Chemical Engineering Commons^™

Investigating The Performance Of High Viscosity Friction Reducers Used For Proppant Transport During Hydraulic Fracturing, Mohammed Salem Ba Geri

Doctoral Dissertations

"Over the last few recent years, high viscosity friction reducers (HVFRs) have been successfully used in the oil and gas industry across all premier shale plays in North America including Permian, Bakken, and Eagle Ford. However, selecting the most suitable fracture fluid system plays an essential role in proppant transport and minimizing or eliminating formation damage.

This study investigates the influence of the use of produced water on the rheological behavior of HVFRs compared to a traditional linear guar gel. Experimental rheological characterization was studied to investigate the viscoelastic property of HVFRs on proppant transport. In addition, the successful implication …

Experimental Study On Enhanced Oil Recovery (Eor) Mechanisms Of Nanogel Combining With Low Salinity Water For Carbonate Reservoirs, Pu Han

Doctoral Dissertations

"Nanomaterials have been widely studied and applied in the oil and gas industry. Among the developed nanomaterials, nano-sized crosslinked polymeric gel particle (nanogel) has shown great potential in recovering residual oil and improving oil recovery. This dissertation carried out their potential EOR mechanisms and the synergetic effect between nanogel and low salinity water. Nanogel used in this study was synthesized through the suspension polymerization process in our lab. The morphology, size distribution, and zeta potential were studied for nanogel dispersed in brine with variable ionic strength. The injectivity of nanogel was elucidated at first to ensure their in-depth penetration ability. …

Thermomechanical Analysis Of Rock Asperity In Fractures Of Enhanced Geothermal Systems, Chao Zeng

Doctoral Dissertations

"Enhanced Geothermal Systems (EGS) offer great potential for dramatically expanding the use of geothermal energy and become a promising supplement for fossil energy. The EGS is to extract heat by creating a subsurface system to which cold water can be added through injection wells. Injected water is heated by contact with rock and returns to the surface through production well. Fracture provides the primary conduit for fluid flow and heat transfer in natural rock. Fracture is propped by fracture roughness with varying heights which is called asperity. The stability of asperity determines fracture aperture and hence imposes substantial effect on …

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 …

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 …

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.

Catalytic Dehydraton Of Ethanol To Ethylene And Diethyl Ether Over Modified Beta Zeolite Catalysts, Tanutporn Kamsuwan

Chulalongkorn University Theses and Dissertations (Chula ETD)

The gas-phase dehydration of ethanol is one of the most suitable catalytic reactions to produce diethyl ether (DEE) and ethylene. It has been studied over different types of Si- and Al- based solid acid catalysts including H-beta zeolite (HBZ), g-c-Al2O3 (M-Al) and g-Al2O3 (G-Al) with palladium (Pd) modification at temperature range of 200-400ºC. It revealed that the catalytic activity of the solid acid catalysts depended on the nature of acid properties on the catalysts. The Pd-modified catalysts can improve the ethanol conversion and product yield, especially with Pd-HBZ. Furthermore, the different gas pretreatment (N2, air and H2) over Pd-HBZ was …

การวิเคราะห์การผลิตไฟฟ้าจากกระบวนการเผาไหม้แบบฟลูอิดไดซ์เบดที่เกิดการหมุนเวียนร่วมกับเครื่องกังหันไอน้ำโดยใช้เชื้อเพลิงชีวมวลผสม, พิชชาพร นิละนนท์

Chulalongkorn University Theses and Dissertations (Chula ETD)

