Chemical Engineering Commons^™

Effect Of Microreactor Geometry In Performance Of Catalytic Microreactor Of Hydrogen Production By Cfd Modeling, Mohsen Behnam, Ali Fazeli, Shohreh Fatemi, Yadolah Mortazavi, A. Khodadai

Ali Fazeli

Hydrogen production from steam reforming of methanol for fuel cell application was modeled in a wall coated micro channel reactor by CFD approach. Heat of steam reforming was supplied from catalytic total oxidation (TOX) of methanol in neighboring channel of steamreforming (SR) channel and conduct from TOX to SR channel through metal divider wall of the channels. Heat integration was compared in zigzag and straight geometry of microreactor by CFD modeling. The model is 2 dimensional, steady state and containing five zones: TOX fluid, TOX catalyst layer, steel wall of the channel, SR catalyst layer, SR fluid. Set of partial …

Photopolymerization-Induced Crystallization And Phase Separation In Poly(Ethylene Oxide)/Triacrylate Blends, Soo Jeoung Park, Thein Kyu

College of Polymer Science and Polymer Engineering

The present article describes experimental and theoretical investigations of miscibility and crystallization behavior of blends of poly(ethylene oxide) (PEO) and triacrylate monomer (TA) using differential scanning calorimetry and optical microscopy. The PEO/TA blends manifested a single T(g) varying systematically with composition suggestive of a miscible character in their amorphous states. Moreover, there occurs melting point depression of PEO crystals with increasing TA. A phase diagram was subsequently established that exhibited a solid+liquid coexistence region bound by the liquidus and solidus lines, followed by an upper critical solution temperature (UCST) at a lower temperature. The emerging phase morphology was investigated to …

Process Modeling And Optimization Of Mono Ethylene Glycol Quality In Commercial Plant Integrating Artificial Neural Network And Differential Evolution,, Nadeem Muhammed Khalfe

Nadeem Khalfe

This paper presents an artificial intelligence based process modeling and optimization strategies, namely artificial neural network – differential evolution (ANN-DE) for modeling and optimization of ultraviolet (UV) transmittance of mono ethylene glycol (MEG) product. UV transmittance is one of the most important quality variable of MEG that has impact on the polyester product quality. UV transmittance measures the presence of undesirable compounds in MEG that absorb light in the ultraviolet region of the spectrum and indirectly measures the purity of MEG product. They are in trace quantities in the ppb ranges and primarily unknown in chemical structure. Thus, they cannot …

Process Modeling And Optimization Strategies,, Nadeem Muhammed Khalfe

Nadeem Khalfe

This paper presents artificial intelligence-based process modeling and optimization strategies, namely, support vector regression – differential evolution (SVR-DE) for modeling and optimization of catalytic industrial ethylene oxide (EO) reactor. In the SVR-DE approach, a support vector regression model is constructed for correlating process data comprising values of operating and performance variables. Next, model inputs describing process operating variables are optimized using Differential Evolution (DE) with a view to maximize the process performance. DE possesses certain unique advantages over the commonly used gradient-based deterministic optimization algorithms. The SVR-DE is a new strategy for chemical process modeling and optimization. The major advantage …

Process Modeling And Optimization Of Mono Ethylene Glycol Quality In Commercial Plant Integrating Artificial Neural Network And Differential Evolution, Nadeem Muhammed Khalfe

Nadeem Khalfe

This paper presents an artificial intelligence based process modeling and optimization strategies, namely artificial neural network – differential evolution (ANN-DE) for modeling and optimization of ultraviolet (UV) transmittance of mono ethylene glycol (MEG) product. UV transmittance is one of the most important quality variable of MEG that has impact on the polyester product quality. UV transmittance measures the presence of undesirable compounds in MEG that absorb light in the ultraviolet region of the spectrum and indirectly measures the purity of MEG product. They are in trace quantities in the ppb ranges and primarily unknown in chemical structure. Thus, they cannot …

