Chemical Engineering Commons^™

Synthesis And Reactivity Of Hy Zeolite-Supported Rhodium Complexes, Artem D. Vityuk

Theses and Dissertations

The growing interest in the design of heterogeneous analogs of highly active and selective homogeneous catalysts prompted researchers to invest significant efforts in understanding of synthetic pathways, structure, and reactivity of supported single-site metal complexes. Synthesis of catalytically active organometallic species on solid supports with properties resembling those of their homogeneous counterparts could offer the opportunities to perform efficiently the solution organic reactions by utilizing flow instead of batch reactors. In this regard, rhodium carbonyl complexes and their derivatives are viewed as very attractive candidates for heterogenization due to their extensive application as catalysts for variety of industrially important reactions. …

Bioremediation Of Hydrocarbons Via Geobacillus, Amanda T. Lade

Honors Theses and Capstones

Hydrocarbon remediation is a vital aspect of environmental cleanup, especially in soil and groundwater to ensure the health and safety of the public’s drinking water. A possible solution to this contamination is bioremediation, the use of microorganisms to degrade pollutants. This research analyzes the effectiveness of Geobacillus as a hydrocarbon degrader for the use of bioremediation. Twelve strains were identified from oil-contaminated sources and grown in minimal media with crude oil as the carbon source. Growth was observed in the crude oil samples, demonstrating the possibility of bioremediation of hydrocarbons via Geobacillus.

Facile Fabrication Of Mesostructured Zn2sno4 Based Anode Materials For Reversible Lithium Ion Storage, Sai Karthik Karthik Addu

Wayne State University Theses

Increase in all electric and hybrid car sales from Electric drive transportation association show that Lithium-ion batteries stands as a promising option for these vehicles. Hence improving these batteries is the objective of this thesis. We try to improve the electrode material by using unique structures and coating carbon layers on the material.

We chose Zinc tin oxide (ZTO) as it has been shown in literature to be a good oxide for batteries. We tried improving it by making new Rubik-cube like microstructure of it and more interestingly coating a layer of carbon on it. We could show from our …

Phenol Deoxygenation Over Hydrotreating Catalysts, Madelyn R B Ball

Honors Theses and Capstones

Phenol deoxygenation has been investigated as a model reaction for the deoxygenation of fatty acid methyl esters in biodiesel. Hydrodeoxygenated biodiesel is a drop-in fuel for petroleum diesel, and is a premium diesel with a high cetane number. As the first step in this research, two molybdenum catalysts were prepared, characterized and tested in a small-scale reactor. These catalysts were found to produce small amounts of benzene and cyclohexanol in the product stream, and confirmed the activity of the catalyst. A commercial cobalt molybdenum catalyst (Harshaw HT-400) was also tested and benzene, cyclohexanol, and cyclohexane were identified as products. Future …

Co2 Char Gasification Rates Of Sawdust, Switchgrass, And Corn Stover In A Pressurized Entrained-Flow Reactor, Thomas H. Fletcher, Aaron D. Lewis, Emmett G. Fletcher

Faculty Publications

An entrained-flow flat-flame burner reactor was used to measure apparent CO2 gasification rates of near-spherical biomass chars of poplar sawdust, switchgrass, and corn stover using particle residence times1258−1891 K and 6.1− 13.5 atm, respectively. A new method was developed to produce near-spherical particles from nonspherical biomass chars. The apparent CO2 gasification rates for the three biomass chars with mean diameters near 100 μm were fit to a global first-order model, and the optimal kinetic parameters are reported. The measured gasification rate of poplar sawdust was about 3.9 times faster than that of switchgrass char, but only about 20% faster than …

Application Of L-Systems To Geometrical Construction Of Chamise And Juniper Shrubs, Dallan R. Prince, Marianne E. Fletcher, Chen Shen, Thomas H. Fletcher

Faculty Publications

Improved models of fire spread and fire characteristics are desired for live shrub fuels, since the majority of existing research efforts focus on either dead fuel beds or crown fires in trees. Efforts have been made to improve live fuel modeling, including detailed studies of individual leaf combustion, with results incorporated into a shrub combustion model for broadleaf species. However, this approach was not well-suited to non-broadleaf shrubs since their fuel consists of long needle-covered branches rather than easily discretized leaves. Methods were therefore developed to simulate the branching structure of chamise (Adenostoma fasciculatum) and Utah juniper (Juniperus osteosperma). The …

Simulation Of The Evolution Of Pressure In A Lignite Particle During Pyrolysis, He Yang, Sufen Li, Thomas H. Fletcher, Ming Dong, Weishi Zhou

