Photocatalytic Powder Layer Reactor:  A Uniformly Mixed Gas Phase Occurring in a Catalytic Fixed-Bed Flow Reactor

2002 ◽  
Vol 41 (25) ◽  
pp. 6409-6412 ◽  
Author(s):  
David F. Ollis
Keyword(s):  
Gas Phase ◽  
Flow Reactor ◽  
Fixed Bed ◽  
Powder Layer ◽  
Mixed Gas

Effects of the Gas Phase Composition and Genesis of the Active Sodium Carbonate on Its Reactivity Towards Gaseous Mixture SO2 + NOx

1997 ◽  
Vol 62 (3) ◽  
pp. 387-391
Author(s):  
Květoslava Stejskalová ◽  
Pavel Bach ◽  
Erich Lippert ◽  
Karel Mocek
Keyword(s):  
Carbon Dioxide ◽  
Gas Phase ◽  
Sodium Carbonate ◽  
Flow Reactor ◽  
Fixed Bed ◽  
Gaseous Mixture ◽  
Solid Substance ◽  
Integral Conditions ◽  
Active Sodium ◽  
Partial Pressures

The reactivity of the solid active sodium carbonate towards gaseous mixture SO2 + NOx has been measured in the dependence on oxygen and carbon dioxide contents and on genesis of the solid substance. The fixed bed flow reactor working under integral conditions has been used. It was found that the reactivity of the active sodium carbonate of the 1st generation towards gaseous mixture SO2 + NOx is higher than the reactivity of the active sodium carbonate of the 2nd generation. In the temperature range of 130-180 °C the partial pressures of oxygen and carbon dioxide have no decisive influence on the reactivity of the active sodium carbonate of the 1st generation.

Modeling of aerated upflow fixed bed reactors for nitrification

1999 ◽  
Vol 39 (4) ◽  
pp. 85-92 ◽  
Author(s):  
J. Behrendt
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Liquid Phase ◽  
Gas Phase ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Bulk Liquid ◽  
Initial Value ◽  
Fixed Bed Reactors ◽  
Number Of Cells

A mathematical model for nitrification in an aerated fixed bed reactor has been developed. This model is based on material balances in the bulk liquid, gas phase and in the biofilm area. The fixed bed is divided into a number of cells according to the reduced remixing behaviour. A fixed bed cell consists of 4 compartments: the support, the gas phase, the bulk liquid phase and the stagnant volume containing the biofilm. In the stagnant volume the biological transmutation of the ammonia is located. The transport phenomena are modelled with mass transfer formulations so that the balances could be formulated as an initial value problem. The results of the simulation and experiments are compared.

scholarly journals Development of a tubular continuous flow reactor for the investigation of improved gas–solid interaction in photocatalytic CO2 reduction on TiO2

2019 ◽  
Vol 18 (2) ◽  
pp. 314-318 ◽  
Author(s):  
Martin Dilla ◽  
Ahmet E. Becerikli ◽  
Alina Jakubowski ◽  
Robert Schlögl ◽  
Simon Ristig
Keyword(s):  
Gas Phase ◽  
Continuous Flow ◽  
Flow Reactor ◽  
Tubular Reactor ◽  
Co2 Reduction ◽  
Continuous Flow Reactor ◽  
Reactor Geometry

Newly developed tubular reactor geometry allows intensive gas–solid interaction in photocatalytic gas-phase CO2 reduction.

Gas phase interaction with catalytic oxidation reactions

1972 ◽  
Vol 326 (1565) ◽  
pp. 215-227 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Maleic Anhydride ◽  
Catalytic Oxidation ◽  
Gas Phase ◽  
Major Part ◽  
Oxidation Reactions ◽  
Mixed Gas ◽  
Kinetics Of ◽  
Oxidation Of Benzene ◽  
Homogeneous Decomposition

Studies of the catalytic oxidation of benzene to maleic anhydride and carbon dioxide over vanadia/molybdena catalysts show that the major part of the reaction involves interacting gas and gas-solid processes. The results are consistent with a mechanism in which a benzeneoxygen adduct is formed catalytically, desorbs and then reacts to give maleic anhydride entirely in the gas phase. On the basis of this proposed mechanism, the kinetics of individual reactions have been investigated in some depth. The over-oxidation of maleic anhydride has been found to be not significant under the conditions of reaction. The kinetic relationships governing the homogeneous decomposition of the adduct and the oxidation of the adduct to maleic anhydride and to carbon dioxide have been established. The results show that essentially all of the anhydride originates from mixed gas-solid/gas reaction while substantial amounts of carbon dioxide are produced entirely catalytically.