Fingering Instabilities On Reaction Fronts In The Co Oxidation Reaction On Pt(100), D. Bilbao, Jochen A. Lauterbach

Faculty Publications

Fingering instabilities arising from local perturbations to planar reaction fronts in the CO oxidation reaction on Pt(100) are presented. CO oxidation represents a heterogeneous nonlinear system with the necessary kinetic and diffusive transport properties to support the development of fingered wave fronts. External forcing was utilized to create CO wave fronts on an otherwise monostable, O-covered surface, which, upon destabilization, gave rise to fingers of adsorbed CO extending into the O adlayer ahead of the reaction front. Finger spreading and tip-splitting were observed as the finger pattern evolved towards an intrinsic wavelength, independent of the length of the reaction front, …

Multidimensional Modeling Of Solid Propellant Burning Rates And Aluminum Agglomeration And One-Dimensional Modeling Of Rdx/Gap And Ap/Htpb, Matthew Wilder Tanner

Theses and Dissertations

This document details original numerical studies performed by the author pertaining to solid propellant combustion. Detailed kinetic mechanisms have been utilized to model the combustion of the pseudo-propellants RDX/GAP and AP/HTPB. A particle packing model and a diffusion flame model have been utilized to develop a burning rate and an aluminum agglomeration model. The numerical model for RDX/GAP combustion utilizes a "universal" gas-phase kinetic mechanism previously applied to combustion models of several monopropellants and pseudo-propellants. The kinetic mechanism consists of 83 species and 530 reactions. Numerical results using this mechanism provide excellent agreement with RDX and GAP burning rate data, …

Book I, Otto Vogl: Papers And Patents, 1948-1970, Jane C. Vogl

Emeritus Faculty Author Gallery

Books I-XII include citations to Otto Vogl's publications and patents. Printed versions of these twelve volumes are also available in the Integrated Sciences and Engineering Library of the University of Massachusetts in Amherst. MA, Lederle Graduate Research Center. The printed volumes include the full reprints of all cited publications.

Centers Of Polymer Science: Introduction, Otto Vogl

Emeritus Faculty Author Gallery

Centers of Polymer Science describes polymer research activities taking place in Europe, Asia, and Australia primarily during the years between 1980 and 2000. This series of articles shows and records the activity in Polymer Science in this part of polymer history.

From Elastic Deformation To Terminal Flow Of A Monodisperse Entangled Melt In Uniaxial Extension, Yangyang Wang, Shi-Qing Wang

College of Polymer Science and Polymer Engineering

Using a well-entangled monodisperse styrene-butadiene random-copolymer (SBR) melt as a model system, we illustrate generic features of uniaxial extension behavior that may be shared by all well-entangled thermoplastic and elastomeric materials. Depending on the imposed extensional rate, the same sample may behave like a viscous liquid or an elastic "solid." Analogous to the recently revealed shear inhomogeneity, the SBR melt inevitably undergoes cohesive failure in the form of sample breakage whenever the Weissenberg number is much greater than unity, making it challenging to reach steady state. In the elastic deformation regime where the external deformation rate is faster than Rouse …

Fault Diagnosis For Large Complex Petrochemical Plant,, Nadeem Muhammed Khalfe

Nadeem Khalfe

Often it is time consuming to monitor the plant condition in modern complex process industries as there is abundance of instrumentation that measure thousands of process variables in every few seconds. This has caused a "data overload" and due to the lack of appropriate analyses very little is currently being done to utilize this wealth of information. Fortunately, in process, groups of variables often moves together because more than one variable may be measuring the same driving principle governing the behavior of the process. Multivariate statistical methods such as Principal Component Analysis (PCA) are capable of compressing the information down …

Effective Medium Equations For Chemotaxis In Porous Media, Francisco J. Valdes-Parada, Mark L. Porter, K. Narayanaswamy, Roseanne Ford, Brian D. Wood

