Literatura académica sobre el tema "Production de CH4"
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Artículos de revistas sobre el tema "Production de CH4"
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Chen, Chung-Nan, Tzu-Tai Lee y Bi Yu. "19. Improving the Prediction of Methane Production Determined by in Vitro Gas Production Technique for Ruminants". Annals of Animal Science 16, n.º 2 (1 de abril de 2016): 565–84. http://dx.doi.org/10.1515/aoas-2015-0078.
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Abstract Twelve feedstuffs (cereals, fibrous byproducts, protein-rich byproducts and forages) were determined for methane (CH4) production by the in vitro gas production technique (IVGPT) and were correlated with their chemical compositions to predict enteric CH4 originating from these feedstuffs in ruminants. Corn, soybean hull, soybean meal and corn silage generated the highest CH4 production from their respective categories. The average CH4 production of fibrous byproducts (44.6 ml/g DM incubated) was significantly higher than that of cereals (40.3 ml/g DM incubated), forages (33.3 ml/g DM incubated) and protein-rich byproducts (31.0 ml/g DM incubated) after the 48-h incubation (P≤0.05). The highest average total volatile fatty acid (VFA) concentration was determined in cereals (53.6 mM). The acetate to propionate ratio was significantly lower in cereals when compared with other categories of feedstuff (P≤0.05). The correlation analysis showed that in vitro true digestibility (IVTD) positively correlated with the CH4 production in all four categories of feedstuffs (P≤0.05). The neutral detergent fiber (NDF) and acid detergent fiber (ADF) content positively correlated with CH4 production in every category of feedstuffs except cereals. The starch content negatively correlated with CH4 production for fibrous and protein-rich byproducts (P≤0.05), but it positively correlated with CH4 production for forages (P≤0.05). The CH4 production was predicted more accurately by the equations proposed for each category (R2=0.944, 0.876, 0.942 and 0.915 for cereals, fibrous and protein-rich byproducts and forages, respectively) than for the unclassified feedstuffs (R2=0.715). In conclusion, the contribution of individual chemical composition to CH4 production differed depending on the category of feedstuffs. The precision of CH4 prediction could be substantially improved by classifying feedstuffs into categories according to their chemical composition, and selecting the appropriate predictors for each category. Information about the CH4 output of these feedstuffs will be useful in formulating low CH4-producing diets for ruminants.
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SAUVANT, D., S. GIGER-REVERDIN, A. SERMENT y L. BROUDISCOU. "Influences des régimes et de leur fermentation dans le rumen sur la production de méthane par les ruminants". INRAE Productions Animales 24, n.º 5 (8 de diciembre de 2011): 433–46. http://dx.doi.org/10.20870/productions-animales.2011.24.5.3276.
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Ce travail s'appuie sur l'étude de plusieurs bases de données en vue d'extraire des modèles de prévision de la production de CH4 enfonction des régimes et des fermentations ruminales. La méthanogenèse est décrite en relation avec les principaux principes de la stoechiométrieet de la thermodynamique des fermentations ruminales. Il apparaît en particulier une relation étroite entre la productionde CH4 et le rapport des acides acétique/propionique du jus de rumen (Ac/Pr). Les variations du profil des AGV et de la productionde CH4 traduisent des phénomènes d'adaptation des microorganismes du rumen à la quantité d'énergie disponible. Au sein desdifférents critères alimentaires de prévision de la production de CH4, la teneur en matière organique digestible (MOD) est intéressante: elle est globalement bien liée à la MO fermentescible du rumen, donc au CH4 produit, et à la valeur énergétique des aliments.Cependant, le rapport CH4/MOD varie également en fonction de certains facteurs de variation qui modifient aussi le rapport Ac/Prdans le rumen : le niveau alimentaire, la qualité du fourrage, la teneur en concentré du régime et l'apport de matières grasses.Une dernière partie du texte est consacrée à l'étude de modèles plus mécanistes qui s'appuient sur les principes de stoechiométrie desAGV, ces modèles constituant une étape vers une modélisation intégrative de l'ensemble des phénomènes digestifs et fermentaires durumen.
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Setyanto, P., Rosenani A.B., A. K. Makarim, Che Fauziah I., A. Bidin y Suharsih Suharsih. "SOIL CONTROLLING FACTORS OF METHANE GAS PRODUCTION FROM FLOODED RICE FIELDS IN PATI DISTRICT, CENTRAL JAVA". Indonesian Journal of Agricultural Science 3, n.º 1 (25 de octubre de 2016): 1. http://dx.doi.org/10.21082/ijas.v3n1.2002.1-11.
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Atmospheric methane (CH4) is recognized as one of the most important greenhouse gases. Methane, with some 15-30 times greater infrared-absorbing capability than CO2 on a mass basis, may account for 20% of anticipated global warming. Soils are one of the key factors, which play an important role in CH4 production and emission. However, data on CH4 emission from different soil types and the characteristics affecting CH4 production are lacking when compared to data on agronomic practices. This study was conducted to investigate the potential of CH4 production of selected soils in Java, and determine the limiting factors of CH4 production. The results showed that addition of 1% glucose to the soils led to an increase in CH4 production by more than twelve fold compared to no glucose addition. The CH4 production potential ranged between 3.21 and 112.30 mg CH4 kg-1 soil. The lowest CH4 production potential occurred in brown-grayish Grumosol, while the highest was in dark-gray Grumosol. Chemical and physical properties of the soils have great influence on CH4 production. Stepwise multiple regression analysis of CH4 production and soil characteristics showed that pH and the contents of Fe2O3, MnO2, SO4, and silt in the soil strongly influenced CH4 production. Results of this study can be used for further development of a model on CH4 emission from rice fields.
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Setyanto, P., Rosenani A.B., A. K. Makarim, Che Fauziah I., A. Bidin y Suharsih Suharsih. "SOIL CONTROLLING FACTORS OF METHANE GAS PRODUCTION FROM FLOODED RICE FIELDS IN PATI DISTRICT, CENTRAL JAVA". Indonesian Journal of Agricultural Science 3, n.º 1 (25 de octubre de 2016): 1. http://dx.doi.org/10.21082/ijas.v3n1.2002.p1-11.
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Atmospheric methane (CH4) is recognized as one of the most important greenhouse gases. Methane, with some 15-30 times greater infrared-absorbing capability than CO2 on a mass basis, may account for 20% of anticipated global warming. Soils are one of the key factors, which play an important role in CH4 production and emission. However, data on CH4 emission from different soil types and the characteristics affecting CH4 production are lacking when compared to data on agronomic practices. This study was conducted to investigate the potential of CH4 production of selected soils in Java, and determine the limiting factors of CH4 production. The results showed that addition of 1% glucose to the soils led to an increase in CH4 production by more than twelve fold compared to no glucose addition. The CH4 production potential ranged between 3.21 and 112.30 mg CH4 kg-1 soil. The lowest CH4 production potential occurred in brown-grayish Grumosol, while the highest was in dark-gray Grumosol. Chemical and physical properties of the soils have great influence on CH4 production. Stepwise multiple regression analysis of CH4 production and soil characteristics showed that pH and the contents of Fe2O3, MnO2, SO4, and silt in the soil strongly influenced CH4 production. Results of this study can be used for further development of a model on CH4 emission from rice fields.
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Tenorio, Sandy E. y Laura Farías. "Picoplanktonic methane production in eutrophic surface waters". Biogeosciences 21, n.º 8 (25 de abril de 2024): 2029–50. http://dx.doi.org/10.5194/bg-21-2029-2024.
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Abstract. Over the past decade, extensive research has delved into the methane (CH4) paradox, which involves aerobic CH4 production. We present noteworthy observations of CH4 oversaturation within the surface layer of the central Chile upwelling zone (36° S, 73° W) over two consecutive seasonal cycles (2018–2021). Complementing these observations, CH4 cycling experiments were conducted, utilizing distinct plankton fractions (encompassing the natural planktonic community, fractions < 150, < 3 and < 0.2 µm), in different productivity periods of phytoplanktonic production and composition throughout the year. Our findings underscore the pivotal role of picoplankton (< 3 µm) in CH4 production on the ocean surface, contrasting with the limited contribution of larger microorganisms (< 150 µm). Notably, incubations with methylated substrates, such as methylphosphonic acid (MPn) and trimethylamine (TMA), induce heightened CH4 production within the picoplanktonic fraction. This phenomenon is consistently observed during both upwelling (austral spring–summer) and non-upwelling (winter) seasons, with significance in the latter period, when Synechococcus sp. exhibits notably high relative abundance. Long-term microcosm experiments highlight the crucial roles played by heterotrophic bacteria and cyanobacteria in methylotrophic methanogenesis. This process enhances CH4 production, facilitated by the recycling of dissolved organic carbon (DOC). Picoplankton emerges as a pivotal factor influencing the recycling of methylated substrates, and it is responsible for maintaining CH4 supersaturation. These findings provide valuable insights into the biogeochemical processes driving CH4 dynamics, particularly in highly productive upwelling areas.
