound.

  11. Automotive fuels from cellulose materials. [Production of ethanol and methane simultaneously

    Energy Technology Data Exchange (ETDEWEB)

    Higginson, B.; Thornton, R.H.

    1980-01-01

    The results of this investigation showed that it was feasible to link the alcohol fermentation and anaerobic digestion processes into a system for the production of both alcohol and methane from organic substrates. The rate of ethanol production has been determined with respect to cell concentration and the prerequisite of both a high cell concentration and yeast recycling has been shown. Ethanol fermentation under reduced pressure has been shown to be feasible and to give higher ethanol productivities. Although optimization of fermentation has been attempted in this report, with due regard to energy conservation, for industrial application the cost of sugar will be the overriding factor. Cysewski and Wilke (7) pointed out that the cost of sugar overwhelms all other costs in the production of ethanol by fermetation: up to 70 to 80% of the total cost of the ethanol. Results showed that the resultant fermentation spent wash and extracted crop residues could be anaerobically digested to produce methane (and carbon dioxide). A hydraulic retention time of 10 days or longer was needed for effective digestion in which a reduction of chemical oxygen demand (COD) of up to 85% was achieved. Results indicated that further reduction in retention time may be possible if the microbial biomass could be either retained on support media, or recycled more effectively. A gas production rate of 4270 liters gas/m/sup 3/ culture/day at 11.6 day retention time was obtained with the anaerobic contact digester using fodder beet spent wash. Using the same substrate, results over short periods with the anaerobic filter system could produce up to 4.8 liters gas/litre culture/day. The high methane composition of this gas (75 to 80%) make this an attractive proposition.

  12. Development of a combined bio-hydrogen- and methane-production unit using dark fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Brunstermann, R.; Widmann, R. [Duisburg-Essen Univ. (Germany). Dept. of Urban Water and Waste Management

    2010-07-01

    Hydrogen is regarded as a source of energy of the future. Currently, hydrogen is produced, predominantly, by electrolysis of water by using electricity or by stream reforming of natural gas. So both methods are based on fossil fuels. If the used electricity is recovered from renewable recourses, hydrogen produced by water electrolysis may be a clean solution. At present, the production of hydrogen by biological processes finds more and more attention world far. The biology provides a wide range of approaches to produce hydrogen, including bio-photolysis as well as photo-fermentation and dark-fermentation. Currently these biological technologies are not suitable for solving every day energy problems [1]. But the dark-fermentation is a promising approach to produce hydrogen in a sustainable way and was already examined in some projects. At mesophilic conditions this process provides a high yield of hydrogen by less energy demand, [2]. Short hydraulic retention times (HRT) and high metabolic rates are advantages of the process. The incomplete transformation of the organic components into various organic acids is a disadvantage. Thus a second process step is required. Therefore the well known biogas-technique is used to degrade the organic acids predominantly acetic and butyric acid from the hydrogen-production unit into CH{sub 4} and CO{sub 2}. This paper deals with the development of a combined hydrogen and methane production unit using dark fermentation at mesophilic conditions. The continuous operation of the combined hydrogen and methane production out of DOC loaded sewages and carbohydrate rich biowaste is necessary for the examination of the technical and economical implementation. The hydrogen step shows as first results hydrogen concentration in the biogas between 40 % and 60 %.The operating efficiency of the combined production of hydrogen and methane shall be checked as a complete system. (orig.)

  13. Methane as a biomarker in the search for extraterrestrial life: Lessons learned from Mars analog hypersaline environments

    Science.gov (United States)

    Bebout, B.; Tazaz, A.; Kelley, C. A.; Poole, J. A.; Davila, A.; Chanton, J.

    2010-12-01

    -60 ‰ to -30 ‰, while the hydrogen isotopic composition (δ2H) ranged from about -350 to -300‰. These isotopic values are outside the range generally considered to be biogenic, however incubations of the sediments and salt crusts revealed that the methane is indeed produced there. The highest rate of methane production was 20 nmol/g/d, in a gypsum crust with endolithic microbial communities. Currently we are studying the mechanisms that control the isotopic signatures of methane in these environments. These studies are of special relevance given the projected analysis of Mars atmospheric methane by the Mars Science Laboratory in 2012, and by the ExoMars Trace Gas Orbiter in 2017.

  14. Geologically controlling factors on coal bed methane (CBM) productivity in Liulin

    Institute of Scientific and Technical Information of China (English)

    GAO Li-jun; TANG Da-zhen; XU Hao; MENG Shang-zhi; ZHANG Wen-zhong; MENG Yan-jun; WANG Jun-jian

    2012-01-01

    It is of great significance to forecast high yield of CBM wells and analyze dynamic production by having an overall study on the characteristics of the produced CBM and determining the main factors influencing the productivity of CBM.With the test report and the related geological parameters of a single well,methods of combining the productivity data and typical production curves were used to analyze different geological factors and how to influence the capacity of a single layer.Then,the paper proposed a new understanding about capacity characteristics of the study area and geological control factors:First,the Shanxi formation production capacity characteristics was divided into two-stages,showing signs of gas and gas breakthrough for 100 days.Second,two parameters,which include potential of gas production and gas production capacity,were better than the single parameter,such as gas content,coal thickness,and penetration to analyze affecting factors of single well production.Finally,comprehensive analysis concluded that the ratio of critical desorption pressure to reservoir pressure has greater influence on the production of vertical CBM wells.Besides,the potential of gas production capacity has greater impact at stage of showing gas signs; the coal reservoir pressure and gas production capacity have greater impact at stage of gas breakthrough for 100 days.Thus,to seek the coal bed methane with high ratio of critical desorption pressure to reservoir pressure and high yield of gas will be important guarantee to the success of the coal bed methane exploration and development.

  15. Butachlor inhibits production and oxidation of methane in tropical rice soils under flooded condition.

    Science.gov (United States)

    Mohanty, S R; Nayak, D R; Babu, Y J; Adhya, T K

    2004-01-01

    In laboratory incubation experiments, application of a commercial formulation of the herbicide butachlor (N-butoxymethyl-2-chloro-2',6'-diethyl acetanilide) to three tropical rice soils, widely differing in their physicochemical characteristics, under flooded condition inhibited methane (CH4) production. The inhibitory effect was concentration dependent and most remarkable in the alluvial soil. Thus, following application of butachlor at 5, 10, 50 and 100 microg g(-1) soil, respectively, cumulative CH4 production in the alluvial soil was inhibited by 15%, 31%, 91% and 98% over unamended control. Since CH4 production was less pronounced in the sandy loam and acid sulfate soil, the impact of amendment with butchalor, albeit inhibitory, was less extensive than the alluvial soil. Inhibition of CH4 production in butachlor-amended alluvial soil was related to the prevention in the drop in redox potential as well as low methanogenic bacterial population especially at high concentrations of butachlor. CH4 oxidation was also inhibited in butachlor-amended alluvial soil with the inhibitory effect being more prevalent under flooded condition. Inhibition in CH4 oxidation was related to a reduction in the population of soluble methane monooxygenase producing methanotrophs. Results demonstrate that butachlor, a commonly used herbicide in rice cultivation, even at very low concentrations can affect CH4 production and its oxidation, thereby influencing the biogeochemical cycle of CH4 in flooded rice soils.

  16. Enzymatic and metabolic activities of four anaerobic sludges and their impact on methane production from ensiled sorghum forage.

    Science.gov (United States)

    Sambusiti, C; Rollini, M; Ficara, E; Musatti, A; Manzoni, M; Malpei, F

    2014-03-01

    Biochemical methane potential (BMP) tests were run on ensiled sorghum forage using four inocula (urban, agricultural, mixture of agricultural and urban, granular) and differences on their metabolic and enzymatic activities were also discussed. Results indicate that no significant differences were observed in terms of BMP values (258±14NmLCH4g(-1)VS) with a slightly higher value when agricultural sludge was used as inoculum. Significant differences can be observed among different inocula, in terms of methane production rate. In particular the fastest biomethanization occurred when using the urban sludge (hydrolytic kinetic constant kh=0.146d(-1)) while the slowest one was obtained from the agricultural sludge (kh=0.049d(-1)). Interestingly, positive correlations between the overall enzymatic activities and methane production rates were observed for all sludges, showing that a high enzymatic activity may favour the hydrolysis of complex substrate and accelerate the methanization process of sorghum.

  17. Biohydrogen and methane production via a two-step process using an acid pretreated native microalgae consortium.

    Science.gov (United States)

    Carrillo-Reyes, Julian; Buitrón, Germán

    2016-12-01

    A native microalgae consortium treated under thermal-acidic hydrolysis was used to produce hydrogen and methane in a two-step sequential process. Different acid concentrations were tested, generating hydrogen and methane yields of up to 45mLH2gVS(-1) and 432mLCH4gVS(-1), respectively. The hydrogen production step solubilized the particulate COD (chemical oxygen demand) up to 30%, creating considerable amounts of volatile fatty acids (up to 10gCODL(-1)). It was observed that lower acid concentration presented higher hydrogen and methane production potential. The results revealed that thermal acid hydrolysis of a native microalgae consortium is a simple but effective strategy for producing hydrogen and methane in the sequential process. In addition to COD removal (50-70%), this method resulted in an energy recovery of up to 15.9kJ per g of volatile solids of microalgae biomass, one of the highest reported.

  18. Enhancement of bioenergy production from organic wastes by two-stage anaerobic hydrogen and methane production process

    DEFF Research Database (Denmark)

    Luo, Gang; Xie, Li; Zhou, Qi

    2011-01-01

    The present study investigated a two-stage anaerobic hydrogen and methane process for increasing bioenergy production from organic wastes. A two-stage process with hydraulic retention time (HRT) 3d for hydrogen reactor and 12d for methane reactor, obtained 11% higher energy compared to a single......-stage methanogenic process (HRT 15d) under organic loading rate (OLR) 3gVS/(Ld). The two-stage process was still stable when the OLR was increased to 4.5gVS/(Ld), while the single-stage process failed. The study further revealed that by changing the HRThydrogen:HRTmethane ratio of the two-stage process from 3...

  19. Methane assisted solid oxide co-electrolysis process for syngas production

    Science.gov (United States)

    Wang, Yao; Liu, Tong; Lei, Libin; Chen, Fanglin

    2017-03-01

    In this study, methane assisted high temperature steam/CO2 co-electrolysis process is performed on symmetrical cells with a configuration of SFM-SDC/LSGM/SFM-SDC to produce high-quality synthesis gas (syngas, a mixture of H2 and CO). The Nernst potential has been evaluated for solid oxide cells in the methane assisted mode, which is reduced by nearly one order of magnitude through substituting the anode atmosphere from air to methane. The open circuit voltage (OCV) is -0.06 V at 800 °C, and an electrolysis current density of -242 mAcm-2 has been obtained at 850 °C and 0.3 V. Effects of operating conditions on products composition have been revealed by using the chemical equilibrium co-electrolysis model and HSC software. High-quality syngas with high conversion rate of CO2 to CO as well as ideal H2/CO molar ratio of 2 could be achieved in both electrode sides by adjusting appropriate operating conditions. The short-term cell voltage is slightly fluctuant less than 0.05 V at 850 °C and -120 mAcm-2, in which condition carbon deposition has been observed in the SFM-SDC anode due to the low O2-/CH4 ratio.

  20. Methane Production from Protozoan Endosymbionts Following Stimulation of Microbial Metabolism within Subsurface Sediments

    Directory of Open Access Journals (Sweden)

    Dawn Elena Holmes

    2014-08-01

    Full Text Available Previous studies have suggested that protozoa prey on Fe(III- and sulfate-reducing bacteria that are enriched when acetate is added to uranium contaminated subsurface sediments to stimulate U(VI reduction. In order to determine whether protozoa continue to impact subsurface biogeochemistry after these acetate amendments have stopped, 18S rRNA and ß-tubulin sequences from this phase of an in situ uranium bioremediation field experiment were analyzed. Sequences most similar to Metopus species predominated, with the majority of sequences most closely related to M. palaeformis, a cilitated protozoan known to harbor methanogenic symbionts. Quantification of mcrA mRNA transcripts in the groundwater suggested that methanogens closely related to Metopus endosymbionts were metabolically active at this time. There was a strong correlation between the number of mcrA transcripts from the putative endosymbiotic methanogen and Metopus ß-tubulin mRNA transcripts during the course of the field experiment, suggesting that the activity of the methanogens was dependent upon the activity of the Metopus species. Addition of the eukaryotic inhibitors cyclohexamide and colchicine to laboratory incubations of acetate-amended subsurface sediments significantly inhibited methane production and there was a direct correlation between methane concentration and Metopus ß-tubulin and putative symbiont mcrA gene copies. These results suggest that, following the stimulation of subsurface microbial growth with acetate, protozoa harboring methanogenic endosymbionts become important members of the microbial community, feeding on moribund biomass and producing methane.

  1. Production of carbon molecular sieves from palm shell through carbon deposition from methane

    Directory of Open Access Journals (Sweden)

    Mohammadi Maedeh

    2011-01-01

    Full Text Available The possibility of production of carbon molecular sieve (CMS from palm shell as a waste lignocellulosic biomass was investigated. CMS samples were prepared through heat treatment processes including carbonization, physiochemical activation and chemical vapor deposition (CVD from methane. Methane was pyrolyzed to deposit fine carbon on the pore mouth of palm shell-based activated carbon to yield CMS. All the deposition experiments were performed at 800 ºC, while the methane flow rate (100, 200, 300 mL min-1 CH4 diluted in 500 mL min-1 N2 and deposition time (30 to 60 min were the investigated parameters. The textural characteristics of the CMSs were assessed by N2 adsorption. The largest BET surface area (752 m2 g-1, micropore surface area (902.2 m2 g-1 and micropore volume (0.3466 cm3 g-1 was obtained at the CH4 flow rate of 200 mL min-1 and deposition time of 30 min. However, prolonging the deposition time to 45 min yielded in a micropouros CMS with a narrow pore size distribution.

  2. Influence of Oxygenated Compounds on Reaction Products in a Microwave Plasma Methane Pyrolysis Assembly for Post-Processing of Sabatier Methane

    Science.gov (United States)

    Mansell, J. Matthew; Abney, Morgan B.

    2012-01-01

    The state-of-the-art Carbon Dioxide Reduction Assembly (CRA) was delivered to the International Space Station (ISS) in April 2010. The system is designed to accept carbon dioxide from the Carbon Dioxide Removal Assembly and hydrogen from the Oxygen Generation Assembly. The two gases are reacted in the CRA in a Sabatier reactor to produce water and methane. Venting of methane results in an oxygen resupply requirement of about 378 lbs per crew member per year. If the oxygen is supplied as water, the total weight for resupply is about 476 lb per crew member per year. For long-term missions beyond low Earth orbit, during which resupply capabilities will be further limited, recovery of hydrogen from methane is highly desirable. For this purpose, NASA is pursuing development of a Plasma Pyrolysis Assembly (PPA) capable of recovering hydrogen from methane. Under certain conditions, water vapor and carbon dioxide (nominally intended to be separated from the CRA outlet stream) may be present in the PPA feed stream. Thus, testing was conducted in 2010 to determine the effect of these oxygenated compounds on PPA performance, particularly the effect of inlet carbon dioxide and water variations on the PPA product stream. This paper discusses the test set-up, analysis, and results of this testing.

  3. The cumulative methane production from dairy cattle slurry can be explained by its volatile solid, temperature and length of storage.