Francisco J. Valdes-Parada

Biodegradation is an important mechanism for contaminant reduction in groundwater environments; in fact, in-situ bioremediation and bioaugmentation methods represent alternatives to traditional methods such as pump-and-treat. Chemotaxis has shown to enhance bacterial transport toward or away from concentration gradients of chemical species in laboratory experiments and can signifficantly increase contaminant flux undergoing degradation at the interfaces of lowand high-permeability regions. In this work, the method of volume averaging is used to upscale the microscale description of chemotactic microbial transport in order to obtain the corresponding macroscale equations for bacteria and the attractant. As a first apprach, cellular growth/death and consumption …

Process Modeling And Optimization Strategies, Sandip K. Lahiri

Dr. Sandip Kumar Lahiri

This paper presents artificial intelligence-based process modeling and optimization strategies, namely, support vector regression – differential evolution (SVR-DE) for modeling and optimization of catalytic industrial ethylene oxide (EO) reactor. In the SVR-DE approach, a support vector regression model is constructed for correlating process data comprising values of operating and performance variables. Next, model inputs describing process operating variables are optimized using Differential Evolution (DE) with a view to maximize the process performance. DE possesses certain unique advantages over the commonly used gradient-based deterministic optimization algorithms. The SVR-DE is a new strategy for chemical process modeling and optimization. The major advantage …

Integrated System Approach To Sustainability Bio-Fuels And Bio-Refineries, Seif-Eddeen K. Fateen

Seif-Eddeen K Fateen

No abstract provided.

Separation Of Time Scales For Transient Dispersion, Mark L. Porter, Francisco J. Valdes-Parada, Brian D. Wood

Francisco J. Valdes-Parada

No abstract provided.

Prediction Of Pressure Drop Of Slurry Flow In Pipeline By Hybrid, Sandip K. Lahiri

Dr. Sandip Kumar Lahiri

This paper describes a robust support vector regression (SVR) methodology, which can offer superior performance for important process engineering problems. The method incorporates hybrid support vector regression and genetic algorithm technique (SVR-GA) for efficient tuning of SVR meta-parameters. The algorithm has been applied for prediction of pressure drop of solid liquid slurry flow. A comparison with selected correlations in the literature showed that the developed SVR correlation noticeably improved the prediction of pressure drop over a wide range of operating conditions, physical properties, and pipe diameters

Process Modeling And Optimization Of Mono Ethylene Glycol Quality In Commercial Plant Integrating Artificial Neural Network And Differential Evolution, Sandip K. Lahiri

Dr. Sandip Kumar Lahiri

This paper presents an artificial intelligence based process modeling and optimization strategies, namely artificial neural network – differential evolution (ANN-DE) for modeling and optimization of ultraviolet (UV) transmittance of mono ethylene glycol (MEG) product. UV transmittance is one of the most important quality variable of MEG that has impact on the polyester product quality. UV transmittance measures the presence of undesirable compounds in MEG that absorb light in the ultraviolet region of the spectrum and indirectly measures the purity of MEG product. They are in trace quantities in the ppb ranges and primarily unknown in chemical structure. Thus, they cannot …

Computational Fluid Dynamics Simulation Of The Solid Liquid Slurry Flow In A Pipeline, Sandip K. Lahiri

Dr. Sandip Kumar Lahiri

A comprehensive computational fluid dynamics (CFD) model was developed in the present study to gain insight into the concentration profile of solid liquid slurry flow in pipelines. The preliminary simulations highlighted the need for the correct modeling of the interphase drag force. In light of the shortcomings of appropriate drag co-efficient model (namely Syamlal O’-Brien model, Gidaspow model and Wen & Yu model), an effort was made in the present study to modify the existing models to incorporate the effect of solid concentration at drag co-efficient. A two-dimensional user defined model was then developed using CFD to understand the influence …

Centers Of Polymer Science: Introduction, Otto Vogl

Otto Vogl

Centers of Polymer Science describes polymer research activities taking place in Europe, Asia, and Australia primarily during the years between 1980 and 2000. This series of articles shows and records the activity in Polymer Science in this part of polymer history.

