The Experts below are selected from a list of 50616 Experts worldwide ranked by ideXlab platform
Peter N. Hannerup - One of the best experts on this subject based on the ideXlab platform.
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Hydrodemetallization in Resid Hydroprocessing
Studies in Surface Science and Catalysis, 1991Co-Authors: Jesper Bartholdy, Peter N. HannerupAbstract:Summary The study of the Vanadium deposition profiles in spent Catalyst particles from resid hydro-processing confirms that HDM is a sequential reaction. Furthermore, it is shown that the distribution parameter for the deposited Vanadium Qv is constant through the reactor for each Catalyst Type and that Qv is proportional to the efficiency of the Vanadium removal reaction.
Peter Reiss - One of the best experts on this subject based on the ideXlab platform.
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Influence of the Catalyst Type on the growth of carbon nanotubes via methane chemical vapor deposition.
The journal of physical chemistry. B, 2006Co-Authors: Lucie Jodin, Anne-claire Dupuis, Emmanuelle Rouviere, Peter ReissAbstract:The preparation of the Catalyst is one of the key parameters which governs the quality of carbon nanotubes (CNTs) grown by catalyzed chemical vapor deposition (CVD). We investigated the influence of three different procedures of Catalyst preparation on the Type and diameter of CNTs formed under identical growth conditions via methane CVD. In the first one, chemically synthesized colloidal iron oxide or iron molybdenum alloy nanoparticles were used, which were homogeneously deposited on silicon substrates by spin coating to prevent them from coalescence under CVD growth conditions. The obtained multiwall CNTs (MWNTs) exhibited diameters corresponding to the Catalyst particle size, whereas no formation of single-wall CNTs (SWNTs) was observed. In the second method, commercial porous alumina nanoparticles were used in association with iron and molybdenum salts and the Fe/Mo Catalyst was formed in situ. We determined that the alumina concentration significantly influenced the morphology of the Catalyst and that below a critical value of the range of 1 g/L no CNTs were formed. While yielding nearly defect-free SWNTs, their diameter could not be controlled using this procedure, resulting in a large distribution of tube sizes. In a third, new preparation method, associating alumina and iron-based nanoparticles, SWNTs of a different size and narrower diameter distribution as compared to the second method were obtained. Our results are evidence of the essential role of alumina particles in the formation of SWNTs, and the newly developed method opens up a way to the synthesis of diameter-controlled SWNTs via catalyzed CVD.
Minoru Terano - One of the best experts on this subject based on the ideXlab platform.
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Deviation of hydrogen response during propylene polymerization with various Ziegler–Natta Catalysts
Journal of Molecular Catalysis A-chemical, 1999Co-Authors: Hideharu Mori, Masahiro Endo, Minoru TeranoAbstract:Abstract The influence of the Catalyst Type on the hydrogen response during propylene polymerization with Ziegler–Natta Catalysts was investigated in terms of the variations in kinetic behavior, Catalyst activity, molecular weight and its distribution, and microstructure of the resulting polymers. Three different Types of supported Ziegler Catalysts and a TiCl 3 Catalyst were used in this study. In all cases, the Catalyst activity was found to significantly increase with the addition of hydrogen along with a sharp decrease in the molecular weights. The activity enhancement by hydrogen was remarkable during polymerizations with supported Catalysts compared to the case of a TiCl 3 Catalyst system. Hydrogen was found to activate all of the supported Catalysts to same degree, regardless of the Type of internal donor and the preparation method. This phenomenon is considered to be mainly ascribed to no significant difference in the number of dormant sites formed on the supported Catalysts. The influence of the Catalyst Type on the hydrogen response was remarkable for the molecular weight and its distributions, which may be due to the difference in the states of the active species on each Catalyst.
Donny Lesmana - One of the best experts on this subject based on the ideXlab platform.
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Pyrolysis of waste oil in the presence of a spent Catalyst
Journal of environmental chemical engineering, 2015Co-Authors: Donny LesmanaAbstract:Abstract A spent Catalyst has great potential to convert waste oil into diesel oil. This study investigated the pyrolysis of waste oils in the presence of a spent Catalyst, as well as the regeneration properties of the spent Catalyst, such as the Type of regeneration (in situ and ex situ) and time and temperature for spent Catalyst regeneration. In addition, the effect of the spent Catalyst, Type of waste oil, weight ratio of the spent Catalyst to the waste oil, and stability of the spent Catalyst were evaluated. The yield of diesel oil was higher than 60% when waste oil was pyrolyzed at 370 °C.
Yuda Yürüm - One of the best experts on this subject based on the ideXlab platform.
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Effect of Reaction Temperature and Catalyst Type on the Formation of Boron Nitride Nanotubes by Chemical Vapor Deposition and Measurement of Their Hydrogen Storage Capacity
Industrial & Engineering Chemistry Research, 2012Co-Authors: Burcu Saner Okan, Züleyha Özlem Kocabaş, Asli Nalbant Ergün, Mustafa Baysal, Ilse Letofsky-papst, Yuda YürümAbstract:Boron nitride nanotubes (BNNT) were synthesized over both Fe3+ impregnated MCM-41 (mobil composition of matter no. 41) and Fe2O3/MCM-41 complex Catalyst systems at relatively low temperatures for 1 h by the chemical vapor deposition technique in large quantities. The formation of BNNT was tailored at different reaction temperatures by changing Catalyst Type. The use of Fe3+-MCM-41 and Fe2O3 as a complex Catalyst system led to thin and thick tube formations. The diameters of BNNTs were in the range of 2.5–4.0 nm for thin tubes and 20–60 nm for thick tubes. The thin tube formation originated from the growth of BNNT over Fe3+-MCM-41 due to its average pore size of 4 nm. Higher reaction temperatures caused both BNNT and iron-based side product formations. The hydrogen uptake capacity measurements by the Intelligent Gravimetric Analyzer at room temperature showed that BNNTs could adsorb 0.85 wt % hydrogen which was two times larger than that for commercial carbon nanotubes.