Chemical Engineering Commons^™

Modeling Of Rotary Packed Beds For Reactive And Non-Reactive Systems, Chinyere Evangeline Ezeobinwune

Graduate Theses, Dissertations, and Problem Reports (ETD)

Rotary packed beds (RPBs) are used in a wide range of reactive and non-reactive applications. In this research, a 2-d, first-principles, dynamic model of a non-reactive RPB that is used for heat exchange between the outgoing flue gas from a power plant and the incoming air to the boiler/pulverizer of the power plant is developed. A 2-d, first-principles model of a reactive RPB is developed where a functionalized metal-organic framework (MOF) is used for CO₂ capture.

For the non-reactive system, a Ljungstrom-type air preheater (APH) is considered. Existing models for these rotating heat exchangers are typically 1-d. There are …

Cu-Based Electrocatalysts For Carbon Dioxide Conversion To Value-Added Chemicals, Qingyang Li

Graduate Theses, Dissertations, and Problem Reports (ETD)

Massive usage of fossil fuel has being causing considerable emission of CO₂, which increases the temperature of the planet and greatly threaten human living environment, such as soil degradation, lower agricultural productivity, desertification, less biodiversity, fresh-water reduction, ocean acidification, ozone sphere destruction, etc. A number of technologies are being developed to reduce the CO₂ amount, however, all existing technologies except utilizing CO₂ as a feedstock, are hardly to essentially close the anthropogenic carbon loop. Currently, considering the economy and operability, electroreduction of CO₂ seems to be the most promising strategy to convert CO₂ to …

Application Of Flowing Material Balance In Unconventional Reservoirs, Salem Alharbi

Graduate Theses, Dissertations, and Problem Reports (ETD)

The application of the horizontal drilling and hydraulic fracturing to unconventional reservoirs, such as Marcellus Shale, has resulted in a significant increase in gas production in the United States. The estimation of the original hydrocarbons in place is an essential element for evaluating the economic success of any reservoir. There are a number of techniques available for estimating the original hydrocarbon in place such as decline curve analysis, volumetric method, and the material balance equation. Flowing Material Balance (FMB) is a more advanced techniques which has become popular in recent years because it does not require static (shut-in) pressure data …

Formulation And Validation Of Nanoparticle Controlled Delivery For Chemotherapeutic Drug Products, Shani L. Levit

Theses and Dissertations

Taxol, a formulation of paclitaxel (PTX), is one of the most widely used anticancer drugs, particularly for treating recurring ovarian carcinomas following surgery. Clinically, PTX is used in combination with other drugs such as lapatinib (LAP) to increase treatment efficacy. Delivering drug combinations with nanoparticles has the potential to improve chemotherapy outcomes. In this study, we use Flash NanoPrecipitation, a rapid, scalable process to encapsulate weakly hydrophobic drugs (logP in vitro. Encapsulating either PTX or LAP into nanoparticles increases drug potency. When PTX and LAP are co-loaded in the same nanoparticle, they have a synergistic effect that is greater than …

Dendrimer-Based Therapeutic Delivery Vehicle For The Treatment Of Ocular Diseases, Remy C. Cooper

Theses and Dissertations

The treatment of ocular diseases poses a significant challenge to drug delivery design, due to the eye’s complex anatomy, with a semi-permeable blood-ocular barrier and associated immune privilege. To address some of the delivery challenges, polycationic dendrimers are explored as vehicle for the treatment of posterior chamber disease. Dendrimers are a class of polymeric nanoparticles that are highly branched, multivalent and monodisperse, whose three-dimensional globular architecture has given them the nickname of “synthetic proteins”. Dendrimers are synthesized by reacting monomers in a step-wise fashion to produce generationally and radially increasing structures, with core, interior and surface chains that are highly …

Modeling Of Zinc-Air Batteries Using Theoretical And Empirical Approach, Woranunt Lao-Atiman

