Engineering Commons^™

Synthesis, Design, And Evaluation Of The Fluorescent Detection Of Polychlorinated Biphenyls(Pcbs) In Aqueous System, Irfan Ahmad

Theses and Dissertations--Chemical and Materials Engineering

The exposure to halogenated persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), has been linked to numerous inflammatory diseases, including diabetes, cancer and lowered immune response. PCBs have low solubility in water, and they interact with other contaminants, making their detection quite challenging. While, there have been several attempts at improving the ease of detection and sensing of PCBs, gas chromatography-mass spectrometry (GC-MS) remains the gold standard. However, despite its ubiquitous use, GC-MS is a challenging technique that requires high skill and careful sample preparation, which are time-consuming and costly. As such, there is still a need to develop …

Operation And Process Control Development For A Pilot-Scale Leaching And Solvent Extraction Circuit Recovering Rare Earth Elements From Coal-Based Sources, Douglas Kweku Addo

Theses and Dissertations--Mining Engineering

The US Department of Energy in 2010 has identified several rare earth elements as critical materials to enable clean technologies. As part of ongoing research in REEs (rare earth elements) recovery from coal sources, the University of Kentucky has designed, developed and is demonstrating a ¼ ton/hour pilot-scale processing plant to produce high-grade REEs from coal sources. Due to the need to control critical variables (e.g. pH, tank level, etc.), process control is required. To ensure adequate process control, a study was conducted on leaching and solvent extraction control to evaluate the potential of achieving low-cost REE recovery in addition …

Design Process For The Containment And Manipulation Of Liquids In Microgravity, Chris Meek

Theses and Dissertations--Mechanical and Aerospace Engineering

In order to enhance accessibility to microgravity research, the design process for experiments on the ISS must be streamlined and accessible to all scientific disciplines, not just aerospace engineers. Thus, a general design and analysis toolbox with accompanying best practices manual for microgravity liquid containment is proposed. The work presented in this thesis improves the design process by introducing a modular liquid tank design which can be filled, drained, or act as a passive liquid-gas separation device. It can also be pressurized, and used for aerosol spray. This tank can be modified to meet the design requirements of various experimental …

Novel Adsorbent For Industrial Wastewater Treatment Applications, Islam M. Al-Akraa, Ahmed Y. Zakaria Eng, Dalia A. Ali Eng, Hany A. Elazab Dr, Hoda A. Elsawy Dr

Chemical Engineering

In this study, the hydroxyapatite powder is investigated for both of methylene blue and thymol blue in aqueous solution. The physical and chemical properties of the adsorbent were evaluated systematically using the different techniques including Microsoft Excel programming, linear regression model and also the coefficient of determination. Batch adsorption experiments were conducted to determine the effect of contact time, solution pH, initial dye concentrations, and also the adsorbent dosage on adsorption. The adsorption kinetic parameters confirmed the better fitting of pseudo-second order kinetic model for both of methylene blue and thymol blue. The isotherm data of methylene blue and thymol …

Enhanced Electro-Oxidation Of Methanol At Pt-Au Nanocatalyst For Direct Methanol Fuel Cells, Islam M. Al-Akraa Dr., Yaser M. Asal Mr, Ahmad M. Mohammad Prof

Chemical Engineering

In this investigation, a Pt-Au nanocatalyst prepared by the coelectrodeposition of Pt (PtNPs) and Au (AuNPs) nanoparticles is assembled onto a glassy carbon (GC) electrode for efficient methanol oxidation (MO). Several molar ratios between PtNPs and AuNPs have been used and the corresponding catalytic activity towards MO is tracked. The Pt1:Au1 catalyst showed the highest catalytic activity (5 times higher oxidation peak current (Ip) and a 126 mV negative shift in the onset potential (Eonset) toward MO). The catalyst’s morphology, composition and activity are investigated and the ehancement mechanism is recognized.

