Catalysis and Reaction Engineering Commons^™

Catalytic Conversion Of Benzothiophene Over A H-Zsm5 Catalyst, Reactivity And A Kinetic Model, Saad A. Al-Bogami

Electronic Thesis and Dissertation Repository

Nowadays and due to environmental legislations, a world-wide attention has been given towards clean transportation fuels with emphasis on sulfur contents reduction. These efforts on the other hand are challenged by the poor qualities of crude oils. The existing desulfurization technologies such as hydrodesulfurization are not capable to cope with new firm standards. Hence, it is extremely desirable to develop a catalytic desulfurization process to meet both sulfur limits and refining economics. As one aspect of this objective, it is of great importance to study and comprehend the behaviour and chemistry of individual sulfur species present in transportation fuels cuts. …

Photocalytic Degradation Of Malic Acid Under Thin Coated Tio2, Vanessa Silveira Rodgher

Electronic Thesis and Dissertation Repository

Opaque fluids have a limited irradiation transmission. Thus, their decontamination employing near UV irradiation poses significant technical challenges. In the present study, a thin UV-transparent/waterproof glue layer coated with a 1.5 wt% of TiO₂ and a new PhotoReactor Cell were implemented. TiO₂ irradiation in the PhotoReactor Cell was effected on the TiO₂ particle side, not directly in contact with the fluid, allowing the postulation of an “h⁺” site mobility mechanism on photocatalysis.

Photocatalytic degradation experiments with malic and malonic acid in water at 10, 20, 30 and 40 ppm showed the complete degradation of malic …

Controlled Synthesis Of Single-Walled Carbon Nanotubes By Methane Decomposition And Their Application As Heterogeneous Partial Oxidation Catalyst, Inusa Abdullahi

Electronic Thesis and Dissertation Repository

Single-walled carbon nanotubes (SWCNTs) are materials with unique electronic and mechanical properties suitable for a large number of applications. Although, since their discovery many strategies for SWCNT synthesis have been explored, most of these are either tremendously energy intensive or require complex SWNCT purification strategies. These issues have resulted in expensive SWCNT production processes which in turn have hampered the development of a large range of SWCNT applications. This study deals with the controlled growth of SWCNTs from methane decomposition over iron and cobalt catalysts supported on MgO and the application of the CCVD grown SWCNTs as a catalyst for …

Nano Tio2/Graphene Composites For Photovoltaic And Photocatalytic Materials, Nasrin Farhangi

Electronic Thesis and Dissertation Repository

Graphene has been recognized as one of the most exciting carbon based materials of the present decade due to its unique electronic, mechanical and thermal properties. High surface area exfoliated graphene sheets with controllable surface functionality is an attractive two-dimensional surface for attaching different metals and semiconductors for improving the performance of catalysts, sensors, photoelectronic and energy conversion devices. Graphene is an ideal material which can be used for improving various metal oxide properties such as those of titania (TiO₂). TiO₂/graphene composites have shown excellent properties compared to bare TiO₂ in various applications. In high …

Water Treatment Using Advanced Oxidation Processes: Application Perspectives, Charles R. Gilmour

Electronic Thesis and Dissertation Repository

Advanced oxidation processes (AOPs) using hydroxyl radicals and other oxidative radical species are being studied extensively for removal of organic compounds from various waste streams. However, large scale applications of these highly effective technologies in water and wastewater treatment are still very limited due to cost and inadequate information about the resultant water quality. This study focuses on the evaluation of the upstream processing and downstream post treatment analysis of selective AOPs. In the first stage of research, the performance of a proprietary catalyst (VN-TiO₂) was compared with the industry standard P25 TiO₂, for the use …

Disinfection Of Low Uv Transmittance Fluids: Fundamentals And Applications, Housyn Mahmoud

