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Lioubov Kiwiminsker - One of the best experts on this subject based on the ideXlab platform.
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the use of pd catalysts on carbon based structured materials for the catalytic hydrogenation of bromates in different types of water
Applied Catalysis B-environmental, 2014Co-Authors: A E Palomares, Lioubov Kiwiminsker, C Franch, T Yuranova, Enrique Garciabordeje, Salim DerrouicheAbstract:The aim of this work is to study the activity of new Pd catalysts, supported on two different nano structured carbon materials, for bromate catalytic hydrogenation. The influence of the support has been studied, obtaining the best results with a palladium catalyst supported on carbon nanoFibers (CNF) grown in sintered Metal Fibers (SMF). The results have shown the importance of the catalyst support in order to minimize the mass-transfer limitations ensuring an efficient catalyst use. In this way the most active catalysts are those with a mesoporous structure containing high dispersed Pd nanoparticles. The activity of this catalyst for bromate reduction has been tested in different types of water, namely, distilled water, natural water and industrial wastewater. It has been shown that the catalyst activity depends on the water matrix and bromate reduction rate depends on the hydrogen partial pressure. The potential use of the catalyst has been studied in a continuous reactor. It has been observed that the catalyst is active without any important deactivation at least during 100 h of reaction, but is necessary to avoid salt precipitation and plugging problems. (C) 2013 Elsevier B.V. All rights reserved.
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bromate catalytic reduction in continuous mode using Metal catalysts supported on monoliths coated with carbon nanoFibers
Chemical Engineering Journal, 2013Co-Authors: Yanila Marco, C Franch, A E Palomares, T Yuranova, Lioubov KiwiminskerAbstract:Nitrogen-doped and un-doped carbon nanoFibers layers, denoted as N-CNFs and CNFs respectively, coating the walls of cordierite monoliths have been used as support for Pd and Ru catalyst. They have been tested in bromate reduction in batch and continuous operation employing different reactor configurations. The CNF/monolith catalysts were benchmarked with Pd catalyst on CNF coated on another structured support, namely sintered Metal Fibers. CNF/monolith is a robust, active and stable catalyst for bromate reduction. The catalyst shows stable performance when operating in monolithic reactor and the CNFs showed excellent attachment to the monolith. The comparison of intrinsic activity of catalysts in batch experiments (free of diffusional limitations) revealed that Pd supported on CNF/monolith exhibited higher intrinsic activity than Pd on CNF/SMFs. Pd Metal showed significantly higher specific activity than Ru. The doping of CNF with nitrogen, although contribute to decrease reoxidation propensity of Metal does not supplies higher activity in bromate reduction. (C) 2013 Elsevier B.V. All rights reserved.
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novel catalytic non thermal plasma reactor for the abatement of vocs
Chemical Engineering Journal, 2007Co-Authors: Ch Subrahmanyam, A Renken, Lioubov KiwiminskerAbstract:A novel dielectric barrier discharge (DBD) reactor has been designed and tested for the abatement of diluted volatile organic compounds (VOCs) of different nature. The novelty of the DBD reactor is that a Metallic catalyst made of sintered Metal Fibers (SMF) also acts as the inner electrode. The SMF electrodes modified with oxides of Ti, Mn and Co were efficient during the destruction of toluene, isopropanol (IPA) and trichloroethylene (TCE). Total oxidation of IPA was achieved at lower specific input energy (SIE) compared to toluene and TCE. Among the catalysts studied, MnOx/SMF showed the best performance, involving the formation of active oxygen species by in situ decomposition of ozone on the catalyst surface. The selectivity to CO2 as the total oxidation product during TCE destruction was improved up to ∼70% by modifying MnOx/SMF with TiO2.