ปัจจุบันสถานการณ์การใช้พลังงานไฟฟ้ามีแนวโน้มสูงขึ้นอย่างต่อเนื่องจากการเติบโตทางเศรษฐกิจและเทคโนโลยี และด้วยกับการตระหนักถึงปัญหาสิ่งแวดล้อม จึงทำให้เชื้อเพลิงชีวมวลได้รับความสนใจและการส่งเสริมจากภาครัฐและเอกชนในการผลิตพลังงานไฟฟ้า แต่พบว่าโรงไฟฟ้าชีวมวลส่วนใหญ่มีการใช้เชื้อเพลิงชีวมวลเพียงชนิดเดียว ทำให้เสี่ยงต่อการขาดแคลนวัตถุดิบตั้งต้นและยังพบว่ามีการปลดปล่อยก๊าซคาร์บอนไดออกไซด์สู่บรรยากาศในปริมาณที่สูง โดยงานวิจัยนี้ศึกษาแบบจำลองกระบวนการผลิตพลังงานไฟฟ้าด้วยระบบการเผาไหม้แบบฟลูอิดไดซ์เบดหมุนเวียนร่วมกับเครื่องกังหันไอน้ำ โดยใช้ชีวมวลผสมจาก 5 ภูมิภาคของประเทศไทย และพัฒนาร่วมกับการดูดซึมก๊าซคาร์บอนไดออกไซด์ด้วยวิธีการดูดซึมทางเคมี โดยมีศึกษาตัวทำละลายที่แตกต่างกัน 2 ชนิดคือ โมโนเอทาโนลามีน และ 2-อะมิโน-2-เมทิล-1-โพรพานอล แบบจำลองทั้งสองถูกพัฒนาขึ้นโดยใช้โปรแกรมจำลองกระบวนการ แอสเพน พลัส จากการวิจัยพบว่าชีวมวลผสมจากภาคกลาง ได้แก่ ชิ้นไม้สับ แกลบ และชานอ้อย มีศักยภาพและเหมาะสมต่อการใช้เป็นวัตถุดิบตั้งต้น โดยส่งผลกระทบในระดับต่ำต่อหม้อกำเนิดไอน้ำ และสามารถผลิตพลังงานไฟฟ้าได้ตามที่โรงไฟฟ้าชีวมวลกำหนดที่ 103.43 เมกะวัตต์ โดยที่ใช้ปริมาณเชื้อเพลิง 107.89 ตัน/ชั่วโมง และพบว่าชีวมวลผสมจากภาคกลางมีการปลดปล่อยก๊าซคาร์บอนไดออกไซด์สู่บรรยากาศสูงสุดที่ 12.5% โดยการศึกษาการดักจับก๊าซคาร์บอนไดออกไซด์พบว่า การใช้สารละลาย 2-อะมิโน-2-เมทิล-1-โพรพานอล ที่อัตราส่วนตัวทำละลายต่อก๊าซเท่ากับ 4.03 สามารถดักจับก๊าซคาร์บอนไดออกไซด์ได้สูงสุด 90.82% เมื่อใช้พลังงานในการรีเจนเนอเรชั่นเท่ากับ 13.75 เมกกะจูล/กิโลกรัมคาร์บอนไดออกไซด์ แต่ในการใช้สารละลายโมโนเอทาโนลามีนจะใช้อัตราส่วนตัวทำละลายต่อก๊าซเท่ากับ 4.24 และพลังงานในการรีเจนเนอเรชั่นที่สูงกว่าเท่ากับ 21.91 เมกกะจูล/กิโลกรัมคาร์บอนไดออกไซด์

Superstructure Development Of Lignocellulosic Biomass From Empty Fruit Bunch Of Palm For Optimal Design Of Bio-Based Chemical Productions, Nusara Plodprong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Apart from palm oil, the left-over parts of palm trees such as leaves, trunks and empty fruit brunches are low in value that typically used for producing fertilizer. In fact, considering the constituents in these wastes, they comprise of valuable components including cellulose, hemicelluloses and lignin. Recovery of these components is beneficial since they can be used as precursors for a wide range of productions of other chemicals such as bio-ethanol, succinic acid, lactic acid and other aromatic compounds. In this work, therefore, we gather experimental works in the literature in order to establish a super-structure, the network of processes …

