Chemical Engineering Commons^™

Microwave-Assisted Synthesis Of Pd Nanoparticles Supported On Fe3o4, Co3o4, And Ni(Oh)2 Nanoplates And Catalysis Application For Co Oxidation, Hany A. Elazab

Chemical Engineering

In this paper, we report a simple, versatile, and rapid method for the synthesis of Pd nanoparticle catalysts supported on Fe3O4, Co3 O4, and Ni(OH)2 nanoplates via microwave irradiation. The important advantage of microwave dielectric heating over convective heating is that the reactants can be added at room temperature (or slightly higher temperatures) without the need for high-temperature injection. Furthermore, the method can be used to synthesize metal nanoparticle catalysts supported on metal oxide nanoparticles in one step. We also demonstrate that the catalyst-support interaction plays an important role in the low temperature oxidation of CO. The current results reveal …

Graphene-Supported Metal Nanoparticles And Its Potential Civilian And Military Applications, Hany A. Elazab Dr

Chemical Engineering

It is now well established that nanoparticles (1-100 nm) exhibit unique chemical and physical properties that differ from those of the corresponding bulk materials. The dependence of the properties of nanoscale materials on the size, shape and composition of the nanocrystal is a phenomenon of both fundamental scientific interest and many practical and technological applications. These properties are often different, and sometimes superior, to those of the corresponding bulk materials. Due to its unique properties and high surface area, Graphene has become a good candidate as an effective solid support for metal catalysts. The Nobel Prize in Physics for 2010 …

Approximations To The Solution Of The Frank-Kamenetskii Equation In A Spherical Geometry, Moustafa A. Soliman

Chemical Engineering

In this paper, an approximate analytical solution for Frank-Kamenetskii equation modeling a thermal explosion in a sphere, is obtained. The approximate solution is obtained by perturbation methods in terms of small and large distance parameter. The approximate solution is compared with the numerical solution obtained from an initial value problem formulation to the original boundary value problem. The approximate solution obtained is valid for all values of the distance parameter. For the original boundary value problem and for a given Frank-Kamenetskii parameter, a nonlinear algebraic equation needs to be solved to be able to apply the approximate solution.

Reuse Of The Product Obtained On Grinding Kiln Rollers In The Manufacture Of Ceramic Wall Tiles, Mai H. Roushdy, Shereen K. Amin, Marwa Mohamed, Magdi F. Abadir

Chemical Engineering

The production of ceramic tiles and to a lesser extent flat dinner ware and pottery is increasingly being done by firing in roller kilns. These kilns offer several advantages over conventional tunnel kilns: lower fuel consumption, computer controlled firing curves, low maintenance due to lack of kiln cars, rapid firing cycles of less than one hour and the possibility of shutting down the kiln on short notice.1 One recurrent problem in the operation of such kilns is the periodic need to grind the kiln rollers. These are usually fabricated from high alumina clays and are continuously contaminated by depositions of …

Development Of Nickel Oxide And Manganese Oxide Nanostructured Binary Modified Anodes For Methanol Electro-Oxidation, Ghada El-Nowihy

Chemical Engineering

No abstract provided.

Development Of Nickel Oxide And Manganese Oxide Nanostructured Binary Modified Anodes For Methanol Electro-Oxidation, Ghada El-Nowihy

Chemical Engineering

In this investigation, a nanoparticle-based binary catalyst composed of nickel oxide (nano-NiOx) and manganese oxide (nano-MnOx), both were assembled on a platinum substrate, was developed for the direct methanol electro-oxidation (MO) in an alkaline medium. The morphological investigation was performed using field-emission SEM and revealed the electrodeposition of MnOx in a nanorod structure and NiOx in round-shaped nanospheres. The electrocatalytic activity of the modified electrodes towards MO depended critically on the order of deposition of the two oxides. The optimum electrocatalytic activity was obtained at the MnOx/NiOx/Pt electrode (in which nano-NiOx was directly electrodeposited onto the Pt surface followed by …

A Modified Orthogonal Collocation Method For Reaction Diffusion Problems, Moustafa A. Soliman, Yousef S. Al-Zeghayer, Abdelhamid M. Ajbar

Chemical Engineering

A low-order collocation method is often useful in revealing the main features such as concentration and temperature profiles and the effectiveness factor for porous catalyst particles. Two modifications are introduced in this paper to make the method more efficient. The first modification is to add an extra collocation point at the center of the particle. It is shown that such extra point introduces a single variable non-linear equation to be solved after obtaining the standard collocation method solution. In the second modification, the polynomial solution obtained from the application of the orthogonal collocation method is transformed to a rational function …

Model-Based Energy Analysis Of An Integrated Midrex-Based Iron/Steel Plant, Abdelhamid M. Ajbar, Khalid I. Alhumaizi, Moustafa A. Soliman, Emadadeen Ali

Chemical Engineering

This article presents modeling and simulations of an integrated plant for the production of steel using the direct reduced iron (DRI)=electric arc furnace (EAF) route. In a previous work (Alhumaizi et al., 2012), a comprehensive mathematical model of an iron plant based on MIDREX technology was developed, validated, and simulated. In this article, the model is extended to account for an empirical model of an EAF plant. Numerical simulations were carried out for the effect of different operating parameters of the integrated plant. Useful profiles as well as a summary table were compiled to illustrate the results of the sensitivity …

Partial Oxidation Of Ethane To Acetic Acid On Titania Supported Movnbpd Catalyst, Yousef S. Al-Zeghayer, Abdulrhman S. Al-Awadi, Baba Y. Jibril, Moustafa A. Soliman, Sulaiman Al-Mayman

Chemical Engineering

Partial oxidation of ethane was studied on unsupported and supported Mo-V-Nb oxides. Different grades of titania (Crystal-AF4.60, AF7.70 and AF12.5 and Degussa P25) were explored as supports. Samples of the catalyst were characterized using XRD, SEM and BET surface area. The reaction was carried out at 200-275°C and 200 psi. At ethane conversion (6%), unsupported samples exhibited selectivities to ethylene and acetic acid of 76 and 23%, while for Degussa P25-supported sample, the values were 54 and 35%, respectively. Addition of Pd (0.196%) led to an increase in selectivity to acetic acid of 75%.