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improved performance of non thermal plasma reactor during decomposition of trichloroethylene optimization of the reactor geometry and introduction of catalytic electrode
Applied Catalysis B-environmental, 2007Co-Authors: M Magureanu, Ch Subrahmanyam, A Renken, N B Mandache, Vasile I Parvulescu, Lioubov KiwiminskerAbstract:The decomposition of trichloroethylene ITCE) by non-thermal plasma was investigated in a dielectric barrier discharge (DBD) reactor with a copper rod inner electrode and compared with a plasma-catalytic reactor. The particularity of the plasma-catalytic reactor is the inner electrode made of sintered Metal Fibers (SMF) coated by transition Metal oxides. In order to optimize the geometry of the plasma reactor, the efficiency of TCE removal was compared for different discharge gap lengths in the range of 1-5 mm. Shorter gap lengths (1-3 mm) appear to be more advantageous with respect to TCE conversion. In this case TCE conversion varies between 67% and 100% for input energy densities in the range of 80-480 J/l, while for the 5 turn discharge gap the conversion was lower (53-97%) for similar values of the input energy. As a result of TICE oxidation carbon monoxide and carbon dioxide were detected in the effluent gas. Their selectivity was rather low, in the range 14-24% for CO2 and 11-23% for CO, and was not influenced by the gap length. Several other chlorinated organic compounds were detected as reaction products. When using MnOx/SMF catalysts as the inner electrode of the DBD reactor, the TCE conversion was significantly enhanced, reaching similar to 95% at 150 J/l input energy. The selectivity to CO2 showed a major increase as compared to the case without catalysts, reaching 58% for input energies above 550 J/l. (C) 2007 Elsevier B.V. All rights reserved.
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novel catalytic dielectric barrier discharge reactor for gas phase abatement of isopropanol
Plasma Chemistry and Plasma Processing, 2007Co-Authors: Ch Subrahmanyam, A Renken, Lioubov KiwiminskerAbstract:Catalytic gas-phase abatement of air containing 250 ppm of isopropanol (IPA) was carried out with a novel dielectric barrier discharge (DBD) reactor with the inner catalytic electrode made of sintered Metal Fibers (SMF). The optimization of the reactor performance was carried out by varying the voltage from 12.5 to 22.5 kV and the frequency in the range 200–275 Hz. The performance was significantly improved by modifying SMF with Mn and Co oxide. Under the experimental conditions used, the MnO x /SMF showed a higher activity towards total oxidation of IPA as compared to CoO x /SMF and SMF electrodes. The complete destruction of 250 ppm of IPA was attained with a specific input energy of ∼235 J/L using the MnO x /SMF catalytic electrode, whereas, the total oxidation was achieved at 760 J/L. The better performance of the MnO x /SMF compared to other catalytic electrodes suggests the formation of short-lived active species on its surface by the in-situ decomposition of ozone.
Ch Subrahmanyam - One of the best experts on this subject based on the ideXlab platform.
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Non-thermal plasma assisted decomposition of H 2 Sinto H 2 and S
2019Co-Authors: E, Linga Reddy, M V Biju, Ch SubrahmanyamAbstract:The direct decomposition of hydrogen sulfide into hydrogen and sulfur was studied in a dielectric barrier discharge plasma reactorwith an inner electrode made of a stainless steel rod that was later replaced with a modified sintered Metal Fibers to introduce catalystinside the plasma zone. The feasibility of DBD plasmolysis for the hydrogen production by H 2 S decomposition was assessed. Typicalresults indicate that H 2 selectivity is ~100% throughout the range of present study. The influence of several parameters like thedischarge gap between the electrodes, residence time of the gas in the discharge zone, the applied voltage and the effect of catalysthave been studied to find the optimal process conditions
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the catalytic effect of mnox and coox on the decomposition of nitrobenzene in a non thermal plasma reactor
Chemical Engineering Journal, 2012Co-Authors: R Karvembu, J Karuppiah, Ch SubrahmanyamAbstract:Influence of water vapor on the oxidative decomposition of nitrobenzene in a dielectric barrier discharge (DBD) plasma reactor was investigated, where a sintered Metal Fibers (SMF) sheet modified with MnOx and CoOx has been used as the inner electrode. The designed in-plasma catalytic reactor in the presence of water vapor showed improved conversion and selectivity to total oxidation, which may be due to the formation of a strong oxidant hydroxyl radical. Optimization of various parameters like concentration, flow rate and applied energy has been carried out and it has been observed that CoOx supported SMF electrode showed better performance, especially for low concentrations of organic compound. In situ decomposition of ozone on the surface of the transition Metal oxide modified SMF may also have favored better performance of the plasma reactor.
