Chemical Engineering Commons^™

Extrusion-Based Additive Manufacturing Of Magnetic Heat Exchange Structures For Caloric Applications, Vaibhav Sharma

Theses and Dissertations

Currently, the commercial building sector accounts for 18% of total U.S. end-use energy consumption, of which almost a third was from on-site combustion of fossil fuels for space and water heating. Magnetic heat pumping (MHP) technology is an energy-efficient, sustainable, environmentally-friendly alternative to conventional vapor-compression cooling technology. Several MHP designs today are predicted to be highly energy efficient, on condition that suitable working materials can be developed. This materials challenge has proven to be daunting due to issues associated with intricate synthesis/post-processing protocols and complications related to shaping the mostly brittle magnetocaloric alloys into thin-walled channeled regenerator structures to facilitate …

Synthesis Of Lithium Nickel Cobalt Manganese Oxide (Ncm) Cathodes For Lithium-Ion Batteries, Jethrine H. Mugumya

Theses and Dissertations

There are various ways to produce lithium nickel manganese cobalt oxide (NCM) based cathodes for lithium-ion batteries, among them; co-precipitation synthesis carried out in tank-based reactors followed by lithiation is commonly employed because of its cost-effectiveness and scalability. Although it is the preferred synthesis method, it has several issues and challenges. Discussed in this dissertation are some of these issues as well as potential solutions. Physical and chemical properties of the co-precipitation product such as yield, particle size, morphology, and tap density, depend on various reaction parameters, which include pH, chelating agents, metal salt concentrations, and stirring speed. In the …

Impacts Of Key Degradation Byproducts On Amine Scrubbing For Post-Combustion Carbon Capture, Thomas Jorgensen

Theses and Dissertations--Chemistry

The increasing atmospheric CO₂ concentration causes significant concern about global warming and its environmental impact. Industrial sectors, including power generation, transportation, and production factories, contribute most of the anthropogenic sources of CO₂ emissions. Researchers search for methods to mitigate these CO₂ emissions without compromising the benefits of industrial processes, including CO₂ capture, utilization, and sequestration (CCUS). Post-combustion carbon capture (PCCC) by amine scrubbing is the most technology ready CCUS, with various pilot-scale projects worldwide showing small-scale to fully operational plants. While researchers have made significant progress in amine scrubbing, they strive to improve the efficiency and …

Novel Supercritical Biodiesel Plant Design & Process Scale-Up, Ghana Shyam Paudel

Doctoral Dissertations

"Current energy prices, national energy security, and global climate change fuel our momentum to find efficient advanced fuels choices. In this study, biodiesel processing, and a novel design for next generation biodiesel plants are explored. During a National Science Foundation (NSF) I-Corps project we identified three creative and profitable improvements to the process: 1. Incorporating Energy intensive separations and reactions 2. Utilizing Low commodity glycerol and 3. Applying process intensification principles.

Current biodiesel processes are catalyzed processes using continuous stir reactors with distillation systems to separate material constituents. We tested a lab-scale nocatalyst supercritical biodiesel process using waste cooking oil …

The Comprehensive Study Of High Viscosity Friction Reducers In High-Tds And High-Temperature Environments, Xiaojing Ge

Doctoral Dissertations

"High viscosity friction reducers (HVFRs) have been recently gaining more attention and increasing in use, not only as friction-reducing agents but also as proppant carriers. Reusing of produced water has also been driven by both environmental and economic benefits. Currently, most friction reducers on the market are anionic friction reducers, which are fully compatible with most produced water with low to medium level of Total Dissolved Solids (TDS) but show a significant drop at high TDS conditions in term of their friction reduction performance in most cases. On the contrary, cationic friction reducers are believed to have better TDS tolerance …

Effects Of Electron Beam Irradiation On Crmnv And Crmntiv High Entropy Alloys: Nano-Mechanical, Structural, And Thermodynamic Perspectives, N. A. Sultana, Y. S. Mohammed, S. J. Pendleton, J. Vennekate, G. Ciovati, X. Li, H. Baumgart, A. A. Elmustafa

