Chemical Engineering Commons^™

Effect Of Citric Acid On Hydrodesulfurization Activity Of Dibenzothiophene And 4,6 Dimethyldibenzothiophene Over Como Catalyst On Al2o3-Zro2 Support, Pawinee Sintarako

Chulalongkorn University Theses and Dissertations (Chula ETD)

The effect of citric acid on the HDS activity of DBT and 4,6 DMDBT on CoMo/γ-Al2O3-ZrO2 catalysts has been investigated. It has been found that the CoMo/γ-Al2O3-ZrO2 physically mixed with 10wt.% of ZrO2 shows the highest HDS conversion of DBT in the presence of pyridine. The addition of ZrO2 as a secondary support obviously suppresses the influence of pyridine on HDS activity of DBT over CoMo/γ-Al2O3 based catalyst. The synergistic benefits of ZrO2 and citric acid on HDS activity of DBT and 4,6 DMDBT over CoMo/γ-Al2O3 catalyst are not found. The modification of CoMo/γ-Al2O3 catalyst by citric acid can inhibit …

Natural Selectivity Of Nickel And Vanadium In Crude Oil, Olienka P. De La O Fernandez

Open Access Theses & Dissertations

Nickel and Vanadium have always been found in crude oil all around the world. The metal content is found mainly in porphyrin structures in the asphaltene fraction of the petroleum. In order to determine the reason for this natural preference, a set of experiments testing thermodynamics, kinetics, and other factors were performed. Candidate metalloporphyrins containing Vanadyl, Chromium, Iron, Nickel, Copper and Zinc were analyzed through chemical reactions characterized using Silica Column Chromatography, HPLC, MS and UV-Visible. Theoretical analysis of the stability of metalloporphyrins was conducted using DFT/NRLMOL for computational calculation. The analysis of all factors leads us to conclude that …

Design Of Three Different Particle Size Distributions In Silver Paste Through Computer Simulation For Higher Electrical Conductivity, Kyungdeok Jang

Open Access Theses & Dissertations

In the field of printed electronics technology, researchers have tried to print highly conductive electrodes with fine width and height in order to manufacture high performance devices.

The purpose of this research is to print particle monolayer silver patterns which have better electrical conductivity than existing ones. The key idea of this experiment is to analyze silver inks with different sized particles. Let us consider a particle monolayer pattern printed with silver ink consisting of mono-sized particles. Inside of the pattern, there are some vacant spaces between the particles, which can lead to low electrical conductivity and discontinuity of the …

Poroelastic Inhomogeneities: Applications In Reservoir Geomechanics, Houman Bedayat

LSU Doctoral Dissertations

The scarce amount of conventional hydrocarbon reservoirs and increase of fuel consumption in the world have made production from unconventional hydrocarbon resources inevitable. Because of the low permeability of unconventional formations, fractures are the main paths for the fluid to flow. Therefore, detailed knowledge of the size, orientation, and permeability of the fracture systems are essential for reservoir engineers. Permeability of the fractures is function of their volume and opening, and stress and fluid pore pressure distribution in the formation. Since reservoir pressure may change over the production life of the reservoir, studying stress redistribution and mechanical behavior of the …

Catalytic Active Site, Mechanistic And Kinetic Studies Of Dry (Co2) Reforming Of Methane Over Lanthanum Zirconate (La2zr2o7) Pyrochlores, Devendra Pakhare

LSU Doctoral Dissertations

Dry (CO2) reforming of CH4 (DRM) produces commercially important synthesis gas (H2 and CO) with H2/CO ≤ 1, which can be used for synthesis of higher alkanes and oxygenates. DRM is highly endothermic and requires temperatures as high as 800°C-1000°C to attain high equilibrium conversions. A major problem associated with DRM is catalyst deactivation due to carbon deposition. Thus it is imperative that the catalyst used for DRM must resist deactivation due to sintering and carbon deposition. DRM is well studied in the literature over various catalysts, however, there is no literature, except the Ashcroft (1993) article, for DRM over …

Continuous Reservoir Modeling Updating By Integrating Experimental Data Using An Ensemble Kalman Filter, Ting Sun

LSU Doctoral Dissertations

The continuous researvoir model updating is widely used to calibrate reservoir simulation models to production data, but many challenges remain. First, few real field data are available to test the new history matching method, and most of the data sets are synthetic cases. Second, computational cost may be high when using non-Gaussian priors or nonlinear models. Third, with large complex models, the simulation runs and history matching method require huge memory allocations. This dissertation achieves a continuous reservoir model updating workflow with a meter-scale , two-phase flow experiment. Both production and seismic data are collected in the experiment. Because the …

Less Is More: Long-Term In Vitro Exposure To Low Levels Of Silver Nanoparticles Provides New Insights For Nanomaterial Evaluation, Kristen K. Comfort, Laura K. Braydich-Stolle, Elizabeth I. Maurer, Saber M. Hussain

Chemical and Materials Engineering Faculty Publications

In view of the vast number of new nanomaterials (NMs) that require testing and the constraints associated with animal models, the majority of studies to elucidate nanotoxicological effects have occurred in vitro, with limited correlation and applicability to in vivo systems and realistic, occupational exposure scenarios.