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novel catalytic non thermal plasma reactor for the abatement of vocs
Chemical Engineering Journal, 2007Co-Authors: Ch Subrahmanyam, A Renken, Lioubov KiwiminskerAbstract:A novel dielectric barrier discharge (DBD) reactor has been designed and tested for the abatement of diluted volatile organic compounds (VOCs) of different nature. The novelty of the DBD reactor is that a Metallic catalyst made of sintered Metal Fibers (SMF) also acts as the inner electrode. The SMF electrodes modified with oxides of Ti, Mn and Co were efficient during the destruction of toluene, isopropanol (IPA) and trichloroethylene (TCE). Total oxidation of IPA was achieved at lower specific input energy (SIE) compared to toluene and TCE. Among the catalysts studied, MnOx/SMF showed the best performance, involving the formation of active oxygen species by in situ decomposition of ozone on the catalyst surface. The selectivity to CO2 as the total oxidation product during TCE destruction was improved up to ∼70% by modifying MnOx/SMF with TiO2.
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improved performance of non thermal plasma reactor during decomposition of trichloroethylene optimization of the reactor geometry and introduction of catalytic electrode
Applied Catalysis B-environmental, 2007Co-Authors: M Magureanu, Ch Subrahmanyam, A Renken, N B Mandache, Vasile I Parvulescu, Lioubov KiwiminskerAbstract:The decomposition of trichloroethylene ITCE) by non-thermal plasma was investigated in a dielectric barrier discharge (DBD) reactor with a copper rod inner electrode and compared with a plasma-catalytic reactor. The particularity of the plasma-catalytic reactor is the inner electrode made of sintered Metal Fibers (SMF) coated by transition Metal oxides. In order to optimize the geometry of the plasma reactor, the efficiency of TCE removal was compared for different discharge gap lengths in the range of 1-5 mm. Shorter gap lengths (1-3 mm) appear to be more advantageous with respect to TCE conversion. In this case TCE conversion varies between 67% and 100% for input energy densities in the range of 80-480 J/l, while for the 5 turn discharge gap the conversion was lower (53-97%) for similar values of the input energy. As a result of TICE oxidation carbon monoxide and carbon dioxide were detected in the effluent gas. Their selectivity was rather low, in the range 14-24% for CO2 and 11-23% for CO, and was not influenced by the gap length. Several other chlorinated organic compounds were detected as reaction products. When using MnOx/SMF catalysts as the inner electrode of the DBD reactor, the TCE conversion was significantly enhanced, reaching similar to 95% at 150 J/l input energy. The selectivity to CO2 showed a major increase as compared to the case without catalysts, reaching 58% for input energies above 550 J/l. (C) 2007 Elsevier B.V. All rights reserved.
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novel catalytic dielectric barrier discharge reactor for gas phase abatement of isopropanol
Plasma Chemistry and Plasma Processing, 2007Co-Authors: Ch Subrahmanyam, A Renken, Lioubov KiwiminskerAbstract:Catalytic gas-phase abatement of air containing 250 ppm of isopropanol (IPA) was carried out with a novel dielectric barrier discharge (DBD) reactor with the inner catalytic electrode made of sintered Metal Fibers (SMF). The optimization of the reactor performance was carried out by varying the voltage from 12.5 to 22.5 kV and the frequency in the range 200–275 Hz. The performance was significantly improved by modifying SMF with Mn and Co oxide. Under the experimental conditions used, the MnO x /SMF showed a higher activity towards total oxidation of IPA as compared to CoO x /SMF and SMF electrodes. The complete destruction of 250 ppm of IPA was attained with a specific input energy of ∼235 J/L using the MnO x /SMF catalytic electrode, whereas, the total oxidation was achieved at 760 J/L. The better performance of the MnO x /SMF compared to other catalytic electrodes suggests the formation of short-lived active species on its surface by the in-situ decomposition of ozone.
