The effect of Co in hydrodesulphurization of 2,3-dihydrobenzo[b]thiophene on Co-Mo catalyst

1986 ◽  
Vol 51 (6) ◽  
pp. 1195-1205 ◽  
Author(s):  
Rudolf Peter ◽  
Vlastimil Matějec ◽  
Miroslav Zdražil
Keyword(s):  
Kinetic Equation ◽  
Equilibrium Constant ◽  
Hydrogen Sulphide ◽  
Atmospheric Pressure ◽  
Flow Reactor ◽  
Reaction Network ◽  
Sulphur Compound ◽  
Partial Equilibrium ◽  
Mo Catalyst ◽  
Elimination Scheme

Hydrodesulphurization of benzo[b]thiophene and 2,3-dihydrobenzo[b]thiophene on Mo/alumina and Co-Mo/alumina catalysts has been studied in a flow reactor at atmospheric pressure and temperature 543 K. The amount of dihydrobenzo[b]thiophene formed in hydrodesulphurization of benzo[b]thiophene and the amount of benzo[b]thiophene formed in hydrodesulphurization of dihydrobenzo[b]thiophene were much lower on Co-Mo catalyst then on Mo catalyst. The equilibrium constant of the hydrogenation of benzo[b]thiophene to dihydrobenzo[b]thiophene at 543 K was determined. This partial equilibrium was attained during hydrodesulphurization on Mo catalyst irrespectively of the fed sulphur compound but was not approached during hydrodesulphurization on Co-Mo catalyst. Kinetic equation describing simultaneously the reaction of both heterocycles was derived from consecutive hydrogenation-elimination scheme which does not contain step referred to as direct hydrogenolysis of the thiophenic ring. It was concluded that the effect of Co in the reaction network is localized in the section between partially hydrogenated benzothiophene and hydrogen sulphide

Analogues of the active and inactive sodium carbonate

1982 ◽  
Vol 47 (12) ◽  
pp. 3348-3361 ◽  
Author(s):  
Erich Lippert ◽  
Karel Mocek ◽  
Emerich Erdös
Keyword(s):  
Thermal Decomposition ◽  
Time Dependence ◽  
Water Vapour ◽  
Sulphur Dioxide ◽  
Atmospheric Pressure ◽  
Flow Reactor ◽  
Kinetic Measurements ◽  
Sodium Potassium ◽  
Alkaline Metals ◽  
Hydrogen Carbonates

The reactivity of the anhydrous carbonates of alkaline metals with sulphur dioxide has been studied experimentally in dependence both on the nature of the cation and on the way of preparation of the anhydrous carbonate. The carbonates were prepared either by thermal decomposition of hydrogen carbonates or by thermal dehydration of carbonate hydrates. The carbonates of lithium, sodium, potassium, rubidium and caesium have been investigated. Kinetic measurements were carried out in a flow reactor in the integral regime at 423 K under atmospheric pressure, with a gas containing 0.2 vol.% of sulphur dioxide and 2.0 vol.% of water vapour in the nitrogen as a carrier gas. The reactivities have been compared on the basis of time dependence of the conversion of carbonate to sulphite.

Kinetics of the catalytic hydrodesulphurization reaction system; hydrogenolysis of thiophene

1980 ◽  
Vol 45 (10) ◽  
pp. 2728-2741 ◽  
Author(s):  
Pavel Fott ◽  
Petr Schneider
Keyword(s):  
Atmospheric Pressure ◽  
Active Sites ◽  
Flow Reactor ◽  
Kinetic Equations ◽  
Reaction System ◽  
Reaction Products ◽  
Molybdenum Catalyst ◽  
Cobalt Molybdenum Catalyst ◽  
Kinetics Of ◽  
Reaction Schemes

