Chemical Engineering Commons^™

The Deactivation Of Gamma-Alumina Based Catalyst During Aqueous Phase Reaction Using Density Function Theory, Phakaorn Aphichoksiri

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, biomass conversion has become a more attractive process to produce fuels and various high-value chemicals from biological materials. From many kinds of catalysts, the metal-supported gamma-alumina (γ-Al2O3) is a widely used catalyst for various transformation processes, especially in the aqueous phase reaction. Typically, coke formation on γ-Al2O3 causes catalyst deactivation in the thermal reaction process. Moreover, incorporation of aqueous phase medium initiates hydroxylation of γ-Al2O3 and phase transformation of γ-AlOOH, leading to the catalyst deactivation. Not only coke formation and phase transformation are the cause of catalytic deactivation, but the oxygen vacancy, changing the activity of the catalyst, should …

Effect Of Hydrochloric Acid Modification On Different Clay Catalystsfor Esterification Of Ethanol And Acetic Acid, Kwanchanok Netcharoen

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aims to investigate the catalytic performance and characteristics of different clays with 0.5 M hydrochloric acid modification such as montmorillonite (HA-MMT), montmorillonite modified with Al (HA/Al-MMT), and kaolinite (HA-K) as a solid catalysts for esterification of ethanol and acetic acid. The reaction was performed in a batch reactor at 80oC, molar ratio of ethanol/acetic acid at 1.5, atmospheric pressure, and catalyst 10%wt of acetic acid for 1 hour. It revealed that hydrochloric acid-activated did not affect to the main structure and functional group of clays. All catalysts were tested for the catalytic performance in esterification of ethanol and …

Development Of Graft Copolymers Of Ultrafine Fully Vulcanized Powdered Natural Rubber With Styrene Or Acrylonitrile Monomers, Niratchaporn Rimdusit

Chulalongkorn University Theses and Dissertations (Chula ETD)

Ultrafine fully vulcanized powdered natural rubber (UFPNRs) were prepared by electron beam irradiation of graft copolymers, i.e. DPNR-graft-polystyrene (DPNR-g-PS) and DPNR-graft-polyacrylonitrile (DPNR-g-PAN), followed by spray drying process. The graft copolymers were prepared by grafting with styrene or acrylonitrile monomer onto deproteinized natural rubber (DPNR) via emulsion polymerization. The effects of monomer contents and radiation doses on thermal properties, chemical structure, swelling behaviors, and morphology of UFPNRs, i.e. UFPNR-GST and UFPNR-GAN were investigated. The results found that the highest grafting efficiency of the DPNR-g-PS and the DPNR-g-PAN were obtained at 15 phr of styrene or acrylonitrile content which provided the highest …

Development Of High Performance Ballistic Hard Armor Based On Fibers Reinforced Polybenzoxazine Alloy Filled With Nanoparticles, Phattarin Mora

Chulalongkorn University Theses and Dissertations (Chula ETD)

The multilayered armor based on fabric reinforced polybenzoxazine (poly(BA-a)) nanocomposites was developed in this research. The effect of nano-SiO2 contents on mechanical property and ballistic impact response of poly(BA-a) nanocomposites is determined for using as strike panel. Essential properties of aramid fabric reinforced polybenzoxazine/urethane (poly(BA-a/PU)) composites influenced by multiwalled carbon nanotube (MWCNT) contents is also investigated for using as support panel. From the results, the mechanical property of the nanocomposite was improved with the addition of nanoparticles. The experimental energy absorption (EAbs) and ballistic limit velocity (Vbl) of the nanocomposites were subjected by 7.62×51 mm projectile at velocity of 847 …

The Potential Of Gold Mine Development Project : A Case Study Of Chifunde District In Mozambique, Sara Mario Mabecuane

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research presents the results of the gold exploration activities developed in the district of Chifunde, Province of Tete in Mozambique. The works showed that in the study area there are two types of deposits which are primary and secondary deposits. There was clear evidence that they have undergone high-grade metamorphism of greenschist due to the grenade occurrences in hornblende in the form of porphyroblast which indicated a high probability of gold occurrence inside amphibolic schist. The results of the SGS laboratory revealed that all samples collected in the area contained gold ranging from 1 to 2,500 ppb, whereas in …

Integrative Co2 Capture And Utilization Process For Methanol Production Through Hydrogenation Reaction Of Co2-Rich Aqueous Penta-Ethylene Hexamine, Wachiramon Khuenkaew

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this study, integration of CO2 capture process with CO2 conversion to methanol process was simulated by Aspen Plus 8.8. The integrative carbon capture and utilization of methanol production can be divided into three main units; CO2 capture unit, methanol synthesis unit, and purification unit. A comparative study between conventional methanol production (case I) and CO2-rich Penta-Ethylene Hexamine (PEHA) conversion to methanol (case II and III) was carried out. Process in case II and III has different product purification processes. In the conventional process, monoethanolamine (MEA) was used in absorber to capture CO2 while PEHA was used in case II …

