Chemical Engineering Commons^™

Photocatalytic Efficiency Of Graphene Quantum Dots Incorporated With Tio2 Under Visible Light For Degradation Of Organic Dye, Ilada Sanprasert

Chulalongkorn University Theses and Dissertations (Chula ETD)

The rapid industrialization and increased use of organic dyes for production in many industries have led to extensive environmental pollution concerns. At present, photocatalytic dye degradation is an outstanding environmentally friendly process for removal and treatment of organic dyes from water pollutants that cause no harm to the environment. In this research, we investigated the performance of different crystallographic structure of TiO2 (anatase, rutile, and mixed anatase/rutile P25 TiO2) under visible light irradiation. Furthermore, the TiO2 was modified using graphene quantum dots to evaluate their effect on photocatalytic efficiency. The characterization results of the GQDs/TiO2 photocatalyst composites demonstrated that GQDs …

Temperature Control In The Steam Methane Reformer Using Model Predictive Control Based On A Neural Network Model, Rasiq Dipta Alkindi

Chulalongkorn University Theses and Dissertations (Chula ETD)

Hydrogen is a critical energy vector, and magnetic heating reactors represent a promising production technology where current-induced magnetization raises system temperature. Due to the nonlinear and complex thermal dynamics, this study applies a hybrid Echo State Network (ESN) and Long Short-Term Memory (LSTM) model to capture system behavior, combining ESN’s nonlinear dynamic identification with LSTM’s ability to learn long-term dependencies. Hyperparameters were optimized for best performance at 30 reservoir nodes, 0.5 spectral radius, 0.9 connectivity, batch size 4, 50 LSTM units, and 60 epochs. The ESN-LSTM models with 3-input and 4-input feature sets were tested on three winding coil geometries …

Graphene Quantum Dot Spray-Coated Indium Tin Oxide Electrode For Fe3+ Detection, Firadao Bennui

Chulalongkorn University Theses and Dissertations (Chula ETD)

Ferric ion (Fe3+) contamination in water sources poses significant risks, making reliable detection technologies essential. In this study, electrochemical sensors were developed by spray-coating Graphene quantum dots (GQDs) on indium tin oxide (ITO) electrodes to enhance Fe3+ detection in aqueous systems. The performance of Assembly GQDs and GQDs on ITO electrodes was compared, and the electrochemical sensing of Fe3+ was investigated. GC-358 exhibited a 3D structure with aggregated particles and high electroconductivity, while CLS-3 showed a broad absorption peak around 300 nm and green photoluminescence at 505 nm due to carboxyl groups. Cyclic voltammetry showed the highest current response for …

Lead-Free Perovskite/Metal Oxide Heterojunction Photocatalyst For Sustainable Toluene Oxidation, Zakarya Hazaea

Chulalongkorn University Theses and Dissertations (Chula ETD)

An important field of study is the ecologically benign synthesis of useful compounds such as benzaldehyde and benzyl alcohol from the organic contaminant toluene. Lead-free halide perovskites are excellent options for photocatalysis due to their exceptional photoelectric properties. Nonetheless, they have notable challenges, such as fast charge recombination and ineffective charge separation. In this work, we present a simple anti-solvent technique to create a heterojunction between lead-free halide perovskite Cs2AgBiBr6 (CABB) with Cu2O and Cu-Cu2O. This combination facilitates the photocatalytic activation of C(sp3)−H bonds, which in turn increases the oxidation of toluene. The Cu2O and Cu-Cu2O creating a Z-scheme heterojunction …

Effect Of Graphene Nanoplatelets Addition During Electroless Plating Of Abs On The Quantity Of Pdcl2 Usage For Copper-Nickel-Chromium Coated Abs, Wantana Chuakamhod

Chulalongkorn University Theses and Dissertations (Chula ETD)

Acrylonitrile Butadiene Styrene (ABS) with chromium coating is widely used in applications requiring high strength, durability, and aesthetic appeal, such as automotive parts, electronics, appliances, sanitary fixtures, and decorative consumer goods. Before electroplating, nickel electroless plating is applied to ABS to create a conductive base, but this process traditionally relies on palladium (Pd), a costly material. This research explores reducing Pd usage by incorporating graphene into the plating bath, enabling a decrease in Pd concentration from the industrial standard of 16-25 ppm to just 6 ppm with the addition of 15 mg/L of graphene. The Ni-coated ABS achieved an electrical …