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, an energy storage system (ESS) is attracting widespread research interest. Zinc-air battery (ZAB) is a promising candidate for ESS owing to its high energy density at low cost. Although ZAB has been researched in various aspects, the modeling aspect is still insufficient. Therefore, this work aims to study the modeling of ZAB using both theoretical and empirical approaches. At first, the ZAB system was analyzed using a theoretical approach. The studied system was an integrated system of zinc-air flow battery (ZAFB) and zinc electrolyzer. The zero-dimensional mathematical model was developed in MATLAB and validated against experimental data. The model …

Synthesis, Characteristic And Application Of Mesocellular Foam Carbon (Mcf-C) As Catalyst For Dehydrogenation Of Ethanol, Yoottapong Klinthongchai

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aims to investigate the synthesis of MCF-C as catalyst for dehydrogenation of ethanol. The study was classified into 3 parts. In the first part, the mesocellular foam silica (MCF-Si) was converted to mesocellular foam carbon using a surfactant residue as a carbon source, and followed by testing the dehydrogenation of ethanol to acetaldehyde. Surfactant residue in the inside of MCF-Si could be used as the carbon source for MCF-C synthesis. The obtained material could maintain the meso-structure, and exhibited higher activity for ethanol dehydrogenation in comparison to MCF-Si. For the second part, MCF-C was examined for 12 h …

การเตรียมเเละวิเคราะห์คุณลักษณะของอนุภาคลิโพโซมสำหรับกักเก็บสารอาร์บูตินด้วยเครื่องโฮโมจิไนเซอร์เเรงดันสูง, รัชพล ชูทับ

Chulalongkorn University Theses and Dissertations (Chula ETD)

การกักเก็บสารสำคัญในรูปแบบของอนุภาคลิโพโซม เป็นวิธีการที่ได้รับความนิยมเป็นอย่างมาก เนื่องจากอนุภาคลิโพโซมมีส่วนประกอบที่สามารถเข้ากับร่างกายได้ ไม่มีความเป็นพิษ และสามารถย่อยสลายได้เอง รวมไปถึงช่วยเพิ่มเสถียรภาพของสารที่นำมากักเก็บให้ดีขึ้น วิธีการเตรียมอนุภาคลิโพโซมเพื่อกักเก็บสารเป็นหนึ่งปัจจัยที่จะต้องคำนึงถึง เพราะจะส่งผลต่อการกระจายตัวและขนาดของอนุภาค รวมไปถึงอัตราการปลดปล่อยของสารและเสถียรภาพความคงตัวของอนุภาคลิโพโซมด้วย งานวิจัยนี้มีความสนใจที่จะศึกษาการเตรียมอนุภาคลิโพโซมสำหรับกักเก็บสารอาร์บูตินด้วยเครื่องโฮโมจิไนเซอร์แรงดันสูง เนื่องจากอาร์บูตินเป็นสารที่มีเสถียรภาพต่ำการกักเก็บสารในรูปแบบของอนุภาคลิโพโซมมีความเป็นไปได้ที่จะช่วยเพิ่มเสถียรภาพให้กับสารอาร์บูติน การเตรียมอนุภาคด้วยเครื่องโฮโมจิไนเซอร์แรงดันสูงเป็นวิธีที่สะดวกและรวดเร็ว สามารถเตรียมอนุภาคลิโพโซมได้ในปริมาณที่มาก อีกทั้งยังมีความต่อเนื่องของกระบวนการโดยไม่ต้องผ่านหลายขั้น โดยวัตถุประสงค์ของงานวิจัยต้องการศึกษาปัจจัยต่างๆ ได้แก่ อัตราส่วนระหว่างฟอสโฟลิพิด คลอเรสเตอรอล และสารอาร์บูติน อัตราการปลดปล่อยของสารอาร์บูตินและเสถียรภาพความคงตัวของอนุภาคลิโพโซม รวมไปถึง สภาวะของเครื่องโฮโมจิไนเซอร์แรงดันสูง ได้แก่ ความดันและจำนวนรอบ ที่ใช้ในการเตรียมอนุภาคลิโพโซมเพื่อกักเก็บสารอาร์บูติน จากการศึกษาพบว่า การเตรียมอนุภาคลิโพโซมที่กักเก็บสารอาร์บูตินด้วยเครื่องโฮโมจิไนเซอร์แรงดันสูง ทำให้ได้ลิโพโซมขนาดเล็กที่มีผนังสองชั้นเพียงชั้นเดียว ซึ่งจะมีขนาดของอนุภาคลดลงอย่างมีนัยสำคัญเมื่อเพิ่มความดันและจำนวนรอบของเครื่องโฮโมจิไนเซอร์แรงดันสูง โดยมีขนาดเฉลี่ยอยู่ระหว่าง 150 ถึง 200 นาโนเมตร ผลการทดลองความเข้มข้นของลิพิดต่อความสามารถในการกักเก็บสารอาร์บูติน พบว่า เมื่อเพิ่มความเข้มข้นโดยรวมของลิพิด ประสิทธิภาพการกักเก็บสารมีค่าเพิ่มขึ้น ซึ่งมีค่าประสิทธิภาพการกักเก็บสารเฉลี่ยสูงสุดอยู่ที่ 74.29 เปอร์เซ็นต์ นอกจากนั้น ผลการทดลองยังแสดงให้เห็นว่าการกักเก็บสารสำคัญไว้ในรูปแบบของอนุภาคลิโพโซมและมีการเติมสารคลอเรสเตอรอลลงไปจะสามารถช่วยควบคุมอัตราการปลดปล่อยของสารสำคัญได้ รวมไปถึงช่วยเพิ่มเสถียรภาพความคงตัวให้กับอนุภาคลิโพโซมได้อีกด้วย ดังนั้น สภาวะของเครื่องโฮโมจิไนเซอร์แรงดันสูงและสัดส่วนระหว่างฟอสโฟลิพิดกับคลอเรสเตอรอลที่เหมาะสมในการเตรียมอนุภาคลิโพโซมสำหรับกักเก็บสารอาร์บูติน คือ ความดัน 1000 บาร์ จำนวน 3 รอบ ที่ความเข้มข้นโดยรวมของลิพิดร้อยละ 2 โดยน้ำหนัก อัตราส่วนระหว่างฟอสโฟลิพิดกับคลอเรสเตอรอล 10:2 โดยน้ำหนัก และสภาวะอุณหภูมิในการเก็บรักษาที่ 4 องศาเซลเซียส