A Renken - One of the best experts on this subject based on the ideXlab platform.
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novel catalytic non thermal plasma reactor for the abatement of vocs
Chemical Engineering Journal, 2007Co-Authors: Ch Subrahmanyam, A Renken, Lioubov KiwiminskerAbstract:A novel dielectric barrier discharge (DBD) reactor has been designed and tested for the abatement of diluted volatile organic compounds (VOCs) of different nature. The novelty of the DBD reactor is that a Metallic catalyst made of sintered Metal Fibers (SMF) also acts as the inner electrode. The SMF electrodes modified with oxides of Ti, Mn and Co were efficient during the destruction of toluene, isopropanol (IPA) and trichloroethylene (TCE). Total oxidation of IPA was achieved at lower specific input energy (SIE) compared to toluene and TCE. Among the catalysts studied, MnOx/SMF showed the best performance, involving the formation of active oxygen species by in situ decomposition of ozone on the catalyst surface. The selectivity to CO2 as the total oxidation product during TCE destruction was improved up to ∼70% by modifying MnOx/SMF with TiO2.
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improved performance of non thermal plasma reactor during decomposition of trichloroethylene optimization of the reactor geometry and introduction of catalytic electrode
Applied Catalysis B-environmental, 2007Co-Authors: M Magureanu, Ch Subrahmanyam, A Renken, N B Mandache, Vasile I Parvulescu, Lioubov KiwiminskerAbstract:The decomposition of trichloroethylene ITCE) by non-thermal plasma was investigated in a dielectric barrier discharge (DBD) reactor with a copper rod inner electrode and compared with a plasma-catalytic reactor. The particularity of the plasma-catalytic reactor is the inner electrode made of sintered Metal Fibers (SMF) coated by transition Metal oxides. In order to optimize the geometry of the plasma reactor, the efficiency of TCE removal was compared for different discharge gap lengths in the range of 1-5 mm. Shorter gap lengths (1-3 mm) appear to be more advantageous with respect to TCE conversion. In this case TCE conversion varies between 67% and 100% for input energy densities in the range of 80-480 J/l, while for the 5 turn discharge gap the conversion was lower (53-97%) for similar values of the input energy. As a result of TICE oxidation carbon monoxide and carbon dioxide were detected in the effluent gas. Their selectivity was rather low, in the range 14-24% for CO2 and 11-23% for CO, and was not influenced by the gap length. Several other chlorinated organic compounds were detected as reaction products. When using MnOx/SMF catalysts as the inner electrode of the DBD reactor, the TCE conversion was significantly enhanced, reaching similar to 95% at 150 J/l input energy. The selectivity to CO2 showed a major increase as compared to the case without catalysts, reaching 58% for input energies above 550 J/l. (C) 2007 Elsevier B.V. All rights reserved.
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novel catalytic dielectric barrier discharge reactor for gas phase abatement of isopropanol
Plasma Chemistry and Plasma Processing, 2007Co-Authors: Ch Subrahmanyam, A Renken, Lioubov KiwiminskerAbstract:Catalytic gas-phase abatement of air containing 250 ppm of isopropanol (IPA) was carried out with a novel dielectric barrier discharge (DBD) reactor with the inner catalytic electrode made of sintered Metal Fibers (SMF). The optimization of the reactor performance was carried out by varying the voltage from 12.5 to 22.5 kV and the frequency in the range 200–275 Hz. The performance was significantly improved by modifying SMF with Mn and Co oxide. Under the experimental conditions used, the MnO x /SMF showed a higher activity towards total oxidation of IPA as compared to CoO x /SMF and SMF electrodes. The complete destruction of 250 ppm of IPA was attained with a specific input energy of ∼235 J/L using the MnO x /SMF catalytic electrode, whereas, the total oxidation was achieved at 760 J/L. The better performance of the MnO x /SMF compared to other catalytic electrodes suggests the formation of short-lived active species on its surface by the in-situ decomposition of ozone.