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Schroll, Moritz, Katharina Lenhart, Thomas Bender, Piet Hötten, Alexander Rudolph, Sven Sörensen y Frank Keppler. "Fungal Methane Production Controlled by Oxygen Levels and Temperature". Methane 3, n.º 2 (19 de abril de 2024): 257–75. http://dx.doi.org/10.3390/methane3020015.
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Saprotrophic fungi, key players in global carbon cycling, have been identified as methane (CH4) sources not yet accounted for in the global CH4 budget. This study, for the first time, explores the influence of oxygen (O2) and temperature on CH4 production by two fungi, Laetiporus sulphureus and Pleurotus sapidus. To explore the relationship between these parameters and fungal CH4 formation, we examined CH4 formation under varying O2 levels (0 to 98%) and temperatures (17, 27, and 40 °C) during fungal growth on pine wood, beech wood, and grass under sterile conditions. Our findings show that fungal CH4 formation strongly depends on O2 levels. Methane formation was highest when O2 levels exceeded 5%, whilst no CH4 formation was observed after complete O2 consumption. Reintroducing O2 immediately resumed fungal CH4 production. Methane formation normalized to O2 consumption (CH4_norm) showed a different pattern. L. sulphureus showed higher CH4_norm rates with higher O2 levels, whereas P. sapidus showed elevated rates between 0 and 5%. Temperature also significantly influenced CH4 and CH4_norm rates, with the highest production at 27 °C, and comparatively lower rates at 17 and 40 °C. These findings demonstrate the importance of O2 levels and temperature in fungal CH4 emissions, which are essential for refining CH4 source predictions.
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Zheng, Jianqiu, Taniya RoyChowdhury, Ziming Yang, Baohua Gu, Stan D. Wullschleger y David E. Graham. "Impacts of temperature and soil characteristics on methane production and oxidation in Arctic tundra". Biogeosciences 15, n.º 21 (8 de noviembre de 2018): 6621–35. http://dx.doi.org/10.5194/bg-15-6621-2018.
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Abstract. Rapid warming of Arctic ecosystems accelerates microbial decomposition of soil organic matter and leads to increased production of carbon dioxide (CO2) and methane (CH4). CH4 oxidation potentially mitigates CH4 emissions from permafrost regions, but it is still highly uncertain whether soils in high-latitude ecosystems will function as a net source or sink for CH4 in response to rising temperature and associated hydrological changes. We investigated CH4 production and oxidation potential in permafrost-affected soils from degraded ice-wedge polygons on the Barrow Environmental Observatory, Utqiaġvik (Barrow), Alaska, USA. Frozen soil cores from flat and high-centered polygons were sectioned into organic, transitional, and permafrost layers, and incubated at −2, +4 and +8 ∘C to determine potential CH4 production and oxidation rates. Significant CH4 production was only observed from the suboxic transition layer and permafrost of flat-centered polygon soil. These two soil sections also exhibited highest CH4 oxidation potentials. Organic soils from relatively dry surface layers had the lowest CH4 oxidation potential compared to saturated transition layer and permafrost, contradicting our original assumptions. Low methanogenesis rates are due to low overall microbial activities measured as total anaerobic respiration and the competing iron-reduction process. Our results suggest that CH4 oxidation could offset CH4 production and limit surface CH4 emissions, in response to elevated temperature, and thus must be considered in model predictions of net CH4 fluxes in Arctic polygonal tundra. Future changes in temperature and soil saturation conditions are likely to divert electron flow to alternative electron acceptors and significantly alter CH4 production, which should also be considered in CH4 models.
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Heslop, J. K., K. M. Walter Anthony, A. Sepulveda-Jauregui, K. Martinez-Cruz, A. Bondurant, G. Grosse y M. C. Jones. "Thermokarst lake methanogenesis along a complete talik profile". Biogeosciences 12, n.º 14 (24 de julio de 2015): 4317–31. http://dx.doi.org/10.5194/bg-12-4317-2015.
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Abstract. Thermokarst (thaw) lakes emit methane (CH4) to the atmosphere formed from thawed permafrost organic matter (OM), but the relative magnitude of CH4 production in surface lake sediments vs. deeper thawed permafrost horizons is not well understood. We assessed anaerobic CH4 production potentials from various depths along a 590 cm long lake sediment core that captured the entire sediment package of the talik (thaw bulb) beneath the center of an interior Alaska thermokarst lake, Vault Lake, and the top 40 cm of thawing permafrost beneath the talik. We also studied the adjacent Vault Creek permafrost tunnel that extends through ice-rich yedoma permafrost soils surrounding the lake and into underlying gravel. Our results showed CH4 production potentials were highest in the organic-rich surface lake sediments, which were 151 cm thick (mean ± SD: 5.95 ± 1.67 μg C–CH4 g dw−1 d−1; 125.9 ± 36.2 μg C–CH4 g C−1org d−1). High CH4 production potentials were also observed in recently thawed permafrost (1.18 ± 0.61 μg C–CH4g dw−1 d−1; 59.60± 51.5 μg C–CH4 g C−1org d−1) at the bottom of the talik, but the narrow thicknesses (43 cm) of this horizon limited its overall contribution to total sediment column CH4 production in the core. Lower rates of CH4 production were observed in sediment horizons representing permafrost that has been thawing in the talik for a longer period of time. No CH4 production was observed in samples obtained from the permafrost tunnel, a non-lake environment. Our findings imply that CH4 production is highly variable in thermokarst lake systems and that both modern OM supplied to surface sediments and ancient OM supplied to both surface and deep lake sediments by in situ thaw and shore erosion of yedoma permafrost are important to lake CH4 production.
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Heslop, J. K., K. M. Walter Anthony, A. Sepulveda-Jauregui, K. Martinez-Cruz, A. Bondurant, G. Grosse y M. C. Jones. "Thermokarst-lake methanogenesis along a complete talik profile". Biogeosciences Discussions 12, n.º 6 (24 de marzo de 2015): 4865–905. http://dx.doi.org/10.5194/bgd-12-4865-2015.
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Abstract. Thermokarst (thaw) lakes emit methane (CH4) to the atmosphere formed from thawed permafrost organic matter (OM), but the relative magnitude of CH4 production in surface lake sediments vs. deeper thawed permafrost horizons is not well understood. We assessed anaerobic CH4 production potentials from various depths along a 590 cm long lake sediment core that captured the entire sediment package of the talik (thaw bulb) beneath the center of an interior Alaska thermokarst lake, Vault Lake, and the top 40 cm of thawing permafrost beneath the talik. We also studied the adjacent Vault Creek permafrost tunnel that extends through ice-rich yedoma permafrost soils surrounding the lake and into underlying gravel. Our results showed CH4 production potentials were highest in the organic-rich surface lake sediments, which were 151 cm thick (mean ± SD 5.95 ± 1.67 μg C-CH4 g dw−1 d−1; 125.9± 36.2 μg C-CH4 g C−1org d−1). High CH4 production potentials were also observed in recently-thawed permafrost (1.18± 0.61 μg C-CH4g dw−1 d−1; 59.60± 51.5 μg C-CH4 g C−1org d−1) at the bottom of the talik, but the narrow thicknesses (43 cm) of this horizon limited its overall contribution to total sediment column CH4 production in the core. Lower rates of CH4 production were observed in sediment horizons representing permafrost that has been thawed in the talik for longer periods of time. No CH4 production was observed in samples obtained from the permafrost tunnel, a non-lake environment. Our findings imply that CH4 production is highly variable in thermokarst-lake systems and that both modern OM supplied to surface sediments and ancient OM supplied to both surface and deep lake sediments by in situ thaw as well as shore erosion of yedoma permafrost are important to lake CH4 production.
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Jentsch, W., B. Piatkowski, M. Schweigel y M. Derno. "Quantitative results for methane production of cattle in Germany". Archives Animal Breeding 52, n.º 6 (10 de octubre de 2009): 587–92. http://dx.doi.org/10.5194/aab-52-587-2009.