Effects Of Graphite/Partially Carbonized Hemp Hurd Particle Mass Ratios On Tribological Properties Of Polybenzoxazine Composites, Nuttarika Kunaroop

Chulalongkorn University Theses and Dissertations (Chula ETD)

This work aims to study effects of friction modifiers, i.e., synthetic graphite and carbonized hemp hurd (CHH) on thermal stability, dynamic mechanical properties, mechanical properties, and tribological performances of polybenzoxazine-based friction composites. Simulation of brake pad and disc brake by using ANSYS simulation program to study behaviors of the friction modifier filled-polybenzoxazine composites, i.e. pressure distribution and wear rate was also investigated. The results show that when the CHH is added to the polybenzoxazine composites, the tribological, dynamic mechanical, and mechanical properties were significantly improved because of some lignocellulose structure of the partially CHH. While, thermal property i.e., thermal degradation …

Fabrication And Electrochemical Performance Of Nickel-Alloy-Foam-Supported Solid Oxide Electrolysis Cell For Hydrogen Production From Steam, Ramin Visvanichkul

Chulalongkorn University Theses and Dissertations (Chula ETD)

The effect of CuO as a sintering additive on the electrolyte of solid oxide electrolysis cell (SOEC) was investigated. 0.5 wt.% CuO was added into Sc0.1Ce0.05Gd0.05Zr0.89O2 (SCGZ) electrolyte as a sintering additive. An electrolyte-supported cell (Pt/SCGZ/Pt) was fabricated. Phase formation, relative density, and electrical conductivity were investigated. The cells were sintered at 1373 K to 1673 K for 4 h. The CuO significantly affected the sinterability of SCGZ. The SCGZ with 0.5 wt.% CuO achieved 95% relative density at 1573 K while the SCGZ without CuO could not be densified even at 1673 K. Phase transformation and impurity after CuO …

Electrochemical Reduction Of Co2 To Value-Added Chemicals On Zn/Cu Alloy Catalysts Prepared By Electrodeposition, Phongsathon Klongklaew

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this work, Zn/Cu alloy electrocatalysts prepared by electrodeposition of Zn on Cu foil (Zn/Cu) and electrodeposition of Zn and Cu on Cu foil (ZnCu/Cu) in different electrodeposition baths consisting of NaCl bath (Zn/Cu-Na, ZnCu/Cu-Na) and HCl bath (Zn/Cu-H, ZnCu/Cu-H) with deposition times 60 and 200 s were investigated in the electrochemical reduction of CO2 (CO2-ERC). As revealed by SEM-EDX and XRD results, the electroplating conditions affected the Zn structure being formed (dendrite or bulky). Under the conditions used, the electrochemical reduction of CO2 using these electrodes led to the formation of gaseous products including carbon monoxide and hydrogen and …

Capillary Forces In Partially Saturated Thin Fibrous Media, Ali Moghadam

Theses and Dissertations

Capillarity is often exploited in self-cleaning, drag reducing and fluid absorption/storage (sanitary products) purposes just to name a few. Formulating the underlying physics of capillarity helps future design and development of optimized structures. This work reports on developing computational models to quantify the capillary pressure and capillary forces on the fibrous surfaces. To this end, the current study utilizes a novel mass-spring-damper approach to incorporate the mechanical properties of the fibers in generating virtual fibrous structures that can best represent fibrous membranes. Such virtual fibrous structures are then subjected to a pressure estimation model, developed for the first time in …

The Effect Of Curing And Zirconium Content On The Wettability And Structure Of A Silicate Hybrid Sol-Gel Material, Emma Machugh, Maikki Cullen, Alicja Kaworek, Brendan Duffy, Mohamed Oubaha

