Ahmed Khacef | Université d'Orléans (Loire Valley University) (original) (raw)
Papers by Ahmed Khacef
HAL (Le Centre pour la Communication Scientifique Directe), Feb 21, 2007
Applied Surface Science, 2019
CO 2 reforming in CH 4 over Ni/γ-Al 2 O 3 nano catalyst: Effect of cold plasma surface discharge,
HAL (Le Centre pour la Communication Scientifique Directe), Sep 7, 2008
HAL (Le Centre pour la Communication Scientifique Directe), 2016
HAL (Le Centre pour la Communication Scientifique Directe), 2005
Applied Physics Letters, Jul 15, 2019
SAE Technical Paper Series, Sep 24, 2001
No efficient catalyst presently exists for deNOx in lean burn conditions. Furthermore, actual cat... more No efficient catalyst presently exists for deNOx in lean burn conditions. Furthermore, actual catalysts generally deactivate during reaction. A cylindrical DBD non-thermal plasma reactor was coupled with a stable three-function catalyst in order to verify the nature of the effect of the plasma on the catalytic process. A mixture of NO/O2/C3H6 in N2 was used as a lean model exhaust. The plasma was found to perform two of the three functions: NO oxidation to NO2 and propene activation through the partial oxidation of the hydrocarbon to aldehyde or alcohol. A complete catalyst containing the first two previous functions and the associative chemisorption of NO (third function) was used, as well as a simplified catalyst containing only the third function. Results suggest an advantageous plasma-catalyst coupling effect on NOx remediation in accordance with the proposed catalytic model.
HAL (Le Centre pour la Communication Scientifique Directe), Mar 18, 2013
HAL (Le Centre pour la Communication Scientifique Directe), Oct 15, 2007
HAL (Le Centre pour la Communication Scientifique Directe), 2008
HAL (Le Centre pour la Communication Scientifique Directe), Jun 24, 2012
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
HAL (Le Centre pour la Communication Scientifique Directe), Jul 27, 2009
Enhancement of light hydrocarbon conversion in diluting air can be easily performed using a Diele... more Enhancement of light hydrocarbon conversion in diluting air can be easily performed using a Dielectric Barrier Discharges reactor at atmospheric pressure with a moderate heating. A heating (up to 800 K) leads to a decrease of the energetic cost keeping a high conversion rate. This paper presents results obtained for ethane or propane diluted with air. Main produced species are CO and CO 2 .
HAL (Le Centre pour la Communication Scientifique Directe), Sep 10, 2012
A unique set-up consisting of two reactors to produce a high-energy syngas is employed. The first... more A unique set-up consisting of two reactors to produce a high-energy syngas is employed. The first gasification reactor (50 kW) converts the pellets into syngas (20 kg.m-3), which follows into a plasma reactor (600 °C). A significant part of the impurities produced by the first stage is transformed, in the plasma reactor, into H2 and CO and thus increasing the syngas calorific value. Few studies have been conducted to examine the effect of O2 concentrations on the gasification of woody biomass above 300 °C. Plasma-assisted gasification and TGA-MS experiments are carried out to study the evolution of the produced gas (H2, CO, CO2 and light hydrocarbon species) during the degradation process. The biomass is first pyrolyzed and the carbon residue produced is submitted to partial oxidation and further isothermal decomposition in an oxidizing atmosphere with TGA at different heating rates. The O2 content in the gasifying mixture varied from 1 to 35 % vol. The MS signals in combination with the TGA data are used to elucidate the reactivity of the biomass samples in the range of 300 to 600 °C. The results revealed that reactivity is highly dependent on the process parameters. It is concluded that the O2 concentration can be optimized to improve the production of H2-rich gas mixtures from woody biomass gasification.
AIP Conference Proceedings, 1988
Super-Langevin rates have been demonstrated for the reactions of He2+ with molecular gases and no... more Super-Langevin rates have been demonstrated for the reactions of He2+ with molecular gases and no evidence of saturation at 6 atm pressure of helium diluent was found. For the reactions of He(23S), three-body channels have been well characterized, and they occur at rates of the order of 10-31 cm6s-1.