    Science.gov (United States)

    Sawamoto, Takuji; Nakamura, Megumi; Nekomoto, Kenji; Hoshiba, Shinji; Minato, Keiko; Nakayama, Motoo; Osada, Takashi

    2016-06-01

    In order to refine the national estimate of methane emission from stored cattle slurry, it is important to comprehend the basic characteristics of methane production. Two dairy cattle slurries were obtained from livestock farms located in Hokkaido (a northern island) and Kyushu (a southern island). The slurries were diluted with water into three levels: undiluted, three times diluted, and 10 times diluted. Three hundred mL of the slurries were put into a bottle with a headspace volume of 2.0 L, which was filled with nitrogen gas and then sealed by butyl rubber. Four levels of temperature were used for incubation: 35, 25, 15 and 5 °C. The time course of the cumulative methane production per volatile solid (VS) was satisfactorily expressed by an asymptotic regression model. The effect of dilution on the methane production per VS was not distinctive, but that of temperature was of primary importance. In particular, higher temperature yields a higher potential production and a shorter time when the cumulative production reaches half of the potential production. The inclusive and simple models obtained in this study indicate that the cumulative methane production from stored cattle slurry can be explained by VS, temperature and length of storage.

  4. Temperature response of methane production in liquid manures and co-digestates.

    Science.gov (United States)

    Elsgaard, Lars; Olsen, Anne B; Petersen, Søren O

    2016-01-01

    Intensification of livestock production makes correct estimation of methanogenesis in liquid manure increasingly important for inventories of CH4 emissions. Such inventories currently rely on fixed methane conversion factors as knowledge gaps remain with respect to detailed temperature responses of CH4 emissions from liquid manure. Here, we describe the temperature response of CH4 production in liquid cattle slurry, pig slurry, and fresh and stored co-digested slurry from a thermophilic biogas plant. Subsamples of slurry were anoxically incubated at 20 temperatures from 5-52°C in a temperature gradient incubator and CH4 production was measured by gas chromatographic analysis of headspace gas after a 17-h incubation period. Methane production potentials at 5-37°C were described by the Arrhenius equation (modelling efficiencies, 79.2-98.1%), and the four materials showed a consistent activation energy (Ea) which averaged 81.0kJmol(-1) (95% confidence interval, 74.9-87.1kJmol(-1)) corresponding to a temperature sensitivity (Q10) of 3.4. In contrast, the frequency factor (A) differed among the slurry materials (30.1emissions from livestock manure.

  5. Establishment and assessment of an integrated citric acid-methane production process.

    Science.gov (United States)

    Xu, Jian; Chen, Yang-Qiu; Zhang, Hong-Jian; Bao, Jia-Wei; Tang, Lei; Wang, Ke; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

    2015-01-01

    To solve the problem of extraction wastewater in citric acid industrial production, an improved integrated citric acid-methane production process was established in this study. Extraction wastewater was treated by anaerobic digestion and then the anaerobic digestion effluent (ADE) was stripped by air to remove ammonia. Followed by solid-liquid separation to remove metal ion precipitation, the supernatant was recycled for the next batch of citric acid fermentation, thus eliminating wastewater discharge and reducing water consumption. 130U/g glucoamylase was added to medium after inoculation and the recycling process performed for 10 batches. Fermentation time decreased by 20% in recycling and the average citric acid production (2nd-10th) was 145.9±3.4g/L, only 2.5% lower than that with tap water (149.6g/L). The average methane production was 292.3±25.1mL/g CODremoved and stable in operation. Excessive Na(+) concentration in ADE was confirmed to be the major challenge for the proposed process.

  6. Enhancing methane production from waste activated sludge using a novel indigenous iron activated peroxidation pre-treatment process.

    Science.gov (United States)

    Zhou, Xu; Wang, Qilin; Jiang, Guangming

    2015-04-01

    Methane production from anaerobic digestion of waste activated sludge (WAS) is limited by the slow hydrolysis rate and/or poor methane potential of WAS. This study presents a novel pre-treatment strategy based on indigenous iron (in WAS) activated peroxidation to enhance methane production from WAS. Pre-treatment of WAS for 30 min at 50mg H2O2/g total solids (dry weight) and pH 2.0 (iron concentration in WAS was 7 mg/g TS) substantially enhanced WAS solubilization. Biochemical methane potential tests demonstrated that methane production was improved by 10% at a digestion time of 16d after incorporating the indigenous iron activated peroxidation pre-treatment. Model-based analysis indicated that indigenous iron activated peroxidation pre-treatment improved the methane potential by 13%, whereas the hydrolysis rate was not significantly affected. The economic analysis showed that the proposed pre-treatment method can save the cost by $112,000 per year in a treatment plant with a population equivalent of 300,000.

  7. Temperature response of methane production in liquid manures and co-digestates

    DEFF Research Database (Denmark)

    Elsgaard, Lars; Olsen, Anna Berg; Petersen, Søren O.

    2016-01-01

    of CH4 emissions fromliquid manure. Here, we describe the temperature response of CH4 production in liquid cattle slurry, pig slurry, and fresh and stored co-digested slurry from a thermophilic biogas plant. Subsamples of slurry were anoxically incubated at 20 temperatures from 5–52 °C in a temperature...... gradient incubator and CH4 production was measured by gas chromatographic analysis of headspace gas after a 17-h incubation period. Methane production potentials at 5–37 °C were described by the Arrhenius equation (modelling efficiencies, 79.2–98.1%), and the four materials showed a consistent activation...... of the manure affect this parameter. The Ea estimate, based on individual slurry materials,was intermediate when compared to published values of 63 and 112.7 kJ mol−1 derived from composite data, but was similar to Ea estimated for CH4 production at microbial community level across aquatic ecosystems, wetlands...

  8. Gas productivity related to cleat volumes derived from focused resistivity tools in coalbed methane (CBM) fields

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y.H.; Peeters, M.; Cloud, T.A.; Van Kirk, C.W. [Kerr McGee Rocky Mountain Corporation, Denver, CO (United States)

    2006-06-15

    Cleats are critical for coal-bed methane (CBM) production, but operators usually lack a viable method to determine productivity except for costly well tests. Wireline logs, run over the CBM deposits of the Drunkards Wash Unit located in the Uinta Basin of Utah, were used to develop a new method to relate productivity to the cleat volume. The latter is derived from a focused resistivity log and the wellbore-fluid resistivity. Induction tools are unsuitable for this method, because they are dominated by borehole effects in high resistivity coals and low resistivity mud. Moreover, they read too deep to be significantly affected by the substitution of formation fluid by borehole fluid in the cleats on which the method is based. The method was demonstrated by relating cleat volume to CBM gas productivity in 24 wells, an exercise that clearly separated good from poor producers.

  9. 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.

  10. Seasonal variation in rates of methane production from peat of various botanical origins: effects of temperature and substrate quality.

    Science.gov (United States)

    Bergman; Klarqvist; Nilsson

    2000-09-01

    The methane produced in peat soils can vary over the growing season due to variations in the supply of available substrate, the activity of the microbial community or changes in temperature. Our aim was to study how these factors regulate the methane production over the season from five different peat types of different botanical origin. Peat samples were collected on seven occasions between June and September. After each sampling, the peat soils were incubated at five different temperatures (7, 10, 15, 20 and 25 degrees C) without added substrate, or at 20 degrees C with added substrate (glucose, or H(2)/CO(2), or starch). Rates of methane production averaged over the season differed significantly (Pmethane production from each plant community varied significantly (Ptemperature, explains the seasonal variation in methane production. However, addition of saturating amounts of glucose, H(2)/CO(2) or starch at 20 degrees C significantly reduced the seasonal variation (Pmethane production in peat from the minerotrophic lawn, wet carpet and mud-bottom plant communities. This suggests that substrate supply (e.g. root exudates) for the micro-organisms also varied over the season at these sites. Seasonal variation in methane production rates was apparent in peat from the hummock and ombrotrophic lawn plant communities even after addition of substrates, suggesting that the active biomass of the anaerobic microbial populations at these sites was regulated by other factors than the ones studied.

  11. Methane production from sweet sorghum residues via a two-stage process

    Energy Technology Data Exchange (ETDEWEB)

    Stamatelatou, K.; Dravillas, K.; Lyberatos, G. [University of Patras (Greece). Department of Chemical Engineering, Laboratory of Biochemical Engineering and Environmental Technology

    2003-07-01

    The start-up of a two-stage reactor configuration for the anaerobic digestion of sweet sorghum residues was evaluated. The sweet sorghum residues were a waste stream originating from the alcoholic fermentation of sweet sorghum and the subsequent distillation step. This waste stream contained high concentration of solid matter (9% TS) and thus could be characterized as a semi-solid, not easily biodegradable wastewater with high COD (115 g/l). The application of the proposed two-stage configuration (consisting of one thermophilic hydrolyser and one mesophilic methaniser) achieved a methane production of 16 l/l wastewater under a hydraulic retention time of 19 d. (author)

  12. Enteric methane production from beef cattle that vary in feed efficiency.

    Science.gov (United States)

    Freetly, H C; Brown-Brandl, T M

    2013-10-01

    We hypothesized that CH4 production will decrease with increased feed efficiency. Two experiments were conducted to determine CH4 production of cattle that differed in feed efficiency. Cattle in both studies were selected from larger contemporary groups. Animals furthest from the confidence ellipse that resulted from regressing BW gain on DMI were selected. In the first experiment, 113 crossbred steers were evaluated for feed efficiency for 64 d. Steers were 355 ± 1 d of age and weighed 456 ± 10 kg when they began the study. Steers were fed a ration that consisted of (DM basis) 82.8% corn, 12.8% corn silage, and 4.5% supplement [contains 0.065% monensin, 32% CP (28% NPN), 7.5% Ca, 0.8% P, 4.8% NaCl, 1.8% K, and 55,116 IU/kg vitamin A]. Thirty-seven steers were selected to measure CH4 production. In the second experiment, 197 heifers were evaluated for feed efficiency for 64 d. Heifers were 286 ± 1 d of age and weighed 327 ± 2 kg when they began the study. Heifers were fed a ration that consisted of (DM basis) 60% corn silage, 30% alfalfa hay, and 10% wet distillers grains with solubles. Forty-seven heifers were selected to measure CH4 production. Methane production was measured with respiration calorimeters. In both experiments, cattle had ad libitum access to feed, and DMI consumed during the 24 h before CH4 production was measured. Methane production was collected for a 6-h period on untrained cattle. Consequently, methane production is not a quantitative measure of daily methane production; rather, it is an index value to rank cattle. Multiple regression analysis was used to determine the relationship between either BW gain:DMI ratio or residual feed intake (RFI) on CH4 production after adjusting for the previous 24-h DMI. In the steers, BW gain:DMI ratio and previous 24-h feed intake accounted for little of the variance in CH4 production (R(2) = 0.009), and neither did RFI and previous 24-h feed intake (R(2) = 0.001). In the heifers, the BW gain:DMI ratio

  13. Methane production potential of leachate generated from Korean food waste recycling facilities: a lab-scale study.

    Science.gov (United States)

    Lee, Dae Hee; Behera, Shishir Kumar; Kim, Ji Won; Park, Hung-Suck

    2009-02-01

    This paper examines the applicability of food waste leachate (FWL) in bioreactor landfills or anaerobic digesters to produce methane as a sustainable solution to the persisting leachate management problem in Korea. Taking into account the climatic conditions in Korea and FWL characteristics, the effect of key parameters, viz., temperature, alkalinity and salinity on methane yield was investigated. The monthly average moisture content and the ratio of volatile solids to total solids of the FWL were found to be 84% and 91%, respectively. The biochemical methane potential experiment under standard digestion conditions showed the methane yield of FWL to be 358 and 478 ml/g VS after 10 and 28 days of digestion, respectively, with an average methane content of 70%. Elemental analysis showed the chemical composition of FWL to be C(13.02)H(23.01)O(5.93)N(1). The highest methane yield of 403 ml/g VS was obtained at 35 degrees C due to the adaptation of seed microorganisms to mesophilic atmosphere, while methane yields at 25, 45 and 55 degrees C were 370, 351 and 275 ml/g VS, respectively, at the end of 20 days. Addition of alkalinity had a favorable effect on the methane yield. Dilution of FWL with salinity of 2g/l NaCl resulted in 561 ml CH(4)/g VS at the end of 30 days. Considering its high biodegradability (82.6%) and methane production potential, anaerobic digestion of FWL in bioreactor landfills or anaerobic digesters with a preferred control of alkalinity and salinity can be considered as a sustainable solution to the present emergent problem.

  14. Study on the inhibition of methane production from anaerobic digestion of biodegradable solid waste.

    Science.gov (United States)

    Tiantao Zhao; Lijie Zhang; Youcai Zhao

    2010-04-01

    The inhibition effects and mechanisms of chlorinated methane, anthraquinone and acetylene on methanogenesis in the anaerobic digestion process of biodegradable solid wastes were investigated. It was found that both chloroform and acetylene could effectively inhibit methanogens. Acetylene inhibited the activity of methanogens, while chloroform inhibited metabolic process of methanogenesis. A central composite design (CCD) and response surface regression analysis (RSREG) were employed to determine the optimum conditions and interaction effects of chloroform and acetylene in terms of methane and hydrogen production. Acetylene promoted the inhibition efficiency (F = 31.14; P 0.05). In addition, a maximum hydrogen production of 1.6 ml was estimated under the optimum conditions of chloroform concentration of 6.69 mg kg(-1) and acetylene concentration of 3.08 x 10(-3) (v/v). Chloroform had a significant effect on enhancing the production of propionic acid and a minimum molar ratio of acetic acid to propionic acid of 0.707 was reached with the chloroform concentration of 9.24 mg kg(-1) and acetylene concentration of 4.0 x 10(-3) (v/v). Hence, methanogens can be inhibited while the stabilization process of solid wastes can still work well. Moreover, co-inhibition technology practice at landfills was feasible and the environmental damage was negligible, according to the analysis and experimental results.

  15. Air-adapted Methanosarcina acetivorans shows high methane production and develops resistance against oxygen stress.

    Directory of Open Access Journals (Sweden)

    Ricardo Jasso-Chávez

    Full Text Available Methanosarcina acetivorans, considered a strict anaerobic archaeon, was cultured in the presence of 0.4-1% O2 (atmospheric for at least 6 months to generate air-adapted cells; further, the biochemical mechanisms developed to deal with O2 were characterized. Methane production and protein content, as indicators of cell growth, did not change in air-adapted cells respect to cells cultured under anoxia (control cells. In contrast, growth and methane production significantly decreased in control cells exposed for the first time to O2. Production of reactive oxygen species was 50 times lower in air-adapted cells versus control cells, suggesting enhanced anti-oxidant mechanisms that attenuated the O2 toxicity. In this regard, (i the transcripts and activities of superoxide dismutase, catalase and peroxidase significantly increased; and (ii the thiol-molecules (cysteine + coenzyme M-SH + sulfide and polyphosphate contents were respectively 2 and 5 times higher in air-adapted cells versus anaerobic-control cells. Long-term cultures (18 days of air-adapted cells exposed to 2% O2 exhibited the ability to form biofilms. These data indicate that M. acetivorans develops multiple mechanisms to contend with O2 and the associated oxidative stress, as also suggested by genome analyses for some methanogens.

  16. Influence of pretreatment with Fenton's reagent on biogas production and methane yield from lignocellulosic biomass.

    Science.gov (United States)

    Michalska, Karina; Miazek, Krystian; Krzystek, Liliana; Ledakowicz, Stanisław

    2012-09-01

    Biomass from Miscanthus giganteus, Sida hermaphrodita and Sorghum Moensch was treated with Fenton's reagent for 2 hours under optimal conditions (pH=3, mass ratio of [Fe(2+)]:[H(2)O(2)] equals 1:25 for Miscanthus and Sorghum and 1:15 for Sida). The degrees of delignification were 30.3%, 62.3% and 48.1% for the three plant species, respectively. The volatile fatty acids concentration after chemical pretreatment was high enough for production of biogas with a high methane content. Combined chemical oxidation and enzymatic hydrolysis with cellulase and cellobiase led to glucose contents of above 4 g/L. Among the tested plants, the highest biogas production (25.2 Ndm(3)/kg TS fed) with a 75% methane content was obtained with Sorghum Moensch. The results of the three-step process of biomass degradation show the necessity of applying a chemical pretreatment such as oxidation with Fenton's reagent. Moreover, the coagulation of residual Fe(3+) ions is not required for high biogas production.