Fabrication And Characterization Of Bacterial Cellulose-Chitosan/Alginate/Gelatin Hydrogel Scaffolds For Application In Cartilage Tissue Engineering, Phasuwit Phassorn Phatchayawat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Biopolymers of bacterial cellulose (BC), chitosan (C), alginate (A) and gelatin (G) were combined to fabricate three-dimensional (3D) hydrogel composite scaffolds for tissue engineering applications. The bacterial cellulose-chitosan/alginate/gelatin (BCC-AG) hydrogel scaffolds were characterized for chemical property by Fourier transform infrared (FT-IR) spectroscopic analysis, morphology by scanning electron microscopy (SEM), mechanical properties, degradability, biocompatibility and potential application in cartilage tissue engineering. Results from Fourier transform infrared (FT-IR) spectroscopy showed some weak interactions among BC, chitosan, alginate and gelatin, but no chemical interaction between those biopolymers was observed. The morphology of BCC-AG hydrogel scaffolds under SEM observation revealed that alginate and gelatin …

Development Of A Method For Quantification Of Toluene Diisocyanate And Methylenediphenyl Diisocyanate Migration From Polyurethane Foam Sample Surface To Artificial Sweat By Hplc-Uv-Ms, Aleksandra Donchenko, Simon Aubin, Sébastien Gagné, Mark Spence, Livain Breau, Jacques Lesage

Études primaires

The US Environmental protection agency (EPA) has published guidance that includes test procedures for evaluating indoor exposure to chemicals from products. One of the test procedures represents the migration test for evaluating potential dermal exposure from home furniture. Such an evaluation involves the chemical measurement of the sweat which is currently unavailable in the literature. The objective of this project was to develop and validate an analytical method for quantification of migration of 4,4′-methylenediphenyl diisocyanate (MDI), 2,6-toluene diisocyanate (2,6-TDI) and 2,4-toluene diisocyanate (2,4-TDI) from a polyurethane (PU) flexible foam to artificial sweat that meets the recommendations of the EPA test …

อิเล็กโทรดีโพสิชันของโครงสร้างนาโนของทองแดงออกไซด์บนแผ่นรองรับทองแดงสำหรับการรีดักชันเชิงไฟฟ้าของไนตรัสออกไซด์, สิรภัทร นิลวิเชียร

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้ศึกษาการสังเคราะห์โครงสร้างนาโนของทองแดงออกไซด์บนแผ่นรองรับทองแดงโดยใช้วิธีอิเล็กโทรดีโพสิชันเพื่อให้ทองแดงมีพื้นที่ผิวสูงขึ้นเพื่อใช้เป็นตัวเร่งปฏิกิริยาโลหะทองแดงจากออกไซด์ในการทำปฏิกิริยารีดักชันเชิงไฟฟ้าของแก๊สไนตรัสออกไซด์ จากผลการศึกษาพบว่าปริมาณผลึกทองแดงออกไซด์แปรผันตามความหนาแน่นกระแสไฟฟ้าซึ่งหากมีค่าสูงเกินไปจะส่งผลให้เกิดการเกาะติดของผลึกไม่เต็มพื้นผิว นอกจากนี้ อุณหภูมิของอิเล็กโทรไลต์ที่สูงขึ้นทำให้ปริมาณผลึกเพิ่มขึ้นรวมถึงเกิดผลึกขนาดใหญ่ขึ้นอีกด้วย โดยพบว่าการอิเล็กโทรดีโพสิชันด้วยความหนาแน่นกระแสฟ้า -3.33 มิลลิแอมป์ต่อตารางเซนติเมตรและอุณหภูมิของอิเล็กโทรไลต์ 40 องศาเซลเซียสเป็นสภาวะที่ให้พื้นที่ผิวที่สูงที่สุด การอิเล็กโทรดีโพสิชันที่อุณหภูมิ 50 องศาเซลเซียสก่อให้เกิดผลึกขนาดใหญ่อย่างเห็นได้ชัดส่งผลให้พื้นที่ผิวในการทำปฏิกิริยาต่ำลง สำหรับการทำปฏิกิริยารีดักชันเชิงไฟฟ้าของแก๊สไนตรัสออกไซด์ด้วยตัวเร่งปฏิกิริยาโลหะทองแดงจากออกไซด์นั้น พบว่าความหนาแน่นกระแสไฟฟ้าสำหรับการเกิดแก๊สไนโตรเจนแปรผันตามปริมาณตัวเร่งปฏิกิริยาซึ่งเป็นผลมาจากการควบคุมระยะเวลาในการอิเล็กโทรดีโพสิชัน โดยเวลาอิเล็กโทรดีโพสิชันที่เหมาะสมคือ 30 นาที โดยเกิดปฏิกิริยารีดักชันของแก๊สไนตรัสออกไซด์ที่ศักย์ไฟฟ้าเริ่มต้นประมาณ 0.2 V vs RHE และเกิดปฏิกิริยาการผลิตไฮโดรเจนที่ประมาณ -0.3 V vs RHE และเมื่อศักย์ไฟฟ้าสูงขึ้นทำให้ความหนาแน่นกระแสไฟฟ้าสำหรับการเกิดแก๊สไนโตรเจนสูงขึ้นจนถึงศักย์ไฟฟ้าเท่ากับ -0.12 V vs RHE และลดต่ำลงที่ศักย์ไฟฟ้าที่สูงขึ้น ซึ่งให้ความหนาแน่นกระแสไฟฟ้าสำหรับการเกิดไนโตรเจนสูงสุดเท่ากับ -8.61 มิลลิแอมป์ต่อตารางเซนติเมตร และประสิทธิภาพเชิงฟาราเดย์ของการเกิดไนโตรเจนเท่ากับร้อยละ 98.5±1.7 นอกจากนี้ยังพบว่าตัวเร่งปฏิกิริยาทองแดงจากออกไซด์มีความเสถียรต่อการรีดักชันแก๊สไนตรัสออกไซด์เป็นเวลาอย่างน้อย 7 ชั่วโมง