Articles

Functional hybrid sol-gel coatings have been developed for numerous applications with a wide range of wettabilities. This study proposes to investigate the relationship between the structure and the wetting properties of a zirconium modified silicate hybrid sol-gel coating. The structures of the coatings were altered by varying the content of zirconium, and the curing process, while keeping the sol-gel preparation conditions identical. The structure of the materials was characterized by FTIR, 29Si NMR and SEM. The thermal properties and the wettability are identified by DSC and contact angle measurements, respectively. By corroborating the structural and wettability analyses, it is shown …

Enhancing The Thermal Stability Of Carbon Nanomaterials With Dna, Mohammad Moein Safee, Mitchell Gravely, Adeline Lamothe, Megan Mcsweeney, Daniel E. Roxbury

Chemical, Biomolecular, and Materials Engineering Faculty Publications

Single-walled carbon nanotubes (SWCNTs) have recently been utilized as fillers that reduce the flammability and enhance the strength and thermal conductivity of material composites. Enhancing the thermal stability of SWCNTs is crucial when these materials are applied to high temperature applications. In many instances, SWCNTs are applied to composites with surface coatings that are toxic to living organisms. Alternatively, single-stranded DNA, a naturally occurring biological polymer, has recently been utilized to form singly-dispersed hybrids with SWCNTs as well as suppress their known toxicological effects. These hybrids have shown unrivaled stabilities in both aqueous suspension or as a dried material. Furthermore, …

Biomolecular Functionalization Of A Nanomaterial To Control Stability And Retention Within Live Cells, Mitchell Gravely, Mohammad Moein Safaee, Daniel E. Roxbury

Chemical, Biomolecular, and Materials Engineering Faculty Publications

Noncovalent hybrids of single-stranded DNA and single-walled carbon nanotubes (SWCNTs) have demonstrated applications in biomedical imaging and sensing due to their enhanced biocompatibility and photostable, environmentally responsive near-infrared (NIR) fluorescence. The fundamental properties of such DNA-SWCNTs have been studied to determine the correlative relationships between oligonucleotide sequence and length, SWCNT species, and the physical attributes of the resultant hybrids. However, intracellular environments introduce harsh conditions that can change the physical identities of the hybrid nanomaterials, thus altering their intrinsic optical properties. Here, through visible and NIR fluorescence imaging in addition to confocal Raman microscopy, we show that the oligonucleotide length …

Ultrasonic Generation Of Pulsatile And Sequential Therapeutic Delivery Profiles From Calcium-Crosslinked Alginate Hydrogels, Tania Emi, Kendra Michaud, Emma Orton, Grace Santilli, Catherine Linh, Meaghan O'Connell, Fatima Issa, Stephen Kennedy

Chemical, Biomolecular, and Materials Engineering Faculty Publications

Control over of biological processes can potentially be therapeutically regulated through localized biomolecular deliveries. While implantable hydrogels can provide localized therapeutic deliveries, they do not traditionally provide the temporally complex therapeutic delivery profiles required to regulate complex biological processes. Ionically crosslinked alginate hydrogels have been shown to release encapsulated payloads in response to a remotely applied ultrasonic stimulus, thus potentially enabling more temporally complex therapeutic delivery profiles. However, thorough characterizations of how different types of therapeutic payloads are retained and ultrasonically released need to be performed. Additionally, the impact of potentially disruptive ultrasonic stimulations on hydrogel structure and temperature need …

Primary Dendrite Trunk Diameter In Al-7wt% Si Alloy Directionally Solidified Aboard The International Space Station, S. R. Upadhyay, Surendra N. Tewari, M. Ghodes, R. N. Grugel, D. R. Poirier, M. Lauer

Chemical & Biomedical Engineering Faculty Publications

Under a NASA (National Aeronautics and Space Agency)-ESA (European Space Agency) collaborative research project, MICAST (Microstructure formation in casting of technical alloys under a diffusive and magnetically controlled convection conditions), three Al-7wt% Si samples (MICAST-6, MICAST-7 and MICAST2-12) were directionally solidified at growth speeds varying from 10 to 50 µm s^-1 aboard the International Space Station to determine the effect of mitigating convection on the primary dendrite array. The observed primary dendrite trunk diameters during steady-state growth of MICAST samples show a good agreement with predictions from a coarsening based model developed by the authors. The trunk diameters in …