  17. Methane production of two roughage and total mixed ration as influenced by cellulase and xylanase enzyme addition

    Directory of Open Access Journals (Sweden)

    Belete Shenkute Gemeda

    2015-02-01

    Full Text Available In recent decades supplementation of animal feeds with exogenous fibrolytic enzymes has substantially improved digestibility and animal performance. However, information related to associated methane production is limited and inconsistent. This study evaluated the effect of cellulase and xylanase enzymes on in vitro methane production of Eragrostis curvula hay, maize (Zea mays stover and a total mixed ration (TMR at seven levels of the two enzymes. Feed samples were incubated for 2, 12, 24 and 48 h in an in vitro batch culture with buffer and rumen fluid, and fibrolytic enzymes. Gas production was measured using a pressure transducer connected to a data tracker, while methane gas was analysed using a gas chromatograph which was calibrated with standard CH4 and CO2. Increases in the level of enzyme application resulted in increases in gas volume, total volatile fatty acid (VFA production, dry matter (DM disappearance and associated increases in methane production. The linear increase in percentage and volume of methane production in tandem with increases in level of enzyme application might be due to increased fermentation, and organic matter degradability that resulted in a shift in VFA production towards acetate. Considering the efficiency of DM and neutral detergent fiber degradation and production of associated VFA with levels of enzymes, the use of 1 mg g−1 DM of enzyme can be a good option for the feeds tested. However, they cannot decrease methane production. It will be very important to consider other hydrogen sinks that can capture directly extra H+ produced by the addition of enzyme so that their supplementation could be very efficient and environmentally sound.

  18. Anthropogenic Sulfur Perturbations on Biogenic Oxidation: Impacts of Sulfur Dioxide Additions on Bulk Gas Phase OH Oxidation Products of Alpha and Beta Pinene.

    Science.gov (United States)

    Friedman, B.; Brophy, P.; Brune, W. H.; Farmer, D.

    2015-12-01

    The evolution of biogenic volatile organic compounds (BVOCs) in the atmosphere is impacted by concurrent emissions of anthropogenic pollutants, such as sulfur dioxide (SO2) and nitrogen oxides (NOx), which can impact air quality and SOA formation in regions of biogenic and anthropogenic influence. We present the impacts of anthropogenic perturbations in the form of sulfur dioxide on the oxidation systems of α- and β-pinene. An oxidative flow reactor simulated atmospheric aging by OH oxidation on the order of days, and high-resolution time-of-flight mass spectrometry (HR-TOF-CIMS) was utilized to identify gas-phase oxidation products and changes to the ensemble system as a function of the SO2 perturbation. Results show that the SO2 perturbation impacted the oxidation systems of α- and β-pinene, and that these perturbations affected the oxidation systems of α- and β-pinene differently. Bulk analysis comparing the perturbed system to the unperturbed system indicated a change in oxidation pathway or mechanism leading to an ensemble of products with a lesser degree of oxygenation, on the order of a 30% decrease in the bulk oxidation state and a 10% decrease in the bulk O:C ratio for both BVOC systems. Increasing the relative humidity in the oxidative flow reactor was found to dampen the impact of the perturbation. Experiments involving other anthropogenic emissions, such as NOx, as well as other pairs of BVOC structural isomers, were conducted to investigate if changes in the oxidation system were due to the BVOC structure or the specific anthropogenic pollutant.

  19. Evaluation of methane-utilising bacteria products as feed ingredients for monogastric animals

    DEFF Research Database (Denmark)

    Øverland, Margareth; Tauson, Anne-Helene; Shearer, Karl;

    2010-01-01

    Methylococcus capsulatus (Bath), is a promising source of protein based on criteria such as amino acid composition, digestibility, and animal performance and health. Future research challenges include modified downstream processing to produce value-added products, and improved understanding of factors......Bacterial proteins represent a potential future nutrient source for monogastric animal production because they can be grown rapidly on substrates with minimum dependence on soil, water, and climate conditions. This review summarises the current knowledge on methane-utilising bacteria as feed...... ingredients for animals. We present results from earlier work and recent findings concerning bacterial protein, including the production process, chemical composition, effects on nutrient digestibility, metabolism, and growth performance in several monogastric species, including pigs, broiler chickens, mink...

  20. Use of short-term breath measures to estimate daily methane production by cattle.

    Science.gov (United States)

    Velazco, J I; Mayer, D G; Zimmerman, S; Hegarty, R S

    2016-01-01

    Methods to measure enteric methane (CH4) emissions from individual ruminants in their production environment are required to validate emission inventories and verify mitigation claims. Estimates of daily methane production (DMP) based on consolidated short-term emission measurements are developing, but method verification is required. Two cattle experiments were undertaken to test the hypothesis that DMP estimated by averaging multiple short-term breath measures of methane emission rate did not differ from DMP measured in respiration chambers (RC). Short-term emission rates were obtained from a GreenFeed Emissions Monitoring (GEM) unit, which measured emission rate while cattle consumed a dispensed supplement. In experiment 1 (Expt. 1), four non-lactating cattle (LW=518 kg) were adapted for 18 days then measured for six consecutive periods. Each period consisted of 2 days of ad libitum intake and GEM emission measurement followed by 1 day in the RC. A prototype GEM unit releasing water as an attractant (GEM water) was also evaluated in Expt. 1. Experiment 2 (Expt. 2) was a larger study based on similar design with 10 cattle (LW=365 kg), adapted for 21 days and GEM measurement was extended to 3 days in each of the six periods. In Expt. 1, there was no difference in DMP estimated by the GEM unit relative to the RC (209.7 v. 215.1 g CH(4)/day) and no difference between these methods in methane yield (MY, 22.7 v. 23.7 g CH(4)/kg of dry matter intake, DMI). In Expt. 2, the correlation between GEM and RC measures of DMP and MY were assessed using 95% confidence intervals, with no difference in DMP or MY between methods and high correlations between GEM and RC measures for DMP (r=0.85; 215 v. 198 g CH(4)/day SEM=3.0) and for MY (r=0.60; 23.8 v. 22.1 g CH(4)/kg DMI SEM=0.42). When data from both experiments was combined neither DMP nor MY differed between GEM- and RC-based measures (P>0.05). GEM water-based estimates of DMP and MY were lower than RC and GEM (PCattle

  1. Effect of industrial by-products containing electron acceptors on mitigating methane emission during rice cultivation.

    Science.gov (United States)

    Ali, Muhammad Aslam; Lee, Chang Hoon; Kim, Sang Yoon; Kim, Pil Joo

    2009-10-01

    Three industrial by-products (fly ash, phosphogypsum and blast furnace slag), were evaluated for their potential re-use as soil amendments to reduce methane (CH(4)) emission resulting from rice cultivation. In laboratory incubations, CH(4) production rates from anoxic soil slurries were significantly reduced at amendment levels of 0.5%, 1%, 2% and 5% (wt wt(-1)), while observed CO(2) production rates were enhanced. The level of suppression in methane production was the highest for phosphogypsum, followed by blast slag and then fly ash. In the greenhouse experiment, CH(4) emission rates from the rice planted potted soils significantly decreased with the increasing levels (2-20 Mg ha(-1)) of the selected amendments applied, while rice yield simultaneously increased compared to the control treatment. At 10 Mg ha(-1) application level of the amendments, total seasonal CH(4) emissions were reduced by 20%, 27% and 25%, while rice grain yields were increased by 17%, 15% and 23% over the control with fly ash, phosphogypsum, and blast slag amendments, respectively. The suppression of CH(4) production rates as well as total seasonal CH(4) flux could be due to the increased concentrations of active iron, free iron, manganese oxides, and sulfate in the amended soil, which acted as electron acceptors and controlled methanogens' activity by limiting substrates availability. Among the amendments, blast furnace slag and fly ash contributed mainly to improve the soil nutrients balance and increased the soil pH level towards neutral point, but soil acidity was developed with phosphogypsum application. Conclusively, blast slag among the selected amendments would be a suitable soil amendment for reducing CH(4) emissions as well as sustaining rice productivity.

  2. Coalbed Methane Production System Simulation and Deliverability Forecasting: Coupled Surface Network/Wellbore/Reservoir Calculation

    Directory of Open Access Journals (Sweden)

    Jun Zhou

    2017-01-01

    Full Text Available As an unconventional energy, coalbed methane (CBM mainly exists in coal bed with adsorption, whose productivity is different from conventional gas reservoir. This paper explains the wellbore pressure drop, surface pipeline network simulation, and reservoir calculation model of CBM. A coupled surface/wellbore/reservoir calculation architecture was presented, to coordinate the gas production in each calculation period until the balance of surface/wellbore/reservoir. This coupled calculation method was applied to a CBM field for predicting production. The daily gas production increased year by year at the first time and then decreased gradually after several years, while the daily water production was reduced all the time with the successive decline of the formation pressure. The production of gas and water in each well is almost the same when the structure is a star. When system structure is a dendritic surface system, the daily gas production ranked highest at the well which is the nearest to the surface system collection point and lowest at the well which is the farthest to the surface system collection point. This coupled calculation method could be used to predict the water production, gas production, and formation pressure of a CBM field during a period of time.

  3. Understanding the anthropogenic influence on formation of biogenic secondary organic aerosols via analysis of organosulfates and related oxidation products

    Directory of Open Access Journals (Sweden)

    Q. T. Nguyen

    2014-01-01

    Full Text Available Anthropogenic emissions of sulfur dioxide (SO2 and nitrogen oxides (NOx may affect concentration levels and composition of biogenic secondary organic aerosols (BSOA through photochemical reactions with biogenic organic precursors to form organosulfates and nitrooxy organosulfates. We investigated this influence in a field study from 19 May–22 June 2011 at two sampling sites in Denmark. Within the study, we identified a substantial number of organic acids, organosulfates and nitrooxy organosulfates in the ambient urban curbside and semi-rural background air. A high degree of correlation in concentrations was found among a group of specific organic acids, organosulfates and nitrooxy organosulfates, which may originate from various precursors, suggesting a common mechanism or factor affecting their concentration levels at the sites. It was proposed that the formation of those species most likely occurred on a larger spatial scale with the compounds being long-range transported to the sites on the days with highest concentrations. The origin of the long-range transported aerosols was investigated using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT model in addition to modeled emissions of related precursors including isoprene and monoterpenes using the global Model of Emissions of Gases and Aerosols from Nature (MEGAN and SO2 emissions using the European Monitoring and Evaluation Program (EMEP database. The local impacts were also studied by examining the correlation between selected species which showed significantly enhanced concentrations at the urban curbside site and the local concentrations of various gases including SO2, ozone (O3, carbon monoxide (CO, NOx, aerosol acidity and other meteorological conditions. This investigation showed that an inter-play of the local parameters such as the aerosol acidity, NOx, relative humidity (RH, temperature and global radiation seemed to influence the concentration level of those

  4. Autothermal catalytic pyrolysis of methane as a new route to hydrogen production with reduced CO{sub 2} emissions

    Energy Technology Data Exchange (ETDEWEB)

    Muradov, Nazim; Smith, Franklyn; Huang, Cunping; T-Raissi, Ali [Florida Solar Energy Center, University of Central Florida, Cocoa, FL 32922 (United States)

    2006-08-15

    Hydrogen production plants are among major sources of CO{sub 2} emissions into the atmosphere. The objective of this paper is to explore new routes to hydrogen production from natural gas (or methane) with drastically reduced CO{sub 2} emissions. One approach analyzed in this paper is based on thermocatalytic decomposition (or pyrolysis) of methane into hydrogen gas and elemental carbon over carbon-based catalysts. Several heat input options to the endothermic process are discussed in the paper. The authors conduct thermodynamic analysis of methane decomposition in the presence of small amounts of oxygen in an autothermal (or thermo-neutral) regime using AspenPlus(TM) chemical process simulator. Methane conversion, products yield, effluent gas composition, process enthalpy flows as a function of temperature, pressure and O{sub 2}/CH{sub 4} ratio has been determined. CO{sub 2} emissions (per m{sup 3} of H{sub 2} produced) from the process could potentially be a factor of 3-5 less than from conventional hydrogen production processes. Oxygen-assisted decomposition of methane over activated carbon (AC) and AC-supported iron catalysts over wide range of temperatures and O{sub 2}/CH{sub 4} ratios was experimentally verified. Problems associated with the catalyst deactivation and the effect of iron doping on the catalyst stability are discussed. (author)

  5. Long-term effect of the antibiotic cefalexin on methane production during waste activated sludge anaerobic digestion.

    Science.gov (United States)

    Lu, Xueqin; Zhen, Guangyin; Liu, Yuan; Hojo, Toshimasa; Estrada, Adriana Ledezma; Li, Yu-You

    2014-10-01

    Long-term experiments herein were conducted to investigate the effect of cefalexin (CLX) on methane production during waste activated sludge (WAS) anaerobic digestion. CLX exhibited a considerable inhibition in methane production during the initial 25 days while the negative effect attenuated subsequently and methane production recovered depending on CLX doses used (600 and 1000 mg/L). The highest methane yield reached 450 mL at 1000 mg-CLX/L after 157 days of digestion, 63.8% higher than CLX-free one. Stimulated excretion of extracellular polymeric substances (EPS) by CLX served as microbial protecting layers, creating a suitable environment for microbes' growth and fermentation. Further examination via ultraviolet visible (UV-Vis) spectra also verified the elevated slime EPS, LB-EPS and TB-EPS indicated by UV-254 in the presence of CLX. Unlike the commonly accepted adverse effect, this study demonstrated the beneficial role of CLX in methane production, providing new insights into its true environmental impacts.

  6. Anaerobic biodegradability of Category 2 animal by-products: methane potential and inoculum source.

    Science.gov (United States)

    Pozdniakova, Tatiana A; Costa, José C; Santos, Ricardo J; Alves, M M; Boaventura, Rui A R

    2012-11-01

    Category 2 animal by-products that need to be sterilized with steam pressure according Regulation (EC) 1774/2002 are studied. In this work, 2 sets of experiments were performed in mesophilic conditions: (i) biomethane potential determination testing 0.5%, 2.0% and 5.0% total solids (TS), using sludge from the anaerobic digester of a wastewater treatment plant as inoculum; (ii) biodegradability tests at a constant TS concentration of 2.0% and different inoculum sources (digested sludge from a wastewater treatment plant; granular sludge from an upflow anaerobic sludge blanket reactor; leachate from a municipal solid waste landfill; and sludge from the slaughterhouse wastewater treatment anaerobic lagoon) to select the more adapted inoculum to the substrate in study. The higher specific methane production was of 317 mL CH(4)g(-1) VS(substrate) for 2.0% TS. The digested sludge from the wastewater treatment plant led to the lowest lag-phase period and higher methane potential rate.

  7. The effect of biofuel production on swine farm methane and ammonia emissions.

    Science.gov (United States)

    Harper, Lowry A; Flesch, Thomas K; Weaver, Kim H; Wilson, John D

    2010-01-01

    Methane (CH) and ammonia (NH3) are emitted to the atmosphere during anaerobic processing of organic matter, and both gases have detrimental environmental effects. Methane conversion to biofuel production has been suggested to reduce CH4 emissions from animal manure processing systems. The purpose of this research is to evaluate the change in CH4 and NH3 emissions in an animal feeding operation due to biofuel production from the animal manure. Gas emissions were measured from swine farms differing only in their manure-management treatment systems (conventional vs. biofuel). By removing organic matter (i.e., carbon) from the biofuel farms' manure-processing lagoons, average annual CH4 emissions were decreased by 47% compared with the conventional farm. This represents a net 44% decrease in global warming potential (CO2 equivalent) by gases emitted from the biofuel farms compared with conventional farms. However, because of the reduction of methanogenesis and its reduced effect on the chemical conversion of ammonium (NH4+) to dinitrogen (N2) gas, NH3 emissions in the biofuel farms increased by 46% over the conventional farms. These studies show that what is considered an environmentally friendly technology had mixed results and that all components of a system should be studied when making changes to existing systems.

