Kinetic study of model reactions in the gas phase at the early stage of coke formation

1992 ◽  
Vol 31 (1) ◽  
pp. 14-19 ◽  
Author(s):  
Daisuke Nohara ◽  
Tomoya Sakai
Keyword(s):  
Kinetic Study ◽  
Gas Phase ◽  
Early Stage ◽  
Coke Formation ◽  
Model Reactions

Experimental Study of Gas-Phase Pyrolysis Reaction of Benzene to Investigate the Early Stage of Coke Formation

2014 ◽  
Vol 47 (5) ◽  
pp. 406-415 ◽  
Author(s):  
Akihiro Kousoku ◽  
Ryuichi Ashida ◽  
Akio Miyasato ◽  
Mikio Miyake ◽  
Kouichi Miura
Keyword(s):  
Experimental Study ◽  
Gas Phase ◽  
Early Stage ◽  
Coke Formation ◽  
Pyrolysis Reaction

Reesterification of ethyl acetate by propanol catalysed by glycidyl methacrylate copolymers containing sulphonic acid groups

1981 ◽  
Vol 46 (8) ◽  
pp. 1941-1946 ◽  
Author(s):  
Karel Setínek
Keyword(s):  
Liquid Phase ◽  
Ethyl Acetate ◽  
Kinetic Study ◽  
Gas Phase ◽  
Nonlinear Regression ◽  
Kinetic Data ◽  
Glycidyl Methacrylate ◽  
Kinetic Equations ◽  
Methacrylate Copolymers ◽  
Styrene Divinylbenzene

A series of differently crosslinked macroporous 2,3-epoxypropyl methacrylate-ethylenedimethacrylate copolymers with chemically bonded propylsulphonic acid groups were used as catalysts for the kinetic study of reesterification of ethyl acetate by n-propanol in the liquid phase at 52 °C and in the gas phase at 90 °C. Analysis of kinetic data by the method of nonlinear regression for a series of equations of the Langmuir-Hinshelwood type showed that kinetic equations which describe best the course of the reaction are the same as for the earlier studied sulphonated macroporous styrene-divinylbenzene copolymers. Compared types of catalysts differ, however, in the dependence of their activity on the degree of crosslinking of the copolymer used.

An homogeneous growth model of gallium arsenide epitaxial layers from the gas phase

1989 ◽  
Vol 54 (11) ◽  
pp. 2933-2950
Author(s):  
Emerich Erdös ◽  
Petr Voňka ◽  
Josef Stejskal ◽  
Přemysl Klíma
Keyword(s):  
Experimental Data ◽  
Gallium Arsenide ◽  
Kinetic Study ◽  
Gas Phase ◽  
Growth Model ◽  
Epitaxial Layers ◽  
Inhomogeneous Model ◽  
Homogeneous Models ◽  
Active Centres

This paper represents a continuation and ending of the kinetic study of the gallium arsenide formation, where a so-called inhomogeneous model is proposed and quantitatively formulated in five variants, in which two kinds of active centres appear. This model is compared both with the experimental data and with the previous sequence of homogeneous models.

scholarly journals Study of deactivation in mesocellular foam carbon (MCF-C) catalyst used in gas-phase dehydrogenation of ethanol

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yoottapong Klinthongchai ◽  
Seeroong Prichanont ◽  
Piyasan Praserthdam ◽  
Bunjerd Jongsomjit
Keyword(s):  
Catalytic Activity ◽  
Pore Size ◽  
Gas Phase ◽  
Surface Area ◽  
Active Sites ◽  
Operating Temperature ◽  
Coke Formation ◽  
Ethanol Conversion ◽  
Deactivation Of Catalyst ◽  
Dehydrogenation Of Ethanol

AbstractMesocellular foam carbon (MCF-C) is one the captivating materials for using in gas phase dehydrogenation of ethanol. Extraordinary, enlarge pore size, high surface area, high acidity, and spherical shape with interconnected pore for high diffusion. In contrary, the occurrence of the coke is a majority causes for inhibiting the active sites on catalyst surface. Thus, this study aims to investigate the occurrence of the coke to optimize the higher catalytic activity, and also to avoid the coke formation. The MCF-C was synthesized and investigated using various techniques. MCF-C was spent in gas-phase dehydrogenation of ethanol under mild conditions. The deactivation of catalyst was investigated toward different conditions. Effects of reaction condition including different reaction temperatures of 300, 350, and 400 °C on the deactivation behaviors were determined. The results indicated that the operating temperature at 400 °C significantly retained the lowest change of ethanol conversion, which favored in the higher temperature. After running reaction, the physical properties as pore size, surface area, and pore volume of spent catalysts were decreased owing to the coke formation, which possibly blocked the pore that directly affected to the difficult diffusion of reactant and caused to be lower in catalytic activity. Furthermore, a slight decrease in either acidity or basicity was observed owing to consumption of reactant at surface of catalyst or chemical change on surface caused by coke formation. Therefore, it can remarkably choose the suitable operating temperature to avoid deactivation of catalyst, and then optimize the ethanol conversion or yield of acetaldehyde.