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Abstract. An extensive number of investigations on the energetic utilization efficiency of nutrients and feedstuffs by cattle were carried out in the former Oskar-Kellner-Institute (now the »Oskar Kellner« Research Unit of Nutritional Physiology at the Research Institute for the Biology of Farm Animals (FBN), Dummerstorf). The amounts of methane (CH4) that they produced were compiled and stratified with regard to various performances, dietary nutrient composition and nutrition levels. With increasing food intake and performance, an increase of CH4 emission per animal was observed. However, with increasing performance, a strong decrease of CH4 production per unit of product was determined. Altogether, the 12.74 million cattle in Germany produce 1.04 million tons of CH4 per year. This represents 1.25 % of the CH4 production of the 1.3 thousand million (UK)/billion (US) cattle in the world or 0.22 % of the total emission on the earth. As a greenhouse gas, CH4 from cattle worldwide and from cattle in Germany account for 3.5 % and 0.04 % of global warming, respectively. In addition, opportunities for a further reduction of enteric CH4 release are discussed.
Tesis sobre el tema "Production de CH4"
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Helin, S., E. Arponen, J. Rajander, J. Aromaa, S. Johansson y O. Solin. "Increased target volume and hydrogen content in [11C]CH4 production". Helmholtz-Zentrum Dresden - Rossendorf, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-166344.
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Introduction
High starting radioactivity is usually advantageous for producing radiopharmaceuticals with high specific radioactivity. However, the [11C]CH4 yields from N2-H2 gas target fall short from theoretical amounts, as calculated from the cross section for the well-known 14N(p,α)11C nuclear reaction1. The beneficial effect of increased target chamber temperature on [11C]CH4 yields has recently been brought forward by us2 and others3. In addition to the temperature effect, our attention has also been on the hydrogen content factor.
This study intends to examine the N2-H2 target performance in a substantially larger target chamber and at higher temperatures than our setup before and compare the results to the existing data.
Materials and Methods
Aluminium bodied custom design target chamber is used in fixed 17 MeV proton beam irradiations. Target chamber is equipped with heating elements and cooling circuit for temperature control. In addition to the target chamber body temperature, the target gas loading pressure and irradiation current can be varied.
The irradiation product is collected into an ad-sorbent trap that was immersed in a liquid argon cooling bath within a dose calibrator.
Results and Conclusion
Pursued data will show [11C]CH4 saturation yields (Ysat [GBq/µA]) at different irradiation and target parameters.
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Rêgo, de Vasconcelos Bruna. "Phosphates-based catalysts for synthetic gas (syngas) production using CO2 and CH4". Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2016. http://www.theses.fr/2016EMAC0004/document.
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Parmi les produits issus de la biomasse ou de la transformation des déchets organiques, le CO2 et le CH4 sont des intermédiaires chimiques importants qui ont de forts impacts environnementaux. En effet, ils sont les principaux gaz responsables de l'effet de serre et leur atténuation est un enjeu majeur. Une voie intéressante pour la valorisation de ces gaz est le reformage à sec du méthane (DRM), qui convertit le CO2 et le CH4 en gaz de synthèse (mélange d'hydrogène et de monoxyde de carbone). Ce mélange peut être utilisé pour plusieurs applications telles que la production de méthanol, d'éther diméthylique, d'hydrogène et des hydrocarbures liquides. Malgré cet intérêt, l'exploitation du DRM à l'échelle industrielle n'a pas encore vu le jour. La raison principale est la désactivation rapide des catalyseurs en raison des conditions sévères de fonctionnement du procédé (température élevée, dépôt de carbone). Cette thèse porte sur le développement de nouveaux catalyseurs à base de phosphate de calcium (CaP) dopés avec des métaux de transition pour la valorisation du CO2 et du CH4 en gaz de synthèse par DRM. Les CaP sont utilisés car ils possèdent des propriétés avantageuses en catalyse hétérogène comme la présence simultanée de sites acides et basiques, bonne stabilité thermique, large gamme de surface spécifique ... Dans un premier temps, des études sur les méthodes de synthèse de catalyseurs et sur la performance de différents métaux de transition (Zn, Fe, Co, Cu, Ni) ont été effectuées dans le but de sélectionner le catalyseur et sa méthode de préparation. Un réacteur à lit fixe capable de fonctionner à hautes température et pression a ensuite été testé pour un long temps de réaction afin d'évaluer correctement la performance des catalyseurs préparés. Ensuite, une étude paramétrique détaillée a été menée. L'influence des paramètres tels que le prétraitement des catalyseurs, la température (T = 400-700°C) et la pression (P = 1-25bar) de la réaction et les différents supports (hydroxyapatite, alumine) ont été étudiés. Enfin, la stabilité thermique et catalytique a été étudiée durant 300h de réaction. Les catalyseurs à base de CaP ont montré des rendements plus élevés en gaz de synthèse en comparaison aux catalyseurs commerciaux. Ces catalyseurs sont donc compétitifs dans les mêmes conditions opératoires (T = 700°C, P = 1bar, WHSV = 12272mLh-1gcat-1, t = 300h). Ce travail a montré l'intérêt des catalyseurs à base de CaP pour des processus à haute température, tel que le reformage à sec du méthaneAmong the products resulting from biomass or organic waste transformation, CO2 and CH4 are important chemical intermediates. They also have a strong environmental impact since they are primarily responsible for the greenhouse effect and their mitigation is a key issue. An attractive way of valorization of such gases is the dry reforming of methane (DRM), which converts CO2 and CH4 into syngas (mixture of hydrogen and carbon monoxide). This mixture can be used for several applications, such as the production of methanol, dimethyl ether, hydrogen and liquid hydrocarbons. Despite such interest, the exploitation of DRM on industrial scale has not emerged yet. The main reason is the rapid deactivation of the catalysts due to the severe operating conditions of the process (high temperature, carbon deposition). This thesis focuses on the development of new catalysts based on calcium phosphate (CaP) doped with transition metals for the valorization of CO2 and CH4 through DRM. Actually,CaP has advantageous properties in heterogeneous catalysis, as the simultaneous presence of acid and basic sites, good thermal stability, and wide range of surface area... Initially, a study on the catalyst synthesis methods and an investigation of the performance of different transition metals (Zn, Fe, Co, Cu, Ni) were carried out in order to select the catalyst system and the preparation method. Secondly, a fixed-bed reactor capable of operating at high temperature and pressure and for log time on stream was built and implemented during this work in order to properly evaluate the performance of the preparedcatalysts. Then, a detailed parametric study was conducted. The influence of parameters such as catalyst pre-treatment, temperature (T = 400-700°C) and pressure (P = 1-25bar) of the reaction and support (hydroxyapatite, alumina-based supports) were investigated. Finally, the catalytic stability was studied for 300h of time on stream (TOS). The CaP catalysts showing higher yields on syngas were compared to commercial catalysts. Our catalysts showed to be competitive in the same operating conditions (T = 700°C, P = 1bar, WHSV = 12272mLh-1gcat-1,TOS = 300h). This work shows the interest of CaP catalysts for high temperature process, such as dry reforming of methane
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GOMEZ, CAMACHO CARLOS ENRIQUE. "Enhancement of bioenergy production (H2 + CH4) from organic waste in anaerobic fermentation processes". Doctoral thesis, Politecnico di Torino, 2019. http://hdl.handle.net/11583/2738393.
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YAMASHITA, Hiroshi. "Numerical Study on NOx Production of Transitional Fuel Jet Diffusion Flame". The Japan Society of Mechanical Engineers, 2000. http://hdl.handle.net/2237/8999.
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Gregoire, Manon. "Valorisation catalytique du CO2 via l’hydrogénation pour la production de méthane". Electronic Thesis or Diss., Littoral, 2024. http://www.theses.fr/2024DUNK0713.
