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Enhancement Of Dibenzothiophene Hydrodesulphurization Via Hydrogenation Route On Nimow Catalyst Supported On Hms Modified With Ti, Rafael Maya-Yescas 2018 Universidad Michoacana de San Nicolas de Hidalgo

Enhancement Of Dibenzothiophene Hydrodesulphurization Via Hydrogenation Route On Nimow Catalyst Supported On Hms Modified With Ti, Rafael Maya-Yescas

Rafael Maya-Yescas

This study shows that ternary Ni-Mo-W sulfide catalysts supported on hexagonal mesoporous silica modified with Ti (HMS-Ti) showed a high enhancement of dibenzothiophene (DBT) transformation via hydrogenation route with respect to their Ti-free counterpart. The reaction of hydrodesulphurization (HDS) of DBT was carried out at in a batch reactor at 320 °C and 5.5 MPa of total H2 pressure. The catalysts were characterized by a variety of techniques (chemical analysis, N2 adsorption-desorption isotherms, low- and wide-angles XRD, TPR, TPDNH, DRS UV–vis, TPO/TG and HRTEM). At reaction time of 5 h, all synthetized catalysts exhibited higher DBT conversion ...


Selective Conversion Of Biomass-Derived Oxygenates Over Bimetallic Catalysts, Steven Zhou, Jason Yang 2018 Selected Works

Selective Conversion Of Biomass-Derived Oxygenates Over Bimetallic Catalysts, Steven Zhou, Jason Yang

Steven Zhou

Biomass contains a large variety amounts of oxygenates, which can be converted into bio-fuels and valuable chemicals. Pt-based and Pd-based catalysts show good activity for these reactions. However, these mono-metallic catalysts typically cause issues of either poor selectivity towards target product or low stability (thus deactivation). Bimetallic catalysts could alter selectivity and improve stability, especically for cases when methane is involved for biomass-derived oxygenate conversions. The present study proposes a roadmap for using such bimetallic
catalysts for biomass-derived oxygenate conversion.


Selective Conversion Of Biomass-Derived Oxygenates Over Bimetallic Catalysts, Steven Zhou, Jason Yang 2018 Selected Works

Selective Conversion Of Biomass-Derived Oxygenates Over Bimetallic Catalysts, Steven Zhou, Jason Yang

Jason Yang

Biomass contains a large variety amounts of oxygenates, which can be converted into bio-fuels and valuable chemicals. Pt-based and Pd-based catalysts show good activity for these reactions. However, these mono-metallic catalysts typically cause issues of either poor selectivity towards target product or low stability (thus deactivation). Bimetallic catalysts could alter selectivity and improve stability, especically for cases when methane is involved for biomass derived oxygenate conversions. The present study proposes a roadmap for using such bimetallic
catalysts for biomass-derived oxygenate conversion.


Decoupling The Stationary Navier-Stokes-Darcy System With The Beavers-Joseph-Saffman Interface Condition, Yong Cao, Yuchuan Chu, Xiaoming He, Mingzhen Wei 2018 Missouri University of Science and Technology

Decoupling The Stationary Navier-Stokes-Darcy System With The Beavers-Joseph-Saffman Interface Condition, Yong Cao, Yuchuan Chu, Xiaoming He, Mingzhen Wei

Xiaoming He

This paper proposes a domain decomposition method for the coupled stationary Navier-Stokes and Darcy equations with the Beavers-Joseph-Saffman interface condition in order to improve the efficiency of the finite element method. The physical interface conditions are directly utilized to construct the boundary conditions on the interface and then decouple the Navier-Stokes and Darcy equations. Newton iteration will be used to deal with the nonlinear systems. Numerical results are presented to illustrate the features of the proposed method.


Parallel Synthesis And High Throughput Dissolution Testing Of Biodegradable Polyanhydride Copolymers, Brandon M. Vogel, Joao T. Cabral, Naomi Eidelman, Balaji Narasimhan, Surya K. Mallapragada 2018 National Institute of Standards and Technology

Parallel Synthesis And High Throughput Dissolution Testing Of Biodegradable Polyanhydride Copolymers, Brandon M. Vogel, Joao T. Cabral, Naomi Eidelman, Balaji Narasimhan, Surya K. Mallapragada

Brandon M Vogel

We have demonstrated that polycondensation reactions can be carried out in a combinatorial fashion and that the polymer library can be screened at high throughput using a rapid prototyping technique to fabricate multiwell substrates. A linearly varying compositional library of 100 different biodegradable polyanhydride random copolymers that are promising carriers for controlled drug delivery was designed, fabricated, and characterized by IR microscopy within a few hours. The polyanhydride copolymer library was based on 1,6-bis(p-carboxyphenoxy)hexane (CPH) and sebacic anhydride (SA) and was characterized with infrared microspectroscopy to determine the composition within each well. Since degradation and release rates ...


