Chemical Engineering Commons^™

Catalyst Regeneration/Wax Solubility, Steven Gale Smith, Dr. Calvin Bartholomew

Journal of Undergraduate Research

Catalysts are widely used throughout many industries to decrease reaction time and make processes economically favorable. In the synthetic fuels industry a catalyst is used to convert carbon monoxide gases (CO) to hydrocarbon liquids (CnH2n+2). In this process, the catalyst becomes coated with the heavier hydrocarbon products. This coating is a wax and deactivates the catalyst (inhibits the catalyst from reacting). The catalyst is currently one of the largest expenses for this process and prevents the process from being competitive with natural fuels. Hence, a method to remove the waxes from the catalysts was studied. The process of removing the …

Is Dna A Good Model Polymer?, Douglas R. Tree, Abhiram Muralidhar, Patrick S. Doyle, Kevin D. Dorfman

Faculty Publications

The details surrounding the crossover from wormlike-specific to universal polymeric behavior has been the subject of debate and confusion even for the simple case of a dilute, unconfined wormlike chain. We have directly computed the polymer size, form factor, free energy, and Kirkwood diffusivity for unconfined wormlike chains as a function of molecular weight, focusing on persistence lengths and effective widths that represent single-stranded and double-stranded DNA in a high ionic strength buffer. To do so, we use a chain-growth Monte Carlo algorithm, the pruned-enriched Rosenbluth method (PERM), which allows us to estimate equilibrium and near-equilibrium dynamic properties of wormlike …

Computer Simulated Multi-Component Aerosol Thermodynamics And Chemistry, Eric Halpenny, Dr. Larry Baxter

Journal of Undergraduate Research

Aerosols are small (sub-micron) particles formed mainly in combustion processes by the vaporization and subsequent re-condensation of volatile, inorganic compounds. Cloud formation is an example of an aerosol process. However, unlike clouds, most aerosol-generating processes produce negative effects on both the process that forms them and the environment. Aerosols represent major process and emissions issues for essentially all systems employing low-grade fuel (coal, biomass, and black liquor). An accurate, predictive understanding of aerosol formation and chemistry would substantially improve the efficiency and environmental performance of many processes.

Streamline-Based Novel Dynamic Grid Reservoir Simulation, Bradley C. Bundy, Dr. Larry Lin Baxter, Dr. Hugh Bradley Hales

Journal of Undergraduate Research

Oil is one of the most important commodities we have. It provides energy, transportation, and chemicals to provide a better life for mankind. However, it is a depleting recourse that is getting harder and harder to find and recover. Simulation techniques have been used for many years to determine the best place to drill wells and when it is the best time economically to stop pumping slurry. Unfortunately, current simulators often take weeks to months to complete and are only an estimate of what may occur. The industry is currently limited by slow, inaccurate simulation techniques. Faster simulators with increased …

Three-Dimensional Cfd Model Of A Reacting Char Bed, Michael M. Choi, Dr. Larry Baxter

Journal of Undergraduate Research

Black liquor is a recycled byproduct formed during the pulping of wood in the papermaking industry. In this process, cellulose is used to form paper fibers while lignin is combined with water and chemical used for the extraction to form black liquor. Black liquor is burned in a recovery boiler to produce steam and electricity and is the second largest renewable energy next to hydro energy.

Bacteriorhodopsin-Based Sensors, Craig Friedrich, Donald Lueking, Mark Griep

Michigan Tech Patents

A sensor comprising a membrane containing bacteriorhodopsin. In one embodiment, the sensor comprises a layer of purple membrane between a first and a second electrode, wherein the electrodes are connected to a circuit such that a signal is produced when a charge is transferred across the membrane. In another embodiment, the sensor comprises a field effect transistor with a layer of purple membrane deposited on the gate. The layer of purple membrane may be further functionalized by adding fluorophores to the layer of purple membrane. The fluorophores may be deposited adjacent to the layer of purple membrane, or the fluorophores …

Analysis Of Electrical Current As An Agent For Bacterial Killing, Taylor Turner, Dr. William Pitt

Journal of Undergraduate Research

Previously it has been shown that antibiotic killing of bacteria, especially biofilms, can be enhanced by various non-invasive treatments. Low-level electric current has been shown to increase killing of Streptococcus gordonii biofilms when applied during treatment with gentamicin.1 Others have partially tested the feasibility of electrically killing bacteria on prosthetic joints.2 Ultrasonic exposure has also been shown to increase killing of bacterial biofilms.3 Our group previously observed that ultrasound increased the transport of gentamicin through biofilms.4 Electrical treatment of S. gordonii in the absence of gentamicin also generates a 1.9 log reduction in biofilm cell counts.1 Our previous findings showed …

An Experimental Study Of The Mechanisms Of Fine Particle Deposition In Kraft Recovery Boilers, Larry Baxter