Faculty Publications

The evolution of pressure in a lignite particle during pyrolysis was simulated on the basis of the gas motion equation in porous media and considering the Klinkenberg effect. The chemical percolation devolatilization (CPD) model was used to describe pyrolysis. The pore diameter in the particle is close to the average free path of volatile gas molecules; therefore, the solid phase restrains the movement of gas. Because flow out of the particle is restricted, the internal pressure rises. The internal pressure first increases and then decreases during pyrolysis, and the evolution is influenced by heating conditions. The pressure rise is larger …

Characterization Of Macromolecular Structure Elements From A Green River Oil Shale, I. Extracts, Mark S. Solum, Charles L. Mayne, Anita M. Orendt, Ronald J. Pugmire, Jacob Adams, Thomas H. Fletcher

Faculty Publications

This paper is the first of two associated papers describing the structural details of three sections of an oil shale core taken at the Skyline 16 mine in the Utah Uinta Basin. Bitumen was extracted from the shale using methanol/dichloromethane. Kerogen was isolated from the shale, using a nine-step extraction procedure using HCl and HF. Bitumen samples from the three cores were analyzed using high-resolution ¹³C NMR liquid-state spectroscopy, showing carbon aromaticities of 7%−11%. Aliphatic carbons were dominated by methylene structures, with average aliphatic chain lengths of 24 carbons. The three parent shales and the demineralized kerogens were each …

Differences In Burning Behavior Of Live And Dead Leaves, Part 1: Measurements, Thomas H. Fletcher, Dallan R. Prince

Faculty Publications

Burning behaviors of individual live and dead leaves were measured in a well-instrumented, well-controlled flat-flame burner. Manzanita (Arctostaphylos glandulosa) branches were harvested from the Chaparral near Riverside, California. Leaves were conditioned to several moisture contents. Two “live” (i.e., not fully dried) groups remained above the fiber saturation point at 34% moisture content (MC; dry basis) and 63% MC. Two “dead” groups were dried to about 4% MC, and one was rehydrated back up to 26% MC. Distinct plateaus in surface temperatures at 175◦C were observed while burning live leaves, but dead leaves showed weaker plateaus, if any. Evidence of high …

Domain Engineering Of Physical Vapor Deposited Two-Dimensional Materials, Tarek Alam, Baoming Wang, Raghu Pulavarthy, M. Amanul Haque, Christopher Muratore, Nicholas R. Glavin, Ajit K. Roy, Andrey A. Voevodin

Chemical and Materials Engineering Faculty Publications

Physical vapor deposited two-dimensional (2D) materials span larger areas compared to exfoliated flakes, but suffer from very small grain or domain sizes. In this letter, we fabricate freestanding molybdenum disulfide (MoS2) and amorphous boron nitride (BN) specimens to expose both surfaces. We performed in situ heating in a transmission electron microscope to observe the domain restructuring in real time. The freestanding MoS2 specimens showed up to 100× increase in domain size, while the amorphous BN transformed in to polycrystalline hexagonal BN (h-BN) at temperatures around 600 °C much lower than the 850–1000 °C range cited in the literature.

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 …

Comparison Of Role Of Nano-Sized Extra Supports On Pt-Based Catalyst For Propane Dehydrogenation And Wox-Based Catalyst For Propene Metathesis, Adisak Guntida

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this thesis, the role of nano-sized extra supports was studied. The different types of nano-sized supports (ZrO2, TiO2, Al2O3, and SiO2) were physically mixed with WOx-based catalysts for propene metathesis reaction and Pt-based catalysts for propane dehydrogenation reaction as extra support. The dispersions of active sites were improved in both metathesis and dehydrogenation catalysts by the addition of nano-sized extra supports. The migration of active sites from the main catalyst onto the nano-sized extra support during thermal treatment via thermal spreading is a key for this improvement. The surface energy of nano-sized extra support and concentration of metal active …

The Effects Of Additives In Ethylene Glycol Based Lubricant On Slider Lapping Process, Patara Paranusorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Lapping process is a key technology in magnetic recording head manufacturing process. Thin film of metal alloys and metal oxides are fabricated on ceramic substrate called wafer to create the recording heads. In order to control surface properties of the recording head, the precise chemical mechanical nano grinding process is used. In this process the recording heads are treated to achieve the designed surface properties by using lubricants to control the selectivity of material removal. The aim of this study was to determine the effects of additives in ethylene glycol based lubricant on the selectivity of material removal of slider …

Polydopamine As Active Templates For Fabrication Of Conductive Of Copper Line Pattern, Raweewan Thongprachan

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this research, copper conductive patterns were fabricated on polyethylene terephthalate (PET) substrate by combination of spray drying of polydopamine nanoparticles, and consequently electroless plating process. The polydopamine nanoparticle ink was synthesized by self-polymerization of dopamine hydrochloride at different initial pH 8, 8.5, 9 and 10. The patterns were deposited by site-selective Cu electroless plating process on top of the PDA pattern at the controlled temperature 30 C. The effects of plating time in electroless plating and storage time were studied. Moreover, the adhesion and aspect ratio were also investigated. The conductive lines fabricated were characterized by two-point probe measurement, …