In this study, we developed and implemented a chronic in vitromodel coupled with lower, regulatory dosages in order to provide a more realistic assessment of NM-dependent consequences and illuminate the implications of long-term NM exposure. When keratinocytes were exposed to 50 nm silver nanoparticles (Ag-NPs), we determined that chronically dosed cells operated …

Image-Based Pore-Scale Modeling Of Inertial Flow In Porous Media And Propped Fractures, Yijie Shen

LSU Doctoral Dissertations

Non-Darcy flow is often observed near wellbores and in hydraulic fractures where relatively high velocities occur. Quantifying additional pressure drop caused by non-Darcy flow and fundamentally understanding the pore-scale inertial flow is important to oil and gas production in hydraulic fractures. Image-based pore-scale modeling is a powerful approach to obtain macroscopic transport properties of porous media, which are traditionally obtained from experiments and understand the relationship between fluid dynamics with complex pore geometries. In image-based modeling, flow simulations are conducted based on pore structures of real porous media from X-ray computed tomographic images. Rigorous pore-scale finite element modeling using unstructured …

Modeling Of Foam Flow In Porous Media For Subsurface Environmental Remediation, Seungjun Lee

LSU Doctoral Dissertations

Among numerous foam applications in a wide range of disciplines, foam flow in porous media has been spotlighted for improved/enhanced oil recovery processes in petroleum-bearing geological formations and shallow subsurface in-situ NAPL (non-aqueous phase liquid) environmental remediation in contaminated soils and aquifers. In those applications, foams are known to reduce the mobility of gas phase by increasing effective gas viscosity and improve sweep efficiency by mitigating subsurface heterogeneity. This study investigates how surfactant/foam process works fundamentally for environmental remediation purpose by using MoC (Method of Characteristics) based foam modeling and simulation techniques. It consists of two main parts: Part 1, …

Quantifying Phase Configuration Inside An Intact Core Based On Wettability Using X-Ray Computed Tomography, Dinara Dussenova

LSU Master's Theses

The ability to evaluate rock and fluid properties on the order of a few microns opens new areas in reservoir engineering and reservoir simulation. Multiple studies have been done on the application of x-ray computed tomography (microCT) for the pore-scale evaluation of fluid interfaces and rock-fluid interaction. A majority of the fluid flow governing interactions occur at the pore scale level and is usually overseen on large reservoir scales. Hence, it is important to carefully investigate such interactions. Multi-fluid-phase distribution and interaction of two immiscible fluids such as oil and water is one of the most important and constantly investigated …

Applications Of Cfd Simulations On Studying The Multiphase Flow In Microfluidic Devices, Yuehao Li

LSU Doctoral Dissertations

Microfluidics has been extensively investigated as a unique platform to synthesize nanoparticles with desired properties, e.g., size and morphology. Compared to the conventional batch reactors, wet-chemical synthesis using continuous flow microfluidics provides better control over addition of reagents, heat and mass transfer, and reproducibility. Recently, millifluidics has emerged as an alternative since it offers similar control as microfluidics. With its dimensions scaled up to millimeter size, millifluidics saves fabrication efforts and potentially paves the way for industrial applications. Good designs and manipulations of microfluidic and millifluidic devices rely on solid understanding of fluid dynamics. Fluid flow plays an important role …

Experimental Assessment Of Expandable Casing Technology As A Solution For Microannular Gas Flow, Darko Kupresan

LSU Master's Theses

Microannular gas flow in the wellbore is known to be one of the major reasons for Sustained Casing Pressure (SCP). Low success rate (under 50%) of costly remedial cementing operations and increasing difficulty in sealing off problematic areas motivated the industry to look for more practical remediation solutions. Expandable casing technology is one of those new proposed techniques. A bench-scale physical model tested the potential of expandable casing technology for remediation of microannular gas migration. The composite samples with pipe-inside-pipe cemented annulus were designed to simulate a wellbore system including a pre-manufactured microannulus on the inner pipe/cement interface. Multi-rate flow-through …

Sinking Of Hydrocarbon Mixtures Due To Evaporative And/Or Dissolution Weathering On The Surface And Submerged In Water, Christopher Clayton Stevens

LSU Master's Theses

The appearance of on-bottom oil following surface and deep water spills has been well documented. A very likely, yet sparingly studied, cause of this phenomenon is the evaporation and/or dissolution of the light constituents of the mixture, leaving a heavy residual fraction that may sink. A binary mixture of a light, volatile/soluble and a heavy, nonvolatile/insoluble component was used in numerous laboratory experiments, with binary and multi-component mixtures, to confirm this event is possible. A binary-component model was developed based on the law of conservation of mass for “oil” spilled on the surface to predict sinking time requirements based on …