Mechanical & Aerospace Engineering Faculty Publications

Beam exit windows are crucial components of any particle accelerator as they provide an interface between the beamline vacuum and target material at atmospheric media. For high beam power machines, special materials and designs are required to withstand high radiation and mechanical loads, while minimizing energy loss during transition and maximizing window lifetime. This research investigates the impact of electron beam exposure to bulk CrMnV and CrMnTiV high entropy alloys (HEAs) with the primary goal of identifying suitable candidate materials for the design of robust and durable exit window settings. The selection criteria include intrinsic characteristics, power dissipation, and mechanical …

Investigation Wettability Contact Angle Using 2d Imaging Technology, Saleh Alsayegh

Doctoral Dissertations

"Investigation wetting preference of tight carbonate reservoir rocks and several other unconventional reservoir rocks, and their relation to oil production, is becoming noticeably important for field development in Kuwait, as in many future unconventional tight carbonate reservoirs in the Middle East. The overall objective of this investigating and modeling study is to discover many fundamental relationships from totality wettability preference as a tool for reservoir recovery predictions and management. The investigation includes advancing position of water wet preference into smaller capillaries of the matrix voids and incrementally more oil-wet into larger capillaries of natural fractures (NF). Also, investigating water/ oil …

Investigating The Potential Of Blended Feedstocks For Biofuel Production Via Pyrolysis Process: Experimental And Aspen Simulation Approach, Hasan Jawad Hammood Al-Abedi

Doctoral Dissertations

"The development of renewable energy sources has become increasingly urgent considering the climate crisis and the need to reduce greenhouse gas emissions. Pyrolysis, which is decomposition of an organic feedstock without oxygen, is a thermo-chemical process that has garnered significant attention as a promising technology for sustainable energy production, capable of converting biomass and waste materials into biofuels.

The primary objective of this study is to investigate the pyrolysis and co-pyrolysis behaviors of corn stover (CS), refuse-derived fuel (RDF), and oil shale (OS) in equal mass ratios. Utilizing a thermogravimetric analyzer and differential scanning calorimetry (DSC), the co-pyrolysis process is …

Paleoecological And Paleoclimatic Reconstructions Based On Holocene Sediment Cores, Lake Izabal, Eastern Guatemala, Erdoo Mongol

Doctoral Dissertations

"The Maya Region in Central America is characterized by pronounced discrepancies in precipitation, resulting in high precipitation gradients that support large-scale differences in vegetation across the region. Several lake deposits and other paleoclimate archives in the region have been studied to reconstruct past climates and palaeoecological conditions. However, actual data from proxy records have not been qualitatively and quantitatively utilized to interpret the behavior of the vegetation in moister areas within the Maya Region, such as the Lake Izabal Basin (LIB). The palynomorphs from two sediment cores in the LIB provided a good opportunity to infer the patterns of past …

Topography Of The 410 And 660 Km Discontinuities Beneath The Tibetan Plateau And Adjacent Areas, Zexin Miao

Doctoral Dissertations

"The Tibetan Plateau represents the ongoing geotectonic aftermath of a continental collision initiated approximately 65 million years ago. Despite numerous seismological studies, controversies remain regarding the structure, evolution, and dynamics of the crust and mantle beneath Tibetan Plateau. In this study, we used teleseismic broadband data to investigate the topography of the mantle transition zone (MTZ) discontinuities. A total of ~655,000 receiver functions from 735 stations was utilized to image the 410 and 660 km discontinuities bordering the MTZ. Combining the observed and velocity corrected results, several areas in the central Tibet exhibit a typical d410 and an anomalously deep …

The Effects Of Uv-Radiation On The Removal Of Microplastics In Water Using Agglomeration-Micro-Flotation, Palot Srichonphaisarn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Microplastics, plastic particles with diameter 1 micrometer to 5 millimeters, can disturb marine ecosystems due to their small size and surface properties which can be a carrier for hazardous matters. While wastewater treatment plants could remove some microplastics but some of them remain. Among the various removal techniques, flotation is a potential method due to the hydrophobic nature of microplastics. This study investigates the effects of ultraviolet radiation on the surface wettability of microplastics and removal efficiency of microplastics. The 6 types of microplastics were prepared from plastic boards. After the ultraviolet radiation, the results showed that ultraviolet radiation could …

Effect Of Zeolite Support Of Nickel-Copper Catalyst On Conversion Of Palm Oil To Sustainable Aviation Fuel, Natnicha Ritmun

Chulalongkorn University Theses and Dissertations (Chula ETD)