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Cette étude porte sur la valorisation du CO2 par le procédé de méthanation. Elle vise à développer des matériaux catalytiques efficaces et stables pour cette réaction. L’espèce active utilisée dans différentes familles de matériaux sera le nickel. Dans un premier temps, nous avons focalisé notre travail sur des catalyseurs au nickel supporté sur différentes silices afin d’étudier l’influence de la taille des particules. Le premier, Ni/SiO2 est le catalyseur classiquement utilisé de Ni sur de la silice commerciale avec des tailles de particules métalliques d’environ 12 nm assez élevées et situées principalement à l’extérieur de la silice. Le second, Ni/IWI, possède des NPs de Ni confinées dans les mésopores de la SBA-15 avec une taille moyenne de 9 nm. Le troisième, Ni/MIA, avec des NPs de Ni confinées dans les micropores de la SBA-15 et une taille moyenne de 3 nm. Les meilleures performances catalytiques sont obtenues avec le catalyseur Ni/MIA avec un rendement maximal de 86 % à 430 °C. Il offre donc un grand potentiel d'utilisation en raison de sa capacité à résister au frittage dû au confinement des nanoparticules de Ni. Ensuite, une série de x%Ni/Phyllo (avec x = 5 %, 10 %, 20 % et 40 % de Ni) a été synthétisée afin d’étudier l’influence de la teneur en Ni. Les tests catalytiques ont montré que 20%Ni/Phyllo avait des activités catalytiques intéressantes. Afin d’étudier l’influence de la température de réduction des phyllosilicates sur la réaction de méthanation, ce matériau a été réduit à plusieurs températures et c’est la réduction à 800 °C qui a permis de meilleures performances catalytiques, avec un rendement en CH4 de 91 % à 375 °C. De plus, le matériau n’a montré aucune désactivation après 48 h. Par la suite, la composition gazeuse et la durée de réduction ont été étudiées sur des matériaux réduits à plus basses températures. Cependant, les résultats n’ont pas été concluants. Enfin, plusieurs séries de pérovskites, qui ont un grand nombre de propriétés intéressantes pour la réaction de méthanation, ont été synthétisées à partir de LaNiO3, en modifiant les cations A et B et la stœchiométrie du lanthane. Le cation B offrant les meilleures performances catalytiques est le nickel et la stœchiométrie idéal pour le lanthane est 0,9. En revanche, la substitution du cation A par d’autres éléments alcalino-terreux, comme le strontium et le calcium, peut être bénéfique (80 % à 330 °C pour La0,9Sr0,1NiO3). Pour finir le cation A a été substitué totalement et le calcium offre des résultats prometteurs avec un rendement en CH4 de 89 % à 300 °C grâce à la présence de carbonatesThis study focuses on the recovery of CO2 by the methanation process. It aims to develop efficient and stable catalytic materials for this reaction. First, we focused our work on nickel catalysts supported on different silicas in order to study the influence of particle size. The first, Ni/SiO2 is the conventionally used nickel catalyst on commercial silica with metal particle sizes of about 12 nm quite high and located mainly outside the silica. The second, Ni/IWI, has Ni NPs confined in the mesopores of SBA-15 with an average size of 9 nm. The third, Ni/MIA, with NI NPs confined in the micropores of SBA-15 and an average size of 3 nm. The best catalytic performance is achieved with the Ni/MIA catalyst with a maximum efficiency of 86 % at 430 °C. It therefore offers great potential for use due to its ability to resist sintering due to the confinement of Ni nanoparticles. Then, a series of x%Ni/Phyllo (with x = 5 %, 10 %, 20 % and 40 % nickel) was synthesized in order to study the influence of Ni content. Catalytic tests showed that 20%Ni/Phyllo had interesting catalytic activities. In order to study the influence of the phyllosilicate reduction temperature on the methanation reaction, this material was reduced to several temperatures and it was the reduction to 800 °C that allowed better catalytic performance, with a CH4 yield of 92 % at 350 °C. Post-test characterizations do not show particle sintering or carbon formation on the surface of the materials. In addition, the material showed no deactivation after 48 hours. Subsequently, the gaseous composition and reduction duration were studied on reduced materials at lower temperatures in order to approximate the performance of a reduced material at 800 °C. However, the results were inconclusive. Finally, several series of perovskites have been synthesized. Indeed, these materials offer a large number of interesting properties for the methanation reaction. A number of perovskites have been synthesized from LaNiO3, completely or partially modifying the A and B cations and modifying the lanthanum stoichiometry. The B cation with the best catalytic performance is nickel and the ideal stoichiometry for lanthanum is 0.9. On the other hand, substituting the A cation with other alkaline earth elements may be beneficial. Indeed, strontium, sodium and calcium increase the catalytic performance up to 80 % at 330 °C for La0.9Sr0.1NiO3. Finally, cation A has been completely substituted and calcium offers promising results thanks to the presence of carbonates. It has therefore been calcined at a lower temperature in order to promote the formation of carbonates and allows a CH4 yield of 89 % at 300 °C
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Chhajed, Pawan. "Diffusion Characterization of Coal for Enhanced Coalbed Methane Production". OpenSIUC, 2011. https://opensiuc.lib.siu.edu/theses/645.
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This thesis explores the concept of displacement of sorbed methane and enhancement of methane recovery by injection of CO2 into coal, while sequestering CO2. The objective of this study was to investigate the diffusion behavior of San Juan Basin coal under single and competitive gas environments. The movement of gas in a coalbed reservoir starts in the coal matrix with diffusion towards the naturally occurring cleat network surrounding the matrix blocks. The gas production potential from coalbed reservoirs under different gas environments was, therefore, estimated by studying the diffusion behavior of the coal type. The results clearly showed that the rate of diffusion increases with decreasing reservoir pressure, the increase being exponential at low/very low pressure. As a final step, a simulation study was carried out using the experimental results to predict long-term gas production from coalbed reservoirs with and without CO2 injection. This was followed by a preliminary economic analysis in order to estimate the feasibility of enhanced recovery method by CO2 injection by calculating the net present value of a project with and without carbon credits. The results showed that it is possible to obtain significant improvement in methane recovery by CO2 injection. However, it becomes economically feasible only with carbon credits.
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Hao, Yushan. "Characterization of Peat Bog CO2 and CH4 Production Potentials in relation to Peat Physico-chemical Properties and Vegetation Composition". The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1562338709421684.
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Filho, Adibe Luiz Abdalla. "Produção de gases, síntese microbiana pelo radiofósforo e digestibilidade do babaçu e mofumbo em dietas de ovinos". Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/64/64133/tde-05052015-094343/.
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Quando a escassez de alimentos em pastagens naturais compromete a alimentação animal, os pequenos ruminantes podem incorporar em suas dietas as folhas de outras plantas, como árvores e arbustos, muitas delas ricas em metabólitos secundários como taninos e que ainda carecem de estudos acerca de seus efeitos na produtividade animal. Com o objetivo de verificar a possibilidade de utilização das folhas de Orbignya phalerata (Babaçu) e Combretum leprosum (Mofumbo) na alimentação e avaliar o efeito da inclusão na produção de ovinos, dois estudos foram conduzidos no Laboratório de Nutrição Animal do Centro de Energia Nuclear na Agricultura da Universidade de São Paulo, Piracicaba (LANA/CENA-USP). Um primeiro estudo avaliou as variáveis de desempenho, parâmetros bioquímicos e hematológicos, estimativas de síntese de proteína microbiana, digestibilidade aparente dos nutrientes e produção entérica de metano (CH4) dos animais. O segundo estudo avaliou as características de carcaça, coloração e perfil de ácidos graxos da carne dos ovinos machos utilizados no primeiro estudo. Os tratamentos experimentais testados foram dietas, com relação concentrado:volumoso de 50:50, elaboradas com base na utilização das folhas das plantas como substituição de 30 % do feno de Cynodon dactylon (Tifton-85), resultando em três tratamentos: Controle (sem substituição do feno), Babaçu e Mofumbo. No primeiro estudo, foram utilizados 24 ovinos Santa Inês, em um delineamento experimental casualizado com oito repetições para cada tratamento e 48 dias de período experimental avaliando o desempenho dos ovinos. Também nesse período, um ensaio in vitro de síntese de proteína microbiana foi realizado utilizando o radiofósforo em cinco inóculos de cada tratamento. Após o experimento de desempenho, durante nove dias, seis animais de cada tratamento foram alocados em gaiolas metabólicas para a determinação da digestibilidade aparente dos nutrientes, a síntese de proteína microbiana e o balanço de nitrogênio. Simultaneamente foi quantificada a produção de CH4 entérico in vivo. Os ovinos do tratamento Controle apresentaram maior (P < 0,05) digestibilidade aparente da fibra em detergente ácido. A produção entérica de CH4 dos ovinos do tratamento Mofumbo não diferiu do tratamento Controle e foi menor (P < 0,05) que a dos ovinos do tratamento Babaçu. No segundo estudo, os cinco animais machos de cada tratamento foram encaminhados para abate e procedeu-se a avaliação da carcaça, dos componentes não carcaça e a coloração e perfil de ácidos graxos na carne. Não foram observadas diferenças (P > 0,10) nos resultados da avaliação da carcaça, dos componentes não carcaça, coloração e total de ácidos graxos. O tratamento Mofumbo apresentou maiores (P < 0,10) valores da estimativa de atividade da enzima ?9-dessaturase C16. Efeito linear