Structural Analysis Of Deformed Caprock Associated With A Salt Shoulder At Gypsum Valley Salt Wall, Paradox Basin, Colorado, Hanah Draper

Open Access Theses & Dissertations

This study documents the style and distribution of deformation present in Triassic-age gypsic and carbonate caprock associated with the Gypsum Valley Salt Wall Salt Shoulder in the Paradox Basin, Colorado in order to determine the mechanism and timing of deformation. Mapping of gypsic and carbonate capstone facies shows that the caprock layering that was generated during formation has been deformed by large-and-small-scale folding and faulting, brecciation, and boudinage. Deformation within the caprock resulted in widely variable orientations along the length of the salt shoulder, that also varies locally in intensity of deformation and with proximity to the passively rising diapir …

Synergistic Effect Of Hydrophilic Nanoparticles And Anionic Surfactant On The Stability And Viscoelastic Properties Of Oil In Water (O/W) Emulations; Application For Enhanced Oil Recovery (Eor), Sarmad Al-Anssari, Zain-Ul-Abedin Arain, Haider A. Shanshool, Alireza Keshavarz, Mohammad Sarmadivaleh

Research outputs 2014 to 2021

With the rapidly increased global energy demand, great attention has been focused on utilizing nanotechnology and particularly nanofluids in enhanced oil recovery (EOR) to produce more oil from low-productivity oil reservoirs. Nanofluid flooding has introduced as one of the promising methods for enhanced oil recovery using environment-friendly nanoparticles (NPs) to be as an innovative-alternative for chemical methods of EOR. This work investigates the synergistic effects of anionic surfactant and hydrophilic silica nanoparticles on the stability and the mechanical behavior of oil in water (O/W) emulsions for their application in EOR. To achieve this, an extensive series of experiments were conducted …

Organophosphorus-Hydrazides As Potential Reactive Flame Retardants For Epoxy, Alexander B. Morgan, Vladimir Benin, Donald A. Klosterman, Abdulhamid Bin Sulayman, Mustafa Mukhtar, Mary L. Galaska

Chemical and Materials Engineering Faculty Publications

For structural composites used in vehicles and aircraft, flame retardant chemistries which enhance char formation and reduce heat release are preferred. Phosphorus-based and phosphorus–nitrogen flame retardants for epoxies have been well studied to date, but phosphorus hydrazides have not been studied for their flame-retardant potential in epoxy. These hydrazides offer some novel structures and they can potentially offer a combination of vapor and condensed phase flame retardant action. A series of eight compounds were systematically investigated in this study as reactive flame retardants in a bisphenol F epoxy/aliphatic amine resin system at a level of 2.5 wt% phosphorus. Results suggest …

Towards Efficient Water Treatment: Mechanism Of Colloidal Fouling Of Ultrafiltration Membranes, Ikenna Henry Ozofor

Dissertations, Master's Theses and Master's Reports

This research study first reviewed challenges of conventional and membrane separation systems for water treatment. Though membrane separation systems appeared superior to the conventional counterparts for water and wastewater treatment, wider applications of membrane systems have been limited by some factors, most notably is membrane fouling. Experimental studies were therefore conducted to achieve the goal of this research, which is to investigate how feed properties affect fouling of ultrafiltration (UF) membranes by colloids.