Pyrolysis As An Economical And Ecological Treatment Option For Solid Anaerobic Digestate And Municipal Sewage Sludge, Devon J. Barry 2018 The University of Western Ontario

Pyrolysis As An Economical And Ecological Treatment Option For Solid Anaerobic Digestate And Municipal Sewage Sludge, Devon J. Barry

Electronic Thesis and Dissertation Repository

The aim of this thesis was to investigate the potential for pyrolysis of solid anaerobic digestate and municipal sewage sludge. Slow, fast, and autothermal pyrolysis experiments were conducted for the anaerobic digestate while slow and fast pyrolysis experiments were carried out for the sewage sludge. Pyrolysis temperatures ranged from 250 to 550 ᵒC. The effect of pyrolysis conditions on the pyrolysis products was examined.

Fast pyrolysis at higher temperatures was favourable for energy recovery in the bio-oil products. Slow pyrolysis was favourable for the biochar products. Lower pyrolysis temperatures favoured energy recovery in the biochar; while higher temperatures increased biochar ...


The Production Of Pyrolytic Biochar For Addition In Value-Added Composite Material, Douglas Matthew Cuthbertson 2018 The University of Western Ontario

The Production Of Pyrolytic Biochar For Addition In Value-Added Composite Material, Douglas Matthew Cuthbertson

Electronic Thesis and Dissertation Repository

Pyrolytic biochar has recently gained attention for its potential value as a carbon sequestering by-product that can be used in industrial applications. While biochar is typically targeted for soil amendment applications, higher value applications such as addition in consumer products and building materials needs to be investigated.

In this study, biochar is produced from three different Canadian feedstocks using three different pyrolysis methods. The biochar is characterized to determine the effects that feedstock selection and pyrolysis conditions has on biochar properties. The biochar is also incorporated into concrete at varying concentrations to create a lightweight and sustainable material. The effect ...


Turnover Frequency (Tof) For Insight Into Reaction Rates Via Noble Metal Supported Catalysts, Steven Zhou, Jason Yang 2018 Selected Works

Turnover Frequency (Tof) For Insight Into Reaction Rates Via Noble Metal Supported Catalysts, Steven Zhou, Jason Yang

Jason Yang

Turnover frequency (TOF) refers to the number of reacted molecules per surface active site per time for a catalytic reaction. Today, rate data in arbitrary units or plots of conversion versus time are slowly becoming the exception rather than the rule in the scientific literature of catalysis. With only one unit, a value of TOF offers a straightforward way to compare data obtained in different laboratories. In the present work, we show TOF measurement approach and insight into noble metal supported catalysis it provides.


Laboratory Catalytic Reactors For Testing Heterogeneous Catalysts: A Practical Introduction, Steven Zhou, Jason Yang 2018 Selected Works

Laboratory Catalytic Reactors For Testing Heterogeneous Catalysts: A Practical Introduction, Steven Zhou, Jason Yang

Jason Yang

Laboratory catalytic reactors are commonly used to evaluate performance of heterogeneous catalysts. It is of importance to select appropriate reactors for specific catalytic system before actual experiments are carried out. In the present work, various laboratory catalytic reactors are introduced and summarized for testing heterogeneous catalysts.


Laboratory Catalytic Reactors For Testing Heterogeneous Catalysts: A Practical Introduction, Steven Zhou, Jason Yang 2018 Selected Works

Laboratory Catalytic Reactors For Testing Heterogeneous Catalysts: A Practical Introduction, Steven Zhou, Jason Yang

Steven Zhou

Laboratory catalytic reactors are commonly used to evaluate performance of heterogeneous catalysts. It is of importance to select appropriate reactors for specific catalytic system before actual experiments are carried out. In the present work, various laboratory catalytic reactors are introduced and summarized for testing heterogeneous catalysts.


Turnover Frequency (Tof) For Insight Into Reaction Rates Via Noble Metal Supported Catalysts, Steven Zhou, Jason Yang 2018 Selected Works

Turnover Frequency (Tof) For Insight Into Reaction Rates Via Noble Metal Supported Catalysts, Steven Zhou, Jason Yang

Steven Zhou

Turnover frequency (TOF) refers to the number of reacted molecules per surface active site per time for a catalytic reaction. Today, rate data in arbitrary units or plots of conversion versus time are slowly becoming the exception rather than the rule in the scientific literature of catalysis. With only one unit, a value of TOF offers a straightforward way to compare data obtained in different laboratories. In the present work, we show TOF measurement approach and insight into noble metal supported catalysis it provides.


