Surface layering within the grains of an alumina support and its effect on hydrotreating catalysts

1977 ◽  
Author(s):  
J F Kriz ◽  
M Ternan ◽  
R H Packwood
Keyword(s):  
Alumina Support ◽  
Hydrotreating Catalysts ◽  
Surface Layering

Deuterium Tracer Studies on Hydrotreating Catalysts. 2. Contribution of the Hydrogen of the Alumina Support to H-D Exchange

1998 ◽  
Vol 179 (2) ◽  
pp. 495-502 ◽  
Author(s):  
C. Thomas ◽  
L. Vivier ◽  
A. Travert ◽  
F. Maugé ◽  
S. Kasztelan ◽  
...  
Keyword(s):  
Tracer Studies ◽  
Alumina Support ◽  
Hydrotreating Catalysts

scholarly journals Influence of Alumina Precursor Properties on Cu-Fe Alumina Supported Catalysts for Total Toluene Oxidation as a Model Volatile Organic Air Pollutant

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 252
Author(s):  
Tadej Žumbar ◽  
Alenka Ristić ◽  
Goran Dražić ◽  
Hristina Lazarova ◽  
Janez Volavšek ◽  
...  
Keyword(s):  
Surface Characterization ◽  
Iron Concentration ◽  
Catalytic Performance ◽  
Air Pollutant ◽  
Molar Ratio ◽  
Homogeneous Distribution ◽  
Total Oxidation ◽  
Alumina Support ◽  
Determining Factors ◽  
Volatile Organic

The structure–property relationship of catalytic supports for the deposition of redox-active transition metals is of great importance for improving the catalytic efficiency and reusability of the catalysts. In this work, the role of alumina support precursors of Cu-Fe/Al2O3 catalysts used for the total oxidation of toluene as a model volatile organic air pollutant is elucidated. Surface characterization of the catalysts revealed that the surface area, pore volume and acid site concentration of the alumina supports are important but not the determining factors for the catalytic activity of the studied catalysts for this type of reaction. The determining factors are the structural order of the support precursor, the homogeneous distribution of the catalytic sites and reducibility, which were elucidated by XRD, NMR, TEM and temperature programed reduction (TPR). Cu–Fe/Al2O3 prepared from bayerite and pseudoboehmite as highly ordered precursors showed better catalytic performance compared to Cu-Fe/Al2O3 derived from the amorphous alumina precursor and dawsonite. Homogeneous distribution of FexOy and CuOx with defined Cu/Fe molar ratio on the Al2O3 support is required for the efficient catalytic performance of the material. The study showed a beneficial effect of low iron concentration introduced into the alumina precursor during the alumina support synthesis procedure, which resulted in a homogeneous metal oxide distribution on the support.

Effect of Fe and Co promoters on CO methanation activity of nickel catalyst prepared by impregnation – co-precipitation method

2020 ◽  
Vol 18 (5-6) ◽  
Author(s):  
Buyan-Ulzii Battulga ◽  
Tungalagtamir Bold ◽  
Enkhsaruul Byambajav
Keyword(s):  
Synergetic Effect ◽  
Space Velocity ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Alumina Support ◽  
Co Methanation ◽  
Temperature Range ◽  
Co Precipitation ◽  
Catalyst Distribution

AbstractNi based catalysts supported on γ-Al2O3 that was unpromoted (Ni/γAl2O3) or promoted (Ni–Fe/γAl2O3, Ni–Co/γAl2O3, and Ni–Fe–Co/γAl2O3) were prepared using by the impregnation – co-precipitation method. Their catalytic performances for CO methanation were studied at 3 atm with a weight hourly space velocity (WHSV) of 3000 ml/g/h of syngas with a molar ratio of H2/CO = 3 and in the temperature range between 130 and 350 °C. All promoters could improve nickel distribution, and decreased its particle sizes. It was found that the Ni–Co/γAl2O3 catalyst showed the highest catalytic performance for CO methanation in a low temperature range (<250 °C). The temperatures for the 20% CO conversion over Ni–Co/γAl2O3, Ni–Fe/γAl2O3, Ni–Fe–Co/γAl2O3 and Ni/γAl2O3 catalysts were 205, 253, 263 and 270 °C, respectively. The improved catalyst distribution by the addition of cobalt promoter caused the formation of β type nickel species which had an appropriate interacting strength with alumina support in the Ni–Co/γAl2O3. Though an addition of iron promoter improved catalyst distribution, the methane selectivity was lowered due to acceleration of both CO methanation and WGS reaction with the Ni–Fe/γAl2O3. Moreover, it was found that there was no synergetic effect from the binary Fe–Co promotors in the Ni–Fe–Co/γAl2O3 on catalytic activity for CO methanation.

scholarly journals Template-free ZSM-5 membrane preparation on alumina support by secondary hydrothermal synthesis

2020 ◽  
pp. 100049
Author(s):  
Helena Schneider ◽  
Lucas K. Schindel ◽  
Lucas B. Gomes ◽  
Isabel C. Tessaro ◽  
Nilson R. Marcilio
Keyword(s):  
Hydrothermal Synthesis ◽  
Membrane Preparation ◽  
Alumina Support ◽  
Template Free

Separation of Methane from Shuttle Tanker Vents Gases by Adsorption on a Polyurethane/Zeolite Membrane

2017 ◽  
Vol 733 ◽  
pp. 42-46
Author(s):  
Habiba Shehu ◽  
Edidiong Okon ◽  
Edward Gobina
Keyword(s):  
Carbon Dioxide ◽  
Physical Properties ◽  
Crude Oil ◽  
Deep Water ◽  
Separation Factor ◽  
Gas Permeation ◽  
Zeolite Membrane ◽  
Alumina Support ◽  
Molar Flux

Shuttle tankers are becoming more widely used in deep water installations as a means of transporting crude oil to storage plants and refineries. The emissions of hydrocarbon vapours arise mainly during loading and offloading operations. Experiments have been carried out on the use of polyurethane/zeolite membrane on an alumina support for the separation of methane from carbon dioxide and oxygen. The physical properties of the membrane were investigated by FTIR. Single gas permeation tests with methane, propane, oxygen and carbon dioxide at a temperature of 293 K and pressure ranging from 0.1 to 1.0 x 10-5 Pa were carried out. The molar flux of the gases through the membrane was in the range of 3 x 10-2 to 1 x 10-1 molm-2s-1. The highest separation factor of CH4/CO2 and CH4/O2 and CH4/C3H8 was determined to be 1.7, 1.7 and 1.6 respectively.

Influence of the order of the catalysts in the stacked bed of VGO hydrotreating catalysts

Fuel ◽  
2021 ◽  
Vol 306 ◽  
pp. 121672
Author(s):  
K.A. Nadeina ◽  
Yu.V. Vatutina ◽  
P.P. Mukhacheva ◽  
V. Krestyaninova ◽  
A.V. Saiko ◽  
...  
Keyword(s):  
Hydrotreating Catalysts
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