A Simple And Effective Way To Overcome Carbon Monoxide Poisoning Of Platinum Surfaces In Direct Formic Acid Fuel Cells, Islam M. Al-Akraa Dr., Yaser M. Asal Mr, Sohair A. Darwish Ms

Chemical Engineering

A glassy carbon (GC) electrode modified with multi-walled carbon nanotubes (MWCNTs) and platinum nanoparticles (PtNPs), Pt/MWCNTs-GC, has been introduced for formic acid electro-oxidation (FAO). A similar loading of PtNPs has been conserved for a proper comparison between the Pt/MWCNTs-GC and the unmodified Pt/GC electrodes. The modification with MWCNTs could enhance the loading of PtNPs onto the GC electrode in a way that minimizes its agglomeration and increases its dispersion in the CNTs network. This not only increases the surface area exposed to the reaction but also interrupts the contiguity of the Pt active sites minimizing the adsorption of the poisoning …

Empirical Modeling Of Urea Synthesis Chemical Equilibria, Moustafa A. Soliman

Chemical Engineering

In this paper empirical formulas for the chemical equilibrium of reactions involved in urea synthesis are derived. Their accuracy is checked against data obtained from the application of Aspen Plus to a urea plant based on Stamicarbon technology. The accurate results obtained support their application in the simulation of the reactions involved in urea synthesis.

A Promising Modification Of Pt Surfaces With Cnts For Decreasing Poisoning Impact In Direct Methanol Fuel Cells, Islam M. Al-Akraa Dr., Yaser M. Asal Mr, Aya A. Khalifa Ms.

Chemical Engineering

Direct methanol fuel cells (DMFCs) are clean energy sources that have many applications due to the high energy density of methanol as a fuel. However, this type of fuel cells (FCs) has limitations that are preventing it from being commercialized. One such limitation is the adsorption of intermediates such as CO into the surface of the Platinum (Pt) catalyst during methanol oxidation (MO) which deactivates its active sites, where the reaction is taking place, and leads to poisoning of the electrode over the long term. In this study, multi-walled carbon nanotubes (MWCNTs) have been introduced to the Pt-modified glassy carbon …

Exploring The Role And Impact Of Microscale Phenomena On Electrode, Microdevice, And Cellular Function, Sanaz Habibi

Dissertations, Master's Theses and Master's Reports

Microfluidic technologies enable the development of portable devices to perform multiple high-resolution unit operations with small sample and reagent volumes, low fabrication cost, facile operation, and quick response times. Microfluidic platforms are expected to effectively interpret both wanted and unwanted phenomena; however, a comprehensive evaluation of the unwanted phenomena has not been appropriately investigated in the literature. This work explored an attenuative evaluation of unwanted phenomena, also called here as secondary phenomena, in a unique approach.

Upon electric field utilization within microfluidic devices, electrode miniaturization improves device sensitivity. However, electrodes in contact with medium solution can yield byproducts that can …

Charged Nanoparticles Quench The Propulsion Of Active Janus Colloids, Marola W. Issa, Nicky R. Baumgartner, Mohammed A. Kalil, Shawn D. Ryan, Christopher L. Wirth

Mathematics and Statistics Faculty Publications

Active colloidal particles regularly interact with surfaces in applications ranging from microfluidics to sensing. Recent work has revealed the complex nature of these surface interactions for active particles. Herein, we summarize experiments and simulations that show the impact of charged nanoparticles on the propulsion of an active colloid near a boundary. Adding charged nanoparticles not only decreased the average separation distance of a passive colloid because of depletion attraction as expected but also decreased the apparent propulsion of a Janus colloid to near zero. Complementary agentbased simulations considering the impact of hydrodynamics for active Janus colloids were conducted in the …

Modification Of Lipid Microenvironments On Solid Support Structures For Use In Transmembrane Protein Assays, William J. Houlihan

Dissertations and Theses

Gamma-Secretase (γ-secretase) is a transmembrane protease of increasing interest, which has been shown to have significant connections to both cancer and Alzheimer’s disease. γ-secretase cleaves both Notch-1, a transmembrane signaling protein, and Amyloid precursor protein (APP), a transmembrane protein whose cleavage may result in the formation of β-amyloid plaques in the brain. Notch-1 and APP are widely studied proteins that have substantial impacts on the development and proliferation of cancer and Alzheimer’s disease, respectively. Notch-1 partakes in the signaling of apoptosis in damaged and mutated cells, thus its cleavage by γ-secretase within the plasma membrane has ramifications on cell growth …