Enhanced Methane Hydrate Formation Using Promoters For Natural Gas Storage And Transportation Application, Katipot Inkong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Solidified natural gas (SNG) is an alternative technology for natural gas storage and transportation in the clathrate hydrate formed. It has higher volumetric energy storage with the ease to handle not to mention its safety. Effects of different hydrate promoters, including methyl ester sulfonate (MES), tetrahydrofuran (THF), hollow silica (HS), and sodium dodecyl sulfate (SDS), on the methane hydrate formation was investigated. All experiments were performed in an unstirred tank reactor at desired experimental conditions. The results indicated that all promoters significant enhanced the hydrate formation both kinetics and methane uptake compared with pure water. The increase in the MES …

Synthesis Of Mwcnts By Chemical Vapor Deposition From Methane Using Femo/Mgo Catalyst : Role Of Hydrogen And Kinetic Study, Chawalkul Chotmunkhongsin

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this study, carbon nanotubes (CNTs) were synthesized by chemical vapor deposition (CCVD) of methane over FeMo/MgO catalyst in a fixed-bed reactor. The role of hydrogen on CNTs synthesis and kinetics of CNTs formation were experimentally investigated. The study revealed that hydrogen in the catalyst reduction process plays an important role in the structural changes of FeMo/MgO catalyst. The catalyst structure fully transformed into metallic FeMo, resulting in the increased yield of 5 folds higher than the non-reduced catalyst. However, the slightly larger diameter and lower crystallinity ratio of CNTs was obtained. The hydrogen co-feeding during the synthesis can slightly …