Book I, Otto Vogl: Papers And Patents, 1948-1970, Jane C. Vogl

Otto Vogl

Books I-XII include citations to Otto Vogl's publications and patents. Printed versions of these twelve volumes are also available in the Integrated Sciences and Engineering Library of the University of Massachusetts in Amherst. MA, Lederle Graduate Research Center. The printed volumes include the full reprints of all cited publications.

A Fundamental Study Of The Pcr Amplification Of Gc-Rich Dna Templates, T. G. Mamedov, Elsje Pienaar, Scott E. Whitney, Joel R. Termaat, G. Carvill, R. Goliath, Anuradha Subramanian, Hendrik J. Viljoen

Hendrik J. Viljoen Publications

A theoretical analysis is presented with experimental confirmation to conclusively demonstrate the critical role that annealing plays in efficient PCR amplification of GC-rich templates. The analysis is focused on the annealing of primers at alternative binding sites (competitive annealing) and the main result is a quantitative expression of the efficiency (η) of annealing as a function of temperature (T_A), annealing period (t_A), and template composition. The optimal efficiency lies in a narrow region of T_A and t_A for GC-rich templates and a much broader region for normal GC templates. To confirm the …

Flexography Printing Of Silver Based Conductive Inks On Packaging Substrates, Ramesh Chandra Kattumenu

Dissertations

Printing technologies for the production of flexible electronics have gained much interest due to its potential as a means to reduce the complexity and costs of present technology. High volume printing techniques like flexography are of great importance in order to produce rolls of flexible electronics printed directly on paper substrates. The proposed research will be focused on RFID components being in-line printed using flexography printing as the manufacturing platform. The properties of substrates and inks and printing process parameters are evaluated to study their effect on printed traces and RFID antenna. It was found in the study that properties …

Electrodeposition Of Nickel Nanowires And Nanotubes Using Various Templates, Asli Ertan, Surendra N. Tewari, Orhan Talu

Chemical & Biomedical Engineering Faculty Publications

Nickel nanotubes and nanowires are grown by galvanostatic electrodeposition in the pores of 1000, 100, and 15 nm polycarbonate as well as in anodised alumina membranes at a current density of 10 mA cm-2. The effects of pore size, porosity, electrodeposition time, effective current density, and pore aspect ratio are investigated. Nickel nanotube structures are obtained with 1000 nm pore size polycarbonate membrane without any prior treatment method. At the early stages of electrodeposition hollow nickel nanotubes are produced and nanotubes turn into nanowires at longer depositon times. As effective current density accounting for the membrane porosity decreases, the axial …

Antibacterial Coatings For Medical Devices Based On Glass Polyalkenoate Cement Chemistry, A. Coughlan, D. Boyd, C. W.I. Douglas, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

A biofilm is an accumulation of micro-organisms and their extracellular products forming a structured community on a surface. Biofilm formation on medical devices has severe health consequences as bacteria growing in this lifestyle are tolerant to both host defense mechanisms and antibiotic therapies. However, silver and zinc ions inhibit the attachment and proliferation of immature biofilms. The objective of this study is to evaluate whether it is possible to produce silver and zinc-containing glass polyalkenoate cement (GPC) coatings for medical devices that have antibacterial activity and which may therefore inhibit biofilm formation on a material surface. Two silver and zinc-containing …

Gene Expression Analysis Of Immobilized Saccharomyces Cerevisiae, Ryan Michael Summers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Immobilization is an effective method to increase ethanol production, as proven by previous research. Results almost exclusively demonstrate an increase in ethanol production by and decrease in reproduction rate of immobilized Saccharomyces cerevisiae cells. Recently, research has been conducted to determine the cause of this change. The extreme variance in results due to lack of technology makes it difficult to determine the cellular changes induced by immobilization. With the advent of new technology, specifically gene expression analysis, the RNA content of cells can be easily and rapidly analyzed.