Degradation And Hydrate Phase Equilibria Measurement Methods Of Monoethylene Glycol, Khalid Alef, Stefan Iglauer, Ahmed Barifcani

Research outputs 2014 to 2021

Monoethylene glycol (MEG), a common chemical used for the inhibition of gas hydrate formation may undergo degradation in the regeneration/reclamation process. Limited research exists on the effect of degradation of MEG on hydrate formation, production facilities and equipment especially in the presence of other chemical additives. The proposed method allows for streamlining the process of preparing, degrading and analysis of MEG solutions for hydrate testing and degradation products.

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Procedure to prepare accurate MEG solutions avoiding oxidative degradation of MEG (i.e., controlling oxygen ingress).

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Two methods are suggested to mimic field-like degradation of MEG solutions (i.e., degradation by reclamation …

Sorption Enhanced Chemical Looping Steam Ethanol Reforming For Hydrogen Production Using Calcium Oxide/Nickel Oxide/Iron Oxide Multifunctional Catalyst, Janenipa Saupsor

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research studied the hydrogen production via sorption enhanced chemical looping reforming process from ethanol both computationally and experimentally. In the computer simulation work, four hydrogen production processes including conventional ethanol steam reforming (ESR), sorption enhanced steam reforming (SESR), chemical looping reforming (CLR) and sorption enhanced chemical looping reforming (SECLR) were performed using NiO as the oxygen carrier and CaO as the CO2 sorbent, and simulated on the basis of energy self-sufficiency, i.e. process energy requirement supplied by burning some of the produced hydrogen. The process performances in terms of hydrogen productivity, hydrogen purity, ethanol conversion, CO2 capture ability and …

One-Pot Conversion Of Furfural To G-Valerolactone Over Co- And Pt-Doped Zsm-5 Catalysts, Warucha Auppahad

Chulalongkorn University Theses and Dissertations (Chula ETD)

γ-Valerolactone (GVL) is one of the useful biomass compounds produced via different reaction pathways from hemicellulose. Typically, GVL is produced by conversion of furfural using supported metal catalysts. In this study, Co- and Pt-doped /ZSM-5 catalysts with Co loadings (0-10 wt%) and Pt loadings (0.5-2 wt%) were prepared by impregnation method and employed in the one-pot conversion of furfural to GVL. The reactions were carried out in a 100 cm3 batch stainless steel reactor at 120 oC atmospheric pressure for 5 h. The products were analysed by gas chromatography (GC) and gas chromatography-mass spectroscopy (GC-MS). The major products were GVL, …

Geomechanical Modeling Of Salt Cavern Stability For Carbon Dioxide Storage In The Maha Arakham Formation, Northeastern Thailand, Narumas Pajonpai

Chulalongkorn University Theses and Dissertations (Chula ETD)

In Thailand, CO2 emissions quadrupled over the past three decades since 1989, with the power generation sector as the main contributor by burning fossil fuels to produce electricity. Therefore, the power generating industry has come under scrutiny and been pressed by society to take responsibility. Carbon Capture and Storage (CCS) is one of the many methods to deal with CO2 emissions. Generally, CO2 is captured and stored in geological formations, e.g. rock salt deposits. Salt caverns have been intensively studied regarding their usage for CO2 storage because of their favourable characteristics. In this research, the Finite Element Method (FEM, ANSYS …

การขจัดพอลิไซคลิกแอโรแมติกไฮโดรคาร์บอนในน้ำมันไพโรไลซิสจากยางรถยนต์เหลือทิ้ง, สุรีกาญจน์ กิ่งพุทธพงษ์

Chulalongkorn University Theses and Dissertations (Chula ETD)