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catalytic abatement of volatile organic compounds assisted by non thermal plasma part 1 a novel dielectric barrier discharge reactor containing catalytic electrode
Applied Catalysis B-environmental, 2006Co-Authors: Ch Subrahmanyam, M Magureanu, A Renken, Lioubov KiwiminskerAbstract:A novel catalytic reactor with dielectric barrier discharge (DBD) at atmospheric pressure was developed for the abatement of volatile organic compounds (VOCs). The novelty of DBD reactor is the Metallic catalyst serving also as the inner electrode. The catalytic electrode was prepared from sintered Metal Fibers (SMF) in the form of a cylindrical tube. Oxides of Mn and Co were deposited on SMF by impregnation. Decomposition of toluene taken as the model VOC compound (<1000 ppm in air) was investigated. The catalyst composition, toluene concentration, applied voltage and frequency were systematically varied to evaluate the performance of the DBD reactor. At 100 ppm of toluene, the conversion � 100% was achieved in the DBD reactor using a specific input energy (SIE) � 235 J/l independently of the chemical composition of the SMF catalytic electrode, but the selectivity to CO2 was observed to be a function of the catalyst composition. The MnOx/SMF catalytic electrode showed the best performance towards totaloxidation.Ata SIEof295 J/l,theselectivitytoCO2was80%with100%conversion oftoluene.Nocarbonsolid residues were deposited on the electrode. # 2006 Elsevier B.V. All rights reserved.
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structured combustion catalysts based on sintered Metal fibre filters
Applied Catalysis B-environmental, 2003Co-Authors: Igor Yuranov, Lioubov Kiwiminsker, A RenkenAbstract:Novel efficient structured combustion catalysts based on sintered Metal fiber filters (MFF) were developed. To increase sp. surface area (SSA), Metal Fibers were coated by crack-free porous oxide films of SiO2, Al2O3, porous glass, and mesoporous SBA-15 silica. The composite materials presented uniform open macrostructure of the non-treated MFF filters and were suitable supports for deposition of catalytically active phases (Pd, Pt, and Co3O4). These catalysts were tested in hydrocarbon (CH4, C3H8) combustion. Co3O4 supported on MFF without any coating (6.8% Co3O4/MFF) was the most active for propane total oxidn. At the same time in methane combustion the activity of this catalyst was relatively low. Pd supported on the MFF coated by mesoporous SBA-15 film (0.5% Pd/SBA-15/MFF) demonstrated the highest activity in methane total oxidn. due to the high palladium dispersion. The SBA-15 film supported on MFF provided the highest dispersion of the deposited noble Metals (Pd, Pt) with an av. particle size .apprx.2.0 nm. The Metal nanoparticles formed within the mesopore channels were stable against sintering during calcination and the particle diam. was obsd. not to exceed the diam. of the silica pores. These catalysts did not undergo deactivation under reaction conditions at temps. up to 500 Deg. On the contrary, the Pd supported on MFF coated by the microporous SiO2 and Al2O3 films, prepd. by sol-gel technique, suffered from Metal sintering during the calcination step and also during reaction, demonstrating strong catalyst deactivation. The catalytic filters are suitable materials for assembling different multiple layers to obtain structured catalytic beds with the compn./concn. gradients of active component in the axial direction. The enhanced overall catalytic performance was obsd. in adiabatic catalytic reactor during propane combustion due to a synergy of the 0.5% Pd/SBA-15/MFF and the 0.5% Pt/SBA-15/MFF catalytic layers assembled in the appropriate order forming gradient catalytic bed. [on SciFinder (R)]
M Magureanu - One of the best experts on this subject based on the ideXlab platform.