Process Simulation And Techno-Economic Evaluation Of Free Lutein Production From Marigold Flowers, Yada Meayrin

Chulalongkorn University Theses and Dissertations (Chula ETD)

Lutein is a carotenoid widely recognized for its health benefits, including improved vision, cognitive function, and prevention of age-related diseases. This study presents a comprehensive techno-economic and environmental assessment of three crude free lutein production processes using marigold flowers (Tagetes erecta L.) at a processing capacity of 74 tons/year, modeled in Asplen Plus V.11. The evaluated processes include sequential extraction and de-esterification (SQP) using hexane (HEX) or liquefied dimethyl ether (LiqDME), and a one-step simultaneous extraction and de-esterification (SMP) using LiqDME. Among these, the SMP-DME process demonstrated the best performance, with a net present value (NPV) of 146.98 million US$, …

Aluminium-Doped And Carbon-Supported Zinc Oxide Ternary Composite Electrodes For Supercapacitor Applications, Abdulkadeem Sanni

Chulalongkorn University Theses and Dissertations (Chula ETD)

Developing high-performance supercapacitor electrodes requires materials with optimized electrical conductivity, surface area, morphology, energy density, and cyclability. Herein, we report a facile hydrothermal synthesis of carbon nanotubes (CNTs)-supported Al-doped ZnO@CuO composite. Structural characterization reveals that Al doping and CuO incorporation can transform ZnO nanoflakes into nanorod/nanoflower heterostructures. The electrochemical analysis of the quaternary composite in a mixed electrolyte containing 2 M KOH, 0.2 M KFC, and 0.2 M KI exhibits a specific capacitance of 1860 F/g at 1 mV/s. The fabricated asymmetric supercapacitor (ASC) yields an energy density of 36 Wh/kg, a power density of 3502.8 W/kg at 30 mA/g, …

Tuning Selectivity Of Ni/Al2o3 Catalysts In Co2 Hydrogenation By Addition Of N, S-Doped Carbon, Nipitpon Jarumalai

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study investigates the enhancement of Ni/Al₂O₃ catalysts for CO₂ hydrogenation by incorporating nitrogen and sulfur co-doped carbon (NSC). A series of catalysts Ni/Al2O3 and its NSC-modified counterparts (Ni1NSC/Al2O3, Ni3NSC/Al2O3, Ni7NSC/Al2O3, and Ni15NSC/Al2O3) were synthesized via thermal treatment under a nitrogen atmosphere and systematically characterized. Techniques including TGA, Raman spectroscopy, and XPS confirmed successful NSC incorporation. Further structural and surface analysis using TEM, XRD, CO-IR, CO2-TPD, H2-TPD, and H2-TPR revealed that NSC modification influenced Ni dispersion, surface basicity, hydrogen activation, and the electronic state of Ni species. Catalytic performance was evaluated in a fixed-bed reactor under a CO2:H2 ratio of …

Arsenic Removal From Synthetic Produced Water Using Ionic Extractants And Vegetable Oils Via Hollow Fiber Supported Liquid Membrane, Natthawan Srinam

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis presents the separation of arsenic from water derived from synthetic petroleum production using a hollow fiber supported liquid membrane (HFSLM) system. The membrane system incorporates an ionic liquid extractant and a vegetable oil-based diluent. The study began with the selection of suitable extractants and diluents, followed by experimental design to determine optimal operating conditions using response surface methodology (RSM). Box-Behnken Design (BBD) and Central Composite Face-Centered Design (FCCD) were employed, and the data were analyzed through analysis of variance (ANOVA). Kinetic and thermodynamic studies revealed that the HFSLM system could achieve arsenic extraction and stripping efficiencies of up …

Detection And Replacement Of States With Spikes And Noise By Long Short-Term Memory Models Or Neural Networks, Ittikorn Yutto

Chulalongkorn University Theses and Dissertations (Chula ETD)

Spike signals are impulsive disturbances with high amplitude occurring over a very short duration. They are typically caused by external factors such as temperature fluctuations, vibrations, or sensor inaccuracies, leading to erroneous measurements and potential degradation of control system performance. This study aims to develop a Long Short-Term Memory (LSTM) model for detecting and replacing spike signals in a second-order system. The model was trained and validated using datasets contaminated with spike signals of varying amplitudes. Experimental results demonstrated that the proposed model could suppress spike amplitudes by up to 99.79%, with a minimum reduction of 92.42% and an average …