น้ำมันที่ได้จากการไพโรไลซิสยางรถยนต์เหลือทิ้ง (waste tire pyrolysis oil, WTPO) ประกอบไปด้วยสารประกอบพอลิไซคลิกแอโรมาติกส์ไฮโดรคาร์บอน (polycyclic aromatic hydrocarbon, PAHs) ประมาณ 10% โดยน้ำหนักเมื่อเทียบกับปริมาณ WTPO โดย PAHs ที่พบมากที่สุด คือ แนฟทาลีน ซึ่งมีความเป็นพิษต่อมนุษย์และสิ่งแวดล้อม นี่จึงเป็นข้อจำกัดที่ทำให้ไม่สามารถนำ WTPO ไปใช้ในเครื่องยนต์ได้ ในงานวิจัยนี้จึงศึกษาการกำจัดแนฟทาลีนซึ่งเป็นแบบจำลองของ PAHs ผ่านกระบวนการไฮโดรจิเนชัน โดยใช้ตัวเร่งปฏิกิริยานิกเกิลบนตัวรองรับแกมมาอะลูมินา (Ni/γ-Al2O3) ที่มีและไม่มีตัวสนับสนุนโมลิบดินัม (Mo) ทังเสตน (W) หรือ แพลตินัม (Pt) สำหรับภาวะที่ศึกษาในการไฮโดรจิเนชัน ได้แก่ ความดันแก๊สไฮโดรเจนเริ่มต้น (10-40 บาร์) อุณหภูมิ (250-400 องศาเซลเซียส) และระยะเวลาในการทำปฏิกิริยา (2-8 ชม.) ก่อนทำปฏิกิริยาตัวเร่งปฏิกิริยาถูกรีดักชัน (reduction) แบบอิน-ซิทู (in-situ) ที่ความดันแก๊สไฮโดรเจนเริ่มต้น 30 บาร์ อุณหภูมิ 400 องศาเซลเซียส เป็นเวลา 2 ชม. ในกรณีที่ไม่มีตัวสนับสนุน Ni ปริมาณ 1-30% โดยน้ำหนักเมื่อเทียบกับตัวรองรับถูกเตรียมลงบน γ-Al2O3 ที่ถูกเตรียมด้วยวิธีไฮโดรเทอร์มัล และค่าการเปลี่ยนแปลงแนฟทาลีนถูกวิเคราะห์ด้วยแก๊สโครมาโทกราฟี ตัวตรวจวัดชนิดเฟลมไอออไนเซชัน (GC-FID) พบว่าเมื่อใช้ตัวเร่งปฏิกิริยาที่มีปริมาณ Ni 20% โดยน้ำหนักเมื่อเทียบกับตัวรองรับให้ค่าการเปลี่ยนแปลงแนฟทาลีนสูงสุดที่ 29.5% โดยภาวะที่ใช้ คือความดันไฮโดรเจนเริ่มต้น 30 บาร์ อุณหภูมิ 350 องศาเซลเซียส นาน 4 ชั่วโมง ในกรณีมีตัวสนับสนุน ตัวเร่งปฏิกิริยา NiMo NiW และ NiPt ให้ค่าการเปลี่ยนแปลงแนฟทาลีนสูงสุดที่ 44.7 46.4 และ 55.8% เมื่ออัตราส่วนเชิงอะตอมของตัวสนับสนุนเป็น 0.27 0.05 และ …

Investigating The Use Of Different Types Of Sealant Materials For Cement Remedial Applications, Murad Mohammedahmed Abdulfarraj

Doctoral Dissertations

"The overall objective is to investigate the ability of several material to mitigate cement failures such as channels, fractures, and micro-annuli in oil and gas wells. The sealant material that can also be used in the wells that are used for geologic storage of carbon dioxide CO₂. Evaluating the sealant material is critical to improve the zonal isolation of the wells, which would lead to safer operations. The approach of this dissertation is to utilize particles gel that has been used successfully in conformance control application, and epoxy resin systems, that have superior seal characteristics compared to conventional …

Diffusion Kinetics In Promising Adsorbents For Gas Capture Processes, Teresa Gelles