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improved performance of non thermal plasma reactor during decomposition of trichloroethylene optimization of the reactor geometry and introduction of catalytic electrode
Applied Catalysis B-environmental, 2007Co-Authors: M Magureanu, Ch Subrahmanyam, A Renken, N B Mandache, Vasile I Parvulescu, Lioubov KiwiminskerAbstract:The decomposition of trichloroethylene ITCE) by non-thermal plasma was investigated in a dielectric barrier discharge (DBD) reactor with a copper rod inner electrode and compared with a plasma-catalytic reactor. The particularity of the plasma-catalytic reactor is the inner electrode made of sintered Metal Fibers (SMF) coated by transition Metal oxides. In order to optimize the geometry of the plasma reactor, the efficiency of TCE removal was compared for different discharge gap lengths in the range of 1-5 mm. Shorter gap lengths (1-3 mm) appear to be more advantageous with respect to TCE conversion. In this case TCE conversion varies between 67% and 100% for input energy densities in the range of 80-480 J/l, while for the 5 turn discharge gap the conversion was lower (53-97%) for similar values of the input energy. As a result of TICE oxidation carbon monoxide and carbon dioxide were detected in the effluent gas. Their selectivity was rather low, in the range 14-24% for CO2 and 11-23% for CO, and was not influenced by the gap length. Several other chlorinated organic compounds were detected as reaction products. When using MnOx/SMF catalysts as the inner electrode of the DBD reactor, the TCE conversion was significantly enhanced, reaching similar to 95% at 150 J/l input energy. The selectivity to CO2 showed a major increase as compared to the case without catalysts, reaching 58% for input energies above 550 J/l. (C) 2007 Elsevier B.V. All rights reserved.
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catalytic abatement of volatile organic compounds assisted by non thermal plasma part 1 a novel dielectric barrier discharge reactor containing catalytic electrode
Applied Catalysis B-environmental, 2006Co-Authors: Ch Subrahmanyam, M Magureanu, A Renken, Lioubov KiwiminskerAbstract:A novel catalytic reactor with dielectric barrier discharge (DBD) at atmospheric pressure was developed for the abatement of volatile organic compounds (VOCs). The novelty of DBD reactor is the Metallic catalyst serving also as the inner electrode. The catalytic electrode was prepared from sintered Metal Fibers (SMF) in the form of a cylindrical tube. Oxides of Mn and Co were deposited on SMF by impregnation. Decomposition of toluene taken as the model VOC compound (<1000 ppm in air) was investigated. The catalyst composition, toluene concentration, applied voltage and frequency were systematically varied to evaluate the performance of the DBD reactor. At 100 ppm of toluene, the conversion � 100% was achieved in the DBD reactor using a specific input energy (SIE) � 235 J/l independently of the chemical composition of the SMF catalytic electrode, but the selectivity to CO2 was observed to be a function of the catalyst composition. The MnOx/SMF catalytic electrode showed the best performance towards totaloxidation.Ata SIEof295 J/l,theselectivitytoCO2was80%with100%conversion oftoluene.Nocarbonsolid residues were deposited on the electrode. # 2006 Elsevier B.V. All rights reserved.
J Karuppiah - One of the best experts on this subject based on the ideXlab platform.
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the catalytic effect of mnox and coox on the decomposition of nitrobenzene in a non thermal plasma reactor
Chemical Engineering Journal, 2012Co-Authors: R Karvembu, J Karuppiah, Ch SubrahmanyamAbstract:Influence of water vapor on the oxidative decomposition of nitrobenzene in a dielectric barrier discharge (DBD) plasma reactor was investigated, where a sintered Metal Fibers (SMF) sheet modified with MnOx and CoOx has been used as the inner electrode. The designed in-plasma catalytic reactor in the presence of water vapor showed improved conversion and selectivity to total oxidation, which may be due to the formation of a strong oxidant hydroxyl radical. Optimization of various parameters like concentration, flow rate and applied energy has been carried out and it has been observed that CoOx supported SMF electrode showed better performance, especially for low concentrations of organic compound. In situ decomposition of ozone on the surface of the transition Metal oxide modified SMF may also have favored better performance of the plasma reactor.