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Showing 1 to 20 of 66 for “"ZSM-5"”.
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Conversion of n-pentenes over H-ZSM-5
… importance. The conversion of I-pentene over H-ZSM-5 zeolite catalyst was studied in a fixed-bed micro reactor.
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Thermally stable ZSM-5 zeolite materials with new microporosities
… Na-X, Na-Y, the ammonium and sodium forms of the ZSM-5 zeolite were prepared by a process which involves the selective removal of silicon atoms from the parent zeolite in an aqueous basic solution. This treatment has the effect to decrease the Si/Al ratio while keeping the zeolite structure almost …
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The chemical vapour deposition of Tetraethoxysilane on Zeolite ZSM-5
… silica onto the external surface of zeolite ZSM-5. A CVD treatment consists out of a deposition, flushing and heating step followed by calcination in flowing air. Modifications are carried out in up to 33 cycles on one and the same sample employing tetraethoxysilane (TEOS) as silica precursor …
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Aromatization of alkenes by gallium/H-ZSM-5 zeolite catalysts
Gallium/H-ZSM-5 zeolite catalysts have been extensively researched for the aromatization of liquified petroleum gas (LPG). In 1989 BP and UOP collaborated to commission a pilot plant in Grangemouth, Scotland, for the aromatization of propane and butane. This plant, based on a technology called the …
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Desilicated ZSM-5 zeolite as catalyst for the dehydration of ethanol
… new desilicated forms of the zeolites X, Y and ZSM-5 were prepared by the selective removal of silicon atoms from the parent zeolites in an aqueous solution of base. This treatment, which decreases the Si/Al ratio while keeping the zeolite framework almost unmodified, enhanced the ion exchange …
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The characterization and elimination of the external acidity of ZSM-5
The zeolite ZSM-5 is well-known for its unique intersecting channel system. This channel system has a great bearing on the shape-selective properties and the long life-times of ZSM-5. In this study, ZSM-5 was modified in various ways to eliminate the external acidity of the catalyst to further …
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Nitric oxide decomposition over metal ion-modified Cu-ZSM-5 catalysts
Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1996.
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Untersuchungen an nickelhaltigen ZSM-5-Zeolith-Katalysatoren zur simultanen Stickoxidreduktion mit Propen
… und N2O an nickelbeladenen Zeolithen vom Typ H-ZSM-5 mit Propen als Reduktionsmittel untersucht. Die experimentellen Arbeiten wurden unter realitätsnahen Bedingungen mit einem Katalysatorbett durchgeführt. Der Einfluss des Nickelgehalts und der Acidität des zeolithischen Trägermaterials auf …
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Propene oligomerization over steam dealuminated and boron and phospherous modified ZSM-5
ZSM-5 was modified with boron and phosphorus compounds in an attempt to improve the selectivity of the catalyst with respect to the linearity of the liquid product of propene oligomerization. Boron was incorporated into the zeolite framework by inclusion in the synthesis gel. Boralite catalysts …
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The optimization of the ZSM-5 catalyst activity with respect to crystallinity
In the synthesis of zeolites optimization of factors such as crystallinity, which encapsulates morphology, and acidity can result in optimal activity. Optimal activity is vital in chemical industries due to the fact that it results in higher yields, better selectivities and lower operational costs. …
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Aromatization of light olefins and paraffins on pure and hybrid ZSM-5 catalysts
… hydrocarbons. It was found that when an acidic H-ZSM-5 zeolite with Si/Al atomic ratio equal to about 40, was mixed with a ZnO based co-catalyst, aromatization selectivity followed the principles of synergy. For a feed made up of mostly ethylene, as generated in a bench scale propane …
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The effect of oxygenates on the oligomerisation of propene over zeolite ZSM-5
… be predicted from pure component data alone. ZSM-5 has been shown to be an excellent catalyst for alkene oligomerisation and is also active for the conversion of oxygenates. When pure oxygenates are fed over ZSM-5 at oligomerisation temperatures, acetone and MEK cause the catalyst to …
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Catalytic cracking of n-alkanes and n-alkylbenzenes over H-ZSM-5 zeolite
Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1993.
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ZSM-5/thermoplastic polyurethane mixed matrix membranes for pervaporation of dilute aqueous organic solvents
The present study aimed to synthesize ZSM-5/thermoplastic polyurethane (TPU) mixed matrix membranes (MMMs) for efficient pervaporation of n-butanol and ethanol from dilute aqueous solutions as a cheap and easy to fabricate replacement for the benchmark polydimethylsiloxane (PDMS) membranes. Binary …
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The development of a model for high pressure propene oligomerisation over H-ZSM-5
… for high pressure propene oligomerisation over H-ZSM-5. To this end, this introductory chapter first revises the characteristics and applications of catalysts which have been shown to be active for oligomerisation. This is further split into acid catalysts, heterogeneous nickel catalysts, other …
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CONVERSION OF METHANOL AND LIGHT OLEFINS TO GASOLINE OVER A SHAPE SELECTIVE CATALYST ZSM-5
… and 3-methylbutene-1) were studied over Ni-ZSM-5 zoelite catalyst. The product distribution over a broad range of space velocities indicates the reaction sequence: dimethyl paraffins methanol (,ether) C(,2)-C(,5) olefins (,aromatics) Monomethyl aliphatics predominate over both straight-chain …
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In situ ¹³C NMR monitoring of the dehydration of 2-propanol over H-ZSM-5
… described. The dehydration of 2-propanol over H-ZSM-5 was observed using solution type techniques. Although this produces broad lines, several mechanistic details were elucidated. This study indicates that: 1) the dehydration does not proceed through a cyclopropyl carbenium ion intermediate, 2) …
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Synthesis, characterisation and engineering of thin films of ZSM-5 on alumina, quartz and sand supports
… the physical and reactive properties of thin ZSM-5 films supported on alumina, quartz and sand packings. The objective of this work is to evaluate the intrinsic catalytic properties of these materials by estimating the reaction-diffusion model parameters from the results of the …
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The inertisation of the zeolites ZSM-5, mordenite and beta by chemical vapour deposition using tetraethoxysilane
… to the pores. Given the industrial importance of ZSM-5, this is a particularly good zeolite to study in this regard. Chemical vapour deposition (CVD) and chemical liquid deposition (CLD) methods have shown great promise in inertising the external surface acidity of zeolites and thus increasing …
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Factors influencing the catalytic activity of Fe-ZSM-5 during the catalytic conversion of N₂O
… 1970's. In this study, the preparation of iron ZSM-5 zeolite catalysts by mechanochemical means and thermally induced solid-state ion exchange was studied. After grinding the NH4-Zeolite and ferrous chloride, no x-ray reflections characteristic of ferrous chloride are detected. After heating the …
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