  8. Optimization of sugarcane bagasse autohydrolysis for methane production from hemicellulose hydrolyzates in a biorefinery concept.

    Science.gov (United States)

    Baêta, Bruno Eduardo Lôbo; Lima, Diego Roberto Sousa; Adarme, Oscar Fernando Herrera; Gurgel, Leandro Vinícius Alves; Aquino, Sérgio Francisco de

    2016-01-01

    This study aimed to optimize through design of experiments, the process variables (temperature - T, time - t and solid-to-liquid ratio - SLR) for sugarcane bagasse (SB) autohydrolysis (AH) to obtain hemicellulose hydrolyzates (HH) prone to anaerobic digestion (AD) and biochemical methane production (BMP). The results indicated that severe AH conditions, which lead to maximum hemicelluloses dissolution and sugar content in the HH, were not the best for BMP, probably due to the accumulation of toxic/recalcitrant compounds (furans and lignin). Mild AH conditions (170°C, 35min and SLR=0.33) led to the highest BMP (0.79Nm(3)kg TOC(-1)), which was confirmed by the desirability tool. HH produced by AH carried out at the desired condition DC2 (178.6°C, 43.6min and SLR=0.24) showed the lowest accumulation of inhibitory compounds and volatile fatty acids (VFA) and highest BMP (1.56Nm(3)kg TOC(-1)). The modified Gompertz model best fit the experimental data and led to a maximum methane production rate (R) of 2.6mmol CH4d(-1) in the best condition.

  9. Optimizing ethanol and methane production from steam-pretreated, phosphoric acid-impregnated corn stover.

    Science.gov (United States)

    Bondesson, Pia-Maria; Dupuy, Aurélie; Galbe, Mats; Zacchi, Guido

    2015-02-01

    Pretreatment is of vital importance in the production of ethanol and methane from agricultural residues. In this study, the effects of steam pretreatment with phosphoric acid on enzymatic hydrolysis (EH), simultaneous saccharification and fermentation (SSF), anaerobic digestion (AD) and the total energy output at three different temperatures were investigated. The effect of separating the solids for SSF and the liquid for AD was also studied and compared with using the whole slurry first in SSF and then in AD. Furthermore, the phosphoric acid was compared to previous studies using sulphuric acid or no catalyst. Using phosphoric acid resulted in higher yields than when no catalyst was used. However, compared with sulphuric acid, an improved yield was only seen with phosphoric acid in the case of EH. The higher pretreatment temperatures (200 and 210 °C) resulted in the highest yields after EH and SSF, while the highest methane yield was obtained with the lower pretreatment temperature (190 °C). The highest yield in terms of total energy recovery (78 %) was obtained after pretreatment at 190 °C, but a pretreatment temperature of 200 °C is, however, the best alternative since fewer steps are required (whole slurry in SSF and then in AD) and high product yields were obtained (76 %).

  10. Efficient anaerobic digestion of whole microalgae and lipid-extracted microalgae residues for methane energy production.

    Science.gov (United States)

    Zhao, Baisuo; Ma, Jingwei; Zhao, Quanbao; Laurens, Lieve; Jarvis, Eric; Chen, Shulin; Frear, Craig

    2014-06-01

    The primary aim of this study was to completely investigate extensive biological methane potential (BMP) on both whole microalgae and its lipid-extracted biomass residues with various degrees of biomass pretreatment. Specific methane productivities (SMP) under batch conditions for non-lipid extracted biomass were better than lipid-extracted biomass residues and exhibited no signs of ammonia or carbon/nitrogen (C/N) ratio inhibition when digested at high I/S ratio (I/S ratio⩾1.0). SMP for suitably extracted biomass ranged from 0.30 to 0.38LCH4/gVS (volatile solids). For both whole and lipid-extracted biomass, overall organic conversion ranged from 59.33 to 78.50 as a measure of %VS reduction with greater percentage biodegradability in general found within the lipid-extracted biomass. Higher production levels correlated to lipid content with a linear relationship between SMP and ash-free lipid content being developed at a R(2) of 0.814.

  11. Methane production and oxidation patterns along a hydrological gradient in Luther Bog, Ontario

    Science.gov (United States)

    Praetzel, Leandra; Berger, Sina; Blodau, Christian

    2016-04-01

    Methane emissions from natural peatlands contribute significantly to the global budget of atmospheric CH4. In the northern hemisphere, where climate models predict rising temperatures and precipitation rates, these emissions are likely to rise. So far, little is known about the change of processes of methane production and oxidation, which influence the total amount of methane emissions, in peatland soils under warmer and wetter climate conditions. Our work focuses on anaerobic CH4 production and aerobic CH4 oxidation processes along a hydrological gradient in an ombotrophic bog in Ontario, Canada that was induced by creation of a reservoir in 1952. Along this transect, four sites were established differing in hydrologic conditions and vegetation patterns. We examined depth profiles of CO2 and CH4 concentrations and delta 13C isotope ratios in the peat using silicon samplers, dialysis chambers and multi-level piezometers. Chamber flux measurements were used to determine carbon fluxes. Isotope mass balances were calculated based on 13C isotope ratios and concentration profiles. By this approach the contribution of anaerobic CH4 and CO2 production to the total ER flux and the amount of oxidised CH4 can be determined. In addition meteorological data, soil temperatures, moisture and water table levels were recorded. By raising data at different sites and dates and with the help of the additionally recorded parameters, we will be able to make predictions about changing CH4 production and oxidation processes due to changing climate conditions. Preliminary results show that CH4 concentrations in the soil profile are higher at the sites which are exposed to stronger water table fluctuations, whereas CO2 concentration levels are lower at these sites. At all sites, CO2 concentrations in the peat are increasing but CH4 profiles are fairly stable. Moreover, isotopic signatures of 13CH4 indicate that the importance of the production pathway changes with depth from acetoclastic

  12. Methane production and diurnal variation measured in dairy cows and predicted from fermentation pattern and nutrient or carbon flow

    NARCIS (Netherlands)

    Brask, M.; Weisbjerg, M.R.; Hellwing, A.L.F.; Bannink, A.; Lund, P.

    2015-01-01

    Many feeding trials have been conducted to quantify enteric methane (CH4) production in ruminants. Although a relationship between diet composition, rumen fermentation and CH4 production is generally accepted, the efforts to quantify this relationship within the same experiment remain scarce. In

  13. Discrimination of abiogenic and biogenic alkane gases

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We have combined the analytical data of the carbon isotope distribution pattern, R/Ra and CH4/3He values of abiogenic and biogenic (referring to the thermogenic and bacterial or microbial) alkane gases in China with those of alkane gases from USA, Russia, Germany, Australia and other countries. Four discrimination criteria are derived from this comparative study: 1) Carbon isotopic composition is generally greater than -30‰ for abiogenic methane and less than -30‰ for biogenic methane; 2) Abiogenic alkane gases have a carbon isotopic reversal trend (δ 13C1> δ 13C2> δ 13C3> δ 13C4) with δ 13C1>-30‰ in general; 3) Gases with R/Ra >0.5 and δ 13C11 δ 13C2>0 are of abiogenic origin; 4) Gases (meth- ane) with CH4/3He≤106 are of abiogenic origin, whereas gases with CH4/3He≥1011 are of biogenic origin.

  14. Progress in production technology of chlorinated methanes%甲烷氯化物生产技术进展

    Institute of Scientific and Technical Information of China (English)

    徐继红

    2001-01-01

    Production processes of chlorinated methanes includingmonochloromethane, dichloromethane, trichloromethane and carbon tetrachloride at home and abroad are introduced. Suggestions are put forward to domestic chlorinated methanes industry, which include developing large scale production,quickening the production transformation of carbon tetrachloride to dichloromethane or trichloromethane,and developing more varieties of derivatives of chlorinated methanes.%介绍了甲烷氯化物(一氯甲烷、二氯甲烷、三氯甲烷、四氯化碳)的国内外生产方法,认为我国应尽快发展规模化经济,加速四氯化碳向二氯甲烷、三氯甲烷的工艺转换,开发更多的甲烷氯化物衍生物。

  15. Increased anaerobic production of methane by co-digestion of sludge with microalgal biomass and food waste leachate.

    Science.gov (United States)

    Kim, Jungmin; Kang, Chang-Min

    2015-01-01

    The co-digestion of multiple substrates is a promising method to increase methane production during anaerobic digestion. However, limited reliable data are available on the anaerobic co-digestion of food waste leachate with microalgal biomass. This report evaluated methane production by the anaerobic co-digestion of different mixtures of food waste leachate, algal biomass, and raw sludge. Co-digestion of substrate mixture containing equal amounts of three substrates had higher methane production than anaerobic digestion of individual substrates. This was possibly due to a proliferation of methanogens over the entire digestion period induced by multistage digestion of different substrates with different degrees of degradability. Thus, the co-digestion of food waste, microalgal biomass, and raw sludge appears to be a feasible and efficient method for energy conversion from waste resources.

  16. Methane Pyrolysis for Hydrogen & Carbon Nanotube Recovery from Sabatier Products Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of a microgravity and hypogravity compatible catalytic methane pyrolysis reactor is proposed to recover hydrogen which is lost as methane in the...

  17. High Time Resolution Measurements of Methane Fluxes From Enteric Fermentation in Cattle Rumen

    Science.gov (United States)

    Floerchinger, C. R.; Herndon, S.; Fortner, E.; Roscioli, J. R.; Kolb, C. E.; Knighton, W. B.; Molina, L. T.; Zavala, M.; Castelán, O.; Ku Vera, J.; Castillo, E.

    2013-12-01

    Methane accounts for roughly 20% of the global radiative climate forcing in the last two and a half centuries. Methane emissions arise from a number of anthropogenic and biogenic sources. In some areas enteric fermentation in livestock produces over 90% of agricultural methane. In the spring of 2013, as a part of the Short Lived Climate Forcer-Mexico field campaign, the Aerodyne Mobile Laboratory in partnership with the Molina Center for the Environment studied methane production associated with enteric fermentation in the rumen of cattle. A variety of different breeds and stocks being raised in two agricultural and veterinary research facilities located in different areas of Mexico were examined. Methane fluxes were quantified using two methods: 1) an atmospherically stable gaseous tracer release was collocated with small herds in a pasture, allowing tracer ratio flux measurements; 2) respiratory CO2 was measured in tandem with methane in the breath of individual animals allowing methane production to be related to metabolism. The use of an extensive suite of very high time response instruments allows for differentiation of individual methane producing rumination events and respiratory CO2 from possible background interferences. The results of these studies will be presented and compared to data from traditional chamber experiments.

  18. Hydrogen and methane production from swine wastewater using microbial electrolysis cells.

    Science.gov (United States)

    Wagner, Rachel C; Regan, John M; Oh, Sang-Eun; Zuo, Yi; Logan, Bruce E

    2009-03-01

    The production of a useful and valuable product during swine wastewater treatment, such as hydrogen gas, could help to lower treatment costs. Hydrogen can theoretically be produced from wastewater by electrohydrogenesis in a microbial electrolysis cell (MEC) or by fermentation. Using a single-chamber MEC with a graphite-fiber brush anode, hydrogen gas was generated at 0.9-1.0 m(3) m(-3) day(-1) H2 using a full-strength or diluted swine wastewater. COD removals ranged from 8 to 29% in 20-h tests, and from 69 to 75% in longer tests (184 h) using full-strength wastewater. The gas produced was up to 77+/-11% hydrogen, with overall recoveries of up to 28+/-6% of the COD in the wastewater as hydrogen gas. Methane was also produced at a maximum of 13+/-4% of total gas volume. The efficiency of hydrogen production, based on the electrical energy needed (but excluding the energy in the wastewater) compared to the energy of the hydrogen gas produced, was as high as 190+/-39% in 42-h batch tests with undiluted wastewater, but was lower in longer batch tests of 184 h (91+/-6%). Hydrogen gas could not be recovered in fermentation tests using wastewater with a heat-treated inoculum. Hydrogen production was shown to be possible by fermentation when the wastewater was sterilized, but this process would not be practical or energy efficient. We therefore conclude from these tests that MECs are an effective method for hydrogen recovery from swine wastewater treatment, although the process needs to be further evaluated for reducing methane production, increasing the efficiency of converting the organic matter into current, and increasing recovery of hydrogen gas produced at the cathode.

  19. Assessment of the genetic polymorphism and biogenic amine production of indigenous Oenococcus oeni strains isolated from Greek red wines.

    Science.gov (United States)

    Pramateftaki, P V; Metafa, M; Karapetrou, G; Marmaras, G

    2012-02-01

    In the warm climate country of Greece malolactic fermentation (MLF) has received limited attention. Molecular techniques and High Performance Liquid Chromatography (HPLC) were used to study the genetic polymorphism of autochthonous lactic acid bacteria developing towards the end of spontaneous MLF of Greek red wines and for the assessment of their potential to produce harmful biogenic amines. This research revealed that native Oenococcus oeni isolates are very much adapted to specific winery conditions since the majority of spontaneous MLF were driven mostly or exclusively by a single strain of O. oeni. Native O. oeni strains showed only limited dispersion since cluster analysis uncovered only few common genotypes among indigenous isolates from different wineries. The genotype of a frequently used malolactic starter was more than often detected among autochthonous isolates without nevertheless compromising the biodiversity of natural microflora residing in wineries but rather becoming a part of it. For the majority of the wine samples studied, MLF implementation and storage in bottles resulted in negligible changes on the levels of the BA histamine, tyramine, phenylethylamine, cadaverine as well as of ethylamine, methylamine, isobutylamine. We provide evidence that autochthonous O. oeni isolates can only contribute to putrescine accumulation in Greek wines but still the specific trait behaves as strain-specific with a limited dispersion.

  20. Examining the Role of Aquatic Vegetation in Methane Production: Examples From a Shallow High Latitude Lake in Abisko, Sweden.

    Science.gov (United States)

    Horruitiner, C. D.; Varner, R. K.; Palace, M. W.; Johnson, J. E.; Wik, M.; Lundgren, D. J.; Sinclair, S. N.; Nicastro, A. J. D.; Crawford, M.

    2015-12-01

    High latitude lakes and ponds are a large source of atmospheric methane. Emissions from lakes are thought to be controlled primarily by temperature and secondarily by the availability of labile organic carbon. Aquatic plants provide insitu carbon sources to lake bottoms and therefore can potentially impact rates of methane production. We studied vegetation and lake sediment characteristics across shallow depths in Inre Harrsjön, a lake located within the Stordalen Mire in the discontinuous permafrost zone in subarctic Sweden. Vegetation surveys using a submerged quadrat with camera were performed in transects across IH to characterize bottom vegetation. Carbon and nitrogen elemental analysis was performed on vegetation samples from both the lake and surrounding mire ecosystem. Sediment cores representing each vegetation type were analyzed for CH4, δ13CH4, and elemental CHNS. In all cores but one, total organic carbon (TOC) is greatest near the surface and decreases downcore. Methane concentrations correlated with TOC indicating insitu methane production. C:N ratios in sediment cores are more reflective of aquatic than terrestrial mire vegetation indicating that organic carbon in the lake sediments is dominated by aquatic sources. δ13CH4 is relatively constant downcore, which indicates little to no methane oxidation. The methane produced in sediments is consistently within the range of hydrogenotrophic methanogenesis via CO2 reduction. We suggest the role of aquatic vegetation in the production of methane in high latitude shallow lakes may be important and will likely have a positive feedback in a warming climate with longer ice-free seasons.