Masters Theses

"This reports the results of experimental studies aimed at characterizing the transport properties of promising adsorbents for various gas capture processes by the "zero length column" (ZLC) technique. ZLC was used to measure the intracrystalline diffusivities of single and binary components of ethane and ethylene in powder and pellet samples of paraffin-selective adsorbents Ni(bdc)(ted)_0.5 (Ni-BT) and ZIF-7 for the purpose of olefin/paraffin separation. Results show that binary gaseous systems result in intracrystalline diffusion time constants slightly lower than those in single component gaseous streams due to coadsorption effects. It was also found that ethylene diffusion was affected by surface …

Computational Fluid Dynamics Modeling Of Proppant Static Settling Velocity In High Viscosity Friction Reducers, Chen Yuan

Masters Theses

"In the current petroleum fracturing industry, it is necessary to understand the downhole migration and settling velocity of the proppant. If we can master this information well, it will be a great help to obtain effective propped fracture conductivity. In order to study the transport of proppants in the well, we used laboratory experiments and computer numerical simulations to compare the results to get a meaningful conclusion. We spent a lot of time building models on a powerful computer and comparing the experimental conclusions. We finally decided to use computational fluid dynamics (CFD) as the simulation platform, discrete phase method …

Modeling Overpressure Development During Shale Rock Compaction Coupling Poroelasticity And Permeability Evolution Above 3km Depth, Wenyu Zhao

Masters Theses

"The evolution of pore pressure including overpressure during sedimentation is an important process to consider when analyzing whether high pore pressure causes rock failure. High pore pressure is caused by under-compaction due to the rapid burial of low-permeability sediments, and as a result, porosity decreases less rapidly with depth than in normally compacted sediments where porosity decreases exponentially with depth. While under-compaction related pore pressure magnitudes have been determined empirically, in most numerical modeling approaches, the pore pressure is either applied as a static magnitude or coupled to a fluid flow simulator. This study simulates the pore pressure evolution during …

Developing A Model System Of Liquid Lubricants For Space Applications: Multiple Alkylated Cyclopentane In Alumina Enclosed Surface, Vidit Singh

Masters Theses

"Lubricants are substances used for reducing friction wear tear and energy losses between two moving bodies. For space applications, normal lubricants cannot be used as they cannot survive the harsh and demanding conditions of space. Multiple Alkylated Cyclopentanes (MACs) have been utilized as space lubricants in recent times with tremendous results. NASA uses the MACs for their missions in space, in particular 1,3,4- tri-(2-octyldodecyl) cyclopentane sold by Nye Lubricants under the name of Pennzane^TM.

In this research, an effort has been made to identify appropriate potential models for simulating Pennzane molecules and to develop MD simulation codes to …

Methane Dry Reforming Reaction On Cr, V, In, And Ga Supported Sapo-34 Zeolite, Ehigiator Festus Ojo

Masters Theses

”The CO₂ reforming of methane is a significant research area in mitigating and transforming two greenhouse gases for the production of syngas. The reaction has been investigated for four different promoted catalysts to determine their reactant's conversion, product’s selectivity, and their respective syngas ratios.

The catalytic test was investigated under atmospheric conditions at 600⁰C for 6.5h with a WHSV of 4800 ml g^-1 h^-1. The conversion and selectivity of catalysts 9Al 1V-inc SAPO-34, 9Al 1Cr-inc SAPO-34, 9Al 1Ga-inc SAPO-34, and 9Al 1In-inc SAPO-34 were analyzed. The CH₄ conversion for the different catalysts are, 9Al 1Cr-inc …

Design Of Geothermal District Heating And Cooling System For The West Virginia University, Oluwasogo Bolaji Alonge

Graduate Theses, Dissertations, and Problem Reports (ETD)

Recent Appalachian Basin Geothermal Play Fairway Analysis estimated elevated heat flows in north-central West Virginia. This region provides an optimal and unique combination of elevated temperatures and flow necessary for geothermal development along with year-round surface demand for heating and cooling on the campus. Therefore, West Virginia University’s (WVU’s) Morgantown campus has been identified as a prime location in the eastern United States for the development of a geothermal direct-use heating and cooling application. The objective of this study was to perform a feasibility analysis for the development of a geothermal district heating and cooling (GDHC) system for WVU campus …