Journal of Undergraduate Research

Experiments on the deposition of fume (submicron) and particles produced during black liquor combustion indicate that deposit mass accumulation increases linearly with time and is independent of temperature gradient – results that are inconsistent with the classical explanation of thermophoresis as a driving force. Temperature-controlled, cylindrical probes in cross flow collected particles for periods up to ten hours and at Reynolds and Stokes numbers comparable to those in commercial boilers. Fume deposits appear dense and smooth to the unaided eye but under microscopic examination prove to have filamentary structures, with individual filaments radiating from the probe center and consisting of …

Cell-Free Unnatural Amino Acid Incorporation With Alternative Energy Systems And Linear Expression Templates, Prashanta Shrestha, Mark Thomas Smith, Bradley Charles Bundy

Faculty Publications

Site-specific incorporation of unnatural amino acids (uAAs) during protein synthesis expands the proteomic code through the addition of unique residue chemistry. This field provides a unique tool to improve pharmacokinetics, cancer treatments, vaccine development, proteomics and protein engineering. The limited ability to predict the characteristics of proteins with uAA-incorporation creates a need for a low-cost system with the potential for rapid screening. Escherichia coli-based cell-free protein synthesis is a compelling platform for uAA incorporation due to the open and accessible nature of the reaction environment. However, typical cell-free systems can be expensive due to the high cost of energizing …

Encapsulation Of Supported Metal Nanoparticles With An Ultra-Thin Porous Shell For Size-Selective Reactions, Zeyu Shang, Rajankumar L. Patel, Brian W. Evanko, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

A novel nanostructured catalyst with an ultra-thin, porous shell obtained from the thermal decomposition of an aluminum alkoxide film deposited by molecular layer deposition for size-selective reactions was developed. The molecular sieving capability of the porous metal oxide films was verified by examining the liquid-phase hydrogenation of n-hexene versus cis-cyclooctene. © 2013 The Royal Society of Chemistry.

A Tensile Deformation Model For In-Situ Dendrite/Metallic Glass Matrix Composites, J. W. Qiao, T. Zhang, Fuqian Yang, P. K. Liaw, S. Pauly, B. S. Xu

Chemical and Materials Engineering Faculty Publications

In-situ dendrite/metallic glass matrix composites (MGMCs) with a composition of Ti₄₆Zr₂₀V₁₂Cu₅Be₁₇ exhibit ultimate tensile strength of 1510 MPa and fracture strain of about 7.6%. A tensile deformation model is established, based on the five-stage classification: (1) elastic-elastic, (2) elastic-plastic, (3) plastic-plastic (yield platform), (4) plastic-plastic (work hardening), and (5) plastic-plastic (softening) stages, analogous to the tensile behavior of common carbon steels. The constitutive relations strongly elucidate the tensile deformation mechanism. In parallel, the simulation results by a finite-element method (FEM) are in good agreement with the experimental findings and theoretical calculations. The present study gives a mathematical model to clarify …

Spectroscopic And Kinetic Characterization Of Catalytic Materials For The Conversion Of Biomass-Derived Compounds, Paul James Dietrich

Open Access Dissertations

As economies look to transition away from petroleum for social, economic, and political reasons, biomass will continue to attract attention as a renewable feedstock for the fuels and chemicals industry. In order to turn biomass into end use fuels and chemicals, the oxygen content must be lowered significantly, requiring large hydrogen inputs. For these processes to be completely renewable, the hydrogen must come from biomass or biomass-derived compounds. In this work, catalysts for the aqueous phase reforming (APR) of biomass-derived sugars were characterized by a combination of reaction kinetics, X-ray spectroscopy, electron microscopy, and theoretical computation to determine the active …

An Analysis Of The Impact Of Storage Temperature, Moisture Content & Duration Upon The Chemical Components & Bioprocessing Of Lignocellulosic Biomass, Arun Athmanathan

Open Access Dissertations

The successful utilization of lignocellulosic biomass as a feedstock for fuels and chemicals necessitates storage for 2-6 months. It is correspondingly important to understand the impact of storage parameters - moisture concentration, temperature and duration - on biomass quality.

As aerobic storage is the most viable large-scale solution, aerobic storage experiments were carried out with three projected bioenergy feedstocks - sweet sorghum (Sorghum bicolor) bagasse, corn (Zea mays) stover and switchgrass (Panicum virgatum). Stored samples of each were examined for dry matter loss and composition change to develop a material balance around carbohydrates and lignin.

A mean dry matter loss …

Preparation Of Mesoporous Silica Supported Ruthenium Oxides And The Application And Kinetic Study In The Catalysis Of Water Oxidation, Yang Zhang

Open Access Dissertations

Photo-induced water splitting of water into H2 and O2 has been a major focus in the development of clean and renewable energy. The development of viable and efficient catalysts that facilitates O2 production remains the major challenge in the study of the corresponding half-reaction of water oxidation. There are plenty of metal oxides reported active in the catalysis of water oxidation. However, several important performance bench marks of those materials, such as the non-stoichiometric production of O2, slow reaction rate and/or low quantum efficiency, remain to be improved.