Sustainable aviation fuel (SAF) is increasingly recognized as a critical alternative for reducing the environmental impact of the aviation industry, which is a significant source of global greenhouse gas emissions. SAF production primarily utilizes vegetable oils as feedstock rather than biomass, due to their low functional group content and chemical structure that closely resembles that of fossil fuels. This research focuses on the development of bimetallic catalysts made from nickel, with copper as promoters, supported on various zeolites including SAPO-11, Zeolite Y, and Zeolite ZSM-5. The chemical and physical properties of these catalysts were analyzed using several techniques, including X-ray …

Methanol Production Via Co2 Hydrogenation In Gas Phase With 1-Propanol Assisted In Fixed Bed Reactor, Narakorn Ninkaew

Chulalongkorn University Theses and Dissertations (Chula ETD)

The methanol synthesis from CO2 hydrogenation reaction using 1-propanol alcohol was selected to solvent involved in the new reaction pathway with CO2 and H2 as reactants in a gas phase fixed bed reactor. To study the effect of temperature at 160-230 °C, space velocity (GHSV) at 60-592 h-1, the mole ratio of 1 propanol to CO2 at 0-1.25, H2 to CO2 mole ratio of 5 and a pressure of 30 bar. From the experiment, the mole ratio of 1 propanol to CO2 at 1, the temperature of 170 °C and the space velocity of 420 h-1. It was found that …

การผลิตเมทานอลจากปฏิกิริยาไฮโดรจีเนชันของแก๊สคาร์บอนไดออกไซด์ที่มีเอทานอลในสภาวะแก๊สที่เครื่องปฏิกรณ์แบบเบดนิ่ง, ชนาภัทร บุญประคม

Chulalongkorn University Theses and Dissertations (Chula ETD)