Ionic Liquid-Based Composite Thin-Films For Selective Ion Separations In Electrodialysis, Saloumeh Kolahchyan

Electronic Theses and Dissertations

The onset of climate change and rising global population has caused greater water scarcity, a considerable problem which threatens our world. The demand for fresh water is pushing a fast development of water purification technologies. Among these technologies, membrane-based water desalination processes are playing an interesting role in both academia and industry. Electrodialysis (ED) is an electro-membrane separation process aimed at water treatment through ion removal, which is achieved through the selective control and transport of ionic species. ED is a popular water treatment method; however, it is limited by membrane scaling, lack of ion selectivity, and high energy consumption …

Hydrophobization Of Cellulose-Based Fibers For Packaging Applications With Alkyl Ketene Dimers (Akd) And Food-Grade Waxes Via Supercritical Impregnation With Carbon Dioxide – Experimental And Thermodynamic Modeling Approaches, Kolawole Adenekan

Electronic Theses and Dissertations

This modified material has applications in food packaging, where frequently water-repellant surfaces are required. This method is preferable to traditional coating methods because it sizes across the entire thickness of the substrate rather than just the surface and can be used for non-planar surfaces; uses significantly less material than traditional methods and will be an excellent technique for multilayered and intelligent coating.

Cellulose Nanocrystals As 'Green' Emulsifiers Stabilized Crude Oil In Water Emulsions, Omayma Alazzam

Electronic Theses and Dissertations

This study examines the ability of CNC to stabilize crude o/w Pickering emulsions. The effects of concentration of CNC, ionic strength of the aqueous phase, volume fraction of crude oil to water, and the presence of divalent ions on the stability of crude o/w emulsions were examined. Emulsions stabilized with different concentrations of CNC vary from 0.1 to 1.0wt% were prepared and examined by visual assessment for creaming analysis and microscopic pictures to analyze droplet size and size distribution. Low concentration of CNC as 0.1wt% didn’t help with forming stable emulsions. As the concentration of CNC stabilized the emulsions increased, …

An Elastic-Net Logistic Regression Approach To Generate Classifiers And Gene Signatures For Types Of Immune Cells And T Helper Cell Subsets, Arezo Torang, Paraag Gupta, David J. Klinke Ii

Faculty & Staff Scholarship

Background: Host immune response is coordinated by a variety of different specialized cell types that vary in time and location. While host immune response can be studied using conventional low-dimensional approaches, advances in transcriptomics analysis may provide a less biased view. Yet, leveraging transcriptomics data to identify immune cell subtypes presents challenges for extracting informative gene signatures hidden within a high dimensional transcriptomics space characterized by low sample numbers with noisy and missing values. To address these challenges, we explore using machine learning methods to select gene subsets and estimate gene coefficients simultaneously. Results: Elastic-net logistic regression, a type of …

การประเมินค่าพารามิเตอร์ทางจลนศาสตร์ของปฏิกิริยาการออกซิไดซ์โทลูอีนบนตัวเร่งปฏิกิริยา V2o5/Tio2 มาใช้ออกแบบสำหรับปฏิกิริยา Scr, วราภรณ์ คิดการ

