A novel approach for characterizing carbon catalysts by tap experiments

Two samples were used in this study: a coal based carbon obtained by carbonisation and a gas-phase oxidized sample from the raw carbon. These samples were extensively characterized and their NO removal capacity was also determined. TAP-2 (Temporal Analysis of Products) reactor was used to obtain adsorption parameters and diffusion coefficients of the system NO-carbon catalyst. The diffusivity of NO as well as the enthalpy of adsorption does not change after increasing the number of functional groups by an oxidative pretreatment of the carbon.Peer reviewe

Measurements and understanding of radon adsorption in nanoporous materials

International audienceFor many experiments working at low energy and very low counting rate in particle and astroparticle physics, the background from the Radon decay chain is one of the strongest constraints. Most of the time, activated charcoal filters are used to dynamically capture the radon from the air or from the gas of the detectors. In general case activated charcoal is a good adsorptive material. It has large effective surface and broad porosity, going from macro to nanopores. However, the big constraints from futures experiments need ad hoc radon capture filters. The optimal adsorption depends on various parameters such as the correct pore size and shape, the temperature, the microscopic structure of the adsorbent or the competition between radon and carrier gas. In this context, we have developed at Centre de Physique des Particules de Marseille (CPPM), a test bench to study the radon capture in various porous materials1. Several very interesting results have been already obtained with non-standard, commercially and research adsorbents like some Carbon Molecular Sieves (CMS), organic molecular cage (CC3)2, or carbon aerogels.In this talk we present a global quantitative and qualitative study of radon adsorption in porous materials. This work is the results of the analysis of more than 30 porous materials in the framework of the collaboration between particle physicist and chemist from several universities

Confrontation of various adsorption models for assessing the porous structure of activated carbons

International audienceHerein, a comprehensive analysis of DFT methods as a tool for evaluating the impact of the nature of the activating agent on the porous structure of activated carbons derived from hazelnut shells is given. The study was based on the use of NLDFT, QSDFT, and 2D-NLDFT methods applied to nitrogen adsorption isotherms, and the results were compared with those formerly obtained by using DR, BET, and LBET methods. Analyses conducted with NLDFT, QSDFT, and 2D-NLDFT revealed a very strong dependence of the results on assumptions about the specific pore model, which calls into question the reliability and credibility of these methods. However, if one takes into account the measurement errors that may during the determination of the adsorption isotherms, as well as the difficulty of selecting a representative sample in a batch of materials (most often non-homogeneous) to be analysed, some imperfections of the DFT methods become acceptable. The analyses in question revealed some limitations of the LBET method which became obvious when the analysis concerned bimodal porous materials with a considerable proportion of mesopores. In such cases, the LBET method, which was formerly designed for analysing microporous materials, may become less reliable

Enhanced resolution of ultra micropore size determination of biochars and activated carbons by dual gas analysis using N2 and CO2 with 2D-NLDFT adsorption models

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Assessment of hydrogen storage in activated carbons produced from hydrothermally treated organic materials

12 activated carbons (ACs) were prepared by KOH activation using hydrochars as precursors. These hydrochars were prepared by hydrothermal carbonisation (HTC) of sucrose solutions at concentrations ranging from 0.2 to 1.6 mol L-1. The KOH to hydrochar weight ratio (W) was varied from 1 to 5, and the activation temperature was set to 1023K. ACs texture was assessed by nitrogen and carbon dioxide adsorption at 77 and 273 K, respectively; pore size distribution was calculated by using both isotherms and the SAIEUS© software. ACs with surface areas between 790 and 2240 m2 g-1 were obtained. Hydrogen excess adsorption was determined at 298K and pressures up to 10 MPa in a volumetric device, and the isosteric heat of adsorption (Qst) was calculated for four ACs, using hydrogen isotherms obtained at 278, 298 and 308K. Potassium intercalation between graphitic planes was assumed to account for the high Qst values, 7-8 kJ mol-1. Hydrogen uptake at 2 MPa was compared with hydrogen adsorption data of 38 other ACs reported in the open literature. Hydrogen adsorption fundamentally depends on micropore volume and preliminary HTC did not enhance hydrogen storage although it could be a good strategy for doping carbon with heteroelements.The authors gratefully acknowledge the financial support of the CPER 2007-2013 “Structuration du Pôle de Compétitivité Fibres Grand’Est” (Competitiveness Fibre Cluster), through local (Conseil Général des Vosges), regional (Région Lorraine), national (DRRT and FNADT) and European (FEDER) funds. Part of this work was supported by CHEERS project (FEDER funds) and the COST Action MP1103 “Nanostructured materials for solid-state hydrogen storage”.Peer reviewe

Biochar as a catalyst for hydrogen production from methane conversion

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Análisis sobre la existencia y aplicación de la propuesta filosofía para niños en el programa de Licenciatura en Educación Infantil de cuatro universidades de Cundinamarca

82 páginasLa propuesta, Filosofía para Niños (FpN) lleva menos de 70 años en Colombia, brindando a la educación de este país una forma innovadora en la cual los docentes pueden transformar sus prácticas, mejorando paulatinamente su calidad. Con este panorama, se han analizado distintos planes de estudio del programa Licenciatura en Educación Infantil, de cuatro universidades colombianas ubicadas en Cundinamarca, y se ha concluido que no todas cuentan con alguna asignatura que ayude a los docentes en formación a conocer esta propuesta y su forma de ser aplicada. En esta monografía se encuentra un estudio de corte mixto, aplicado a 4 planes de estudio de 4 universidades de Cundinamarca, donde se pretende analizar el valor agregado que representa incluir FpN dentro del programa Licenciatura en Educación Infantil.The proposal, Philosophy for Children (F4C) has been in Colombia for less than 70 years, providing education in this country with an innovative way in which teachers can transform their practices, gradually improving their quality. With this panorama, different study plans of the Bachelor of Early Childhood Education program of Colombian universities located in Cundinamarca have been analyzed, and it has been concluded that not all of them have a subject that helps teachers in training to know this proposal and its form to be applied. In this monograph there is a mixed study, applied to 4 study plans of 4 universities in Cundinamarca, where it is intended to analyze the added value of including F4C within the Bachelor of Early Childhood Education program.Licenciatura en Educación InfantilLicenciado en Educación Infanti

Impacto de la sostenibilidad ambiental en la toma de decisiones del consumidor bogotano estrato 4 de alimentos cárnicos

El objetivo de la presente investigación es analizar el impacto de la sostenibilidad ambiental en la toma de decisiones del consumidor bogotano estrato 4 en la industria de alimentos cárnicos. Desarrollamos nuestro objetivo mediante entrevistas a profundidad a expertos del sector cárnico y nutricionistas, además, de focus groups y encuestas a consumidores de carne y consumidores de dietas veganas o vegetarianas que cumplieran con el criterio declarado en el objetivo.Resumen ; Introducción ; 1. Revisión de literatura ; 2. Metodología ; 3. Oferta y diversidad de sustitutos de los alimentos cárnicos ; 4. Factores que incluyen en la toma de desiciones en el proceso de compra de consumidores de carne 5. Factores que incluyen en las tomas de desiciones en el proceso de compra de veganos-vegetarianos ; 6. Perspectivas de los expertos del sector cárnico sobre las tendencias de consumo ; 7. Conclusiones y Recomendaciones ; ReferenciasAdministrador de EmpresasPregrad

Hydrothermal pre-treatment, an efficient tool to improve activated carbon performances

International audienc