เมทานอลเป็นวัตถุดิบเคมีตั้งต้นที่สำคัญสำหรับอุตสาหกรรมเคมี อุตสาหกรรมยา อุตสาหกรรมเครื่องใช้ไฟฟ้า ในวิทยานิพนธ์นี้จึงมีความสนใจในการศึกษาผลของเอทานอลในการผลิตเมทานอลจากปฏิกิริยาไฮโดรจีเนชันของแก๊สคาร์บอนไดออกไซด์ที่มีเอทานอลในสภาวะแก๊สที่เครื่องปฏิกรณ์แบบเบดนิ่ง สำหรับการศึกษาผลของเอทานอล แบ่งการศึกษาออกเป็น 3 ขั้นตอนหลัก ได้แก่ การศึกษาเส้นทางการเกิดปฏิกิริยา การตรวจสอบปัจจัยที่มีผลต่อการผลิตเมทานอล และการคำนวณที่สภาวะสมดุลด้วยโปรแกรม Aspen Plus การศึกษาภายใต้สมมติฐานว่า การเพิ่มเอทานอลในการผลิตเมทานอลจากปฏิกิริยาไฮโดรจีเนชันของแก๊สคาร์บอนไดออกไซด์ จะสามารถทำให้ผลิตเมทานอลได้ดีที่อุณหภูมิต่ำ ผลการศึกษาพบว่า การเพิ่มเอทานอลในกระบวนการเปลี่ยนเส้นทางปฏิกิริยา ทำให้เกิดเอทธิลฟอร์เมทเป็นตัวกลางในการสร้างเมทานอล การศึกษาอุณหภูมิ พบว่า การลดอุณหภูมิช่วยให้ปฏิกิริยาไฮโดรจีเนชันของคาร์บอนไดออกไซด์เป็นเอทิลฟอร์เมตและปฏิกิริยาไฮโดรจีเนชันของเอทิลฟอร์เมตเป็นเมทานอลและเอทานอลมีประสิทธิภาพมากขึ้น อีกทั้งยังสามารถช่วยลดการเกิดปฏิกิริยาข้างเคียง ทั้งนี้ สันนิษฐานได้ว่าเอทานอลที่ถูกเติมเข้ามามีผลในการแย่งจับตำแหน่งออกฤทธิ์ (active site) บนตัวเร่งปฏิกิริยา ทำให้การเกิดปฏิกิริยาไฮโดรจีเนชันของคาร์บอนมอนอกไซด์ที่อุณหภูมิ 200 และ 230 องศาเซลเซียสไม่สามารถทำได้อย่างมีประสิทธิภาพ นอกจากนี้ การศึกษาของการเพิ่มความเร็วเชิงพื้นที่พบว่า ค่าร้อยละการเปลี่ยนแปลงคาร์บอนไดออกไซด์และค่าร้อยละผลผลิตของเมทานอลลดลง เนื่องจากลดเวลาสัมผัสระหว่างสารตั้งต้นกับตำแหน่งที่เกิดปฏิกิริยาของตัวเร่งปฏิกิริยา ส่งผลให้สารตั้งต้นสัมผัสกับตัวเร่งปฏิกิริยาน้อยลงทำให้ไม่มีเวลามากพอที่จะเกิดปฏิกิริยาอย่างสมบูรณ์ อีกทั้งพบเอทิลฟอร์เมตน้อย สันนิษฐานได้ว่าปฏิกิริยาไฮโดรจีเนชันของเอทิลฟอร์เมตเป็นเมทานอลและเอทานอลนั้นเกิดขึ้นอย่างรวดเร็วในช่วงค่าความเร็วเชิงพื้นที่ที่กำหนด อีกทั้งพบว่าการลดความเร็วเชิงพื้นที่ ที่อุณหภูมิ 200 และ 230 องศาเซลเซียส ทำให้ปฏิกิริยาไฮโดรจีเนชันของคาร์บอนมอนอกไซด์เกิดขึ้นอย่างมีประสิทธิภาพมากยิ่งขึ้น ผลการศึกษาการเพิ่มอัตราส่วนโมลของเอทานอลต่อคาร์บอนไดออกไซด์ โดยคาดว่าจะช่วยให้เพิ่มค่าการเปลี่ยนแปลงคาร์บอนไดออกไซด์และผลผลิตของเมทานอล ผลการทดลองที่ความเร็วเชิงพื้นที่ 296 ชม.-1 ปฏิกิริยาไฮโดรจีเนชันของคาร์บอนไดออกไซด์และการไฮโดรจีเนชันของเอทิลฟอร์เมต พบว่า การเพิ่มเอทานอลในปฏิกิริยาจะช่วยเพิ่มเอทิลฟอร์เมต อย่างไรก็ตาม หากเพิ่มสัดส่วนเอทานอลที่มากเกินไปจะไปจำกัดการผลิตเมทานอล จากผลการศึกษาการเปลี่ยนแปลงอัตราส่วนโมลเอทานอลต่อคาร์บอนไดออกไซด์ภายใต้การเปลี่ยนความเข้มข้นของสารตั้งต้น พบว่า การเพิ่มความเข้มข้นของคาร์บอนไดออกไซด์และไฮโดรเจนในกรณีที่ไม่มีเอทานอล มีค่าร้อยละการเปลี่ยนแปลงคาร์บอนไดออกไซด์และค่าร้อยละผลผลิตของเมทานอลน้อยกว่ากรณีที่มีเอทานอล แสดงให้เห็นถึงอัตราการเกิดปฏิกิริยาที่ช้ากว่ากรณีที่มีเอทานอล จากผลการศึกษานี้ทำให้เอทานอลทำหน้าที่คล้ายกับตัวทำละลายเชิงเร่งปฏิกิริยา (catalytic solvent)

Oxidative Cleavage Of Oleic Acid At High Temperature Under Autogenous Pressure, Nichkamon Suwannit

Chulalongkorn University Theses and Dissertations (Chula ETD)

The oxidative cleavage of oleic acid to produce azelaic acid and nonanoic acid, both of which are high-value chemicals and essential precursors in the pharmaceutical and plastic industries, was investigated. The objectives of this study were to examine the influence of temperature on reaction mechanisms, product formation, and reaction efficiency, as well as to optimize the reaction conditions for potential industrial applications. The research utilized hydrogen peroxide (H2O2) as the oxidizing agent, tungsten oxide (WO3) as the catalyst, and tert-butanol as a co-solvent under self-generated autogenous pressure conditions. The temperature range studied was 80 to 160°C, aiming to evaluate the …

Uv-Enhanced Catalytic Oxidative Cleavage Of Oleic Acid., Trinnasit Wittayakullertsin

Chulalongkorn University Theses and Dissertations (Chula ETD)