Dissecting transmetalation reactions at the molecular level: C–B versus F–B bond activation in phenyltrifluoroborate silver complexes

2021 ◽  
Vol 50 (4) ◽  
pp. 1496-1506
Author(s):  
Fiona Bathie ◽  
Adam W. E. Stewart ◽  
Allan J. Canty ◽  
Richard A. J. O'Hair
Keyword(s):  
Gas Phase ◽  
Bond Activation ◽  
Molecular Level ◽  
Silver Complexes ◽  
Fundamental Model ◽  
Model Reactions

Gas-phase experiments and computation provide fundamental model reactions for aryl and fluoride transfer between silver and boron centres.

Direct Nucleation of Crystalline SiGe on Substrates by Reactive Thermal CVD with Si2H6 and GeF4

1997 ◽  
Vol 467 ◽  
Author(s):  
Fumio Yoshizawa ◽  
Kunihiro Shiota ◽  
Daisuke Inoue ◽  
Jun-ichi Hanna
Keyword(s):  
Growth Rate ◽  
Gas Phase ◽  
Heterogeneous Nucleation ◽  
Homogeneous Nucleation ◽  
Film Growth ◽  
Early Stage ◽  
Gaseous Mixture ◽  
The Other ◽  
Thermal Cvd ◽  
Initial Deposition

ABSTRACTPolycrystalline SiGe (poly-SiGe) film growth by reactive thermal CVD with a gaseous mixture of Si2H6 and GeF4 was investigated on various substrates such as Al,Cr, Pt, Si, ITO, ZnO and thermally grown SiO2.In Ge-rich film growth, SEM observation in the early stage of the film growth revealed that direct nucleation of crystallites took place on the substrates. The nucleation was governed by two different mechanisms: one was a heterogeneous nucleation on the surface and the other was a homogeneous nucleation in the gas phase. In the former case, the selective nucleation was observed at temperatures lower than 400°C on metal substrates and Si, where the activation of adsorbed GeF4 on the surface played a major role for the nuclei formation, leading to the selective film growth.On the other hand, the direct nucleation did not always take place in Si-rich film growth irrespective of the substrates and depended on the growth rate. In a growth rate of 3.6nm/min, the high crystallinity of poly-Si0.95Ge0.05in a 220nm-thick film was achieved at 450°C due to the no initial deposition of amorphous tissue on SiO2 substrates.

Kinetic Study of the Gas-Phase Reactions of Cl Radicals with 3-Pentanone and 3-Hexanone

2004 ◽  
Vol 108 (34) ◽  
pp. 7027-7031 ◽  
Author(s):  
Alfonso Aranda ◽  
Yolanda Díaz de Mera ◽  
Ana Rodríguez ◽  
Lorena Morales ◽  
Ernesto Martínez
Keyword(s):  
Kinetic Study ◽  
Gas Phase ◽  
Gas Phase Reactions

Photocatalytic Degradation of Tetrachloroethylene in Gas Phase on TiO2Films:  A Kinetic Study

2005 ◽  
Vol 44 (16) ◽  
pp. 6075-6085 ◽  
Author(s):  
Gustavo E. Imoberdorf ◽  
Horacio A. Irazoqui ◽  
Alberto E. Cassano ◽  
Orlando M. Alfano
Keyword(s):  
Photocatalytic Degradation ◽  
Kinetic Study ◽  
Gas Phase

Mechanism and kinetic study on the gas-phase reactions of OH radical with carbamate insecticide isoprocarb

2012 ◽  
Vol 60 ◽  
pp. 460-466 ◽  
Author(s):  
Chenxi Zhang ◽  
Wenbo Yang ◽  
Jing Bai ◽  
Yuyang Zhao ◽  
Chen Gong ◽  
...  
Keyword(s):  
Kinetic Study ◽  
Gas Phase ◽  
Oh Radical ◽  
Gas Phase Reactions ◽  
Carbamate Insecticide
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