Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 284 for “"zeolite"”.
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Glycerol Oxidation with Zeolite and Hierarchical Zeolite as Catalysts and Electrocatalysts
… alternative to O2. Four series of different zeolites (X, Y, ZSM-5, and BEA), either in sodic (Na+) and Protonic (H+) forms, were modified with the introduction of ions of transition metals (Cu, Fe, Ni, Zn) via ion-exchange method. The obtained materials were characterized (XRD, N2 …
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Zeolite-Modified Fischer-Tropsch Synthesis
… of alkali from the Fe-FT catalyst tothe HZSM-5 zeolite. The catalytic performance of the combined Fe-FT/HZSM-5system has, however, been observed to considerably decline with time-on-stream, aphenomenon which has been attributed to the migration of alkali from the Fe-FT catalyst to he HZSM-5 …
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Rhodium-zeolite hydroformylation of propylene
… characterize the rhodium exchanged NaX and NaY zeolites as propylene hydroformylation catalysts. Catalytic activity was measured in a differential bed reactor. Flow in situ infrared spectroscopy was used to probe the coordination chemistry of the zeolite modified rhodium carbonyls. The catalytic …
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Hydrothermal aging of zeolite-based catalysts
… GO-40) FCC catalyst, a composite of RE-USY zeolite and alumina-silica gel matrix, was treated hydrothermally under simulated FCC regenerator conditions in a laboratory scale fluidized bed. Fresh and steam-aged catalysts were characterized by surface area reduction using the nitrogen BET and …
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Microwave effects on some zeolite catalysed reactions
… Investigation of this effect was conducted on zeolite catalysed reactions, namely the disproportionation of toluene and the alkylation of toluene with methanol.Most of the reports fail to address the problem of accurate temperature measurement within a microwave field. This is of paramount …
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Liquid phase hydroformylation by zeolite supported rhodium
… research was to directly compare the behavior of zeolites containing rhodium with that of homogeneous rhodium species as catalysts for liquid phase hydroformylation of 1-hexene in order to study the effects of zeolite immobilization. NaX zeolite was cation exchanged with several rhodium salts and …
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Alkene hydrogenation on reduced nickel A-zeolite catalysts.
… isobutene over various nickel metal-loaded 4A zeolites have been investigated. The reaction kinetics were found to be similar to those found by other workers for alkene hydrogenation over pure nickel metal. Reactions were first order in hydrogen and zero order in alkene at lower temperatures. …
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Remediation of acid mine drainage using natural zeolite
… and real AMD from Wheal Jane mine using natural zeolite. Laboratory experiments were performed to investigate the effectiveness of natural zeolite as a potential low cost material for the removal of these heavy metals from AMD. These include, equilibrium tests, batch kinetic studies, column …
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Data Driven Synthesis Planning Applied to Zeolite Materials
… the question "How" to make a specified material. Zeolites are microporous, crystalline aluminosilicates described by this paradigm. Their relevance for chemical and "green" applications has led to sustained interest for many decades with substantial progress made in predicting hypothetical …
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Computational fluid dynamics of water vapor/ Zeolite 13X adsorption
… The considered interactions are between Zeolite 13X and water vapor for the purposes of engineering adsorbent characteristics and harvester device characteristics. Four objectives are evaluated in the development of a predictive model. First, to understand the implementation of adsorption …
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Fly Ash Zeolite Catalyst Support for Fischer-Tropsch Synthesis
… research aimed at evaluating a fly ash zeolite (FAZ) catalyst support for use in heterogeneous catalytic processes. Gas phase Fischer-Tropsch Synthesis (FTS) over a fixed-bed of the prepared catalyst/FAZ support was identified as an appropriate process for evaluation, by comparison with …
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Removal of antibiotics from contaminated waters using natural zeolite
… (OFL), and enrofloxacin (ENR), on natural zeolite was investigated. The impact of pH and natural organic matter (NOM) on the sorption process was examined, and the maximum sorption capacity was calculated using the Langmuir-Freundlich sorption model. The results showed that at a neutral pH …
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Thermally stable ZSM-5 zeolite materials with new microporosities
… 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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Design and characterization of zeolite membranes for fluid separation
… and theoretical methods have been used to study zeolite structures, properties and applications as membranes for separation purposes. Thin layers of silicalite-1 and Na-LTA zeolites have been synthesised onto carbon-graphite supports using a hydrothermal synthesis procedure. The separation …
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Development of a zeolite washcoating technique for microchannel reactors
Microreactor technology is becoming an increasingly active research field in terms of chemical reaction engineering and process intensification. An important feature of microreactor technology is the requirement of a catalyst layer.
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Incorporation of Platinum onto Zeolite KL for aromatisation reactions
… yield the highest platinum dispersion on the zeolite KL. Loading of platinum onto the zeolite KL was mainly via liquid state ion exchange. Loading via impregnation and solid state ion exchange were also briefly investigated in order to compare these techniques with liquid ion exchange. After …
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First-principles control of zeolite synthesis, transformations, and intergrowth
… phase transformations, and intergrowth of zeolites, which are industrially relevant catalysts and molecular sieves known for their hard-to-control phase competition and polymorphism. Part I of this thesis describes the development of methods to simulate and analyze zeolite transformations …
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Design and characterization of zeolite supported cobalt carbonyl catalysts
… system consisting of Co₂(CO)₈ impregnated on zeolites with faujasitic structure has been designed and investigated using a variety of techniques. In situ FTIR spectroscopy and carbon monoxide evolution were used to identify the major products generated, namely Co₄(CO)₁₂ and …
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