Design Of Plantwide Control Structure Of A Small-Scale Concentrated Solar Power Process Cooperated With Organic Rankine Cycle And Thermal Storage Systems, Pathawut Bua-Ngam

Chulalongkorn University Theses and Dissertations (Chula ETD)

This work presents a study on control system design of a small-scale electricity generation process for household applications using plantwide control technique. The process are of three sections including parabolic trough solar collector, thermal energy storage, and organic Rankine cycle system. Synthetic oil Dowtherm©A and acetone were chosen as heat transfer fluid and working fluid, respectively. In terms of control objectives, the control structure can keep the process operation at maximum efficiency and response the required work load. Control performance of the control structure proposed is tested under various disturbance changes by using dynamic simulator (SIMSCI DYNSIM). The scenarios investigated …

Coke Deposition On Wox/Sio2 Catalyst Physically Mixed With Magnesium Oxide For Metathesis Reaction Of Ethylene And 2-Butene, Thidaya Thitiapichart

Chulalongkorn University Theses and Dissertations (Chula ETD)

The presence of MgO physically mixed with silica supported tungsten oxide catalysts was investigated in metathesis reaction using ethylene and trans-2-butene as feeds. Adding MgO could enhance the conversion of trans-2-butene and propylene yield, comparing with a catalyst mixed with SiO2 as a referenced one. However, the presence of MgO with silica supported tungsten oxide catalysts surprisingly elevated the coke deposition. The coke precursor was formed by MgO from isomerization of undesired products like C5+ and moved to deposit on the acid sites of silica supported tungsten oxide catalysts which is a coke site of the catalysts. Furthermore, the distance …

Effect Of Particle Size Of Silica And Sio2/Mao Ratios On Heterogeneous Metallocene Catalyst Performance And Polyethylene Properties, Chalermpong Ramrauytham

Chulalongkorn University Theses and Dissertations (Chula ETD)

The metallocene catalyst is one of the catalysts, used to produce polyethylene having narrow molecular weight distribution. So, the metallocene catalyst has been interesting in many researches. To activate metallocene catalyst in ethylene polymerization, methylaluminoxane has been used as cocatalyst because it makes high activity for metallocene catalyst. However, both of them are in solution form, which make fouling in reactor and not good morphology in slurry ethylene polymerization. This problem has been solved by heterogeneous metallocene catalyst. Silica is widely used for heterogeneous metallocene catalyst because of high surface area and good morphology. This research is aimed to study …

The Effect Of Methylaluminoxane Synthesis Conditions By Non-Hydrolysis Route To Ethylene Polymerization On Supported Metallocene Catalyst, Tareeya Chansaard

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this study, the synthesis conditions of methylaluminoxane by non-hydrolysis route were investigated. Effect of these parameters on the formation of methylaluminoxane which was used for the efficient activator for metallocene catalyst in ethylene polymerization, was focused. Benzoic acid and TMA were used as the reactants in this route. In the first part, the various TMA:BA ratios were investigated. It was found that TMA:BA= 2.4 was the suitable ratio to form MAO, which had the highest conversion of initial TMA and high activity. In the second part, the holding time of reaction was studied to improve the formation of MAO …

Synthesis Of Copper (Core) - Tin (Shell) Nanoparticles By Modified Polyol Process And Replacement Reaction, Bongkot Sakunchangsanoh

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aimed to prevent the oxidation of copper nanoparticles by protecting them with tin as a core-shell structure. Copper (core) nanoparticles were synthesized though modified polyol process and tin (shell) was synthesized though replacement reaction by using glycerol as polyol liquid, sodium phosphinate monohydrate as a reducing agent and thiourea as a surfactant. The effects of sodium phosphinate monohydrate concentration, thiourea concentration and copper ion to tin ion ratio were investigated. The synthesized-nanoparticles were characterized by transmission electron microscopy (TEM), X-ray diffraction techniques (XRD), energy dispersive X-ray spectrometer (EDX), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and differential scanning …

Effect Of Modified Tungsten Based Metathesis Catalysts By Ion Exchange Method With Alkali Metal Group 1a Solutions, Kritsada Pipitthapan

Chulalongkorn University Theses and Dissertations (Chula ETD)

The effect of sodium hydroxide and potassium hydroxide solutions in ion exchange with the WO3/SiO2 catalysts was investigated in the metathesis of trans-2-butene and ethylene for propylene production. The concentrations of alkali solutions used ion exchange were vaired from 0 to 6.75 mmol/L. The results suggested that the active center precursors of the metathesis were diminished at high concentrations of alkali solutions (>2.25 mmol/L). On the other hand at the low concentrations (