significativo (P = 0,01) foi observado quando se analisou a estimativa de atividade da enzima ?9-dessaturase C18 e os teores de TC nas dietas. A inclusão das folhas do Babaçu e Mofumbo não apresentou efeitos deletérios à saúde dos animais, não comprometeu o desempenho, potencial de produção e qualidade da carne dos ovinos, tendo o Mofumbo inclusive apresentado potencial mitigador de CH4, indicando que podem ser utilizadas como ingredientes na composição de dietas para ovinosWhen food shortages in natural pastures is committed to animal nutrition, small ruminants can incorporate into their diets the leaves of other plants, such as trees and shrubs, many of them rich in secondary metabolites such as tannins and which still lack of studies about its effect on animal productivity. In order to verify the possibility of using leaves of Orbignya phalerata (Babassu) and Combretum leprosum (Mofumbo) in feed and to evaluate the effect of their inclusion in the sheep production system, two studies were conducted at the Animal Nutrition Laboratory of Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba (LANA/CENA-USP). The first study evaluated the performance variables, biochemical and hematological parameters and also determined the microbial protein synthesis, nutrient apparent digestibility and enteric production of methane (CH4). The second study assessed the carcass characteristics, fatty acid profile and meat color of male sheep used in the first study. The experimental treatments were diets with forages to concentrate rate of 50:50, drawn up on the basis of using the leaves of the experimental plants replacing 30% of the Cynodon dactylon (Tifton-85) hay, resulting in three treatments: Control (no hay replacement), Babassu and Mofumbo. In the first study, there were used 24 Santa Inês sheep, in a randomized experimental design with eight repetitions for each treatment and 48 days of trial period. Also during this period, an in vitro microbial protein synthesis was performed using the radio phosphorus using five different inocula of each studied treatment. After this period, for nine days, six animals from each treatment were allocated in metabolic cages for determining the nutrient apparent digestibility, microbial protein synthesis and nitrogen balance. Simultaneously it was quantified the enteric CH4 production in vivo. The Control group showed greater (P < 0.05) apparent digestibility of acid detergent fiber. Enteric CH4 production of sheep fed with Mofumbo leaves did not differ from the Control group but was lower (P < 0.05) than the sheep fed Babassu leaves. In the second study, the five male animals of each treatment were sent to slaughter and to precede the assessment of carcass, not carcass components and color and fatty acid profile in the meat. The results of the assessment of carcass, not carcass components, color and overall fatty acids showed no differences between the treatments. Mofumbo treated sheep showed greater (P < 0.10) values of the ?9-desaturase C16 enzyme activity. Significant linear effect (P = 0.01) was observed when it analyzed the enzyme activity estimation ?9-desaturase C18 and TC levels in the diets. The inclusion of Babassu and Mofumbo leaves shown no negative effects on animal health, did not compromise the performance, production potencial or meat quality of the animals, having Mofumbo also presented CH4 mitigating potencial, indicating that those plants can be used as ingredients in the composition of sheep diets
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Wei, Tzu-Hsiang Biotechnology & Biomolecular Sciences Faculty of Science UNSW. "Transient production of biopharmaceutical proteins". Publisher:University of New South Wales. Biotechnology & Biomolecular Sciences, 2009. http://handle.unsw.edu.au/1959.4/43708.
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The creation of stable mammalian cell lines for biopharmaceutical production often require several months, and is unfavourable for the rapid production of multiple drug candidates for screening in the early stages of development. Biopharmaceutical production by transient transfection provides a possible alternative of quickly producing these early stage drug candidates. The Epi-CHO transient expression system, which consists of a Chinese hamster ovary (CHO) cell line (CHO-T) expressing the murine polyomavirus Large T-Antigen (LT), emonstrated enhanced transient recombinant protein production. The aim of this study was to prolong transient recombinant protein prod.Jction of the Epi-CHO expression system by creating a CHO cell line expressing both LT and EBNA1 (ECHO-T). The pEBNA1-LT expression vector encoding LT and EBNA1 was constructed and transfected into CHO-K1. A total of 20 clones were isolated from the antibioticresistant pool and screened for the expression of functional LT and EBNA1. PCR analysis showed 16 of the 20 clones was positive for EBNA1 and LT DNA. Of the 16 clones, six were positive for EBNA1 and LT expression by RT-PCR. Detection of LT and EBNA1 by immunofluorescence showed positive staining for the P7-G3 clone. Western blotting suggested the P7-G3 clone was: positive for EBNA1, and clones P3-C7 and P7-E2 were positive for LT. A plasmid replication assay confirmed the expression of functional LT in all six clones. Plasmid maintenance assay confirmed clone P7-G3 as the ECHO-T clones to express functional EBNA1. The P7-G3 clone demonstrated prolonged and sustained transient recombinant protein expression when compared to CHO-T. The P7-G3 clone achieved sustained transient protein expression for 32 days in the absence of selection, the longest currently reported for CHO cells.
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Kunaparaju, Raj Kumar Biotechnology & Biomolecular Sciences Faculty of Science UNSW. "Epi-CHO, an episomal expression system for recombinant protein production in CHO cells". Publisher:University of New South Wales. Biotechnology & Biomolecular Sciences, 2008. http://handle.unsw.edu.au/1959.4/41499.
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The current project is to develop a transient expression system for Chinese Hamster Ovary (CHO) cells based on autonomous replication and retention of plasmid DNA. The expression system, named Epi-CHO comprises (1) a recombinant CHO-K1 cell line encoding the Polyoma (Py) virus large T-Antigen (PyLT-Ag), and (2) a DNA expression vector, pPy/EBV encoding the Py Origin (PyOri) for autonomous replication and encoding the Epstein-Barr virus (EBV), Nuclear Antigen-1 (EBNA-1) and EBV Origin of replication (OriP) for plasmid retention. The CHO-K1 cell line expressing PyLT-Ag, named CHO-T was adapted to suspension growth in serum-free media (EXCELL-302) to facilitate large scale transient transfection and recombinant (r) protein production. PyLT-Ag-expressed in CHO-T supported replication of PyOri-containing plasmids and enhanced growth and r- protein production. A scalable cationic lipid based transfection was optimised for CHO-T cells using LipofectAMINE-2000??. Destabilised Enhanced Green Fluorescence Protein (D2EGFP) and Human Growth Hormone (HGH) were used as reporter proteins to demonstrate transgene expression and productivity. Transfection of CHO-T cells with the vector pPy/EBV encoding D2EGFP showed prolonged and enhanced EGFP expression, and transfection with pPy/EBV encoding HGH resulted in a final concentration of 75 mg/L of HGH in culture supernatant 11 days following transfection.
Libros sobre el tema "Production de CH4"
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Batista, Gerónimo Alvarez. Le Che: Dans la bataiille-- de la production. Paris: Section des rotativistes du Syndicat général du Livre de Paris, 1994.
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author, Bernardelli Andrea 1962, ed. Che cos'è una serie televisiva. Roma: Carocci editore, 2017.
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Kimambo, Isaria N. Three decades of production of historical knowledge at Dar es Salaam. Dar es Salaam: Dar es Salaam University Press, 1993.
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Chi, Myŏng-hyŏk. Chi Myŏng-hyŏk kyosu ŭi yŏnghwa yesul ŭi ihae. Sŏul T'ŭkpyŏlsi: Chimmundang, 2002.
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Besten, Liesbeth den. Designers on jewellery: Twelve years of jewellery production by Chi ha paura ... ? Melbourne: National Design Centre, 2008.
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author, Chen Jie 1973, ed. Zhongguo liang shi sheng chan diao cha: Survey on China's grain production. Shanghai: Shanghai yuan dong chu ban she, 2014.
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Niu, Chunlong. "Chibi" ce xie: Zhen xiang, ji shi, hua xu = Red cliff. Xiamen Shi: Lu Jiang chu ban she, 2008.
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Sŏng-ok, Yang, Pak, Hyŏn-jŏng (Researcher in dance and art) y Han'guk Yesul Yŏn'guso, eds. Chungyo muhyŏng munhwajae che 92-ho T'aep'yŏngmu kyoyuk pangbŏmnon. Sŏul T'ŭkpyŏlsi: Han'guk Yesul Chonghap Hakkyo Han'guk Yesul Yŏn'guso, 2012.
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Qingyu, Wang. Zhi cha xue: Taiwan cha lei zhi zhi zao sheng chan = Tea making science : production and making of teas in Taiwan. Taibei Shi: Xin xue lin chu ban gu fen you xian gong si, 2018.
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Soy, Eloy Llevat. Mass production makes a better world!: Che fine ha fatto l'utopia fordista nella Torino contemporanea? Siracusa, Italy: LetteraVentidue, 2020.
Buscar texto completoCapítulos de libros sobre el tema "Production de CH4"
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Kumar, Virendra, Purnima Dhall, Rita Kumar y Anil Kumar. "Bioconversion of Lignocellulosic Biomass for Bioethanol Production". En Biofuels Production, 85–118. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118835913.ch4.
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Yeow, Show Kuan y Wong Lai Peng. "Application of Ultrasound Pretreatment for Sludge Digestion". En Biogas Production, 91–136. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118404089.ch4.
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Guillet, Nicolas y Pierre Millet. "Alkaline Water Electrolysis". En Hydrogen Production, 117–66. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2015. http://dx.doi.org/10.1002/9783527676507.ch4.