Feed salinity, pH, and nanoparticle concentration were the variables studied to unravel how different UF membranes are fouled by model silica colloids (with average diameter of 25nm). …

Detection And Thermal Stabilization Of Virus Based On Surface Properties, Xue Mi

Dissertations, Master's Theses and Master's Reports

Viral diseases take the lives of millions of people each year. The most effective methods to prevent viral disease outbreak are viral detection to reduce contact with viral pathogens and vaccines to prevent disease. To reduce the costs of the detection of viruses and improve vaccine formulation, we explored viral surface properties. The properties we have focused on are viral hydrophobicity and surface charge using chemical force microscopy (CFM). CFM is a single-particle technique that measures the adhesion force of a functionalized atomic force microscopy (AFM) probe, and in this study, a virus covalently bound to a surface. The non-enveloped …

Virus Purification Framework And Enhancement In Aqueous Two-Phase System, Pratik Umesh Joshi

Dissertations, Master's Theses and Master's Reports

Viral infections regularly pose detrimental health risks to humans. Preventing viral infections through global immunization requires the production of large doses of vaccines. The increasing demand for vaccines, especially during pandemics such as COVID-19, has challenged current manufacturing strategy to develop advanced unit operations with high throughput capability. Over the decade, the upstream processing responsible for synthesizing viral products in cell cultures has shown significant success in yielding high titers of viruses and virus-like particles. The progress in the upstream stage has now shifted the bottleneck to the downstream processing (DSP). Overlooked for decades, the DSP responsible for viral product …

Continuous Viral Vaccine Manufacturing And Viral Detection Strategies, Dylan G. Turpeinen

Dissertations, Master's Theses and Master's Reports

Viruses are responsible for many human diseases that lead to suffering and death. Acquired immunodeficiency syndrome (AIDS), influenza, and coronavirus disease 2019 (COVID-19) have claimed the lives of millions of people. Two methods have been created to reduce the suffering caused by these diseases. The first is the manufacturing of vaccines that prevent disease and the second is the development of virus detection tests that lead to treatment. The work summarized in this dissertation discusses the development of a continuous virus purification process using an aqueous two-phase system for use in vaccine manufacturing. Additionally, two novel virus detection methods were …

Role Of Flocculation And Dispersion In Pelletization Of Iron Ore, Victor J. Claremboux

Dissertations, Master's Theses and Master's Reports

Traditional modeling of iron ore pellet strength utilizes micromechanical models such as Rumpf’s equation, which correlate attractive forces and pellet properties into an average expected pellet strength. These models combine with repulsive forces within pellets to predict that pellet strength decreases with the introduction of these forces. However, naïvely applying Rumpf’s equation readily leads to incorrect predictions about the resulting behavior. Pellets created with strong repulsive forces arising from dispersion conditions are observed to be significantly stronger overall than pellets formed in the absence of dispersants. A new model is required to understand and predict the effects of these additives …

Virus-Like Particle Vaccine Manufacturing From Yeast, Ananya Ananya

Dissertations, Master's Theses and Master's Reports

Influenza virus has an intrinsic nature to undergo mutations. Hence, there have been struggles to combat this disease since the time when the worst influenza pandemic first hit in 1918. Vaccines have proved to be effective in controlling the spread of the influenza A virus by providing herd immunity. However, the contemporary design of influenza A virus based on egg and cell-culture is not efficient in tackling influenza A virus transformation. Virus-like particles (VLPs) have established themselves as a potental platform for future vaccine candidates. VLPs have all the credentials to supplant contemporary vaccine designs without compromising on immunogenicity. For …

Lipemia Levels Analysis From Human Blood Samples, Zainab Ibrahim Alshoug

Dissertations, Master's Theses and Master's Reports

Worldwide, an estimated 31% of people who die each year have a cardiovascular disease (CVD), an all-encompassing group of diseases and conditions of the heart or blood vasculature. Access to portable, user-friendly tools to test lipid levels accurately and efficiently, without requiring large volume blood draws, will help improve access to wellness management by reducing costs and facilitating early screening and monitoring of CVD thus improving outcomes. Point of care micro or millifluidic chips to test biofluids that are integrated into detection units are an attractive measurement tool because of their potential for ease of use by patients at home …

Innovative Sustainable Wood Preservatives From Pulp And Paper Industry Byproduct, Raisa Carmen Andeme Ela

Dissertations, Master's Theses and Master's Reports

In the modern forest industry, the need for bio-based, renewable, and environmentally-benign wood preservatives is increasing. Preservatives are used to prevent or limit decay and there has been an increasing interest in developing wood preservatives from renewable materials. To support the need for bio-based, environmentally-friendly preservatives, this work employed kraft lignin as a raw material to produce a novel bio-based wood preservative.

For the first project, a statistical design of experiments approach in Minitab® was used to study how fractionation process variables during acid precipitation of lignin influence the lignin mass yield and characteristics. After precipitating lignin from black liquor, …