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 28 for “"Hydrodesulfurization"”.
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Catalytic Hydrogenation and Hydrodesulfurization of Model Compounds
… two related studies on hydrogenation and hydrodesulfurization of heterocyclic S-containing compounds. Alkyl substituted thiophenes are promising candidates for hydrogen carriers as the dehydrogenation reactions are known to occur under mild conditions. Four types of catalysts including …
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Rhodium zeolites as catalysts for hydrodesulfurization reactions
… regulations, these components must be removed. Hydrodesulfurization reactions and the use of catalysts to enhance this process have been under extensive study in recent years. The main hydrodesulfurization catalyst used has been cobalt-molybdenum on an alumina support. This study investigated …
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Investigations on hydrodesulfurization reactions using slurry catalysts and supercritical water
… bears large economic potential. Existing hydrodesulfurization technologies severely suffer from catalyst deactivation, coking and plugging as a result of high asphaltenes, heavy metals, and Conradson Carbon present in the viscous vacuum residue. Slurry phase hydrodesulfurization presents …
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Reduced molybdenum oxidation states in hydrodesulfurization catalysis by Chevrel phases
… been evaluated for thiophene and benzothiophene hydrodesulfurization (HDS) and 1-butene hydrogenation (HYD). These materials have been found to have HDS activities comparable to, or greater than, model unpromoted and cobalt-promoted MoS[subscript]2 catalysts; in contrast, Chevrel phases exhibit …
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The hydrodesulfurization of thiophene by Mo/Co treated oxyaluminum pillared montmorillonites
… pillared montmorillonites as supports for hydrodesulfurization (HDS) catalysts. Several synthesis schemes were evaluated for the preparation of pillared montmorillonites. Successful pillaring was accomplished by addition of cyclohexane solutions of aluminum isopropoxide to aqueous …
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Reactivity and Structure of Supported Nickel Phosphides (Ni₂P) in Deep Hydrodesulfurization Catalysis
… of Ni₂P catalysts and their application in deep hydrodesulfurization (HDS) of a model sulfur compound, 4,6-dimethyldibenzothiophene (4,6-DMDBT), one of the most refractory S-compounds. This topic is of great importance in addressing recently enacted environmental regulations limiting the sulfur …
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Synthesis And Characterization Of Size Controlled Transitionmetal Phosphide Nanoparticles And Their Hydrodesulfurization Catalytic Activity
… metal phosphides are promising catalysts for hydrodesulfurization (HDS). The size-dependent catalytic activity of these metal phosphides for hydrodesulfurization (HDS) remains unstudied because the traditional temperature programmed reduction (TPR) method used in catalyst preparation results …
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Kinetics and interactions of the simultaneous catalytic hydrodenitrogenation of pyridine and hydrodesulfurization of thiophene
Thesis. 1977. Ph.D.--Massachusetts Institute of Technology. Dept. of Chemical Engineering.
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Spectroscopic and Kinetic Studies of Hydrodenitrogenation and Hydrodesulfurization over Supported Nickel Phosphide (Ni₂P)
… of Ni₂P catalysts and their application in hydrodesulfurization (HDS) and hydrodenitrogenation (HDN). The work carried out includes synthesis of Ni₂P on different siliceous supports, SiO2 and MCM-41. It also includes characterization of these catalytic materials using X-ray diffraction …
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Synthesis and characterization of Ir(III) metallacycles derived from thiophene and related compounds: models for the hydrodesulfurization process
… complexes to mimic reactions which occur inside hydrodesulfurization (HDS) reactors. Information obtained from these model studies may often be applied to understanding the mechanisms involved with commercially used catalysts. Certain mechanisms¹ for HDS propose thiophene ring cleavage,forming a …
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Cyclopentadienyl ruthenium sulfide carbonyls and thiophene activation by iron and rhodium
… petroleum products is the objective of catalytic hydrodesulfurization (HDS), one of the largest applications of transition-metal catalysis. However, the specific mechanism for the process is not well understood. This thesis addresses certain aspects of HDS research from an organometallic …
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Transition Metal Complexes With Hydrosulfido and Thiophene Ligands
… dibenzothiophenes from petroleum by catalytic hydrodesulfurization is becoming increasingly important to fossil fuel processing. The reaction mechanism of this process is proposed to involve thiophene coordination to the metal surface and subsequent hydrogen transfer from a surface hydrosulfido …
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Thiophene derivatives of rhenium and titanium
… been made involving organometallic modeling of hydrodesulfurization (HDS). These studies have typically utilized late transition metals with high d-electron counts. This thesis focuses on three areas, (i) the synthesis of high oxidation state metal-oxo derivatives of thiophene, (ii) the …
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Cyclopentadienyl ruthenium chalcogenides
… of their chemical relevance to metal sulfide hydrodesulfurization (HDS) catalysts. Ruthenium sulfur complexes are of interest because of the favorable catalytic properties of RuS$\sb2$ which can act as HDS catalyst as well as an electrocatalyst. The purpose of this thesis was to synthesize, …
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Effects of Ni Promotion and Chelating Reagent On thePreparation, Structure and Performance of Molybdenum-Based Hds Catalysts
… for new catalytic technologies of ultra-deep hydrodesulfurization (HDS) in petroleum refining industry is increasing due to stringent and tightening environmental regulations regarding the sulfur content of diesel fuels. Thus, there is a very strong incentive to develop the next generation of …
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Synthesis, characterization and reactivity of tungsten oxynitride
… activities, but little hydrogenation (HYD) or hydrodesulfurization (HDS) activities.
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Investigation of Dibenzothiophene Removal from I Organic Phase: Enzymatic Approach vs. Ionic Liquids
… these new demands. The conventional process of hydrodesulfurization is unable to achieve the desired sulfur level even with the use of high temperatures and pressures to achieve a maximum reduction of the heavy sulfur compounds. Recently, ionic liquids have emerged as attractive “green” …
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Mechanistic understanding of microbial desulfurization
… that are recalcitrant to the currently employed hydrodesulfurization (HDS) technology. Two of the major obstacles to commercialization of BDS are mass transport limitations and the inability to maintain biocatalyst activity for long periods of time. In this work, the mass transport limitations …
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Cost-benefit analysis of ultra-low sulfur jet fuel
… in the US and elsewhere. The cost of hydrodesulfurization (HDS), the process used to remove sulfur from fuel, is projected to be between 4 and 7 cents per gallon of jet fuel. With 2006 levels of domestic fuel consumption, this translates to a yearly cost of HDS of $540-$940 million …
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Non-thermal Plasma Assisted Catalytic Upgrading of Low-cost Hydrocarbons
… such as catalytic reforming of naphtha and hydrodesulfurization of crude oil. Upon plasma activation, the co-fed methane can effectively accelerate hydrogenation and isomerization reactions for iso-paraffin production over an optimized Ga-based ZSM-5 catalyst. A systematic model compound …
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