Synthesis Of Zif-8 For The Oxidative Dehydrogenation Of Ethane To Produce Ethylene, Fausat Isu

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

การประเมินค่าพารามิเตอร์ทางจลนศาสตร์สำหรับการออกซิไดซ์โทลูอีนบนตัวเร่งปฏิกิริยา Moo3/Tio2 ที่ได้รับการปรับสภาพด้วยกรดซัลฟิวริกและออกแบบมาเพื่อใช้ในปฏิกิริยา Scr ในการรีดิวซ์ Nox ด้วย Nh3, นภสร นารอด

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้ทำการศึกษาตัวเร่งปฏิกิริยา MoO3/TiO2 บนตัวรองรับ TiO2 ที่ได้รับการปรับสภาพด้วยสารละลาย H2SO4 เข้มข้น 0, 0.2 และ 0.5 M ในการทำปฏิกิริยาโทลูอีนออกซิเดชัน เตรียมตัวเร่งปฏิกิริยาด้วยวิธีการเคลือบฝังแบบเปียก ทำการการวิเคราะห์คุณลักษณะของตัวเร่งปฏิกิริยาด้วยเทคนิค Nitrogen Physisorption, XRD, NH3-TPD และ SEM-EDX การทดสอบความสามารถของตัวเร่งปฏิกิริยาทำในช่วงอุณหภูมิ 120 ถึง 400oC โดยใช้แก๊สผสมที่ประกอบด้วยโทลูอีนเข้มข้น 300 ถึง 400 ppm, O2 เข้มข้น 3, 12 และ 21 %vol ในเครื่องปฏิกรณ์แบบเบดนิ่งอุณหภูมิคงที่ จากการศึกษาพบว่าเมื่อพิจารณาผลของ O2 พบว่าเมื่อเพิ่มความเข้มข้นจาก 3 ถึง 12 % ค่า %Toluene conversion เพิ่มขึ้นอย่างเห็นได้ชัด แต่เมื่อเพิ่ม O2 ความเข้มข้น 12 ถึง 21 % กลับไม่ได้เพิ่มขึ้นมากเมื่อเทียบกับช่วงแรกที่ความเข้มข้นของ O2 ต่ำ พฤติกรรมนี้อาจบ่งชี้ได้ว่า เกิดปฏิกิริยาผ่านกลไกของแบบจำลอง REDOX และแม้ว่า %Toluene conversion จะสูง แต่กลับพบ CO2 ในปริมาณที่ต่ำจนไม่สามารถคำนวณหาปริมาณพื้นที่ที่แน่นอนได้ แสดงว่าผลิตภัณฑ์ที่ได้จากการออกซิไดซ์โทลูอีนนั้น อาจกลายเป็นสารประกอบอินทรีย์ที่มีจุดเดือดสูง เมื่อพิจารณาผลของค่าทางจลศาสตร์ ในกรณีของตัวเร่งปฏิกิริยาที่ไม่ได้รับการปรับสภาพด้วยกรด H2SO4 ในทุกความเข้มข้นของ O2 ปฏิกิริยาเกิดขึ้นด้วยกัน 2 ปฏิกิริยา คือปฏิกิริยาแรกมีค่า Ea ต่ำที่อยู่ในช่วง 21 ถึง 27 kJ/mol ซึ่งตรวจพบได้ในช่วงอุณหภูมิ 150 ถึง 275oC และปฏิกิริยาที่ 2 มีค่า Ea ที่สูงที่อยู่ในช่วง 56 ถึง 68 kJ/mol ซึ่งเห็นได้ในช่วงอุณหภูมิ …