Deposition Of Tio2-Coated Cspbbr3 Perovskite Heterostructure Thin Film, Chutikan Sairot

Chulalongkorn University Theses and Dissertations (Chula ETD)

All-inorganic lead halide perovskite quantum dots have been emerged in recent years for optoelectronic and photovoltaic devices due to their excellent optical properties. In this work, surface coating was carried out by titanium dioxide (TiO2) to coat on the surface of CsPbBr3 PQDs to improve the stability and charge separation property. The FTIR spectra confirmed the formation of TiO2 with an amorphous phase (am-TiO2). The crystallite size of CsPbBr3/am-TiO2 QDs composite was increased to be 13.30 nm from 12.65 nm of CsPbBr3. A slightly decrease of energy bandgap was found compare to CsPbBr3 QDs owing to quantum confinement effect. The …

Preparation And Characterization Of Sequential Curing With Off-Stoichiometric Amine-Diglycidyl Ether Of Bisphenol A /Novolac Epoxy Blended Systems, Pakawat Suttitham

Chulalongkorn University Theses and Dissertations (Chula ETD)

B-stage epoxy adhesives are used in many applications such as electronic devices and prepreg composites. The most common available form is in the film form, rolls, sheets, or custom preforms. In this work, B-staged epoxy adhesives were prepared by using sequential curing with off-stoichiometric amine technique. Diethylenetriamine (DETA) was used as the curing agent for the first curing step. While dicyandiamide (DICY) was used as the latent curing agent for the second curing step and 3-(3,4-dichlorophenyl)-1,1dimethylurea (DIURON) as accelerator for reducing the curing temperature of DICY. Novolac epoxy was blended in diglycidyl ether of bisphenol A (DGEBA) with various ratio …

Reaction Profiling Of Extracellular Protein Phosphorylation Through A Microfluidic Reactor Coupled With Raman Spectroscopy, Abigail Casey

Theses and Dissertations

Diseases and disorders in the human body are considered abnormalities of proper cellular function. Understanding the signal transduction mechanisms that cause these abnormalities is crucial to developing earlier detection methods, better treatment options and effective cures. While current diagnostic procedures are powerful tools in diagnosing diseases, they are ineffective in informing physicians on the real-time behavior of the signal transduction mechanisms associated with diseases and disorders. Currently, disease progression is monitored over time through routine patient visits and testing by one or more of the above techniques. By developing an approach that can monitor structural and conformational changes of proteins …

Structure, Morphology And Composition-Property Elucidation Of Ni–Mo And Ni−Mo−P Nanocrystals For Water Splitting Reactions And Group Iv Alloy And Silicate Nanocrystals For Visible To Near Ir Optoelectronics, Ebtesam Hassan Abuelenein Eladgham

Theses and Dissertations

Abstract

Structure, Morphology and Composition-Property Elucidation of Ni–Mo and Ni−Mo−P Nanocrystals for Water Splitting Reactions and Group IV Alloy and Silicate Nanocrystals for Visible to Near IR Optoelectronics

by

Ebtesam Hassan Abuelenein Eladgham

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University.

Advisor: Indika U Arachchige

Associate Professor, Department of Chemistry

Nanomaterials have gained a great attention because of their unique physical properties with size intermediate between molecular materials and extended solids. They have a large surface to volume ratio and display size tunable physical properties that was not …

Emulsion Stability Of Heavy Oil With Surfactants And Nanoparticles, Zainab Abdulmohsein, Baojun Bai, Parthasakha Neogi

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The recovered crude oil is often in form of an emulsion and the recovery is cut off when water to oil ratio exceeds a certain amount. The emulsions vary from water-in-oil to oil-in-water and the step that follows is to coalesce droplets to get two continuous liquids. Difficulties arise when the oil contains emulsifiers. There are naturally occurring surfactants, or the oil recovered is by enhanced oil recovery techniques which have additives that stabilize the droplets. We have considered below a heavy oil (viscosity 650-750 mPa.s) containing one of the three surfactants: a nonionic surfactant or a cationic surfactant or …