Efficient Numerical Scheme Of The Dynamics Of Nonisothermal Thin Film Flow, Moustafa A. Soliman, Khalid I. Alhumaizi

Chemical Engineering

In this work we use Lubrication type method, based on the possibility of the separation of longitudinal and transversal length scales to simplify the analysis of thin film dynamics. We study the dynamics of evaporating thin liquid films on an inclined plane, where the effect of van der Waal forces is significant. The numerical solution of the evolution equation is carried out using the method of orthogonal collocation and is used for the study of the instabilities of evaporating thin film to identify conditions for efficient operation. For symmetric cases where the plane is horizontal, a two spline collocation second …

Dynamics Of A Coating Film Flow On Horizontal Cylinders With Van Der Waals Forces, Moustafa A. Soliman, Khalid I. Alhumaizi

Chemical Engineering

In this work we use the lubrication type method, based on the possibility of the separation of longitudinal and transversal length scales, to simplify the analysis of coating film dynamics. We study the dynamics of coating thin films on horizontal stationary and rotating cylinders in general, and when the effect of van der Waals forces is significant. A computer code based on the method of orthogonal collocation is developed and is used for the study of the instabilities of coating thin film flow on cylinders to identify conditions of stable operation. For stationary cylinders, the equations are symmetric and the …

Self-Assembling Of Gold Nanoparticles Array For Electro-Sensing Applications, Islam M. Al-Akraa Dr, Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof

Chemical Engineering

A colloidal solution of citrate-stabilized gold nanoparticles (AuNPs) with an average size of ca. 2.6 nm has been prepared, characterized and further implemented in electro-sensing applications. This colloidal solution of AuNPs has been prepared via the reduction of NaAuCl4 with sodium tetrahydroborate (NaBH4) using trisodium citrate as a stabilizer. The optical properties of this solution have been studied with UV–Vis spectroscopy. Next, these AuNPs have been immobilized onto a polycrystalline Au (poly-Au) electrode with the assistance of benzenedimethanethiol (BDMT), which served as a binder. Attention has been taken to ensure the formation of a compact impermeable layer of BDMT on …

Development Of Tailor-Designed Gold-Platinum Nanoparticles Binary Catalysts For Efficient Formic Acid Electrooxidation, Islam M. Al-Akraa Dr, Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof

Chemical Engineering

The modification of a glassy carbon (GC) electrode with platinum (PtNPs) and gold (AuNPs) nanoparticles is targeted to fabricate efficient anodes for the electrooxidation of formic acid (FA). A proper adjustment of the deposition sequence of PtNPs and AuNPs could eventually enhance the electrocatalytic activity of the electrode in such a way that suppresses the CO poisoning effect during FA oxidation. The highest catalytic activity is obtained at the Au/Pt/GC electrode (with PtNPs firstly deposited on the GC electrode followed by AuNPs). This superb enhancement is quantified by comparing the relative ratio of the direct vs. the indirect oxidation peaks …

Non-Planar Diamond Electrodes For Biomedical Neural Sensing And Stimulating, Jeffrey M. Halpern

Chemical Engineering

Abstract

Conductive diamond has exceptional chemical stability, making it an appealing candidate material for long-term medical device implants. This work describes the characterization, and fabrication of four diamond-based neural devices. A previously developed 30 µm diamond-disk in vitro needle electrode was characterized. The device could detect 1 nM concentration analytes in a flow cell using fast scan cyclic voltammetry, but the fabrication was not reproducible. A novel in vitro diamond device was developed with diamond selectively grown at the tip of a hollow quartz capillary, resulting in a 2-4 µm tip diameter. The diamond tip shape and size were geometrically …

Coversion Of Hexamine Dinitrate Into Dinitro Pentamethylene Tetramine: Follow-Up And Kinetic Model Selection, Hany A. Elazab

Chemical Engineering

Synthesis of cyclotetramethylene tetramine through the action of nitrating mixture formed of ammonium nitrate and fuming nitric acid on hexamine in presence of acetic acid, acetic anhydride and p-formaldehyde has been proven. The pathway is relatively long and hexamine dinitrate and dinitro pentamethylene tetramine (DPT) are two of the main intermediate compounds. The former was prepared, purified, and then characterized. Conversion of this compound into the latter has been followed up experimentally. Different kinetic models have been tested. The unreacted core model proved to be applicable and the surface reaction was found to be controlling.

Coversion Of Hexamine Dinitrate Into Dinitro Pentamethylene Tetramine: Follow-Up And Kinetic Model Selection, Hany A. Elazab

Chemical Engineering

Synthesis of cyclotetramethylene tetranitramine through the action of nitrating mixture formed of ammonium nitrate and fuming nitric acid on hexamine in presence of acetic acid, acetic anhydride and p-formaldehyde has been proven. The pathway is relatively long and hexamine dinitrate and dinitro pentamethylene tetramine (DPT) are two of the main intermediate compounds. The former was prepared, purified, and then characterized. Conversion of this compound into the latter has been followed up experimentally. Different kinetic models have been tested.