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Brauner, Nadia, Gerd Finke y Maurice Queyranne. "Production Planning". En Applications of Combinatorial Optimization, 73–109. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118600283.ch4.
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Brauner, Nadia, Gerd Finke y Maurice Queyranne. "Production Planning". En Applications of Combinatorial Optimization, 73–109. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2014. http://dx.doi.org/10.1002/9781119005384.ch4.
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Sarker, Bhaba R., Dennis B. Webster y Thomas G. Ray. "Production Planning". En Mechanical Engineers' Handbook, 110–72. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2006. http://dx.doi.org/10.1002/0471777463.ch4.
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Lerner, M., A. Vorozhtsov, Sh Guseinov y P. Storozhenko. "Metal Nanopowders Production". En Metal Nanopowders, 79–106. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2014. http://dx.doi.org/10.1002/9783527680696.ch4.
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He, Peng y Hua Song. "Catalytic Hydrogen Production from Bioethanol". En Hydrogen Production Technologies, 153–206. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2017. http://dx.doi.org/10.1002/9781119283676.ch4.
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Risco, Carlos A. y Mauricio Benzaquen. "Monitoring Health and Looking for Sick Cows". En Dairy Production Medicine, 27–31. Oxford, UK: Blackwell Publishing Ltd., 2011. http://dx.doi.org/10.1002/9780470960554.ch4.
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Jongeneel, Roel y Louis Slangen. "Sustainability and resilience of the dairy sector in a changing world". En Sustainable Dairy Production, 55–86. Oxford: John Wiley & Sons, 2013. http://dx.doi.org/10.1002/9781118489451.ch4.
Texto completoActas de conferencias sobre el tema "Production de CH4"
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Chung, Hegwon, Minseong Park y Jiyong Kim. "Preliminary Examination of the Biogas-to-Hydrogen Conversion Process". En Foundations of Computer-Aided Process Design, 442–47. Hamilton, Canada: PSE Press, 2024. http://dx.doi.org/10.69997/sct.166239.
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Biogas is a promising energy source for sustainable hydrogen production due to its high concentration of CH4. However, determining the optimal process configuration is challenging due to the uncertainty of the fed biogas composition and the sensitivity of the operating conditions. This necessitates early-stage evaluation of the biomass-to-hydrogen process's performance, considering economics, energy efficiency, and environmental impacts. A data-driven model was introduced for early-stage assessment of hydrogen production from biogas without whole process simulation and optimization. The model was developed based on various biogas compositions and generated parameters for mass and energy balance. A database of unit processes was created using simulation models. Sensitivity analysis was performed under four techno-economic and environmental evaluation criteria: Unit Production Cost (UPC), Energy Efficiency (EEF), Net CO2 equivalent Emission (NCE), and Maximum H2 Production (MHP). The early-stage evaluation of the biogas-to-hydrogen process can guide the establishment of biogas utilization strategies and propose effective biogas enhancement process development solutions to respond to market disturbances.
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Carrillo, E. J., J. Lizcano-Prada, V. Kafaro, D. Rodriguez-Vallejo y A. Uribe-Rodr�guez. "Techno economical assessment of a low-carbon hydrogen production process using residual biomass gasification and carbon capture". En Foundations of Computer-Aided Process Design, 681–90. Hamilton, Canada: PSE Press, 2024. http://dx.doi.org/10.69997/sct.153241.
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Aiming to mitigate the environmental impact derived from fossil fuels, we propose an integrated carbon capture-biomass gasification process is proposed to produce low-carbon hydrogen as an alternative energy carrier. The process begins with the pre-treatment of empty fruit bunches (EFB), involving grinding, drying, torrefaction, and pelletization. The resulting EFB pellet is then fed into a dual gasifier, followed by a catalytic cracking of tar and water gas shift reaction to produce syngas, aiming to increase its H2 to CO ratio. Subsequently, we explore two alternatives (DEPG and MEA) for syngas upgrading by removing CO2. Finally, a PSA system is modeled to obtain H2 at 99.9% purity. The pre-treatment stage densifies the biomass from an initial composition (%C 46.47, %H 6.22, %O 42.25) to (%C 54.10, %H 6.09, %O 28.67). The dual gasifier operates at 800�C, using steam as a gasifying agent. The resulting syngas has a volume concentration (%CO 20.0, %CO2 28.2, %H2 42.2, %CH4 5.9). Next stages of the process focus on removing the CO2 and increased H2 through catalytic reactions from the syngas. Thus, the DEPG carbon capture process can decrease the CO2 concentration to 2.9%, increasing the hydrogen to 95.6% in volume. In contrast, the MEA process reduces the concentration of CO2 to 5.2% and increases the concentration of H2 to 93.1%. Moreover, we estimate a levelized costs of hydrogen (LCOH) and carbon capture cost for each method (DEPG and MEA) (LCOC) and CO2 avoided (LCCA). LCOH: 3.05 USD/kg H2, LCOC: 92 and 59 USD/t CO2 and 183 and 119 USD/t CO2, for DEPG and MEA respectively.
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CHEN, QI, JINTAO SUN, JIANYU LIU y BAOMING ZHAO. "ROLES OF IONIC REACTIONSIN NANOSECOND DISCHARGE PLASMA-ASSISTED TEMPERATURE-DEPENDENT PYROLYSISAND OXIDATION OF METHANE FUEL". En 9th International Symposium on Nonequilibrium Processes, Plasma, Combustion, and Atmospheric Phenomena. TORUS PRESS, 2020. http://dx.doi.org/10.30826/nepcap9b-02.
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Kinetic roles of ionic reactions in nanosecond discharge (NSD) plasma-assisted temperature-dependent pyrolysis and oxidation of methane fuel were investigated by integrated studies of experimental measurements and mathematical simulation. A~detailed plasma chemistry mechanism governing the pyrolysis and oxidation processes in a He/CH4/O2 combustible mixture was proposed and studied by including a set of electron impact reactions, ionic reactions, dissociative recombination reactions, reactions involving excited species, and some important three-body recombination reactions. The calculation results of fractional power dissipated by electrons show that at the studied E/N of 78—281~Td, most of the nonequilibrium cold discharge power can be focused on the ion and radical production. The rate coefficients for CH4 and O2 ionization by electron impact increase with the increasing of E/N values, demonstrating that increasing the system temperature and, thus, the E/N values will have increasing kinetic effects on plasma-enhanced decomposition and oxidation. By modeling the reaction pathways of key ions, it is seen that O2+ presents the largest concentration in the discharge mixture, followed by CH4+, CH3+, and CH2+, which agrees well with the molecular beam mass spectrometric investigation. The calculation results further indicate that with the mixture temperature increasing, production of major ions including CH4+, CH3+, CH2, and O2+ play more and more important roles in CH4 pyrolysis and oxidation.
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Kim, Jong Won, Kyu Sung Sim, Hyun Myung Son y Kwang Deog Jung. "Thermochemical Hydrogen Production Using Ni-Ferrite and CH4". En ASME 2003 International Solar Energy Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/isec2003-44084.
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Hydrogen production by a 2-step water-splitting thermochemical cycle using metal oxides (ferrites) redox pairs and CH4 have been studied in this experiment. Reactions were performed in a two-step redox cycle in which the ferrites were reacted with CH4 at 700°C–800°C to produce CO, H2, and various reduced phases (reduction step); these were then reoxidized with water vapor to generate H2 in water-splitting step (oxidation step) at 600°C–700°C. The reduced forms of Ni-Fe2O3, Ni-FeO and Ni-Fe alloy from XRD, showed respectively different reactivity for H2 formation from H2O. These were oxidized to the ferrite phase to produce H2 in the water-splitting step at 600°C–700°C. In reduction reaction at 800°C, carbon deposition arise on surface of Ni-ferrite due to CH4 decomposition. This reduced phase containing carbon, which reacts with H2O at 600°C, produce H2, CO, and CO2. The amount of H2 evolved using reduced phase containing carbon was much than that of other phase.
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Tarnas, Jesse, John Mustard, Barbara Sherwood Lollar, Vlada Stamenkovic y Oliver Warr. "Abiotic CH4 Production in the Subsurface of Terrestrial Planets". En Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.2565.
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Xu, Kun, Jiafei Zhao, Di Liu, Yongchen Song, Weiguo Liu, Kaihua Xue, Chencheng Ye y Yiming Zhu. "A Review on Experimental Research on Natural Gas Production From the Hydrate With CO2". En ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-84047.