  1. Petrophysical Characterization and Reservoir Simulator for Methane Gas Production from Gulf of Mexico Hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Kishore Mohanty; Bill Cook; Mustafa Hakimuddin; Ramanan Pitchumani; Damiola Ogunlana; Jon Burger; John Shillinglaw

    2006-06-30

    Gas hydrates are crystalline, ice-like compounds of gas and water molecules that are formed under certain thermodynamic conditions. Hydrate deposits occur naturally within ocean sediments just below the sea floor at temperatures and pressures existing below about 500 meters water depth. Gas hydrate is also stable in conjunction with the permafrost in the Arctic. Most marine gas hydrate is formed of microbially generated gas. It binds huge amounts of methane into the sediments. Estimates of the amounts of methane sequestered in gas hydrates worldwide are speculative and range from about 100,000 to 270,000,000 trillion cubic feet (modified from Kvenvolden, 1993). Gas hydrate is one of the fossil fuel resources that is yet untapped, but may play a major role in meeting the energy challenge of this century. In this project novel techniques were developed to form and dissociate methane hydrates in porous media, to measure acoustic properties and CT properties during hydrate dissociation in the presence of a porous medium. Hydrate depressurization experiments in cores were simulated with the use of TOUGHFx/HYDRATE simulator. Input/output software was developed to simulate variable pressure boundary condition and improve the ease of use of the simulator. A series of simulations needed to be run to mimic the variable pressure condition at the production well. The experiments can be matched qualitatively by the hydrate simulator. The temperature of the core falls during hydrate dissociation; the temperature drop is higher if the fluid withdrawal rate is higher. The pressure and temperature gradients are small within the core. The sodium iodide concentration affects the dissociation pressure and rate. This procedure and data will be useful in designing future hydrate studies.

  2. Microbial electrolysis cells for production of methane from CO2: long-term performance and perspectives

    NARCIS (Netherlands)

    Eerten-Jansen, van M.C.A.A.; Heijne, ter A.; Buisman, C.J.N.; Hamelers, H.V.M.

    2012-01-01

    A methane-producing microbial electrolysis cell (MEC) is a technology to convert CO2 into methane, using electricity as an energy source and microorganisms as the catalyst. A methane-producing MEC provides the possibility to increase the fuel yield per hectare of land area, when the CO2 produced in

  3. Effect of Natural Mineral on Methane Production and Process Stability During Semi-Continuous Mono-Digestion of Maize Straw.

    Science.gov (United States)

    González-Suárez, A; Pereda-Reyes, I; Pozzi, E; da Silva, A José; Oliva-Merencio, D; Zaiat, M

    2016-04-01

    The effect of natural mineral on the mono-digestion of maize straw was evaluated in continuously stirred tank reactors (CSTRs) at 38 °C. Different strategies of mineral addition were studied. The organic loading rate (OLR) was varied from 0.5 to 2.5 g volatile solid (VS) L(-1) d(-1). A daily addition of 1 g mineral L(-1) in reactor 2 (R2) diminished the methane production by about 11 % with respect to the initial phase. However, after a gradual addition of mineral, an average methane yield of 257 NmL CH4 g VS(-1) was reached and the methane production was enhanced by 30 % with regard to R1. An increase in the frequency of mineral addition did not enhance the methane production. The archaeal community was more sensitive to the mineral than the bacterial population whose similarity stayed high between R1 and R2. Significant difference in methane yield was found for both reactors throughout the operation.

  4. Numerical Simulation of Methane Production from Hydrates Induced by Different Depressurizing Approaches

    Directory of Open Access Journals (Sweden)

    Yanghui Li

    2012-02-01

    Full Text Available Several studies have demonstrated that methane production from hydrate-bearing porous media by means of depressurization-induced dissociation can be a promising technique. In this study, a 2D axisymmetric model for simulating the gas production from hydrates by depressurization is developed to investigate the gas production behavior with different depressurizing approaches. The simulation results showed that the depressurization process with depressurizing range has significant influence on the final gas production. On the contrary, the depressurizing rate only affects the production lifetime. More amount of cumulative gas can be produced with a larger depressurization range or lowering the depressurizing rate for a certain depressurizing range. Through the comparison of the combined depressurization modes, the Class 2 (all the hydrate dissociation simulations are performed by reducing the initial system pressure with the same depressurizing range initially, then to continue the depressurization process conducted by different depressurizing rates and complete when the system pressure decreases to the atmospheric pressure is much superior to the Class 1 (different depressurizing ranges are adopted in the initial period of the gas production process, when the pressure is reduced to the corresponding value of depressurization process at the different depressurizing range, the simulations are conducted at a certain depressurizing rate until the pressure reaches the atmospheric pressure for a long and stable gas production process. The parameter analysis indicated that the gas production performance decreases and the period of stable production increases with the initial pressure for the case of depressurizing range. Additionally, for the case of depressurizing range, the better gas production performance is associated with higher ambient temperature for production process, and the effect of thermal conductivity on gas production performance can be

  5. The coalbed methane production potential method for optimization of wells location selection

    Institute of Scientific and Technical Information of China (English)

    Feng-Ke DOU; Yong-Shang KANG; Shao-Feng QIN; De-Lei MAO; Jun HAN

    2013-01-01

    A gas production potential method for optimization of gas wellsite locations selection is proposed in terms of the coalbed gas resources volume and the recoverability.The method uses the actual data about reservoirs in a coalbed gas field in central China to optimize wellsite locations in the studied area in combination with the dynamic data about actual production in the coalbed gas field,selects a favorable subarea for gas wells deployment.The method is established based on the basic properties of coal reservoirs,in combination with the coalbed thickness and the gas content to make an analysis of the gas storage potential of a coal reservoir,as well as resources volume and the permeability of a coal reservoir.This method can be popularized for optimization of wellsite locations in other methane gas development areas or blocks.

  6. Bioaugmentation as a solution to increase methane production from an ammonia-rich substrate

    DEFF Research Database (Denmark)

    Fotidis, Ioannis; Wang, Han; Fiedel, Nicolai Russell;

    2014-01-01

    production yield. To date there are not any reliable methods to alleviate the ammonia toxicity effect and/or to efficiently digest ammonia-rich waste. In the current study, bioaugmentation as a possible method to alleviate ammonia toxicity effect in a mesophilic continuously stirred-tank reactor (CSTR......) operating under “inhibited steady state” was tested. A fast growing hydrogenotrophic methanogen (i.e. Methanoculleus bourgensis MS2T) was bioaugmented in the CSTR reactor at high ammonia levels (5 g NH4+-N L-1). A second CSTR reactor used as control with no bioaugmentation. The results derived from...... this study clearly demonstrated a 31.3% increase in methane production yield in the CSTR reactor, at steady-state, after bioaugmentation. Additionally, high-throughput 16S rRNA gene sequencing analysis showed a fivefold increase in relative abundance of Methanoculleus spp. after bioaugmentation. On contrary...

  7. Genetic resources for methane production from biomass described with gene ontology

    Directory of Open Access Journals (Sweden)

    Endang ePurwantini

    2014-12-01

    Full Text Available Methane (CH4 is a valuable fuel, constituting 70-95% of natural gas, and a potent greenhouse gas. Release of CH4 into the atmosphere contributes to climate change. Biological CH4 production or methanogenesis is mostly performed by methanogens, a group of strictly anaerobic archaea. The direct substrates for methanogenesis are H2 plus CO2, acetate, formate, methylamines, methanol, methyl sulfides, and ethanol or a secondary alcohol plus CO2. In numerous anaerobic niches in nature, methanogenesis facilitates mineralization of complex biopolymers such as carbohydrates, lipids and proteins generated by primary producers. Thus, methanogens are critical players in the global carbon cycle. The same process is used in anaerobic treatment of municipal, industrial and agricultural wastes, reducing the biological pollutants in the wastes and generating methane. It also holds potential for commercial production of natural gas from renewable resources. This process operates in digestive systems of many animals, including cattle, and humans. In contrast, in deep-sea hydrothermal vents methanogenesis is a primary production process, allowing chemosynthesis of biomaterials from H2 plus CO2. In this report we present Gene Ontology (GO terms that can be used to describe processes, functions and cellular components involved in methanogenic biodegradation and biosynthesis of specialized coenzymes that methanogens use. Some of these GO terms were previously available and the rest were generated in our Microbial Energy Gene Ontology (MENGO project. A recently discovered non-canonical CH4 production process is also described. We have performed manual GO annotation of selected methanogenesis genes, based on experimental evidence, providing gold standards for machine annotation and automated discovery of methanogenesis genes or systems in diverse genomes. Most of the GO-related information presented in this report is available at the MENGO website (http://www.mengo.biochem.vt.edu/.

  8. Biomass production and biochemical methane potential of seasonally flooded inter-generic and inter-specific Saccharum hybrids

    Energy Technology Data Exchange (ETDEWEB)

    Deren, C.W.; Snyder, G.H. (Florida Univ., Belle Glade, FL (United States). Agricultural Research and Education Center); Tai, P.Y.P. (Department of Agriculture, Canal Point, FL (US). Sugarcane Field Station); Turick, C.E.; Chynoweth, D.P. (Florida Univ., Gainesville, FL (United States). Dept. of Agricultural Engineering)

    1991-01-01

    Production of biomass crops for energy can compete with food crop production for quality, arable land. Certain biomass crops may be well suited to marginal sites which do not favor food crop production. This study was conducted to evaluate biomass production on a wetland site which, without extensive and costly conversion, would be unsuitable for conventional agricultural production. Nine clones of the Saccharum taxonomic complex were evaluated for biomass production and methane conversion after being flooded for six months in each of two crop years. Erianthus arundinaceus clones were intolerant of flood and subsequently were low in biomass production. Inter-specific and inter-generic hybrids of commercial sugarcane with E. arundinaceus and S. spontaneum produced well under flood. All clones were more productive in ratoon (regrowth crop). Rates of methane conversion under mesophilic conditions (35{sup o}C) ranged from 0.060 to 0.095 day{sup -1} and methane yield was from 0.266 to 0.314 liter g{sup -1} volatile solids (VS). Biomass dry matter yield varied widely from 0.47 to 20.28 Mg ha{sup -1} in the plant-crop and 4.57 to 60.1 Mg ha{sup -1} in ratoon. Using the mean sample value observed for methane yield, this corresponds to upper methane yields of 5.89 and 17.4 x 10{sup 6} liter ha{sup -1} for the plant and ratoon crops, respectively. The wide crosses appear to have good potential for biomass production in areas prone to periodic flooding. (author).

  9. Effects of gas composition in headspace and bicarbonate concentrations in media on gas and methane production, degradability, and rumen fermentation using in vitro gas production techniques.

    Science.gov (United States)

    Patra, Amlan Kumar; Yu, Zhongtang

    2013-07-01

    Headspace gas composition and bicarbonate concentrations in media can affect methane production and other characteristics of rumen fermentation in in vitro gas production systems, but these 2 important factors have not been evaluated systematically. In this study, these 2 factors were investigated with respect to gas and methane production, in vitro digestibility of feed substrate, and volatile fatty acid (VFA) profile using in vitro gas production techniques. Three headspace gas compositions (N2+ CO2+ H2 in the ratio of 90:5:5, CO2, and N2) with 2 substrate types (alfalfa hay only, and alfalfa hay and a concentrate mixture in a 50:50 ratio) in a 3×2 factorial design (experiment 1) and 3 headspace compositions (N2, N2 + CO2 in a 50:50 ratio, and CO2) with 3 bicarbonate concentrations (80, 100, and 120 mM) in a 3×3 factorial design (experiment 2) were evaluated. In experiment 1, total gas production (TGP) and net gas production (NGP) was the lowest for CO2, followed by N2, and then the gas mixture. Methane concentration in headspace gas after fermentation was greater for CO2 than for N2 and the gas mixture, whereas total methane production (TMP) and net methane production (NMP) were the greatest for CO2, followed by the gas mixture, and then N2. Headspace composition did not affect in vitro digestibility or the VFA profile, except molar percentages of propionate, which were greater for CO2 and N2 than for the gas mixture. Methane concentration in headspace gas, TGP, and NGP were affected by the interaction of headspace gas composition and substrate type. In experiment 2, increasing concentrations of CO2 in the headspace decreased TGP and NGP quadratically, but increased the concentrations of methane, NMP, and in vitro fiber digestibility linearly, and TMP quadratically. Fiber digestibility, TGP, and NGP increased linearly with increasing bicarbonate concentrations in the medium. Concentrations of methane and NMP were unaffected by bicarbonate concentration, but

  10. Measurement of ethylene and methane production in a temperate forest soil using inhibition of acetylene and carbon monoxide

    Institute of Scientific and Technical Information of China (English)

    XU XingKai; INUBUSHI Kazuyuki

    2008-01-01

    We studied in the laboratory the effects of acetylene (C2H2) concentrations on the accumulation and consumption of ethylene and methane in a temperate pine forest soil, and in situ ethylene and methane production and flush effects of nitrogen sources on both productions in the pine forest stand (Pinus sylvestris L.). The addition of C2H2 at concentrations more than 50 Pa C2H2 in the headspace caused a more than 95% reduction in rates of ethylene and methane consumption in forest soil compared to those with no C2H2. Furthermore, addition of acetylene within a range of 50 to 10, 000 Pa C2H2 induced a similar rate of methane accumulation in forest soil. Hence, it can be concluded that presence of more than 50 Pa C2H2 in the headspace is an effective method to measure methane production in forest soil. The addition of C2H2 at concentrations more than 50 Pa C2H2 induced an increasing concentration of ethylene in the headspace (P≤0.05), indicating the reduction of acetylene to ethylene in forest soil. Using inhibition of 0.5 kPa C2H2 in combination with 5 kPa carbon monoxide that inhibits the reduction of acetylene in a short term, it was observed that there was a larger in situ methane production rate (218±26 μg C m-2 h-1 (μg C per square meter per hour, the same below)) than in situethylene produc-tion rate (92 ± 6 μg C m-2 h-1) in the pine forest soil. The addition of nitrogen sources such as urea, urea plus a nitrification inhibitor dicyandiamide, and potassium nitrate, could induce a 5-fold greater in-crease in rates of in situ ethylene and methane production compared to those in the control, particu-larly in the latter (P≤0.05). The results can promote in situ measurement of ethylene and methane production in forest soils at different sites.

  11. The Role of Sedges in Methane Production and Emission From a Temperate Fen

    Science.gov (United States)

    Noyce, G. L.; Szarkowski, E. R.; Bubier, J. L.; Varner, R. K.

    2008-12-01

    Northern peatlands are the largest single natural source of atmospheric methane (CH4) and thus any changes in these fluxes could have global consequences. Positive correlations have been observed between sedge biomass and high CH4 emissions from peatlands. We examined the effect that Carex rostrata has on methane production and transport in Sallie's Fen, Barrington, NH. During the summer of 2008, CH4 fluxes, pore-water CH4 concentrations, and C. rostrata biomass, along with temperature, net ecosystem CO2 exchange (NEE), and water table depth, were measured from both clipped and unclipped plots. In clipped plots, all C. rostrata were clipped below the peat surface and then sealed with petroleum jelly and plastic bags. Unclipped plots were left undisturbed. We observed a strong positive correlation between C. rostrata biomass and CH4 fluxes. Initial findings suggest that sedges have a strong effect on gas transport. The average 18 cm (C. rostrata rooting depth) pore water CH4 concentrations in the clipped plots (6141 ppm CH4) were significantly higher (p<0.001) than in the unclipped plots (3912 ppm CH4). The past 20 years of data at Sallie's Fen also show that plots with more C. rostrata have higher mid-season CH4 fluxes, on average, than shrub-dominated plots. Depth to water table, however, may be a stronger control on CH4 fluxes than vegetation.

  12. Comparison of Chlorella vulgaris and cyanobacterial biomass: cultivation in urban wastewater and methane production.

    Science.gov (United States)

    Mendez, Lara; Sialve, Bruno; Tomás-Pejó, Elia; Ballesteros, Mercedes; Steyer, Jean Philippe; González-Fernández, Cristina

    2016-05-01

    Anaerobic digestion of microalgae is hampered by its complex cell wall. Against this background, cyanobacteria cell walls render this biomass as an ideal substrate for overcoming this drawback. The aim of the present study was to compare the growth of two cyanobacteria (Aphanizomenon ovalisporum and Anabaena planctonica) and a microalga (Chlorella vulgaris) in urban wastewater when varying the temperature (22, 27 and 32 °C). Cyanobacterial optimal growth for both strains was attained at 22 °C, while C. vulgaris did not show remarkable differences among temperatures. For all the microorganisms, ammonium removal was higher than phosphate. Biomass collected was subjected to anaerobic digestion. Methane yield of C. vulgaris was 184.8 mL CH4 g COD in(-1) while with A. ovalisporum and A. planctonica the methane production was 1.2- and 1.4-fold higher. This study showed that cyanobacteria growth rates could be comparable to microalgae while presenting the additional benefit of an increased anaerobic digestibility.

