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
RSC Advances ◽  
2014 ◽  
Vol 4 (108) ◽  
pp. 62809-62816 ◽  
Author(s):  
M. Izadyar ◽  
M. R. Gholami

A combined experimental and computational study was carried out on the gas phase pyrolysis reaction of diallylsulfoxide.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yoottapong Klinthongchai ◽  
Seeroong Prichanont ◽  
Piyasan Praserthdam ◽  
Bunjerd Jongsomjit

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.


1981 ◽  
Vol 59 (11) ◽  
pp. 1615-1621 ◽  
Author(s):  
Scott D. Tanner ◽  
Gervase I. Mackay ◽  
Diethard K. Bohme

Flowing afterglow measurements are reported which provide rate constants and product identifications at 298 ± 2 K for the gas-phase reactions of OH− with CH3OH, C2H5OH, CH3OCH3, CH2O, CH3CHO, CH3COCH3, CH2CO, HCOOH, HCOOCH3, CH2=C=CH2, CH3—C≡CH, and C6H5CH3. The main channels observed were proton transfer and solvation of the OH−. Hydration with one molecule of H2O was observed either to reduce the rate slightly and lead to products which are the hydrated analogues of the "nude" reaction, or to stop the reaction completely, k ≤ 10−12 cm3 molecule−1 s−1. The reaction of OH−•H2O with CH3—C≡CH showed an uncertain intermediate behaviour.


1997 ◽  
Vol 467 ◽  
Author(s):  
Fumio Yoshizawa ◽  
Kunihiro Shiota ◽  
Daisuke Inoue ◽  
Jun-ichi Hanna

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.


2015 ◽  
Vol 48 (4) ◽  
pp. 045204 ◽  
Author(s):  
Pavel Bakule ◽  
Oleksandr Sukhorukov ◽  
Katsuhiko Ishida ◽  
Francis Pratt ◽  
Donald Fleming ◽  
...  

Author(s):  
Svetlana Sineva ◽  
Jeff Chen ◽  
Taufiq Hidayat ◽  
Maksym Shevchenko ◽  
Peter C. Hayes ◽  
...  

Abstract Laboratory experimental study was undertaken to characterise the four-phase slag/matte/metal/tridymite equilibria of the Cu-Fe-O-S-Si system at 1473 K [1200°C], 1523 K [1250° C] and 1573 [1300°C] in a "closed" system without interaction with gas phase. The research methodology involved high temperature equilibration, ultra-fast quenching of the equilibrated samples followed by quantitative measurement of the equilibrated phases by electron probe X-ray microanalysis. Attainment of chemical equilibrium was carefully checked by the 4-points test approach. The results obtained in the present study provide reliable fundamental experimental information, which is crucial for the development and optimisation of the multicomponent thermodynamic database for copper-containing systems.


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