Kinetics have been studied of the reaction system taking place during the reaction of thiophene on the cobalt-molybdenum catalyst in a gradientless circulation flow reactor at 360 °C and atmospheric pressure. Butane has been found present in a small amount in the reaction products even at very low conversion. In view of this, consecutive and parallel-consecutive (triangular) reaction schemes have been proposed. In the former scheme the appearance of butane is accounted for by rate of desorption of butene being comparable with the rate of its hydrogenation. According to the latter scheme part of the butane originates from thiophene via a different route than through hydrogenation of butene. Analysis of the kinetic data has revealed that the reaction of thiophene should be considered to take place on other active sites than that of butene. Kinetic equations derived on this assumption for the consecutive and the triangular reaction schemes correlate experimental data with acceptable accuracy.

Thermocatalytic Hydrodeoxygenation and Depolymerization of Waste Lignin to Oxygenates and Biofuels in a Continuous Flow Reactor at Atmospheric Pressure

2020 ◽  
Vol 8 (35) ◽  
pp. 13195-13205 ◽  
Author(s):  
Swathi Mukundan ◽  
Daria Boffito ◽  
Abhijit Shrotri ◽  
Luqman Atanda ◽  
Jorge Beltramini ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Continuous Flow ◽  
Flow Reactor ◽  
Continuous Flow Reactor

Flow Structure and Heat Transfer in Stagnation Flow CVD Reactor

2010 ◽  
Author(s):  
Nasir Memon ◽  
Yogesh Jaluria
Keyword(s):  
Heat Transfer ◽  
Flow Structure ◽  
Atmospheric Pressure ◽  
Gas Flow ◽  
Flow Reactor ◽  
Chemical Vapor ◽  
Design Parameters ◽  
Stagnation Flow ◽  
Inlet Length ◽  
The Impact

An experimental study is undertaken to investigate the flow structure and heat transfer in a stagnation flow Chemical Vapor Deposition (CVD) reactor at atmospheric pressure. It is critical to develop models that predict flow patterns in such a reactor to achieve uniform deposition across the substrate. Free convection can negatively affect the gas flow as cold inlet gas impinges on the heated substrate, leading to vortices and disturbances in the normal flow path. This experimental research will be used to understand the buoyancy-induced and momentum-driven flow structure encountered in an impinging jet CVD reactor. Investigations are conducted for various operating and design parameters. A modified stagnation flow reactor is built where the height between the inlet and substrate is reduced when compared to a prototypical stagnation flow reactor. By operating such a reactor at certain Reynolds and Grashof numbers it is feasible to sustain smooth and vortex free flow at atmospheric pressure. The modified stagnation flow reactor is compared to other stagnation flow geometries with either a varied inlet length or varied heights between the inlet and substrate. Comparisons are made to understand the impact of such geometric changes on the flow structure and the thermal boundary layer. In addition, heat transfer correlations are obtained for the substrate temperature. Overall, the results obtained provide guidelines for curbing the effects of buoyancy and for improving the flow field to obtain greater film uniformity when operating a stagnation flow CVD reactor at atmospheric pressure.

scholarly journals Atmospheric-Pressure Pulsed Discharge Plasma in a Slug Flow Reactor System for the Synthesis of Gold Nanoparticles

ACS Omega ◽  
2020 ◽  
Vol 5 (28) ◽  
pp. 17679-17685
Author(s):  
Motoki Yamada ◽  
Wahyudiono ◽  
Siti Machmudah ◽  
Hideki Kanda ◽  
Yaping Zhao ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Atmospheric Pressure ◽  
Slug Flow ◽  
Discharge Plasma ◽  
Flow Reactor ◽  
Reactor System ◽  
Pulsed Discharge ◽  
Pulsed Discharge Plasma

scholarly journals Hydrodeoxygenation of Benzofuran over Bimetallic Ni-Cu/γ-Al2O3 Catalysts

Catalysts ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 274
Author(s):  
Tianhan Zhu ◽  
Hua Song ◽  
Feng Li ◽  
Yanguang Chen
Keyword(s):  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Flow Reactor ◽  
Reaction Network ◽  
Product Yield ◽  
X Ray ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry ◽  
Temperature Programmed ◽  
Al2o3 Catalyst