  13. Low temperature anaerobic digestion of mixtures of llama, cow and sheep manure for improved methane production

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Rene [IIDEPROQ, UMSA, Plaza del Obelisco 1175, La Paz (Bolivia)]|[Department of Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund (Sweden); Liden, Gunnar [Department of Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund (Sweden)

    2009-03-15

    Biogas production in anaerobic digestion in farm-scale units is typically performed under mesophilic conditions when used for producing domestic fuel and stabilizing animal waste for the use of digested manure as a fertilizer. Previous studies on the digestion of llama and cow manure have shown the feasibility of producing biogas under altiplano conditions (low pressure and low temperature) and of llama manure as a promising feedstock. The present study concerns the utilization of various mixtures of feedstocks from the Bolivian altiplano under low temperature conditions (18-25 C). Laboratory scale experiments were performed on the digestion of mixtures of llama, sheep and cow manure in a semi-continuous process using ten 2-L stainless steel digesters to determine the effects of organic loading rate (OLR) and the feed composition. The semi-continuous operation of mixture of llama-cow-sheep manure proved to be a reliable system, which could be operated with good stability. The results suggest that in a system digesting a mixture of llama-cow-sheep manure at low temperature (18-25 C) the maximum OLR value is between 4 and 6 kg VS m{sup 3} d{sup -1}. The methane yields obtained in the mixture experiments were in the range 0.07-0.14 m{sup 3} kg{sup -1} VS added, with a methane concentration in the gas of between 47 and 55%. (author)

  14. Effect of pre-treatments on methane production potential of energy crops and crop residues

    Energy Technology Data Exchange (ETDEWEB)

    Lehtomaki, A.; Ronkainen; Rintala, J.A. [Jyvaskla Univ. (Finland). Dept. of Biological and Environmental Sciences; Viinikainen, T.A. [Jyvaskla Univ. (Finland). Dept. of Chemistry

    2004-07-01

    Energy crops, that is, crops grown specifically for energy purposes are an alternative to food production in areas with sufficient agricultural land. Crop residues are also a potential source of energy. The anaerobic digestion of solid materials is limited by hydrolysis of complex polymeric substances such as lignocellulose. The methane producing potential of ligno cellulosic material is to pretreat the substrate in order to break up the polymer chains to more easily accessible soluble compounds. In this study, three different substrates were used: sugar beet tops, grass hay, and straw of oats. Biological pretreatments were the following: enzyme treatment, composting, white-rot fungi treatment. Also, pretreatment in water was tried. Chemical pretreatments included peracetic acid treatment, and treatment with two different alkalis. Alkaline pretreatments of hay and sugar beet tops have the potential to improve the methane yield. For instance, the yield of grass hay was increased 15 per cent by one particular alkaline treatment. Straw did not respond to any of the treatments tried. 18 refs., 1 tab., 2 figs.

  15. Source attribution of methane emissions from global oil and gas production: results of bottom-up simulations over three decades

    Science.gov (United States)

    Höglund-Isaksson, Lena

    2016-04-01

    Existing bottom-up emission inventories of historical methane and ethane emissions from global oil and gas systems do not well explain year-on-year variations estimated by top-down models from atmospheric measurements. This paper develops a bottom-up methodology which allows for country- and year specific source attribution of methane and ethane emissions from global oil and natural gas production for the period 1980 to 2012. The analysis rests on country-specific simulations of associated gas flows which are converted into methane and ethane emissions. The associated gas flows are constructed from country-specific information on oil and gas production and associated gas generation and recovery, and coupled with generic assumptions to bridge regional information gaps on the fractions of unrecovered associated gas that is vented instead of flared. Summing up emissions from associated gas flows with global estimates of emissions from unintended leakage and natural gas transmission and distribution, the resulting global emissions of methane and ethane from oil and gas systems are reasonably consistent with corresponding estimates from top-down models. Also revealed is that the fall of the Soviet Union in 1990 had a significant impact on methane and ethane emissions from global oil and gas systems.

  16. Effect of dietary nitrate level on enteric methane production, hydrogen emission, rumen fermentation, and nutrient digestibility in dairy cows.

    Science.gov (United States)

    Olijhoek, D W; Hellwing, A L F; Brask, M; Weisbjerg, M R; Højberg, O; Larsen, M K; Dijkstra, J; Erlandsen, E J; Lund, P

    2016-08-01

    Nitrate may lower methane production in ruminants by competing with methanogenesis for available hydrogen in the rumen. This study evaluated the effect of 4 levels of dietary nitrate addition on enteric methane production, hydrogen emission, feed intake, rumen fermentation, nutrient digestibility, microbial protein synthesis, and blood methemoglobin. In a 4×4 Latin square design 4 lactating Danish Holstein dairy cows fitted with rumen, duodenal, and ileal cannulas were assigned to 4 calcium ammonium nitrate addition levels: control, low, medium, and high [0, 5.3, 13.6, and 21.1g of nitrate/kg of dry matter (DM), respectively]. Diets were made isonitrogenous by replacing urea. Cows were fed ad libitum and, after a 6-d period of gradual introduction of nitrate, adapted to the corn-silage-based total mixed ration (forage:concentrate ratio 50:50 on DM basis) for 16d before sampling. Digesta content from duodenum, ileum, and feces, and rumen liquid were collected, after which methane production and hydrogen emissions were measured in respiration chambers. Methane production [L/kg of dry matter intake (DMI)] linearly decreased with increasing nitrate concentrations compared with the control, corresponding to a reduction of 6, 13, and 23% for the low, medium, and high diets, respectively. Methane production was lowered with apparent efficiencies (measured methane reduction relative to potential methane reduction) of 82.3, 71.9, and 79.4% for the low, medium, and high diets, respectively. Addition of nitrate increased hydrogen emissions (L/kg of DMI) quadratically by a factor of 2.5, 3.4, and 3.0 (as L/kg of DMI) for the low, medium, and high diets, respectively, compared with the control. Blood methemoglobin levels and nitrate concentrations in milk and urine increased with increasing nitrate intake, but did not constitute a threat for animal health and human food safety. Microbial crude protein synthesis and efficiency were unaffected. Total volatile fatty acid

  17. The effects of leachate recirculation with supplemental water addition on methane production and waste decomposition in a simulated tropical landfill.

    Science.gov (United States)

    Sanphoti, N; Towprayoon, S; Chaiprasert, P; Nopharatana, A

    2006-10-01

    In order to increase methane production efficiency, leachate recirculation is applied in landfills to increase moisture content and circulate organic matter back into the landfill cell. In the case of tropical landfills, where high temperature and evaporation occurs, leachate recirculation may not be enough to maintain the moisture content, therefore supplemental water addition into the cell is an option that could help stabilize moisture levels as well as stimulate biological activity. The objectives of this study were to determine the effects of leachate recirculation and supplemental water addition on municipal solid waste decomposition and methane production in three anaerobic digestion reactors. Anaerobic digestion with leachate recirculation and supplemental water addition showed the highest performance in terms of cumulative methane production and the stabilization period time required. It produced an accumulated methane production of 54.87 l/kg dry weight of MSW at an average rate of 0.58 l/kg dry weight/d and reached the stabilization phase on day 180. The leachate recirculation reactor provided 17.04 l/kg dry weight at a rate of 0.14l/kg dry weight/d and reached the stabilization phase on day 290. The control reactor provided 9.02 l/kg dry weight at a rate of 0.10 l/kg dry weight/d, and reached the stabilization phase on day 270. Increasing the organic loading rate (OLR) after the waste had reached the stabilization phase made it possible to increase the methane content of the gas, the methane production rate, and the COD removal. Comparison of the reactors' efficiencies at maximum OLR (5 kgCOD/m(3)/d) in terms of the methane production rate showed that the reactor using leachate recirculation with supplemental water addition still gave the highest performance (1.56 l/kg dry weight/d), whereas the leachate recirculation reactor and the control reactor provided 0.69 l/kg dry weight/d and 0.43 l/kg dry weight/d, respectively. However, when considering

  18. Impact of different antibiotics on methane production using waste-activated sludge: mechanisms and microbial community dynamics.

    Science.gov (United States)

    Mustapha, Nurul Asyifah; Sakai, Kenji; Shirai, Yoshihito; Maeda, Toshinari

    2016-11-01

    Anaerobic digestion is an effective method for reducing the by-product of waste-activated sludge (WAS) from wastewater treatment plants and for producing bioenergy from WAS. However, only a limited number of studies have attempted to improve anaerobic digestion by targeting the microbial interactions in WAS. In this study, we examined whether different antibiotics positively, negatively, or neutrally influence methane fermentation by evaluating changes in the microbial community and functions in WAS. Addition of azithromycin promoted the microbial communities related to the acidogenic and acetogenic stages, and a high concentration of soluble proteins and a high activity of methanogens were detected. Chloramphenicol inhibited methane production but did not affect the bacteria that contribute to the hydrolysis, acidogenesis, and acetogenesis digestion stages. The addition of kanamycin, which exhibits the same methane productivity as a control (antibiotic-free WAS), did not affect all of the microbial communities during anaerobic digestion. This study demonstrates the simultaneous functions and interactions of diverse bacteria and methanogenic Archaea in different stages of the anaerobic digestion of WAS. The ratio of Caldilinea, Methanosarcina, and Clostridium may correspond closely to the trend of methane production in each antibiotic. The changes in microbial activities and function by antibiotics facilitate a better understanding of bioenergy production.

  19. THE USE OF PRINCIPAL COMPONENT ANALYSIS IN IDENTIFYING AND INTEGRATING VARIABLES RELATED TO FORAGE QUALITY AND METHANE PRODUCTION

    Directory of Open Access Journals (Sweden)

    A. Jayanegara

    2014-10-01

    Full Text Available This research was aimed to explore the use of multivariate statistics i.e. principal componentanalysis (PCA in identifying and integrating variables related to forage quality and ruminal methaneproduction, and in classifying forage species into both characteristics. Seventeen plants were used as adatabase for the above mentioned purposes. Plant samples were determined for their chemicalcomposition, cumulative gas production (represents the nutrient degradation and methane productionafter 24 hours of fermentation period using the Hohenheim gas test. The results showed that the PCAcould clearly identify factors related to forage quality and methane production and separated them intodifferent principal components (PC. The obtained PC1 was related to methane production andsubstantially influenced positively by crude protein, NDF, ADF (positive, total phenols, total tannins,condensed tannins and tannin activity (negative. On the other hand, the obtained PC2 was related tocumulative gas production (forage quality and substantially influenced by crude protein (positive,NDF, ADF and condensed tannins (negative. Classification and screening of forages that have highquality and low methane production are possible using the PCA technique. Rhenum undulatum,Peltiphyllum peltatum and Rhus typhina were found to have such desired characteristics.

  20. EVALUATION OF NUTRITIVE VALUE AND IN VITRO METHANE PRODUCTION OF FEEDSTUFFS FROM AGRICULTURAL AND FOOD INDUSTRY BY-PRODUCTS

    Directory of Open Access Journals (Sweden)

    B. Santoso

    2014-10-01

    Full Text Available The aim of this research was to evaluate the nutrient degradability, in vitro methane (CH4 production ofseveral agricultural and food industry by-products in relation to their chemical composition. Twenty-onesamples of 7 feedstuffs from agricultural and food industry by-products consisted of corn straw, potatostraw, rice straw, cocoa pod, sago waste, rice bran, soybean curd residue were evaluated by an in vitro gasproduction and nutrient degradability. The feedstuffs varied greatly in their crude protein (CP, neutraldetergent fiber (NDF and non-fiber carbohydrate (NFC contents. Crude protein ranged from 1.5 to 21.8%,NDF from 31.6 to 71.1% and NFC from 1.5 to 50.8%. Among the seven feedstuffs, soybean curd residuehad the highest CP content, on the other hand it had the lowest NDF content. Dry matter (DM and organicmatter (OM degradability were highest (P<0.01 in soybean curd residue among the feedstuffs. The CH4production was significantly higher (P<0.01 in rice straw, cocoa pod and corn straw as compared to sagowaste. There was a strong positive correlation (r = 0.60; P<0.01 between NDF concentration and CH4production. However, the total gas productions was negatively correlated (r = -0.75; P<0.01 with NDFcontent. The CH4 production of feedstuff is influenced by NDF content.

  1. Mechanisms for the suppression of methane production in peatland soils by a humic substance analog

    Science.gov (United States)

    Ye, R.; Keller, J. K.; Jin, Q.; Bohannan, B. J. M.; Bridgham, S. D.

    2014-01-01

    Methane (CH4) production is often impeded in many northern peatland soils, although inorganic terminal electron acceptors (TEAs) are usually present in low concentrations in these soils. Recent studies suggest that humic substances in wetland soils can be utilized as organic TEAs for anaerobic respiration and may directly inhibit CH4 production. Here we utilize the humic analog anthraquinone-2, 6-disulfonate (AQDS) to explore the importance of humic substances, and their effects on the temperature sensitivity of anaerobic decomposition, in two peatland soils. In a bog peat, AQDS was not instantly utilized as a TEA, but greatly inhibited the fermentative production of acetate, carbon dioxide (CO2), and hydrogen (H2), as well as CH4 production. When added together with glucose, AQDS was partially reduced after a lag period of 5 to 10 days. In contrast, no inhibitory effect of AQDS on fermentation was found in a fen peat and AQDS was readily reduced as an organic TEA. The addition of glucose and AQDS to both bog and fen peats caused complicated temporal dynamics in the temperature sensitivity of CH4 production, reflecting temporal changes in the temperature responses of other carbon processes with effects on methanogenesis. Our results show that the humic analog AQDS can act both as an inhibitory agent and a TEA in peatland soils. The high concentrations of humic substances in northern peatlands may greatly influence the effect of climate change on soil carbon cycling in these ecosystems.

  2. Trimethylamine stimulated and dissolved organic matter inhibited methane production in sediment from the Poyang Lake, China.

    Science.gov (United States)

    Wang, Jiajia; Liu, Chunying; Gong, Xiaofeng; Liu, Yuanmu; Chen, Chunli

    2016-10-01

    Methane (CH4) emitted from wetlands contributes significantly to the greenhouse effect. The Poyang Lake, the largest freshwater lake in China, is fed by five rivers and connects to the Yangtze River. The area of the lake fluctuates dramatically between drawdown and flood periods with large areas of wetlands. In order to understand the CH4 production capacity and factors that influence CH4 production in the wetland, a static closed chamber combined with a gas chromatograph technique was used to investigate the influence of substrates and electron acceptors on methanogenesis. The results showed that CH4 production capacity of sediments from the Poyang Lake was [Formula: see text] and it was stimulated by trimethylamine (TMA) to a great extent. Incubation temperature played a vital role on CH4 production in sediments and the optimum temperature for methanogenesis was 35°C. Minimum CH4 production capacity occurred with the addition of FeCl3, and the inhibitory effects of electron acceptors decreased in the sequence: FeCl3 > MnO2 > DOM > Fe2O3. In this study, DOM was demonstrated as one of the inhibitors to methanogenesis and TMA was the main substrate of methanogens in the sediments of the Poyang Lake whose pH value is 7.83.