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้ทำการประมาณค่าพารามิเตอร์ทางจลศาสตร์ของปฏิกิริยาการออกซิไดซ์โทลูอีน ด้วยตัวเร่งปฏิกิริยา V2O5/TiO2 ที่ปรับสภาพด้วยสารละลายกรดกำมะถันในการกำจัด โทลูอีน โดยตัวรองรับไทเทเนียได้รับการปรับสภาพด้วยสารละลายกรดกำมะถันที่มีความเข้มข้น 0, 0.2 และ 0.5 M ตัวเร่งปฏิกิริยาเตรียมด้วยวิธีเคลือบฝังแบบเปียก ทำการวิเคราะห์คุณลักษณะของตัวเร่งปฏิกิริยา V2O5/TiO2 ด้วยเทคนิคต่าง ๆ ได้แก่ SEM-EDX, Nitrogen Physisorption, XRD และ NH3-TPD ทำการทดสอบความสามารถในการออกซิไดซ์โทลูอีนที่ความเข้มข้นของโทลูอีน 300 - 400 ppm และความเข้มข้นของ O2 3, 12 และ 21 %vol ในช่วงอุณหภูมิ 150-350 °C จากการศึกษาพบว่าที่ตัวเร่งปฏิกิริยาเดียวกัน เมื่อความเข้มข้นของ O2 เพิ่มขึ้น ส่งผลให้ค่า Conversion ของการออกซิไดซ์โทลูอีนดีขึ้นเล็กน้อย และตรวจพบ CO2 ในปริมาณที่ต่ำแสดงว่าโทลูอีนอาจเกิดการเปลี่ยนแปลงไปเป็นสารอินทรีย์ที่มีจุดเดือดสูง จากการประมาณค่าพารามิเตอร์ทางจลศาสตร์ของตัวเร่งปฏิกิริยา V2O5/TiO2 พบว่าในปฏิกิริยาการออกซิไดซ์โทลูอีน เมื่อความเข้มข้นของ O2 เพิ่มขึ้นค่าพลังงานกระตุ้นมีค่าลดลง โดยค่าพลังงานกระตุ้นที่ความเข้มข้น O2 3 %vol อยู่ในช่วง 44-49 kJ/mol ที่ความเข้มข้น O2 12 %vol อยู่ในช่วง 45-49 kJ/mol และที่ความเข้มข้น O2 21 %vol อยู่ในช่วง 39-45 kJ/mol เมื่อเปรียบเทียบปฏิกิริยาการออกซิไดซ์โทลูอีนในสภาวะที่มี NO ร่วมด้วยนั้น พบว่ามีปฏิกิริยาอื่นเกิดขึ้นร่วมด้วย โดยจะเห็นปฏิกิริยาเกิดขึ้นสองช่วงอย่างเด่นชัด คือ ช่วงอุณหภูมิ 150-200 °C มีพลังงานกระตุ้นที่ต่ำและช่วงอุณหภูมิ 250 °C ขึ้นไป ที่มีพลังงานกระตุ้น 45-50 kJ/mol และตรวจพบ CO2 อย่างเห็นได้ชัด แสดงให้เห็นว่า NO มีบทบาทในการเปลี่ยนสารมัธยันต์ที่เกิดจากการสลายตัวของโทลูอีนให้เปลี่ยนไปเป็น CO2

The Mixed Integer Non-Linear Programming For Combined Heat And Mass Exchanger Network Synthesis With The Effect Of Emcd And Emat On Economic Analysis, Eleonora Amelia

Chulalongkorn University Theses and Dissertations (Chula ETD)

The Combined Heat and Mass Exchanger Network Synthesis (CHAMENS) which comprised a win-win strategy simultaneously diminishing the emission alongside maximizing the profits of the whole systems has been accomplished in this work. The novelty comes from the development of the original stage-wise superstructure (SWS) to be able to overcome the problems including detailed cost considerations by using more accurate formularies to determine the exchanger configurations, initializations, favorable boundaries to solve the complexities, eradicate the number of the heat and mass exchangers, and decrease the TAC. The purpose of this work is generate the new applicable method which is noticeable and …

Effects Of Mixing Methods Of Bifunctional Catalysts On Catalyst Stability Of Dme Synthesis Via Co₂ Hydrogenation, Shoujie Ren, Shiguang Li, Naomi Klinghoffer, Miao Yu, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

The effects of three different mixing methods of CuO/ZnO/Al₂O₃ (CZA) and HZSM-5 bifunctional catalyst on the stability for dimethyl ether (DME) synthesis from carbon dioxide (CO₂) hydrogenation were investigated. When the bifunctional catalyst was prepared by method A (mixing powder without pelletization), there was no significant change in DME production and catalyst stability when the HZSM-5 loading was varied between 0.1 g and 0.5 g with a fixed CZA loading of 0.5 g,. When the bifunctional catalysts were prepared by method B (pressed into pellets of CZA and pellets of HZSM-5 and then mixed) and …