Gas phase pyrolysis of coal-related aromatic compounds in a coiled tube flow reactor

Fuel ◽  
1988 ◽  
Vol 67 (3) ◽  
pp. 334-340 ◽  
Author(s):  
Odolphus S.L. Bruinsma ◽  
Peter J.J. Tromp ◽  
Henry J.J. de Sauvage Nolting ◽  
Jacob A. Moulijn
Keyword(s):  
Gas Phase ◽  
Aromatic Compounds ◽  
Flow Reactor ◽  
Tube Flow ◽  
Coiled Tube

LASER-DRIVEN SYNTHESIS OF CARBON AND SILICON CLUSTERS FROM GAS-PHASE REACTANTS

1996 ◽  
Vol 03 (01) ◽  
pp. 807-811 ◽  
Author(s):  
M. EHBRECHT ◽  
H. FERKEL ◽  
V.V. SMIRNOV ◽  
O. STELMAKH ◽  
W. ZHANG ◽  
...  
Keyword(s):  
Gas Phase ◽  
Flow Reactor ◽  
Carbon Clusters ◽  
Molecular Flow ◽  
Silicon Cluster ◽  
Nanosized Particles ◽  
Silicon Clusters ◽  
Molecular Gases ◽  
Induced Decomposition ◽  
Cluster Beams

A newly developed technique is employed for the production of carbon and silicon cluster beams starting from gaseous compounds. It is based on the CO 2-laser-induced decomposition of molecular gases containing carbon and silicon, such as CO 2H2 and SiH 4, in a flow reactor. In order to decompose acetylene, SF 6 is used as a sensitizer. By introducing a skimmer into the reaction zone, the generated silicon and carbon clusters are transferred to free molecular flow and analyzed with a time-of-flight mass spectrometer. It is shown that the technique can be efficiently employed to produce fullerenes C 60 and C 70 and, in the case of silicon, ultrapure nanosized particles of up to 3-nm diameter.

New Insights into the Kinetics of the Gas-Phase Oxidation of Hexafluoropropene

2016 ◽  
Vol 41 (4) ◽  
pp. 418-427 ◽  
Author(s):  
David Lokhat ◽  
Maciej Starzak ◽  
Deresh Ramjugernath
Keyword(s):  
Gas Phase ◽  
Oxidation Process ◽  
Flow Reactor ◽  
Packed Column ◽  
Phase Reaction ◽  
Analytical Technique ◽  
Tubular Flow Reactor ◽  
Gas Phase Oxidation ◽  
Tubular Flow ◽  
Kinetics Of

The gas-phase reaction of hexafluoropropene and molecular oxygen was investigated in a tubular flow reactor at 450 kPa and within a temperature range of 463–493 K using HFP/O2 mixtures containing 20–67% HFP on a molar basis. Capillary and packed column chromatography served as the main analytical technique. The reaction yielded HFPO, COF2, CF3COF, C2F4 and c-C3F6 as gas-phase products. High molecular weight oligomers were also formed. The oligomers were found to have a polyoxadifluoromethylene structure according to elemental and 19F NMR analysis. At 493 K HFP is proposed to undergo oxygen-mediated decomposition to difluorocarbene radicals, yielding greater quantities of difluorocarbene recombination products. Kinetic parameters for a revised model of the oxidation process were identified through least squares analysis of the experimental data.