  3. Reducing methane production by supplementation of Terminalia chebula RETZ. containing tannins and saponins.

    Science.gov (United States)

    Anantasook, Nirawan; Wanapat, Metha; Gunun, Pongsatorn; Cherdthong, Anusorn

    2016-06-01

    This study investigates the effects of Terminalia chebula Retz. meal supplementation on rumen fermentation and methane (CH4 ) production by using an in vitro gas technique. The experimental design was a completely randomized design (CRD) and the dietary treatments were T. chebula supplementation at 0, 4, 8, 12, 16 and 20 mg with 0.5 g of roughage and concentrate ratio at 60:40. The results revealed that cumulative gas production (96 h of incubation) were higher (P  0.05). The NH3 -N concentrations tended to quadratically increase with increasing levels of T. chebula in the diet. In addition, total volatile fatty acids (VFA) and propionate concentrations were increased (P < 0.01), while acetate concentration, acetate-to-propionate ratio, CH4 production and protozoal populations were decreased (P < 0.01) when supplemented with T. chebula at 8, 12 and 16 mg, respectively. Based on this study, it could be concluded that supplementation of T. chebula at 12 mg could improve rumen fermentation by reducing CH4 production and protozoa populations, thus improving in vitro gas production and VFA profiles.

  4. Mechanisms for the suppression of methane production in peatland soils by a humic substance analog

    Directory of Open Access Journals (Sweden)

    R. Ye

    2014-01-01

    Full Text Available Methane (CH4 production is often impeded in many northern peatland soils, although inorganic terminal electron acceptors (TEAs are usually present in low concentrations in these soils. Recent studies suggest that humic substances in wetland soils can be utilized as organic TEAs for anaerobic respiration and may directly inhibit CH4 production. Here we utilize the humic analog anthraquinone-2, 6-disulfonate (AQDS to explore the importance of humic substances, and their effects on the temperature sensitivity of anaerobic decomposition, in two peatland soils. In a bog peat, AQDS was not instantly utilized as a TEA, but greatly inhibited the fermentative production of acetate, carbon dioxide (CO2, and hydrogen (H2, as well as CH4 production. When added together with glucose, AQDS was partially reduced after a lag period of 5 to 10 days. In contrast, no inhibitory effect of AQDS on fermentation was found in a fen peat and AQDS was readily reduced as an organic TEA. The addition of glucose and AQDS to both bog and fen peats caused complicated temporal dynamics in the temperature sensitivity of CH4 production, reflecting temporal changes in the temperature responses of other carbon processes with effects on methanogenesis. Our results show that the humic analog AQDS can act both as an inhibitory agent and a TEA in peatland soils. The high concentrations of humic substances in northern peatlands may greatly influence the effect of climate change on soil carbon cycling in these ecosystems.

  5. Biogenic amines in raw and processed seafood

    Directory of Open Access Journals (Sweden)

    Pierina eVisciano

    2012-06-01

    Full Text Available The presence of biogenic amines in raw and processed seafood, associated with either time/temperature conditions or food technologies is discussed in the present paper from a safety and prevention point of view. In particular, storage temperature, handling practices, presence of microbial populations with decarboxylase activity and availability of free amino acids are considered the most important factors affecting the production of biogenic amines in raw seafood. On the other hand, some food technological treatments such as salting, ripening, fermentation or marination can increase the levels of biogenic amines in processed seafood. The consumption of high amount of biogenic amines, above all histamine, can result in food borne poisoning which is a worldwide problem. The European Regulation established as maximum limits for histamine, in fishery products from fish species associated with high histidine amounts, values ranging from 100 to 200 mg/kg, while for products which have undergone enzyme maturation treatment in brine, the aforementioned limits rise to 200 and 400 mg/kg. Preventive measures and emerging methods aiming at controlling the production of biogenic amines are also reported for potential application in seafood industries.

  6. Effects of titanium dioxide and zinc oxide nanoparticles on methane production from anaerobic co-digestion of primary and excess sludge.

    Science.gov (United States)

    Zheng, Xiong; Wu, Lijuan; Chen, Yinguang; Su, Yinglong; Wan, Rui; Liu, Kun; Huang, Haining

    2015-01-01

    Anaerobic co-digestion of primary and excess sludge is regarded as an efficient way to reuse sludge organic matter to produce methane. In this study, short-term and long-term exposure experiments were conducted to investigate the possible effects of titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles (NPs) on methane production from anaerobic co-digestion of primary and excess sludge. The data showed that TiO2 NPs had no measurable impact on methane production, even at a high concentration (150 mg/g total suspended solids (TSS)). However, short-term (8 days) exposure to 30 or 150 mg/g-TSS of ZnO NPs significantly decreased methane production. More importantly, these negative effects of ZnO NPs on anaerobic sludge co-digestion were not alleviated by increasing the adaptation time to 105 days. Further studies indicated that the presence of ZnO NPs substantially decreased the abundance of methanogenic archaea, which reduced methane production. Meanwhile, the activities of some key enzymes involved in methane production, such as protease, acetate kinase, and coenzyme F420, were remarkably inhibited by the presence of ZnO NPs, which was also an important reason for the decreased methane production. These results provide a better understanding of the potential risks of TiO2 and ZnO NPs to methane production from anaerobic sludge co-digestion.

  7. Energy-efficient methane production from macroalgal biomass through chemo disperser liquefaction.

    Science.gov (United States)

    Tamilarasan, K; Kavitha, S; Rajesh Banu, J; Arulazhagan, P; Yeom, Ick Tae

    2017-03-01

    In this study, an effort has been made to reduce the energy cost of liquefaction by coupling a mechanical disperser with a chemical (sodium tripolyphosphate). In terms of the cost and specific energy demand of liquefaction, the algal biomass disintegrated at 12,000rpm for 30min, and an STPP dosage of about 0.04g/gCOD was chosen as an optimal parameter. Chemo disperser liquefaction (CDL) was found to be energetically and economically sustainable in terms of liquefaction, methane production, and net profit (15%, 0.14gCOD/gCOD, and 4 USD/Ton of algal biomass) and preferable to disperser liquefaction (DL) (10%, 0.11 gCOD/gCOD, and -475 USD/Ton of algal biomass).

  8. A fuzzy-logic-based controller for methane production in anaerobic fixed-film reactors.

    Science.gov (United States)

    Robles, A; Latrille, E; Ruano, M V; Steyer, J P

    2017-01-01

    The main objective of this work was to develop a controller for biogas production in continuous anaerobic fixed-bed reactors, which used effluent total volatile fatty acids (VFA) concentration as control input in order to prevent process acidification at closed loop. To this aim, a fuzzy-logic-based control system was developed, tuned and validated in an anaerobic fixed-bed reactor at pilot scale that treated industrial winery wastewater. The proposed controller varied the flow rate of wastewater entering the system as a function of the gaseous outflow rate of methane and VFA concentration. Simulation results show that the proposed controller is capable to achieve great process stability even when operating at high VFA concentrations. Pilot results showed the potential of this control approach to maintain the process working properly under similar conditions to the ones expected at full-scale plants.

  9. Comparative study of the methane production based on the chemical compositions of Mangifera Indica and Manihot Utilissima leaves.

    Science.gov (United States)

    Mambanzulua Ngoma, Philippe; Hiligsmann, Serge; Sumbu Zola, Eric; Culot, Marc; Fievez, Thierry; Thonart, Philippe

    2015-01-01

    Leaves of Mangifera Indica (MI, mango leaves) and Manihot Utilissima (MU, cassava leaves) are available in tropical regions and are the most accessible vegetal wastes of Kinshasa, capital of Democratic Republic of Congo. These wastes are not suitably managed and are not rationally valorized. They are abandoned in full air, on the soil and in the rivers. They thus pollute environment. By contrast, they can be recuperated and treated in order to produce methane (energy source), organic fertilizer and clean up the environment simultaneously. The main objective of this study was to investigate methane production from MI and MU leaves by BMP tests at 30°C. The yields achieved from the anaerobic digestion of up to 61.3 g raw matter in 1 l medium were 0.001 l/g and 0.100 l CH4/g volatile solids of MI and MU leaves, respectively. The yield of MU leaves was in the range mentioned in the literature for other leaves because of a poor presence of bioactive substrates, and low C/N ratio. This methane yield corresponded to 7% of calorific power of wood. By contrast, the methane yield from MI leaves was almost nil suggesting some metabolism inhibition because of their rich composition in carbon and bioactive substrates. Whereas classical acidogenesis and acetogenesis were recorded. Therefore, methane production from the sole MI leaves seems unfavorable by comparison to MU leaves at the ambient temperature in tropical regions. Their solid and liquid residues obtained after anaerobic digestion would be efficient fertilizers. However, the methane productivity of both leaves could be improved by anaerobic co-digestion.

  10. Thermo-Catalytic Methane Decomposition for Hydrogen Production: Effect of Palladium Promoter on Ni-based Catalysts

    Directory of Open Access Journals (Sweden)

    Irene Lock Sow Mei

    2016-08-01

    Full Text Available Hydrogen production from the direct thermo-catalytic decomposition of methane is a promising alternative for clean fuel production. However, thermal decomposition of methane can hardly be of any practical and empirical interest in the industry unless highly efficient and effective catalysts, in terms of both catalytic activity and operational lifetime have been developed. In this study, the effect of palladium (Pd as a promoter onto Ni supported on alumina catalyst has been investigated by using co-precipitation technique. The introduction of Pd promotes better catalytic activity, operational lifetime and thermal stability of the catalyst. As expected, highest methane conversion was achieved at reaction temperature of 800 °C while the bimetallic catalyst (1 wt.% Ni -1wt.% Pd/Al2O3 gave the highest methane conversion of 70% over 15 min of time-on-stream (TOS. Interestingly, the introduction of Pd as promoter onto Ni-based catalyst also has a positive effect on the operational lifetime and thermal stability of the catalyst as the methane conversion has improved significantly over 240 min of TOS. Copyright © 2016 BCREC GROUP. All rights reserved Received: 21st January 2016; Revised: 6th February 2016; Accepted: 6th March 2016 How to Cite: Mei, I.L.S., Lock, S.S.M., Vo, D.V.N., Abdullah, B. (2016. Thermo-Catalytic Methane Decomposition for Hydrogen Production: Effect of Palladium Promoter on Ni-based Catalysts. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (2: 191-199 (doi:10.9767/bcrec.11.2.550.191-199 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.2.550.191-199

  11. Effects of a combination of feed additives on methane production, diet digestibility, and animal performance in lactating dairy cows

    NARCIS (Netherlands)

    Zijderveld, van S.M.; Fonken, B.C.J.; Dijkstra, J.; Gerrits, W.J.J.; Perdok, H.B.; Fokkink, W.B.; Newbold, J.R.

    2011-01-01

    Two experiments were conducted to assess the effects of a mixture of dietary additives on enteric methane production, rumen fermentation, diet digestibility, energy balance, and animal performance in lactating dairy cows. Identical diets were fed in both experiments. The mixture of feed additives in

  12. Effects of a gradually increased load of fish waste silage in co-digestion with cow manure on methane production.

    Science.gov (United States)

    Solli, Linn; Bergersen, Ove; Sørheim, Roald; Briseid, Tormod

    2014-08-01

    This study examined the effects of an increased load of nitrogen-rich organic material on anaerobic digestion and methane production. Co-digestion of fish waste silage (FWS) and cow manure (CM) was studied in two parallel laboratory-scale (8L effective volume) semi-continuous stirred tank reactors (designated R1 and R2). A reactor fed with CM only (R0) was used as control. The reactors were operated in the mesophilic range (37°C) with a hydraulic retention time of 30 days, and the entire experiment lasted for 450 days. The rate of organic loading was raised by increasing the content of FWS in the feed stock. During the experiment, the amount (volume%) of FWS was increased stepwise in the following order: 3% - 6% - 13% - 16%, and 19%. Measurements of methane production, and analysis of volatile fatty acids, ammonium and pH in the effluents were carried out. The highest methane production from co-digestion of FWS and CM was 0.400 L CH4 gVS(-1), obtained during the period with loading of 16% FWS in R2. Compared to anaerobic digestion of CM only, the methane production was increased by 100% at most, when FWS was added to the feed stock. The biogas processes failed in R1 and R2 during the periods, with loadings of 16% and 19% FWS, respectively. In both reactors, the biogas processes failed due to overloading and accumulation of ammonia and volatile fatty acids.

  13. Comparative performance of enzymatic and combined alkaline-enzymatic pretreatments on methane production from ensiled sorghum forage.

    Science.gov (United States)

    Rollini, Manuela; Sambusiti, Cecilia; Musatti, Alida; Ficara, Elena; Retinò, Isabella; Malpei, Francesca

    2014-12-01

    This study investigated the effect of enzymatic and combined alkaline-enzymatic pretreatments on chemical composition and methane production from ensiled sorghum forage. Four commercial enzymatic preparations were tested and the two yielding the highest sugars release were added to evaluate any hydrolytic effect on both untreated and alkaline pretreated samples. In the combined alkaline-enzymatic pretreatment trials, the highest sugar release was found with Primafast and BGL preparations (added at a final concentration 0.12 and 0.20 mL/g TS, respectively), with a total monomeric content of 12 and 6.5 g/L. Fibre composition analysis confirmed that the combined alkaline-enzymatic pretreatment led to cellulose (up to 32 %) and hemicelluloses (up to 56 %) solubilisation, compared to the enzymatic pretreatment alone. BMP tests were performed on both untreated and pretreated samples, and time courses of methane production were fitted. Both enzymatic and combined alkaline-enzymatic pretreatment led to a methane production increase (304 and 362 mL CH4/g VS), compared to that of untreated sorghum (265 mL CH4/g VS), as  +15 and  +37 %, respectively. Moreover, higher specific methane production rates, compared to that of untreated sorghum (20.31 mL CH4/g VS/d), were obtained by applying the enzymatic and combined alkaline-enzymatic pretreatment (33.94 and 31.65 mL CH4/g VS/d), respectively.

  14. Anaerobic digestion of selected Italian agricultural and industrial residues (grape seeds and leather dust): combined methane production and digestate characterization.

    Science.gov (United States)

    Caramiello, C; Lancellotti, I; Righi, F; Tatàno, F; Taurino, R; Barbieri, L

    2013-01-01

    A combined experimental evaluation of methane production (obtained by anaerobic digestion) and detailed digestate characterization (with physical-chemical, thermo-gravimetric and mineralogical approaches) was conducted on two organic substrates, which are specific to Italy (at regional and national levels). One of the substrates was grape seeds, which have an agricultural origin, whereas the other substrate was vegetable-tanned leather dust, which has an industrial origin. Under the assumed experimental conditions of the performed lab-scale test series, the grape seed substrate exhibited a resulting net methane production of 175.0 NmL g volatile solids (VS)(-1); hence, it can be considered as a potential energy source via anaerobic digestion. Conversely, the net methane production obtained from the anaerobic digestion of the vegetable-tanned leather dust substrate was limited to 16.1 NmL gVS(-1). A detailed characterization of the obtained digestates showed that there were both nitrogen-containing compounds and complex organic compounds present in the digestate that was obtained from the mixture of leather dust and inoculum. As a general perspective of this experimental study, the application of diversified characterization analyzes could facilitate (1) a better understanding of the main properties of the obtained digestates to evaluate their potential valorization, and (2) a combination of the digestate characteristics with the corresponding methane productions to comprehensively evaluate the bioconversion process.

  15. Effect of coal matrix swelling on enhanced coalbed methane production. A field and laboratory study. Geologica Ultraiectina (315)

    NARCIS (Netherlands)

    van Bergen, F.

    2009-01-01

    Carbon capture and storage (CCS) is considered a key technology to reduce worldwide emissions of carbon dioxide (CO2). One CCS option is to inject CO2 into subsurface coal beds. When combined with simultaneous, enhanced, production of methane naturally present in the coal, this process is referred t

  16. Monitoring Production of Methane and Carbon Dioxide and Consumption of Oxygen at Spills of Gasoline at UST Release Sites

    Science.gov (United States)

    Methane is rarely measured at fuel spill sites, and most commonly the measurements are made on samples of ground water. Many ground water monitoring wells are intentionally screened across the water table. This was done to allow them to sample free product. However, if there is s...