Bimetallic NixCu(10−x)/γ-Al2O3 catalysts (where x is the mass fraction of Ni) with different Ni/Cu mass ratios were prepared. The catalysts were characterized by X-ray diffractometry, N2 adsorption–desorption, inductively coupled plasma mass spectrometry, X-ray photoelectron spectroscopy, H2-temperature programmed reduction, and transmission electron microscopy. The effect of Ni/Cu mass ratio on benzofuran hydrodeoxygenation was investigated in a fixed-flow reactor. Cu addition improved the NiO reducibility. The strong interaction of Ni and Cu led to the formation of smaller and highly dispersed CuO and NiO species over γ-Al2O3, which favors an improvement in catalytic activity. Among the as-prepared catalysts, the Ni5Cu5/γ-Al2O3 showed the highest deoxygenated product yield (79.9%) with an acceptable benzofuran conversion of 95.2%, which increased by 18.3% and 16.9% compared with that of the monometallic Ni/γ-Al2O3 catalyst. A possible reaction network was proposed, which would provide insight into benzofuran hydrodeoxygenation over the Ni5Cu5/γ-Al2O3 catalyst.

The role of mixed cubic/hexagonal nucleation layers on threading dislocation reduction in epitaxial GaN films

1996 ◽  
Vol 54 ◽  
pp. 646-647
Author(s):  
X. H. Wu ◽  
L. M. Brown ◽  
D. Kapolnek ◽  
S. Kellert ◽  
B. Kellert ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Flow Reactor ◽  
Defect Density ◽  
Threading Dislocation ◽  
Growth Substrate ◽  
Dislocation Reduction ◽  
Reactor Operating ◽  
Gan Buffer Layer

The defect density and their configuration in epitaxial GaN films on sapphire are strongly related to the optical and electrical properties of the films. The crystalline quality of GaN on sapphire can be greatly improved by introducing a low temperature GaN buffer layer. However, recent studies in our group demonstrate that the pre-growth substrate treatment can significantly change the defects structure and electron properties of the films. In this paper, we present our results on studies of the film microstructures and their corresponding nucleation layers. We propose a novel mechanism for dislocation reduction for GaN on sapphire.The growths for this study were achieved in a horizontal flow reactor operating at atmospheric pressure. Basal plane AI2O3 (Union Carbide) substrates were first cleaned in solvents and then heated in flowing H2 at 1050°C. Sample A was exposed to an ammonia flow of 3 1/min for 60s, sample B for 400s before the temperature was then reduced to 600°C and a nominal 190 Å thick GaN layer was grown.

Kinetics of the catalytic hydrodesulphurization reaction system; hydrogenation of ethylene and butene

1980 ◽  
Vol 45 (10) ◽  
pp. 2742-2750 ◽  
Author(s):  
Pavel Fott ◽  
Petr Schneider
Keyword(s):  
Atmospheric Pressure ◽  
Active Sites ◽  
Flow Reactor ◽  
Reaction System ◽  
Circulation Flow ◽  
Kinetic Description ◽  
Molybdenum Catalyst ◽  
Cobalt Molybdenum Catalyst ◽  
Kinetics Of ◽  
Hydrogenation Of Ethylene

Hydrogenation has been studied of ethylene and butene in a circulation flow reactor on a cobalt-molybdenum catalyst at 360 °C and atmospheric pressure. The effect has been investigated of simultaneous hydrodesulphurization of thiophene on the hydrogenation. The results have confirmed that different active sites for hydrogenation and hydrodesulphurization must be considered in the kinetic description of simultaneous hydrogenation of ethylene and hydrodesulphurization of thiophene. For isolated hydrogenation of ethylene and butene the absence of hydrogen sulphide in the reaction mixture considerably enhances the hydrogenation activity of the catalyst due to the change of its state.

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