Ruthenium oxide (RuO2) has long been known as one of the most …

High-Pressure Vapor-Phase Catalytic Hydrodeoxygenation Of Lignin-Derived Compounds To Hydrocarbons On Bimetallic Catalysts In The Range Of 0.2-2.4 Mpa., Sara Lynn Yohe

Open Access Dissertations

Biomass, as the only renewable source of carbon, presents a sustainable alternative to liquid fossil fuels for the production of renewable transportation fuels and chemicals. The lignin portion of biomass poses a significant challenge in the upgrading and conversion of lignocellulosic biomass to fuels and chemicals, and in many current biorefineries is not utilized. However, the lignin fraction is a valuable feedstock due to its aromatic structure, lower O:C ratio than cellulose and hemicellulose, and high energy content (up to 40%) and weight fraction (average 25 wt%) of biomass. Several processes (including fast-pyrolysis, fast-hydropyrolysis, and liquid phase processing) are able …

Design And Assembly Of Nanostructured Complex Metal Oxide Materials For The Construction Of Batteries And Thermoelectric Devices, Gautam Ganapati Yadav

Open Access Dissertations

Thermoelectric devices and lithium-ion batteries are among the fastest growing energy technologies. Thermoelectric devices generate energy from waste heat, whereas lithium-ion batteries store energy for use in commercial applications. Two different topics are bound with a common thread in this thesis - nanotechnology! In fact, nanostructuring is a more preferred term for the approach I have taken herein. Another commonality between these two topics is the material system I have used to prove my hypotheses - complex metal oxides.

Complex metal oxides can be used for both energy generation and storage as they are stable at high temperatures, are benign …

Comprehensive Computational Modeling Of Hypergolic Propellant Ignition, Swanand Vijay Sardeshmukh

Open Access Dissertations

Ignition and combustion of hypergolic propellants mono-methyl hydrazine (MMH) and red fuming nitric acid (RFNA) is investigated computationally. A hierarchical approach is chosen to study parametric behavior of isolated processes and complex interactions thereof, in this transient phenomenon. Starting with a homogeneous reactor, performance of three reduced kinetic mechanisms is assessed first, followed by the study of auto-ignition delay as a function of initial composition and thermal state of the mixture. Macroscopic features as well as the structure of opposed diffusion flame are studied next, followed by the study of opposed liquid jets and the gas layer at the interface. …

Development Of Quantitative Ft- Ir Methods For Analyzing The Cure Kinetics Of Epoxy Resins, Sang Ha Son

Open Access Dissertations

Epoxy thermosets are important engineering materials with applications in coating, adhesives, packaging and as structural components in a variety of advanced engineering products. The ultimate performance of polymer critically depends upon the details of the cure chemistry used to produce the thermoset. In order to better understand and monitor the cure chemistry, quantitative analysis of the FT-IR response has been developed for describing the epoxy-amine curing reaction as well as monitoring the hydrogen bonding that occurs in these systems The FT-IR analysis includes (i) quantitative deconvolution of complex peaks into individual spectral contributions, (ii) peak identification via DFT analysis and …

Elucidation Of Chiral Recognition Mechanisms Of Solutes By Amylose Tris[(S)-Alpha-Methylbenzylcarbamate] Sorbent, Hung-Wei Tsui

Open Access Dissertations

Enantioselective separations of chiral molecules are important in various chemical fields, such as pharmaceuticals and agrochemicals industries. Polysaccharide-based sorbents have been widely used in chiral liquid chromatography. The recognition mechanisms which determine their enantioselectivities are not completely understood.

In this dissertation, the chiral recognition mechanisms of a widely used commercial sorbent, amylose tris[(S)-alpha-methylbenzylcarbamate], for benzoin (B) enantiomers were first studied. The HPLC data for benzoin with pure n-hexane as the mobile phase have been obtained. The behavior of sorbent-solute-hexane systems can be interpreted by considering only sorbent solute two-component interactions. Infrared (IR) spectra showed evidence of substantial hydrogen bonding (H-bonding) …

The Effect Of Composition On The Linear And Nonlinear Mechanical Properties Of Particulate Filled Elastomers, Oluwaseyi Ogebule

Open Access Dissertations

Engineering elastomers are materials capable of undergoing large deformation upon load application and recovering upon load removal. From car tires to building vibration isolator systems, elastomers are the most versatile of engineering materials. The inclusion of particulate fillers into elastomers enhances their mechanical properties (modulus, tensile strength, toughness, tear resistance, etc) thereby extending their applicability to more demanding functions. The automotive, healthcare, construction, adhesives and consumer products are some of the many industries that produce finished goods containing elastomeric parts.

Despite the various concepts on reinforcement in filled elastomers, a complete understanding of their linear viscoelastic properties and the nonlinear …