  17. Biological Production of Methane from Lunar Mission Solid Waste: An Initial Feasibility Assessment

    Science.gov (United States)

    Strayer, Richard; Garland, Jay; Janine, Captain

    A preliminary assessment was made of the potential for biological production of methane from solid waste generated during an early planetary base mission to the moon. This analysis includes: 1) estimation of the amount of biodegradable solid waste generated, 2) background on the potential biodegradability of plastics given their significance in solid wastes, and 3) calculation of potential methane production from the estimate of biodegradable waste. The completed analysis will also include the feasibility of biological methane production costs associated with the biological processing of the solid waste. NASA workshops and Advanced Life Support documentation have estimated the projected amount of solid wastes generated for specific space missions. From one workshop, waste estimates were made for a 180 day transit mission to Mars. The amount of plastic packaging material was not specified, but our visual examination of trash returned from stocktickerSTS missions indicated a large percentage would be plastic film. This plastic, which is not biodegradable, would amount to 1.526 kgdw crew-1 d-1 or 6.10 kgdw d-1 for a crew of 4. Over a mission of 10 days this would amount to 61 kgdw of plastics and for an 180 day lunar surface habitation it would be nearly 1100 kgdw . Approx. 24 % of this waste estimate would be biodegradable (human fecal waste, food waste, and paper), but if plastic packaging was replaced with biodegradable plastic, then 91% would be biodegradable. Plastics are man-made long chain polymeric molecules, and can be divided into two main groups; thermoplastics and thermoset plastics. Thermoplastics comprise over 90% of total plastic use in the placecountry-regionUnited States and are derived from polymerization of olefins via breakage of the double bond and subsequent formation of additional carbon to carbon bonds. The resulting sole-carbon chain polymers are highly resistant to biodegradation and hydrolytic cleavage. Common thermoplastics include low

  18. Methane production in the biosphere; La produzione di metano nella biosfera: il ruolo degli animali da allevamento

    Energy Technology Data Exchange (ETDEWEB)

    Sauvant, D. [Stazione di Nutrizione e Alimentazione (Italy)

    1999-04-01

    Methane is a greenhouse gas. A part of methane production is of agricultural origin. The emissions related to animal organisms are evaluated and discussed. [Italian] Il metano e' una molecola che contribuisce all'effetto serra e alle conseguenze climatiche che ne derivano. Una parte di metano e' di orgine agricola, legata in particolare alla produzione animale. Questo breve documento vuole focalizzare le conoscenze su quest'ultimo aspetto, limitandosi alle emissioni attribuibili agli organismi animali, escludendo pero' i loro rifiuti.

  19. Evaluation of the seismic reflection method as a monitoring tool during primary and enhanced coalbed methane production

    Science.gov (United States)

    Lespinasse Fung, Diane Jael

    In this thesis I present an evaluation of the seismic reflection method as a monitoring tool during coalbed methane (CBM) production and enhanced coalbed methane (ECBM) production by CO2 injection. This evaluation is based on a workflow previously developed for monitoring CO2 storage in the Big George coalbeds in the Powder River Basin. I study the changes in seismic and the AVO response associated with coalbeds during primary production using a data set from the Mannville coals, which represent one of the most important CBM resources in the Province of Alberta. Using published data, I perform a single well flow simulation to make an assessment of its production forecast in a 10 year period. The flow simulation provides information on methane saturation and reservoir pressure during production, while the changes in porosity and permeability due to depletion are estimated according to the Palmer and Mansoori permeability model. Using well log data of the Corbett Field and the results of the flow simulation, I complete a Gassmann fluid substitution to replace brine by a mixture of brine and methane in the pore space and estimate the variations in Vp, Vs and density due to changes in fluid saturation. I evaluate offset dependent synthetic seismograms before and after fluid substitution, and I use different coalbed thicknesses to establish resolution limits. To observe significant changes in the character and phase of the wavelet due to the replacement of brine by methane I find that coalbed thickness must be at least 10 m, also in terms of AVO I observe that there is a decrease in amplitude with offset caused by the presence of methane in the pore space. Using the same methodology and production data from the Fruitland Coals Fairway in the North of the San Juan Basin U.S.A, which is considered the most productive CBM reservoir in the world, I evaluate Elastic Impedance (EI) and Elastic Impedance Coefficient (EC) response during ECBM by CO2 injection. In this case, I

  20. Effect of Fodder Tree Species with Condensed Tannin Contents on In vitro Methane Production

    Science.gov (United States)

    Vázquez, Ernestina Gutiérrez; Medina, Leonardo Hernández; Benavides, Liliana Márquez; Caratachea, Aureliano Juárez; Razo, Guillermo Salas; Burgos, Armin Javier Ayala; Rodríguez, Ruy Ortiz

    2016-01-01

    The objective was to evaluate the effect of fodder tree species (FTS) with condensed tannin contents: Cordia elaeagnoides, Platymiscium lasiocarpum, Vitex mollis, and Haematoxylon brasiletto, on in vitro methane (CH4) production at 24 h post incubation. The analysis was performed using the in vitro gas production technique, with three levels of inclusion/species: 600, 800, and 1,000 mg and with 4 replicates/species/level of inclusion. The substrate was incubated at 39°C, and the gas and CH4 production were recorded at 4, 8, 12, and 24 h post incubation. The data collected was analyzed through Pearson correlation, polinomial regression and fixed effects models. There were negative correlations between FTS-total gas volume (r = −0.40; p32.7%), taking into account the total CH4 production at 24 h of the forage used as reference (Avena sativa). It’s suggested that C. elaeagnoides-according to its crude protein, neutral detergent fiber, and condensed tannins content- is the best alternative within the FTS analyzed, for feeding ruminants and for the control of CH4 emissions during the dry season. PMID:26732330

  1. Cultivation of a native alga for biomass and biofuel accumulation in coal bed methane production water

    Science.gov (United States)

    Hodgskiss, Logan H.; Nagy, Justin; Barnhart, Elliott P.; Cunningham, Alfred B.; Fields, Matthew W.

    2016-01-01

    Coal bed methane (CBM) production has resulted in thousands of ponds in the Powder River Basin of low-quality water in a water-challenged region. A green alga isolate, PW95, was isolated from a CBM production pond, and analysis of a partial ribosomal gene sequence indicated the isolate belongs to the Chlorococcaceae family. Different combinations of macro- and micronutrients were evaluated for PW95 growth in CBM water compared to a defined medium. A small level of growth was observed in unamended CBM water (0.15 g/l), and biomass increased (2-fold) in amended CBM water or defined growth medium. The highest growth rate was observed in CBM water amended with both N and P, and the unamended CBM water displayed the lowest growth rate. The highest lipid content (27%) was observed in CBM water with nitrate, and a significant level of lipid accumulation was not observed in the defined growth medium. Growth analysis indicated that nitrate deprivation coincided with lipid accumulation in CBM production water, and lipid accumulation did not increase with additional phosphorus limitation. The presented results show that CBM production wastewater can be minimally amended and used for the cultivation of a native, lipid-accumulating alga.

  2. Thermochemical pretreatment of meat and bone meal and its effect on methane production

    Institute of Scientific and Technical Information of China (English)

    Guangxue WU; Zhenhu HU; Mark G. HEALY; Xinmin ZHAN

    2009-01-01

    Since the solubilization of meat and bone meal (MBM) is a prerequisite in many MBM disposal approaches, enhancement of the solubilization by means of thermochemical pretreatment was investigated in this study at two temperatures (55℃ and 131℃) and six sodium hydroxide (NaOH) concentrations (0, 1.25, 2.5, 5,10 and 20 g/L). The MBM volatile solid (VS) reduction ratio was up to 66% and 70% at 55℃ and 131℃,respectively. At the same temperature, the VS reduction ratio increased with the increase in the dosage of NaOH.The study on the methane (CH4) production potential of pretreated MBM shows that the addition of NaOH at 55℃ did not cause the inhibition of the succeeding CH4 production process. However, CH4 production was inhibited by the addition of NaOH at 131℃. The CH4 production potential was in the range of 389 to 503 mL CH4/g VS MBM and 464 to 555 mL CH4/g VS MBM at 55℃ and 131℃, respectively.

  3. Hydrogen and syngas production from two-step steam reforming of methane using CeO2 as oxygen carrier

    Institute of Scientific and Technical Information of China (English)

    Xing Zhu; Hua Wang; Yonggang Wei; Kongzhai Li; Xianming Cheng

    2011-01-01

    CeO2 oxygen carrier was prepared by precipitation method and tested by two-step steam reforming of methane (SRM).Two-step SRM for hydrogen and syngas generation is investigated in a fixed-bed reactor.Methane is directly converted to syngas at a H2/CO ratio close to 2∶ 1 at a high temperature (above 750 ℃) by the lattice oxygen of CeO2; methane cracking is found when the reduction degree of CeO2 was above 5.0% at 850 ℃ in methane isothermal reaction.CeO2-δ obtained from methane isothermal reaction can split water to generate CO-free hydrogen and renew its lattice oxygen at 700 ℃; simultaneously, deposited carbon is selectively oxidized to CO2 by steam following the reaction (C+2H2O→CO2+2H2).Slight deactivation in terms of amounts of desired products (syngas and hydrogen) is observed in ten repetitive two-step SRM process due to the carbon deposition on CeO2 surface as well as sintering of CeO2.

  4. Methane production improvement by modulation of solid phase immersion in dry batch anaerobic digestion process: Dynamic of methanogen populations.

    Science.gov (United States)

    André, L; Ndiaye, M; Pernier, M; Lespinard, O; Pauss, A; Lamy, E; Ribeiro, T

    2016-05-01

    Several 60L dry batch anaerobic digestion (AD) reactors were implemented with or without liquid reserve on cattle manure. The immersed part modulation of cattle manure increased the methane flow of about 13%. The quantitative real time PCR and the optimized DNA extraction were implemented and validated to characterize and quantify the methanogen dynamic in dry batch AD process. Final quantities of methanogens converged toward the same level in several inocula at the end of AD. Methanogen dynamic was shown by dominance of Methanosarcinaceae for acetotrophic methanogens and Methanobacteriales for the hydrogenotrophic methanogens. Overall, methanogens populations were stabilized in liquid phase, except Methanosaetaceae. Solid phase was colonized by Methanomicrobiales and Methanosarcinaceae populations giving a support to biofilm development. The methane increase could be explained by a raise of Methanosarcinaceae population in presence of a total contact between solid and liquid phases. Methanosarcinaceae was a bio-indicator of the methane production.

  5. Hydrogen production by catalytic decomposition of methane using a Fe-based catalyst in a fluidized bed reactor

    Institute of Scientific and Technical Information of China (English)

    D.Torres; S.de Llobet; J.L.Pinilla; M.J.Lázaro; I.Suelves; R.Moliner

    2012-01-01

    Catalytic decomposition of methane using a Fe-based catalyst for hydrogen production has been studied in this work.A Fe/Al2O3 catalyst previously developed by our research group has been tested in a fluidized bed reactor (FBR).A parametric study of the effects of some process variables,including reaction temperature and space velocity,is undertaken.The operating conditions strongly affect the catalyst performance.Methane conversion was increased by increasing the temperature and lowering the space velocity.Using temperatures between 700 and 900 ℃ and space velocities between 3 and 6 LN/(gcat·h),a methane conversion in the range of 25%-40% for the gas exiting the reactor could be obtained during a 6 h run.In addition,carbon was deposited in the form of nanofilaments (chain like nanofibers and multiwall nanotubes) with similar properties to those obtained in a fixed bed reactor.

  6. Methods for Detecting Microbial Methane Production and Consumption by Gas Chromatography

    OpenAIRE

    Aldridge, Jared T.; Catlett, Jennie L.; Smith, Megan L.; Buan, Nicole R.

    2016-01-01

    Methane is an energy-dense fuel but is also a greenhouse gas 25 times more detrimental to the environment than CO2. Methane can be produced abiotically by serpentinization, chemically by Sabatier or Fisher-Tropsh chemistry, or biotically by microbes (Berndt et al., 1996; Horita and Berndt, 1999; Dry, 2002; Wolfe, 1982; Thauer, 1998; Metcalf et al., 2002). Methanogens are anaerobic archaea that grow by producing methane gas as a metabolic byproduct (Wolfe, 1982; Thauer, 1998). Our lab has deve...

  7. Methane production and digestion of different physical forms of rapeseed as fat supplements in dairy cows.

    Science.gov (United States)

    Brask, M; Lund, P; Weisbjerg, M R; Hellwing, A L F; Poulsen, M; Larsen, M K; Hvelplund, T

    2013-04-01

    The purpose of this experiment was to study the effect of the physical form of rapeseed fat on methane (CH4) mitigation properties, feed digestion, and rumen fermentation. Four lactating ruminal-, duodenal-, and ileal-cannulated Danish Holstein dairy cows (143 d in milk, milk yield of 34.3 kg) were submitted to a 4×4 Latin square design with 4 rations: 1 control with rapeseed meal (low-fat, CON) and 3 fat-supplemented rations with either rapeseed cake (RSC), whole cracked rapeseed (WCR), or rapeseed oil (RSO). Dietary fat concentrations were 3.5 in CON, 5.5 in RSC, 6.2 in WCR, and 6.5% in RSO. The amount of fat-free rapeseed was kept constant for all rations. The forage consisted of corn silage and grass silage and the forage to concentrate ratio was 50:50 on a dry matter basis. Diurnal samples of duodenal and ileal digesta and feces were compiled. The methane production was measured for 4 d in open-circuit respiration chambers. Additional fat reduced the CH4 production per kilogram of dry matter intake and as a proportion of the gross energy intake by 11 and 14%, respectively. Neither the total tract nor the rumen digestibility of organic matter (OM) or neutral detergent fiber were significantly affected by the treatment. Relating the CH4 production to the total-tract digested OM showed a tendency to decrease CH4 per kilogram of digested OM for fat-supplemented rations versus CON. The acetate to propionate ratio was not affected for RSC and WCR but was increased for RSO compared with CON. The rumen ammonia concentration was not affected by the ration. The milk and energy-corrected milk yields were unaffected by the fat supplementation. In conclusion, rapeseed is an appropriate fat source to reduce the enteric CH4 production without affecting neutral detergent fiber digestion or milk production. The physical form of fat did not influence the CH4-reducing effect of rapeseed fat. However, differences in the volatile fatty acid pattern indicate that different

  8. Effects of supplementation frequency on the ruminal fermentation and enteric methane production of beef cattle grazing in tropical pastures

    Directory of Open Access Journals (Sweden)

    Roberta Carrilho Canesin

    2014-11-01

    Full Text Available The objective of this study was to evaluate the characteristics of ruminal fermentation and enteric methane production in beef cattle subjected to different supplementation frequencies while grazing on Brachiaria brizanthacv. Marandu pastures. Nine cattle (325±65.7 kg BW fitted with ruminal and duodenal cannulas were used in the ruminal fermentation study, and 12 cattle (399±32.6 kg BW were used in the enteric methane production study. The treatments included supplementation once daily, supplementation once daily except Saturdays and Sundays, or supplementation on alternate days. The supplementation was equivalent to 10 g kg−1 BW day−1 for all treatments. The design employed was completely randomized with three treatments and three replications. When all supplements were provided (day 1, no effects of supplementation frequency were observed on ruminal pH; concentration of NH3-N; concentration of acetic, propionic, or butyric acids; or total volatile fatty acids (VFA, but there were month effects. During the day on which only daily supplements were provided (day 2, significant differences were observed only on the molar concentration of acetic acid and total VFA; and month effects were noted on all variables. No significant differences were observed in ruminal fluid volume, dilution rate, N intake, bacterial N synthesis and enteric methane production among the studied supplementation frequencies. Differences were observed in the enteric methane production in the different months, with 85 g kg−1 of gross energy intake observed in September and 123 g kg−1 of gross energy intake observed in November. Lower supplementation frequency is a good option to lower labor costs with li