Electronic Thesis and Dissertation Repository

Modern consumer demands for tasty, safe and healthier liquid foods and beverages. Chemical preservatives are usually added to foods to extend their shelf life and to protect against food borne pathogens. Application of ultraviolet (UV) light is gaining more attention as an alternative technology to disinfect fluids with low UV transmittance replacing classical chemical or thermal procedures due to growing negative public reaction over chemicals added. UV light irradiation has a positive consumer image as it is a physical non-thermal method efficient against microbial hazards, chemicals free cost effective and energy efficient methods and has been approved by regulatory agencies. …

Numerical Simulation Of Catalytic Ozone Decomposition Reaction In A Gas-Solids Circulating Fluidized Bed Riser, Lei Kong

Electronic Thesis and Dissertation Repository

Computational fluid dynamics (CFD) modeling of catalytic ozone decomposition reaction in a circulating fluidized bed (CFB) riser using iron impregnated FCC particles as catalyst is carried out. The catalytic reaction is defined as a one-step reaction with an empirical coefficient. Eularian-Eularian method with kinetic theory of granular flow is used to solve the gas-solids two-phase flow in the CFB riser. The simulation results are compared with experimental data, with the reaction rate modified using an empirical coefficient to provide better simulation results than the original reaction rate. Moreover, the particle size has great effects on the reaction rate. Studies on …

Solar And Visible Light Driven Photocatalysis For Sacrificial Hydrogen Generation And Water Detoxification With Chemically Modified Ti02, Pankaj Chowdhury

Electronic Thesis and Dissertation Repository

Photocatalysis is a recognized approach where light energy is employed to excite the semiconductor material producing electron/hole pair which eventually involves in the detoxification of pollutants and/or water splitting producing hydrogen. Existing photocatalysts suffer from poor activity or no activity in visible light irradiation which restricts them from solar light utilization. This work is focused on two key applications of photocatalysis (i) sacrificial hydrogen generation, and (ii) phenol degradation in visible and/or solar light. Platinum was loaded on TiO₂ photocatalyst by solar photo-deposition method. Eosin Y dye was used as a sensitizer for sensitization of platinum loaded TiO_{2 …}

Liquid Distribution From Industrial Scale Spray Jets In Fluidized Beds, Mohammadali Zirgachianzadeh

Electronic Thesis and Dissertation Repository

Liquid injections via spray nozzles are used in fluidized bed reactors such as Fluid Cokers. In such industrial processes, in order to maximize the product yields it is required to optimize the performance of the nozzle. Moreover parts of the bed might become defluidized, bogged, due to high liquid load. Then optimizing the performance of the nozzle and local bed bogging detection is the primary research objectives for this thesis work.

The first part of the research work was focused on developing a novel method employing electrical conductance to characterize the liquid distribution in a large scale fluid bed of …

Gasification Of Bio-Oils To Syngas In Fluidized Bed Reactors, Mohammad Latifi

Electronic Thesis and Dissertation Repository

Bio-fuels are renewable and clean which can be used as alternatives to fossil fuels or can be used in combination with them. Biomass is a main source of bio-fuels production: it is a renewable resource and its conversion to energy releases no net CO₂ to the environment.

Bio-oil, the valuable liquid product obtained from biomass through pyrolysis, may be either combusted to generate carbon-neutral electricity or converted to a synthesis gas from which chemicals or clean fuels can be produced. Producing bio-oil from biomass and then converting the bio-oil to syngas has several advantages: The bio-oil may be generated …

Photocatalytic Reactors For Air Treatment: Energy Efficiencies And Kinetic Modeling, Juan M. Garcia Hernandez

Electronic Thesis and Dissertation Repository

The energy efficiency of the photocatalytic conversion of gas-phase organic pollutants was studied using a redesigned and scaled up Photo-CREC-Air reactor. This photocatalytic unit has the unique feature of allowing an accurate analysis of the irradiation field by establishing macroscopic balances and in-situ measurements. The Photo-CREC-Air reactor operates in a batch mode with the photocatalyst supported by a stainless steel mesh being irradiated by 8 UV lamps. Kinetic modelling, Quantum Yields (QY) and Photochemical Thermodynamic Efficiency Factors (PTEF) were calculated using data for acetone , acetaldehyde and isopropanol photocatalytic degradation in ambient air utilizing a Degussa P25 …