S. cerevisiae cells were immobilized in 3% (w/v) calcium alginate beads and …

High Performance Fuel Cell Catalyst And 5kw Pemfc Stack Without Humidification At Room Temperature And Atmosphere, Xin-Fa Hu, Min Chen, Shi-Jun Liao

Journal of Electrochemistry

The Pt/C catalyst with high dispersion and high performance was prepared successfully by an organic colloidal method and small batch production(10g) of Pt/C catalyst has been realized.The particle sizes of the active components in the catalyst could be as small as 2.8 nm and the active surface area was up to 450 m2/g.A high performance membrane-electrode assembly(MEA) with surface area of 275 cm2 has been prepared by using the home-made catalyst with a catalyst coated membrane method invented in the lab,and a 5 kW stack has been assembled.The stack showed working 10 h at room temperature,atmosphere and without humidification.

The Hydrothermal Synthesis Of Nanoscale Lifepo_4 And Its Electrochemical Performance, Si-Min Wang, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The cathode materials of nanosiged LiFePO4 were prepared by hydrothermal templating synthesis.The grain sizes and electrochemical performance of LiFePO4 were controlled by surfactant.It was shown that the grain sizes varied from less than a hundred to hundreds nanometers by the SEM images.In the charge/discharge tests,the discharge capacities of the sample as a lithium ion battery were achieved to 150 mAh/g at 0.1C,140 mAh/g at 1C,and 126 mAh/g at 2C,with good cycling performance.

Preparations Of Composite Electrodes Of Pt With H_Xwo_3 And Catalytic Activity Toward Oxygen Reduction Reaction, Pan-Pan Guo, You-Ju Huang, Hong-Yan Yang, Wei Li, Qing-Long Zhang, Wei-Shan Li

Journal of Electrochemistry

Three composite electrodes of platinum with hydrogen tungsten bronze(HxWO3)were prepared by voltammetry: hydrogen tungsten bronze deposited on platinum(HxWO3/Pt);platinum deposited on hydrogen tungsten bronze(Pt/HxWO3) and codeposited platinum and hydrogen tungsten bronze(Pt-HxWO3).The eletro-catalytic activities of three electrodes toward oxygen reduction reaction were studied.It is found that the catalytic activity of platinum can be improved by introducing with hydrogen tungsten bronze.Among these composite electrodes Pt/HxWO3,and the electrode shows the best eletro-catalytic activity toward oxygen reduction reaction,hence,provides a new way for reducing loading of noble metal in the application for fuel cell.

Fabrication Of Superhydrophilic Aluminum Oxide Through Single-Step Anodic Oxidation, Qin Zhang, Qi-Ming Yin, Jia-Ming Ye, Yuan-Rong Zhu

Journal of Electrochemistry

Hydrophilic aluminum oxide is popularly used for heat exchanger of air-condition.Herein,we developed a simple method to prepare superhydrophilic aluminum oxide on the surface of aluminum through single-step electrochemical oxidization.The morphologies and water contact angles on surfaces of alumina fabricated under different electrochemical conditions were investgated.Superhydrophilic surfaces fabricated by this method have good stability and high mechanical strength with water contact angle almost 0°.Coated with low surface energy materials,superhydrophilc alumina will be converted to superhydrophobic.

Preparation And Electrocatalystic Performance Of Ir/C Catalyst For Ammonia Oxidation, Qing-Mei Kong, Yi-Ping Han, Ling-Juan Deng, Tian-Hong Lu, Ya-Wen Tang

Journal of Electrochemistry

The Ir/C catalyst with 30%(by mass) Ir was prepared in the CH3CH2OH and H2O binary system.The X-ray diffraction(XRD) data showed that the average sizes of the Ir particles in the Ir/C catalyst was about 2.2 nm.The results of the electrochemical measurements indicated that the electrocatalytic activity of the Ir/C catalyst for the ammonia oxidation in the neutral NaClO4 solution was similar to the Ir catalyst,while electrocatalytic stability was much better than that of the Ir catalyst.Furthermore,the peak current density of the ammonia oxidation at the Ir/C catalyst electrode showed a good linear relationship with the ammonia concentration,illustrating that the Ir/C …