Combining Metabolic Engineering And Electrocatalysis: Application To The Production Of Polyamides From Sugar, Miguel Suastegui, John E. Matthiesen, Jack M. Carraher, Nacú Hernández, Natalia Rodriguez Quiroz, Adam Okerlund, Eric W. Cochran, Zengyi Shao, Jean-Philippe Tessonnier 2018 Iowa State University

Combining Metabolic Engineering And Electrocatalysis: Application To The Production Of Polyamides From Sugar, Miguel Suastegui, John E. Matthiesen, Jack M. Carraher, Nacú Hernández, Natalia Rodriguez Quiroz, Adam Okerlund, Eric W. Cochran, Zengyi Shao, Jean-Philippe Tessonnier

Eric W. Cochran

Biorefineries aim to convert biomass to a spectrum of products ranging from biofuels to specialty chemicals. To achieve economically sustainable conversion it is crucial to streamline the catalytic and downstream processing steps. Here we report a route that integrates bio- and chemical catalysis to convert glucose into bio-based unsaturated nylon 6,6. An engineered strain of Saccharomyces cerevisiae, with the highest reported muconic acid titer of 559.5 mg L-1 in yeast, was used as the initial biocatalyst to convert glucose into muconic acid. Without any separation, muconic acid was further electrocatalytically hydrogenated to 3-hexenedioic acid with 94% yield, despite ...


Photocatalytic Hydrogen Production Using A Mesoporous Tio2 Doped With Pt: Semiconductor Synthesis, Oxidation-Reduction Network And Quantum Efficiencies., Jesus Fabricio Guayaquil-Sosa 2018 The University of Western Ontario

Photocatalytic Hydrogen Production Using A Mesoporous Tio2 Doped With Pt: Semiconductor Synthesis, Oxidation-Reduction Network And Quantum Efficiencies., Jesus Fabricio Guayaquil-Sosa

Electronic Thesis and Dissertation Repository

The present PhD dissertation establishes that hydrogen can be produced using mesoporous TiO2 as a photocatalyst, doped with platinum atoms (Pt), in a slurry medium, under near-UV irradiation and with ethanol as a sacrificial reagent (scavenger). These mesoporous TiO2 photocatalysts were prepared using a sol-gel method. The mesoporous Pt-TiO2 photocatalyst displayed a reduced 2.34 eV band gap compared to the bare TiO2 (3.20 eV).

Photocatalytic hydrogen production experiments were performed in a Photo-CREC Water II Reactor (PCW-II Reactor). This novel unit provides both radial and axial symmetrical irradiation profiles. Furthermore, macroscopic energy balances developed ...


Optimization Of Turbulent Prandtl Number In Turbulent, Wall Bounded Flows, Donald Edward Bernard 2018 University of Vermont

Optimization Of Turbulent Prandtl Number In Turbulent, Wall Bounded Flows, Donald Edward Bernard

Graduate College Dissertations and Theses

After nearly 50 years of development, Computational Fluid Dynamics (CFD) has become an indispensable component of research, forecasting, design, prototyping and testing for a very broad spectrum of fields including geophysics, and most engineering fields (mechanical, aerospace, biomedical, chemical and civil engineering). The fastest and most affordable CFD approach, called Reynolds-Average-Navier-Stokes (RANS) can predict the drag around a car in just a few minutes of simulation. This feat is possible thanks to simplifying assumptions, semi-empirical models and empirical models that render the flow governing equations solvable at low computational costs. The fidelity of RANS model is good to excellent for ...


An Autothermal, Representative Scale Test Of Compost Heat Potential Using Geostatistical Analysis, William J. McCune-Sanders 2018 University of Vermont

An Autothermal, Representative Scale Test Of Compost Heat Potential Using Geostatistical Analysis, William J. Mccune-Sanders

Graduate College Dissertations and Theses

Composting has been practiced for thousands of years as a way of stabilizing and recycling organic matter into useful soil amendments. Thermophilic compost releases significant amounts of heat at temperatures (~140 °F) that are useful for environmental heating or process water. This heat has been taken advantage of in various ways throughout history, but development of a widely adopted technology remains elusive.

The biggest barrier to adoption of compost heat recovery (CHR) systems is projecting accurate, attractive economic returns. The cost of transfer equipment is significant, and with variability in composting substrates and methods, it is difficult to predict the ...