HAL (Le Centre pour la Communication Scientifique Directe), Feb 21, 2007
Applied Surface Science, 2019
CO 2 reforming in CH 4 over Ni/γ-Al 2 O 3 nano catalyst: Effect of cold plasma surface discharge,
HAL (Le Centre pour la Communication Scientifique Directe), Sep 7, 2008
HAL (Le Centre pour la Communication Scientifique Directe), 2016
HAL (Le Centre pour la Communication Scientifique Directe), 2005
Applied Physics Letters, Jul 15, 2019
SAE Technical Paper Series, Sep 24, 2001
No efficient catalyst presently exists for deNOx in lean burn conditions. Furthermore, actual cat... more No efficient catalyst presently exists for deNOx in lean burn conditions. Furthermore, actual catalysts generally deactivate during reaction. A cylindrical DBD non-thermal plasma reactor was coupled with a stable three-function catalyst in order to verify the nature of the effect of the plasma on the catalytic process. A mixture of NO/O2/C3H6 in N2 was used as a lean model exhaust. The plasma was found to perform two of the three functions: NO oxidation to NO2 and propene activation through the partial oxidation of the hydrocarbon to aldehyde or alcohol. A complete catalyst containing the first two previous functions and the associative chemisorption of NO (third function) was used, as well as a simplified catalyst containing only the third function. Results suggest an advantageous plasma-catalyst coupling effect on NOx remediation in accordance with the proposed catalytic model.
HAL (Le Centre pour la Communication Scientifique Directe), Mar 18, 2013
HAL (Le Centre pour la Communication Scientifique Directe), Oct 15, 2007
HAL (Le Centre pour la Communication Scientifique Directe), 2008
HAL (Le Centre pour la Communication Scientifique Directe), Jun 24, 2012
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
HAL (Le Centre pour la Communication Scientifique Directe), Jul 27, 2009
Enhancement of light hydrocarbon conversion in diluting air can be easily performed using a Diele... more Enhancement of light hydrocarbon conversion in diluting air can be easily performed using a Dielectric Barrier Discharges reactor at atmospheric pressure with a moderate heating. A heating (up to 800 K) leads to a decrease of the energetic cost keeping a high conversion rate. This paper presents results obtained for ethane or propane diluted with air. Main produced species are CO and CO 2 .
HAL (Le Centre pour la Communication Scientifique Directe), Sep 10, 2012
A unique set-up consisting of two reactors to produce a high-energy syngas is employed. The first... more A unique set-up consisting of two reactors to produce a high-energy syngas is employed. The first gasification reactor (50 kW) converts the pellets into syngas (20 kg.m-3), which follows into a plasma reactor (600 °C). A significant part of the impurities produced by the first stage is transformed, in the plasma reactor, into H2 and CO and thus increasing the syngas calorific value. Few studies have been conducted to examine the effect of O2 concentrations on the gasification of woody biomass above 300 °C. Plasma-assisted gasification and TGA-MS experiments are carried out to study the evolution of the produced gas (H2, CO, CO2 and light hydrocarbon species) during the degradation process. The biomass is first pyrolyzed and the carbon residue produced is submitted to partial oxidation and further isothermal decomposition in an oxidizing atmosphere with TGA at different heating rates. The O2 content in the gasifying mixture varied from 1 to 35 % vol. The MS signals in combination with the TGA data are used to elucidate the reactivity of the biomass samples in the range of 300 to 600 °C. The results revealed that reactivity is highly dependent on the process parameters. It is concluded that the O2 concentration can be optimized to improve the production of H2-rich gas mixtures from woody biomass gasification.
AIP Conference Proceedings, 1988
Super-Langevin rates have been demonstrated for the reactions of He2+ with molecular gases and no... more Super-Langevin rates have been demonstrated for the reactions of He2+ with molecular gases and no evidence of saturation at 6 atm pressure of helium diluent was found. For the reactions of He(23S), three-body channels have been well characterized, and they occur at rates of the order of 10-31 cm6s-1.