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In this paper, the experimental researches on replacement of CH4 in the hydrate by use of CO2 reported by researchers both at home and abroad are summarized and analyzed, and the advantages and disadvantages of this method on natural gas production from hydrate is discussed. The latest progresses of CH4 replacement experiment with gaseous CO2, liquid CO2 and CO2 emulsion are present, and the superiority of CO2 emulsion on replacement of CH4 is emphasized. Moreover, the latest experimental research on preparation of CO2 emulsion is introduced, and the key technologies on the replacement of CH4 hydrate with different states of CO2 are indicated.
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Panova, A. V., A. P. Torbin, A. V. Demyanov, I. V. Kochetov y P. A. Mikheyev. "Ozone production in a dielectric barrier discharge in air/CH4 mixtures". En INTERNATIONAL CONFERENCE ON PHYSICS AND CHEMISTRY OF COMBUSTION AND PROCESSES IN EXTREME ENVIRONMENTS (COMPHYSCHEM’20-21) and VI INTERNATIONAL SUMMER SCHOOL “MODERN QUANTUM CHEMISTRY METHODS IN APPLICATIONS”. AIP Publishing, 2020. http://dx.doi.org/10.1063/5.0034298.
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Moghiman, M., M. Javadi, M. H. Raad, N. Hosseini y M. Soleimani. "The Effect of H2S on Production of Carbon Black From Sub-Quality Natural Gas". En ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-69053.
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The objective of this paper is computational investigation of the carbon black production through thermal decomposition of waste gases containing CH4 and H2S, without requiring a H2S separation process. The chemical reaction model, which involves solid carbon, sulfur compounds and precursor species for formation carbon black, based on an assumed Probability Density Function (PDF) parameterized by the mean and variance of mixture fraction and β-PDF shape. The soot formation is modeled by using the soot particle number density and the mass density based on acetylene concentrations. The effects of feedstock mass flow rate and reactor temperature on carbon black, soot, CO, S2, SO2, COS and CS2 formation are investigated. The results show that the major factor influencing CH4 and H2S conversions is reactor temperature. The results reveal that at any temperature, H2S conversion is less than that of CH4. For temperatures higher than 1100°K, the reactor CH4 conversion reaches 100%. At temperatures below 1300°K, H2S conversion is too low and usually less than 5%. For temperatures higher than 1300°K, H2S conversion increases sharply with temperature and the major products of the process are S2 and SO2 while COS and CS2 are minor products. The results also show that the production of carbon black from sub-quality natural gas, process involving the formation of carbon monoxide which is occurring in parallel, play a very significant role. For lower values of feedstock flow rate, CH4 mostly burns to CO and consequently, the production of carbon black is low.
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SAVELIEVA, V. A., N. S. TITOVA y O. N. FAVORSKII. "NUMERICAL STUDY OF H2 PRODUCTION DURING THE PARTIAL OXIDATION OF CH4-H2S MIXTURE". En NONEQUILIBRIUM PROCESSES. TORUS PRESS, 2018. http://dx.doi.org/10.30826/nepcap2018-1-08.
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Pinkard, Brian R., Elizabeth G. Rasmussen, John C. Kramlich, Per G. Reinhall y Igor V. Novosselov. "Supercritical Water Gasification of Ethanol for Fuel Gas Production". En ASME 2019 13th International Conference on Energy Sustainability collocated with the ASME 2019 Heat Transfer Summer Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/es2019-3950.
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Abstract Supercritical water gasification of dilute ethanol at the industrial scale promises a sustainable route to bio-syngas production for use in combined cycle power plants. Cost-effective bio-syngas production would reduce reliance on fossil fuels for electricity generation and reduce greenhouse gas emissions by utilizing waste biomass resources. Continuous supercritical water gasification offers high reactant conversion at short residence times without an added catalyst. The decomposition of ethanol in supercritical water is studied in a continuous reactor at 560 °C, 25 MPa, residence times between 3 and 8 s, and a constant initial ethanol concentration of 8.1 wt%. High-resolution, in-situ Raman spectroscopy facilitates identification of reaction products. Significant yields of H2, CO, and CH4 indicate the dominance of a dehydrogenation reaction pathway at studied conditions, while minor yields of ethane indicate a secondary dehydration reaction pathway. Ethylene yields are virtually nonexistent, indicating rapid hydrogenation of ethylene to ethane at these conditions. Ethanol dehydrogenation to H2, CO, and CH4 results in an overall fuel value upgrade of 84.5 kJ/mol-EtOH. Dehydration of ethanol to ethane results in an overall fuel degradation of −3.8 kJ/mol-EtOH.
Informes sobre el tema "Production de CH4"
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Gasim, Anwar, Lester Hunt y Jeyhun Mikayilov. Methane Emissions Baseline Forecasts for Saudi Arabia Using the Structural Time Series Model and Autometrics. King Abdullah Petroleum Studies and Research Center, mayo de 2023. http://dx.doi.org/10.30573/ks--2023-dp08.
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Reducing methane (CH4) emissions is key to near-term efforts to limit global warming. CH4 is the second most abundant anthropogenic greenhouse gas (GHG) in the atmosphere after carbon dioxide (CO2). The production, transport, and consumption of fossil fuels, in addition to waste and agriculture, account for most anthropogenic CH4 emissions globally (IPCC 2018). Although CH4has only a 12-year lifetime in the atmosphere, it is 84 times more potent per ton than CO2 in a 20-year period and 28 times more potent in a 100-year period (IPCC 2018). The drastically stronger short-term potency of CH4 explains why its short-term impact on global warming is considerably greater than that of CO2. Therefore, meeting the goals of the Paris Agreement necessitates not only decarbonization but also significant CH4 emissions reductions, especially in the near term.
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Asvapathanagul, Pitiporn, Leanne Deocampo y Nicholas Banuelos. Biological Hydrogen Gas Production from Food Waste as a Sustainable Fuel for Future Transportation. Mineta Transportation Institute, julio de 2022. http://dx.doi.org/10.31979/mti.2021.2141.
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In the global search for the right alternative energy sources for a more sustainable future, hydrogen production has stood out as a strong contender. Hydrogen gas (H2) is well-known as one of the cleanest and most sustainable energy sources, one that mainly yields only water vapor as a byproduct. Additionally, H2 generates triple the amount of energy compared to hydrocarbon fuels. H2 can be synthesized from several technologies, but currently only 1% of H2 production is generated from biomass. Biological H2 production generated from anaerobic digestion is a fraction of the 1%. This study aims to enhance biological H2 production from anaerobic digesters by increasing H2 forming microbial abundance using batch experiments. Carbon substrate availability and conversion in the anaerobic processes were achieved by chemical oxygen demand and volatile fatty acids analysis. The capability of the matrix to neutralize acids in the reactors was assessed using alkalinity assay, and ammonium toxicity was monitored by ammonium measurements. H2 content was also investigated throughout the study. The study's results demonstrate two critical outcomes, (i) food waste as substrate yielded the highest H2 gas fraction in biogas compared to other substrates fed (primary sludge, waste activated sludge and mixed sludge with or without food waste), and (ii) under normal operating condition of anaerobic digesters, increasing hydrogen forming bacterial populations, including Clostridium spp., Lactococcus spp. and Lactobacillus spp. did not prolong biological H2 recovery due to H2 being taken up by other bacteria for methane (CH4) formation. Our experiment was operated under the most optimal condition for CH4 formation as suggested by wastewater operational manuals. Therefore, CH4-forming bacteria possessed more advantages than other microbial populations, including H2-forming groups, and rapidly utilized H2 prior to methane synthesis. This study demonstrates H2 energy renewed from food waste anaerobic digestion systems delivers opportunities to maximize California’s cap-and-trade program through zero carbon fuel production and utilization.
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Asvapathanagul, Pitiporn, Leanne Deocampo y Nicholas Banuelos. Biological Hydrogen Gas Production from Food Waste as a Sustainable Fuel for Future Transportation. Mineta Transportation Institute, julio de 2022. http://dx.doi.org/10.31979/mti.2022.2141.