The Effects of Preparation Methods on Iron Structures of Iron-Supported HZSM-5 and their Catalytic Performance for Methanol Dehydration

2016 ◽  
Vol 723 ◽  
pp. 633-639
Author(s):  
Waenkaew Pantupho ◽  
Arthit Neramittagapong ◽  
Nuttawut Osakoo ◽  
Jatuporn Wittayakun ◽  
Sirinuch Loiha
Keyword(s):  
Flow Reactor ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Active Species ◽  
Iron Complex ◽  
Methanol Dehydration ◽  
Low Carbon ◽  
Zeolite Framework ◽  
Preparation Methods ◽  
Binuclear Iron

Iron-supported HZSM-5 catalysts were prepared by hydrothermal (Fe-HZSM-5_HYD) and impregnation methods (Fe/HZSM-5_IMP). The active species of binuclear-iron complex and iron-substituted zeolite framework, confirmed by EXAFS analysis, were observed on Fe/HZSM-5_IMP and Fe-HZSM-5_HYD, respectively. The catalysts were used for production of dimethyl ether (DME) by methanol dehydration at 200-350 °C using fixed bed flow reactor. Fe/HZSM-5_IMP showed higher catalytic conversion than Fe-HZSM-5_HYD. However, the Fe/HZSM-5_IMP catalyst was less selective to DME product and strongly deactivated for 24h. The deactivation might due to transformation of binuclear-iron to the a-iron site which was strong acidic strengh. The iron-substituted zeolite framework of Fe-HZSM-5_HYD showed high stability toward methanol dehydration. Moreover, the catalyst showed advantages of good selective to DME and low carbon deposition on surface. These results suggested that the iron-substituted zeolite framework structure could improve catalytic performance for mrthanol dehydration.

Effects of Air Flowrate on the Combustion and Emissions of Blended Corn Straw and Pinewood Wastes

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Xiaoxiao Meng ◽  
Wei Zhou ◽  
Emad Rokni ◽  
Honghua Zhao ◽  
Rui Sun ◽  
...  
Keyword(s):  
Gas Phase ◽  
Ignition Delay Time ◽  
Fixed Bed ◽  
Combustion Efficiency ◽  
Fixed Bed Reactor ◽  
Corn Straw ◽  
Excess Air ◽  
Burning Rates ◽  
Excess Air Coefficient ◽  
Hazardous Pollutants

This research investigated the effects of the specific primary (under-fire) air flowrate (m˙air) on the combustion behavior of a 50–50 wt % blend of raw corn straw (CS) and raw pinewood wastes in a fixed-bed reactor. This parameter was varied in the range of 0.079–0.226 kg m−2 s−1, which changed the overall combustion stoichiometry from air-lean (excess air coefficient λ = 0.73) to air-rich (excess air coefficient λ = 1.25) and affected the combustion efficiency and stability as well as the emissions of hazardous pollutants. It was observed that by increasing m˙air, the ignition delay time first increased and then decreased, the average bed temperatures increased, both the average flame propagation rates and the fuel burning rates increased, and the combustion efficiencies also increased. The emissions of CO as well as those of cumulative gas phase nitrogen compounds increased, the latter mostly because of increasing HCN, while those of NO were rather constant. The emissions of HCl decreased but those of other chlorine-containing species increased. The effect of m˙air on the conversion of sulfur to SO2 was minor. By considering all of the aforesaid factors, a mildly overall air-rich (fuel-lean) (λ = 1.04) operating condition can be suggested for corn-straw/pinewood burning fixed-bed grate-fired reactors.

Translucent nanoparticle-based aerogel monoliths as 3-dimensional photocatalysts for the selective photoreduction of CO2 to methanol in a continuous flow reactor

2017 ◽  
Vol 4 (6) ◽  
pp. 1115-1121 ◽  
Author(s):  
Felix Rechberger ◽  
Markus Niederberger
Keyword(s):  
Gas Phase ◽  
Continuous Flow ◽  
Flow Reactor ◽  
Gas Phase Reactions ◽  
3 Dimensional ◽  
Continuous Flow Reactor

A newly developed prototype of a flow reactor enables the exploitation of nanoparticle based aerogel monoliths as macroscopically sized photocatalysts in gas phase reactions.

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