Experimental Assessment Of Cement Integrity Under Thermal Cycle Loading Conditions In Geopressured Geothermal Reservoirs, Kolawole Saheed Bello

LSU Master's Theses

The number of well integrity issues increase as wells are exposed to severe downhole conditions and have longer lifetimes. Techniques for heat extraction from geopressured geothermal reservoirs involve production of hot water and injection of cold water which expose downhole materials to harsh cyclic temperature variations. Heating and cooling make the cement expand and contract as a result of thermal expansion. This volumetric change can influence cement sheaths causing them to fail. Failure of annular cement sheaths can introduce well integrity issues and subsequently lead to sustained casing pressure. This study measures the effect of cyclic thermal loading of cement …

Investigating Different Coding Environments For Simplified Reservoir Characterization Models, Atheer Mohammad Al Attar

LSU Master's Theses

Reservoir characterization is one of the most important tasks that determines the recovery plan for a specific reservoir. This process incorporates a significant amount of data acquisition and processing to finally develop an acceptable model that matches the production history and can forecast the future production behavior. The model also should be able to adapt to changes along the way: adding or removing producers or injectors, changing the injection pattern, recompletions and converting wells are all examples of possible changes that are common in the oil and gas industry. Usually these changes are modeled by running field-scale simulations and providing …

Effects Of Different Preparation Methods On Structure And Catalytic Behavior Of Iron-Based Catalyst Via Fischer Trospch Synthesis Of Biomass-Derived Syngas, Khietlethanh Mai

LSU Master's Theses

Lignocellulosic biomass is a promising feedstock for producing liquid fuels via synthetic gas (syngas) and Fischer Tropsch Synthesis (FTS). Syngas produced from biomass has low H2/CO ratio (~0.7/1) and high concentration of CO2. In order to produce liquid hydrocarbons from this syngas, a catalyst must be used to increase the H2/CO ratio to 2 or higher. This catalyst must also have reasonable reverse water-gas-shift (R-WGS) activity in a CO2 rich environment. In this study, two 100Fe/4Cu/4K/6Zn were prepared using coprecipitation (Cat_C) and impregnation (Cat_I) methods. The effects of these preparation methods on the catalyst structure and FTS performance in biomass …

Removal Of Sustained Casing Pressure By Gravity Displacement Of Annular Fluid, Efecan Demirci

LSU Master's Theses

Sustained Casing Pressure (SCP) is the undesirable casing head pressure of a well annulus that rebuilds when bled-down. As the conventional methods for SCP removal using rigs are expensive, there is a need for improvement. Annular intervention for replacing the fluid above the leaking cement with a heavier fluid to stop gas migration is a solution for SCP removal; however, previous attempts failed due to miscibility of injected fluids. Using hydrophobic heavy fluids for the purpose is a newly proposed technique to the technology. Potential of theoretically selected and produced immiscible heavy fluids are investigated in characterized annular fluids. A …

Investigation Of Dimensionality-Dependent Foam Rheological Properties By Using Mechanistic Foam Model, Woochan Lee

LSU Master's Theses

A numerous laboratory and field tests revealed that foam can effectively control gas mobility, improve sweep efficiency, and increase oil production, if correctly designed. It is believed that there is a significant gap between small laboratory-scale experiments and large field-scale tests because of two main reasons: (i) typical laboratory flow tests are conducted in linear systems, while field-scale foam EOR processes are performed in radial (or spherical partly) systems in general; and (ii) through the complicated in-situ lamella creation and coalescence mechanisms and non-Newtonian behavior, foam rheology is thought to depend on geometry and dimensionality and, as a result, it …

Analysis Of Microseismic Events Associated With Hydraulic Fracture Propagation, Chennu Fan

LSU Master's Theses

Previous practice to determine the source mechanism of microseismic events associated with hydraulic fracture typically includes only far-field terms in moment tensor inversion. The intermediate-field terms and near-field term are normally ignored because of increased complexity in the calculation. Source-receiver distances in hydraulic fracturing are usually 1000 ft and the effects of near and intermediate-field terms are still unknown. We perform a study to improve the precision of the source mechanism by including the intermediate-field term in moment tensor inversion. We find that the intermediate-field term contributes 1/3 of the signal amplitude when the source-receiver distance is 1000 ft. The …

Effect Of Process Mixing On The Size Distribution And Mean Diameter Of The Thiol-Triacrylate Microcapsules, Rubaiyet Abedin

LSU Master's Theses

An important limitation in the development of the microparticles is the difficulty to develop a precise size distribution. Microparticles have a wide spread applicability in different fields including medical, pharmaceutical, textile, cosmetics, pesticide, printing industry, etc. The large and growing impact of microencapsulation in different fields of technology has made this process important. Microparticle size is a primary determinant of control release mechanism and the reaction kinetics and also impacts the allowable routes of administration, The main objective of this research work is to evaluate the effect of the process mixing on the size and size distribution of the trithiol-triacrylate …