Texto completoResumen
In the global search for the right alternative energy sources for a more sustainable future, hydrogen production has stood out as a strong contender. Hydrogen gas (H2) is well-known as one of the cleanest and most sustainable energy sources, one that mainly yields only water vapor as a byproduct. Additionally, H2 generates triple the amount of energy compared to hydrocarbon fuels. H2 can be synthesized from several technologies, but currently only 1% of H2 production is generated from biomass. Biological H2 production generated from anaerobic digestion is a fraction of the 1%. This study aims to enhance biological H2 production from anaerobic digesters by increasing H2 forming microbial abundance using batch experiments. Carbon substrate availability and conversion in the anaerobic processes were achieved by chemical oxygen demand and volatile fatty acids analysis. The capability of the matrix to neutralize acids in the reactors was assessed using alkalinity assay, and ammonium toxicity was monitored by ammonium measurements. H2 content was also investigated throughout the study. The study's results demonstrate two critical outcomes, (i) food waste as substrate yielded the highest H2 gas fraction in biogas compared to other substrates fed (primary sludge, waste activated sludge and mixed sludge with or without food waste), and (ii) under normal operating condition of anaerobic digesters, increasing hydrogen forming bacterial populations, including Clostridium spp., Lactococcus spp. and Lactobacillus spp. did not prolong biological H2 recovery due to H2 being taken up by other bacteria for methane (CH4) formation. Our experiment was operated under the most optimal condition for CH4 formation as suggested by wastewater operational manuals. Therefore, CH4-forming bacteria possessed more advantages than other microbial populations, including H2-forming groups, and rapidly utilized H2 prior to methane synthesis. This study demonstrates H2 energy renewed from food waste anaerobic digestion systems delivers opportunities to maximize California’s cap-and-trade program through zero carbon fuel production and utilization.
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Demina, Regina. J/Ψ from chi Production in proton-antiproton Collisions at √s = 1.8 TeV. Office of Scientific and Technical Information (OSTI), enero de 1994. http://dx.doi.org/10.2172/1372374.
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Boswell, Christopher Mark. Chi Meson Production in Proton - Antiproton Interactions at the Center-of-Mass Energy of 1.8-TeV. Office of Scientific and Technical Information (OSTI), noviembre de 1993. http://dx.doi.org/10.2172/1372842.
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Kowitt, M. S. Hadronic production of J/[psi] at large [chi][sub F] in 800 GeV p+Cu and p+Be collisions. Office of Scientific and Technical Information (OSTI), diciembre de 1992. http://dx.doi.org/10.2172/6690251.
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Palmer, Guy H., Eugene Pipano, Terry F. McElwain, Varda Shkap y Donald P. Knowles, Jr. Development of a Multivalent ISCOM Vaccine against Anaplasmosis. United States Department of Agriculture, julio de 1993. http://dx.doi.org/10.32747/1993.7568763.bard.
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Anaplasmosis is an arthropod+borne disease of cattle caused by the rickettsia Anaplasma marginale and an impediment to efficient production of healthy livestock in both Israel and the United States. Our research focuses on development of a recombinant membrane surface protein (MSP) immunogen to replace current vaccines derived from the blood of infected cattle. The risk of widespread transmission of both known and newly emergent pathogens has prevented licensure of live blood-based vaccines in the U.S. and is a major concern for their continued use in Israel. Briefly, we accomplished the following in our BARD supported research: i) characterization of the intramolecular and intermolecular relationships of the native Major Surface Proteins (MSP) in the outer membrane; ii) expression, purification, and epitope characterization of the recombinant MSP-2, MSP-3, MSP-4, and MSP-5 proteins required to construct the recombinant ISCOM; iii) demonstration that the outer membrane-Quil A induces CD4+ T lymphocytes specific for the outer membrane polypeptides; iv) identification of CD4+ T lymphocytes that recognize outer membrane polypeptide epitopes conserved among other wise antigenically distinct strains; v) determination that immunization with the outer membrane-Quil A construct does not affect the ability of ticks to acquire or transmit A. marginale; and vi) demonstration that the outer membrane-Quil A construct induces complete protection against rickettsemia upon homologous challenge and significant protection against challenge with antigenically distinct strains, including tick transmission. Importantly, the level of protection against homologous challenge in the MSP vaccinates was comparable to that induced by live blood-based vaccines and demonstrates that development of a new generation of vaccines is feasible.
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Núñez Zarantes, Víctor Manuel, Iván Javier Pastrana Vargas, Jorge Cadena Torres y Eduardo Barragán Quijano. Sanjuanera 151 OMG : Variedad de algodón para el Caribe Seco con doble transgénesis. Corporación colombiana de investigación agropecuaria - AGROSAVIA, 2018. http://dx.doi.org/10.21930/agrosavia.folleto.2018.1.
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La variedad Sanjuanera-151 OMG es una variedad de fibra media con tolerancia al herbicida glifosato (gen cp4 epsps) y a algunas especies de insectos de importancia económica de la familia Lepidopterae (genes cry 1Ac y cry 2Ab), lo que permite obtener beneficios como reducción en el número de aplicaciones de insecticidas, mayor facilidad y flexibilidad para el control de malezas, eliminación de labores de control manual de malezas y beneficios ambientales, como disminución de la erosión del suelo y menores riesgos de contaminación ambiental por derivación de productos químicos. Para la obtención de esta variedad de algodón con características transgénicas, se utilizó el método de retrocruzamiento entre una variedad transgénica (DeltaPine® 143 B2RF) y una línea convencional (LC-151), a través del cual se transfieren los genes de la primera (donadora de genes) a la segunda (variedad de interés).
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Droby, Samir, Michael Wisniewski, Ron Porat y Dumitru Macarisin. Role of Reactive Oxygen Species (ROS) in Tritrophic Interactions in Postharvest Biocontrol Systems. United States Department of Agriculture, diciembre de 2012. http://dx.doi.org/10.32747/2012.7594390.bard.
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To elucidate the role of ROS in the tri-trophic interactions in postharvest biocontrol systems a detailed molecular and biochemical investigation was undertaken. The application of the yeast biocontrol agent Metschnikowia fructicola, microarray analysis was performed on grapefruit surface wounds using an Affymetrix Citrus GeneChip. the data indicated that 1007 putative unigenes showed significant expression changes following wounding and yeast application relative to wounded controls. The expression of the genes encoding Respiratory burst oxidase (Rbo), mitogen-activated protein kinase (MAPK) and mitogen-activated protein kinase kinase (MAPKK), G-proteins, chitinase (CHI), phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS) and 4-coumarate-CoA ligase (4CL). In contrast, three genes, peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT), were down-regulated in grapefruit peel tissue treated with yeast cells. The yeast antagonists, Metschnikowia fructicola (strain 277) and Candida oleophila (strain 182) generate relatively high levels of super oxide anion (O2−) following its interaction with wounded fruit surface. Using laser scanning confocal microscopy we observed that the application of M. fructicola and C. oleophila into citrus and apple fruit wounds correlated with an increase in H2O2 accumulation in host tissue. The present data, together with our earlier discovery of the importance of H₂O₂ production in the defense response of citrus flavedo to postharvest pathogens, indicate that the yeast-induced oxidative response in fruit exocarp may be associated with the ability of specific yeast species to serve as biocontrol agents for the management of postharvest diseases. Effect of ROS on yeast cells was also studied. Pretreatment of the yeast, Candida oleophila, with 5 mM H₂O₂ for 30 min (sublethal) increased yeast tolerance to subsequent lethal levels of oxidative stress (50 mM H₂O₂), high temperature (40 °C), and low pH (pH 4). Suppression subtractive hybridization analysis was used to identify genes expressed in yeast in response to sublethal oxidative stress. Transcript levels were confirmed using semi quantitative reverse transcription-PCR. Seven antioxidant genes were up regulated. Pretreatment of the yeast antagonist Candida oleophila with glycine betaine (GB) increases oxidative stress tolerance in the microenvironment of apple wounds. ROS production is greater when yeast antagonists used as biocontrol agents are applied in the wounds. Compared to untreated control yeast cells, GB-treated cells recovered from the oxidative stress environment of apple wounds exhibited less accumulation of ROS and lower levels of oxidative damage to cellular proteins and lipids. Additionally, GB-treated yeast exhibited greater biocontrol activity against Penicillium expansum and Botrytis cinerea, and faster growth in wounds of apple fruits compared to untreated yeast. The expression of major antioxidant genes, including peroxisomal catalase, peroxiredoxin TSA1, and glutathione peroxidase was elevated in the yeast by GB treatment. A mild heat shock (HS) pretreatment (30 min at 40 1C) improved the tolerance of M. fructicola to subsequent high temperature (45 1C, 20–30 min) and oxidative stress (0.4 mol-¹) hydrogen peroxide, 20–60 min). HS-treated yeast cells showed less accumulation of reactive oxygen species (ROS) than non-treated cells in response to both stresses. Additionally, HS-treated yeast exhibited significantly greater (P≥0.0001) biocontrol activity against Penicillium expansum and a significantly faster (Po0.0001) growth rate in wounds of apple fruits stored at 25 1C compared with the performance of untreated yeast cells. Transcription of a trehalose-6-phosphate synthase gene (TPS1) was up regulated in response to HS and trehalose content also increased.
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Farnand, B. y S. H. Noh. Pervaporation as an alternative process for the separation of methanol from C4 hydrocarbons in the production of MTBE and TAME. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1989. http://dx.doi.org/10.4095/304417.
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