Oleic acid, a key component of plant oils such as palm oil, is a versatile feedstock for producing high-value bio-based chemicals. Utilizing its potential aligns with Thailand's objective of promoting sustainability as a premier palm oil producer. The conventional oxidative cleavage of oleic acid typically requires extreme conditions, including high temperatures, and ozone, which are expensive and harmful to the environment. This research provides an innovative method for utilizing ultraviolet (UV) radiation to increase oxidative cleavage at low temperatures (below 80°C). It employs hydrogen peroxide (H2O2) as an oxidizing agent and tungsten trioxide (WO3) as a catalyst to generate hydroxyl …

Ultrafine Fully Vulcanized Natural Rubber Modified By Grafting With Methyl Methacrylate Monomer As Toughening Modifiers For Polylactic Acid, Panyawutthi Rimdusit

Chulalongkorn University Theses and Dissertations (Chula ETD)

This work focused on toughening polylactic acid (PLA) with an abundant and sustainable bio-based filler from natural rubber. Deproteinized natural rubber (DPNR) was modified by grafting with methyl methacrylate monomer (MMA) and further crosslinked via e-beam irradiation and spray drying to achieve ultrafine fully vulcanized powdered natural rubber grafted with polymethylmethacrylate (UFPNR-g-PMMA) to solves in the challenges of incompatibility between the DPNR and PLA. Interestingly, UFPNR-g-PMMA showed no agglomeration between rubber particles compared to that of neat UFPNR which showed partial agglomeration after irradiation crosslinking. The flexural toughness shows a significant improvement (351%) to 11280 ± 1522 kJ/m3 compared to …

Development Of Silica-Based Support Material From Sugarcane Bagasse Ash For Synthesis Of Carbon Nanotubes, Maturada Assawagetmanee

Chulalongkorn University Theses and Dissertations (Chula ETD)

Sugarcane bagasse ash (SCBA), an abundant agricultural residue, is converted into high-value silica powder through a novel route involving calcination and acid leaching. This transformative process not only valorizes waste biomass but also yields silica nanoparticles with tailored microstructural properties suitable for application in carbon nanotube (CNT) production. The resultant silica powder was utilized as a catalyst support impregnated with Fe nanocatalyst for synthesizing CNTs from benzene. The effective route with a process sequence of 1 M HCl acid leaching followed by calcination could provide silica powder with a specific surface area of 12.29 m2/g, which could accommodate Fe nanocatalyst …

Direct Blue 86 Textile Dye Removal From Aqueous Solution Using Rice Husk-Based Adsorbent, M. Zulbahari M. Zua, Muhammad Raza Ul Mustafa, Mohamed Hasnain Isa, Teh Sabariah Binti Abd Manan, Naimah Ibrahim, Rozeana Hj Md Juani, Wida Susanty Hj Suhaili, Asmaal Muizz Sallehhin Bin Hj Mohammad Sultan, Zuliana Binti Hj Nayan

ASEAN Journal on Science and Technology for Development

Adsorption by activated carbon is an effective method of dye removal. However, due to high production and regeneration costs of activated carbon, various studies on low-cost adsorbents have been conducted. Agricultural waste such as rice husk (RH) is seen to be a good adsorbent for dye removal. Moreover, rice husk is readily available. In this study, rice husk-based adsorbents were prepared by chemical and thermal treatments. Standard curve (colour vs absorbance) for Direct Blue 86 (DB 86) was prepared to determine the concentration of dye before and after adsorption. The adsorption potential of the adsorbent for textile dye DB 86 …

Engineering Mussel Foot Protein 5 (Mfp5) For Enhanced Adhesive Performance In Tendon And Bone Repair, Ziyue Zhu

McKelvey School of Engineering Graduate Student Theses & Dissertations

This study explores the development of Mussel Foot Protein 5 (MFP5) bioadhesives to improve tendon-to-tendon and tendon-to-bone adhesive outcomes. MFP5, known for its underwater adhesive properties, was synthesized using recombinant techniques and optimized through coacervation and cross-linking. Adhesion tests demonstrated the superior performance of the optimized MFP5 adhesive on the tendon and bone samples. Improved protein concentration testing and purification methods enhanced MFP5 yield and consistency. Future research will focus on further standardization, exploring alternative purification methods, and evaluating the adhesive's performance in animal models. This study lays a foundation for developing robust MFP5-based bioadhesives, potentially revolutionizing surgical repair techniques …