Electrode Improvement And Neural Network-Based Dynamic Optimization Of Vanadium Redox Flow Battery, Apisada Chutimasakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

The performance improvement of a vanadium redox flow battery (VRFB) was focused on this study. The two objectives of this study were (1) to investigate the effect of the operating temperatures of the Atmospheric Pressure Plasma jets (APPJs) process on the energy efficiency of the VRFB and (2) to determine the optimal electrolyte flow rate of the VRFB by solving a dynamic optimization based on a neural network model of the VRFB. The APPJs graphite felt electrode treatment temperature providing the highest energy efficiency of the VRFB was 550°C, explained by the Energy Dispersive X-ray Spectrometry (EDX) and X-ray photoelectron …

A Comparative Simulation Of Glycerol Steam Reforming With Foam And Conventional Pellet Catalysts In Packed Bed Reactor, Chattharika Phitchayakorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aimed to study the effect of different catalyst structures to the hydrogen production process with glycerol steam reforming in packed bed reactors via the COMSOL Multiphysics program. 2D pseudo-homogeneous steady-state model of a 6-inch diameter adiabatic reactor has been developed to describe a transport phenomenon inside the packed bed reactors with two different catalyst structures of conventional 1-inch pellet catalyst and 10-30PPI foam catalyst. The simulated results show that the novel foam catalyst improved the process performance in terms of pressure drop and hydrogen yield comparing to the conventional 1-inch pellet catalyst. The reactor packed with the conventional …

Property Estimation Of Palmitoylethanolamide And Sucrose Palmitate For Process Design From Methyl Palmitate, Janetiya Wongprathed

Chulalongkorn University Theses and Dissertations (Chula ETD)

Methyl palmitate is the primary component of palm oil-based biodiesel. It is a saturated fatty acid methyl ester which has a high melting point that results in low cold flow properties of biodiesel. Besides, lack of government support may affect the revenue of biodiesel business. For that reason, the producers turn attention to using biodiesel as a raw material for the production of value-added chemicals. Initially, we selected the studied products based on the gross profit margin, production process, market demand and application. This work simulated the production of palmitoylethanolamide, sucrose palmitate and normal alkanes from methyl palmitate using Aspen …

Production Of Γ-Valerolactone (Gvl) From One-Pot Cascade Transformation Of Furfural Over Pt/Zeolite-Based Catalysts, Jukkapan Saengin

Chulalongkorn University Theses and Dissertations (Chula ETD)

γ-valerolactone (GVL) is a green renewable resource, which can be used as fuel additives, organic solvent in food industries, pharmaceutical intermediates. The direct production of GVL from furfural in a one-pot transformation is highly desirable in order to minimize the use of solvents, the number of unit operations, and the production cost. The cascade reaction was carried out in a single reactor, using a secondary alcohol as the hydrogen donor with acid catalysts (so-called Meerwein–Ponndorf–Verley reaction). In this work, the transfer hydrogenation of furfural with 2-propanal as a hydrogen donor was investigated on various zeolites including of HY with Si/Al …

Electrochemical Reduction Of Carbon Dioxide To Formate On Bi And Bisn Electrodes Prepared By Electrodeposition On Copper Foil, Jutamas Wasombut

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this study, The Bix/Cu electrocatalysts were prepared by electrodeposition of Bi on Cu foil, and the BixSny/Cu electrocatalysts were prepared by electrodeposition of Bi and Sn on Cu foil in deposition solution bath with different Bi3+ ion concentrations of 0.05, 0.1, and 0.2 M (Bi0.05/Cu, Bi0.1/Cu, Bi0.2/Cu), while the Sn2+ ion concentration was constant at 0.025 M (Bi0.05Sn0.025/Cu, Bi0.1Sn0.025/Cu, Bi0.2Sn0.025/Cu). The electrocatalysts were characterized by SEM-EDX, XRD, and XPS and tested in the electrochemical CO2 reduction reaction. The results demonstrate that the Bi concentrations in the deposition bath affect the structure of Bi into different forms, including bulky structure …