Strong Stability Of A Class Of Difference Equations Of Continuous Time And Structured Singular Value Problem, Qian Ma, Keqin Gu, Narges Choubedar 2018 Nanjing University of Science and Technology

Strong Stability Of A Class Of Difference Equations Of Continuous Time And Structured Singular Value Problem, Qian Ma, Keqin Gu, Narges Choubedar

SIUE Faculty Research, Scholarship, and Creative Activity

This article studies the strong stability of scalar difference equations of continuous time in which the delays are sums of a number of independent parameters tau_i, i = 1, 2, . . . ,K. The characteristic quasipolynomial of such an equation is a multilinear function of exp(-tau_i s). It is known that the characteristic quasipolynomial of any difference equation set in the form of one-delayper- scalar-channel (ODPSC) model is also in such a multilinear form. However, it is shown in this article that some multilinear forms of quasipolynomials are not characteristic quasipolynomials of any ODPSC difference equation set. The equivalence between local strong ...


A Graphene-Based Microfluidic Platform For Electrocrystallization And In Situ X-Ray Diffraction, Shuo Sui, Yuxi Wang, Christos Dimitrakopoulos, Sarah L. Perry 2018 University of Massachusetts Amherst

A Graphene-Based Microfluidic Platform For Electrocrystallization And In Situ X-Ray Diffraction, Shuo Sui, Yuxi Wang, Christos Dimitrakopoulos, Sarah L. Perry

Chemical Engineering Faculty Publication Series

Here, we describe a novel microfluidic platform for use in electrocrystallization experiments. The device incorporates ultra-thin graphene-based films as electrodes and as X-ray transparent windows to enable in situ X-ray diffraction analysis. Furthermore, large-area graphene films serve as a gas barrier, creating a stable sample environment over time. We characterize different methods for fabricating graphene electrodes, and validate the electrical capabilities of our device through the use of methyl viologen, a redox-sensitive dye. Proof-of-concept electrocrystallization experiments using an internal electric field at constant potential were performed using hen egg-white lysozyme (HEWL) as a model system. We observed faster nucleation and ...


Surface Engineering And Monomer Design For Light-Mediated Ring Opening Metathesis Polymerization, Ishan A. Fursule 2018 University of Kentucky

Surface Engineering And Monomer Design For Light-Mediated Ring Opening Metathesis Polymerization, Ishan A. Fursule

Theses and Dissertations--Chemical and Materials Engineering

Stimuli-responsive materials are changing the landscape of actuated materials, optoelectronics, molecular machines, solar cells, temporary memory storage, and biomedical materials. Specifically, photo-responsive polymers have gained acceleration in research and application since the last two decades in the form of a surface coating and micro-patterns. Light as a stimulus can be coherent, mono or polychromatic, tunable for power (intensity) and energy (wavelength), and has precise spatiotemporal control. Conventional surface coating techniques such as spin coating are unable to impart properties to the coatings in terms of sturdiness, homogeneity, uniformity over the complex surface, post deposition modification, and process efficiency. Also, in ...


On The Hyperbolicity Of The Two-Fluid Model For Gas–Liquid Bubbly Flows, Nithin Panicker, Alberto Passalacqua, Rodney O. Fox 2018 Iowa State University

On The Hyperbolicity Of The Two-Fluid Model For Gas–Liquid Bubbly Flows, Nithin Panicker, Alberto Passalacqua, Rodney O. Fox

Chemical and Biological Engineering Publications

The hyperbolicity condition of the system of partial differential equations (PDEs) of the incompressible two-fluid model, applied to gas–liquid flows, is investigated. It is shown that the addition of a dispersion term, which depends on the drag coefficient and the gradient of the gas volume fraction, ensures the hyperbolicity of the PDEs, and prevents the nonphysical onset of instabilities in the predicted multiphase flows upon grid refinement. A constraint to be satisfied by the coefficient of the dispersion term to ensure hyperbolicity is obtained. The effect of the dispersion term on the numerical solution and on its grid convergence ...


Understanding Inhibition Of A Biodesulfurization Enzyme To Improve Sulfur Removal From Petroleum, Yue Yu 2018 University of Kentucky

Understanding Inhibition Of A Biodesulfurization Enzyme To Improve Sulfur Removal From Petroleum, Yue Yu

Theses and Dissertations--Chemical and Materials Engineering

The biodesulfurization 4S-pathway is a promising complementary enzymatic approach to remove sulfur from recalcitrant thiophenic derivatives in petroleum products that remain from conventional hydrodesulfurization method without diminishing the calorific value of oil. The final step of this pathway involves the carbon-sulfur bond cleavage from HBPS, and the production of the final products 2-hydroxybiphenyl (HBP) and sulfite, has been recognized as the rate-limiting step, partially as a result of product inhibition. However, the mechanisms and factors responsible for product inhibition in the last step have not been fully understood. In this work, we proposed a computational investigation using molecular dynamic simulations ...


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