Chemically Dealloyed Fe-Based Metallic Glass With Void Channels-Like Architecture For Highly Enhanced Peroxymonosulfate Activation In Catalysis, J.C. Wang, S.X. Liang, Z. Jia, W.C. Zhang, W.M. Wang, Y.J. Lui, J. Lu, L.C Zhang

Research outputs 2014 to 2021

Metallic glasses (MGs) with their intrinsic disordered atomic structure and widely controllable atomic components have recently emerged as fascinating functional materials in wastewater treatment. Compared to crystalline alloys, the less-noble atomic components in monolithic metallic glass are more efficient to be selectively dissolved during dealloying process. This work reported a facile chemical dealloying approach to fabricate a void channels-like structured MG with the elemental components of Fe73.5Si13.5B9Cu1Nb3 for methylene blue (MB) degradation. Results indicated that the dealloyed Fe73.5Si13.5B9Cu1Nb3 MGs with the void channels-like morphology presented a significant improvement of catalytic efficiency and reusability. The dye degradation reaction rate (kobs) of …

Multi-Responsive Macromolecular Coacervate Complexes For Efficient Biomolecular Encapsulation And Controlled Release, Adrian Lorenzana

Research Opportunities for Engineering Undergraduates (ROEU) Program 2018-19

The project investigates the mechanistic (entropic) formation of organic-inorganic coacervates with improved mechanical strength. We seek to control and modify material properties and stimuli-responsive characteristics of hybrid coacervates, and to explore new practical applications of organic-inorganic coacervate complexes, i.e. (bio)separation, wastewater treatment, drug delivery, battery electrolyte and electrodes.

Molecular Exchange Monte Carlo. A Generalized Method For Identity Exchanges In Grand Canonical Monte Carlo Simulations, Mohammad Soroush Barhaghi

Wayne State University Theses

A generalized identity exchange algorithm is presented for Monte Carlo simulations in the grand canonical ensemble. The algorithm, referred to as Molecular Exchange Monte Carlo (MEMC), may be applied to multicomponent systems of arbitrary molecular topology, and provides significant enhancements in the sampling of phase space over a wide range of compositions and temperatures. Three different approaches are presented for the insertion of large molecules, and the pros and cons of each method are discussed. The performance of the algorithms is highlighted through grand canonical Monte Carlo histogram-reweighting simulations performed on several systems, including 2,2,4-trimethylpentane+neopentane, butane+perfluorobutane, methane+n-alkanes, and water+impurity. Relative …

Investigating The Use Of Class C Flyash-Based Geopolymer Cement As A Potential Alternative To Portland Cement To Seal Co₂ Storage Wells, Priyesh Parimal Jani

Masters Theses

"Capturing emitted carbon dioxide from the source of emission and storing it underground is one effective way to reduce the amount of CO₂ in the atmosphere and is called carbon capture and storage (CCS). For the successful CCS project, it is necessary to ensure long term storage of injected CO₂ inside these selected reservoirs. Portland cement used to cast wells in these reservoirs degrade in CO₂ environment and can create migration path for leakage of CO₂. The aim of this study was to provide a comprehensive review about the problem, to propose a new geopolymer …

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 …

Gel Composition And Brine Concentration Effect On Hydrogel Dehydration Subjected To Uniaxial Compression, Xinrui Zhao

Masters Theses

"Gel treatment is a process that injects the gel into a reservoir to control the conformance and improve the sweep efficiency of injection fluids. At a certain pressure gradient, the gel dehydrates in a reservoir due to mechanical forces. This work evaluates the effects of the gel composition and brine concentration on gel dehydration under uniaxial compression. A sodium acrylate-co-acrylamide based gel cross-linked with N, N'-Methylenebisacrylamide (MBAA) was used for the study. The compression test is performed with a rheometer with a plate-plate geometry. The gel dehydration under pressure was measured to see how gel dehydration would be impacted by …

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 …