Investigations Of Transesterification Of Canola Oil With Methanol And Ethanol For A New Efficient Method Of Biodiesel Production, Krupal Pal

Electronic Thesis and Dissertation Repository

Transesterification of vegetable oil to biodiesel is a multistep process affected by mass transfer, mixing and chemical reaction equilibrium. Attempts have been made in this study to overcome these limitations by gradually feeding oil into a pool of alcohol. This approach provided large excess of alcohol to allow reaction to proceed further as well as allowed easy dispersion of oil into the alcohol. As a result improved conversion of feed, higher yield and better product quality were achieved. Comparisons have been made with other methods to show the differences and highlight improvements. Reactions were conducted at various reaction conditions for …

Photocatalytic Degradation Of Phenolic Compounds In Water: Irradiation And Kinetic Modeling, Jesus Moreira Del Rio

Electronic Thesis and Dissertation Repository

Scaling up a photoreactor requires both knowledge of optical properties of the slurry medium and an established kinetic model. Measuring the scattering and absorption coefficients of particles suspended in water involves the use of specialized optical equipment, as well as the partial solution of the radiative transfer equation (RTE). In addition, modeling of the radiation field in photoreactors with complicated geometries offers special challenges.

On the other hand, most of the kinetic models (KM) for phenol photodegradation reported in the literature were obtained for a single organic chemical species only. In fact, neglecting all the intermediate species generated during the …

Supercritical Water Gasification Of Biomass & Biomass Model Compounds, Emhemmed A.E.A Youssef

Electronic Thesis and Dissertation Repository

Supercritical water gasification (SCWG) is an innovative, modern, and effective destruction process for the treatment of organic compounds. Hydrogen production using SCWG of biomass or waste feedstocks is a promising approach towards cleaner fuel production while simultaneously providing novel solution for hard-to-treat organic wastes. The main premise of this work was to experimentally examine real waste biomass sources i.e. hog manure and waste biomass model compounds using SCW gasification while examining various commercial catalysts. The improvement of the SCWG process requires an understanding of the waste/biomass reaction chemistry, and thus the knowledge of the reaction mechanisms is critically important for …

Nickel-Based Catalysts For Gasification Of Glucose In Supercritical Water, Muhammad Badrul Islam Chowdhury

Electronic Thesis and Dissertation Repository

Gasification of waste biomass to form hydrogen, H2, is a promising new source of green energy; while providing the additional benefit of treating challenging and hazardous waste streams that pollute the environment. Gasification of biomass in supercritical water (SCW) offers an attractive alternative to avoid the energy intensive drying process. In this approach, biomass is hydrolyzed by water into smaller molecules in the presence of a suitable catalyst. This study was aimed at developing an alumina supported nickel based non-noble metal catalyst suitable for biomass gasification in SCW. A lack of detailed characterization on fresh and spent catalysts in SCW …

Catalytic Steam Gasification Of Biomass Surrogates: A Thermodynamic And Kinetic Approach, Enrique Salaices

Electronic Thesis and Dissertation Repository

Gasification of biomass is an environmentally important technology that offers an alternative to the direct use of fossil fuel energy. Steam gasification is getting increased attention as a potential source of renewable energy since it produces a gaseous fuel suitable for industrial applications in highly efficiently power/heat energy production, transport fuel, and as a feedstock for chemical synthesis. Furthermore, catalytic steam gasification has other advantages hence (i) it produces a gas with higher heating value; (ii) it reduces the diluting effect of N2 from air; (iii) it eliminates the need of cleaning, upgrading and/or conditioning the product gas for certain …