Development Of Quaternized Poly(Vinyl Alcohol)/Chitosan/Two-Dimensional Molybdenum Disulfide Anion Exchange Membrane As A Separator For Electrochemical Processes, Nuttapon Suppanucroa

Chulalongkorn University Theses and Dissertations (Chula ETD)

In response to the global shift toward the expansion of large-scale energy storage systems (ESSs), secondary zinc-air batteries (ZABs) have attracted significant attention as promising candidates for next-generation batteries due to their high energy density, cost-effectiveness, and safety. However, their long-term practical application is hindered by several challenges associated with the membrane separator, including the formation of resistive zinc oxide layers and low hydroxide-ion conductivity. These limitations are attributed to poor ion-selectivity, which impedes electrochemical reactions and degrades battery performance. To address these issues, this study developed a series of innovative membrane separators featuring quaternary ammonium (QA)-functionalized polyvinyl alcohol (PVA), …

Hydrogen Production From Glycerol Using Sorption Enhanced Chemical Looping Steam Reforming With Multifunctional Pellet Catalyst, Talita Nimmas

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this study, the synthesis of a pellet-scale material for hydrogen (H₂) production from glycerol via the Sorption Enhanced Chemical Looping Steam Reforming (SE-CL-SGR) process was investigated. The research focuses on material synthesis, performance enhancement, and the economic and environmental advantages of the developed material. Among the synthesis methods compared, the Stepwise Calcination process demonstrated the best performance, producing structurally stable and mechanically robust pellets. The optimal CaO/support mass ratio for the Ni-supported material (15Ni(70Ca.30Support)) was found to achieve 90% v/v H₂ purity with a pre-breakthrough time of approximately 75 minutes. Rare-earth metal oxides (CeO₂, La₂O₃) addition also improved mechanical …

Regeneration By Electrodialysis Of Secondary Spent Monoethanolamine Solution Obtained After Mineralisation Of Captured Carbon Dioxide With Calcium Sulfate, Ketwarang Nimnualrat

Chulalongkorn University Theses and Dissertations (Chula ETD)

The greenhouse effect has been impacting our planet further than we even realized. In recent years, the earth’s atmosphere has rapidly changed at a faster pace than ever. The main villain, mostly released from industry, is carbon dioxide (CO2), which contributes about 79.7 percent of total greenhouse gases. Consequently, Carbon Capture, Utilization and Storage (CCUS) has now become an important role to mitigate this problem. A widely used industrial medium for capturing CO2 is aqueous solution of monoethanolamine (MEA), which is capable of capturing CO2 from fossil fuel-fired processes. However, current MEA regeneration by stripping has high energy requirements for …

Enhance Effectiveness Of Monitoring Scheme Using Insar On Tailings Storage Facility No. 2, Chatree Gold Mine, Thailand, Shanghai Chea

Chulalongkorn University Theses and Dissertations (Chula ETD)

Tailings storage facility (TSF) is a critical component of the mining industry, serving to safely contain waste generated during mineral extraction. At Chatree Gold Mine, the largest and only active gold mine in Thailand, TSF No.2 handles approximately 5 million tons of tailings annually. Effective monitoring of the facility is crucial for hazard prevention and regulatory compliance. This study aims to enhance the monitoring scheme of TSF No.2 by employing Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) technique, processed via MintPy software, to analyze ground deformation. Despite traditional monitoring methods, such as in-situ geodetic surveying, offering valuable insights, they …

Recovery Of Tin From Kaolin Mine Tailing, Rangoon, Thailand, Archana Pandit

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study investigates the recovery of tin from kaolin waste using gravity, electrostatic, and magnetic separation techniques. A total of 123.500 kg of sand and 103.200 kg of silt were processed using a shaking table, spiral concentrator, high-tension separator, induced roll magnetic separator, and Frantz magnetic separator. Mineralogical and chemical characterization was conducted using X-ray diffractometer (XRD), X-ray fluorescence (XRF), and microscopic analysis to determine tin distribution and occurrence. Experimental results showed that the silt fractions generally exhibited higher tin content than the sand fractions. In this study, Case A refers to the samples (Sand A and Silt A) processed …

Ethanol-Assisted Co2 Hydrogenation To Methanol In A Trickle-Bed Reactor, Pattarapol Akeakkharanusorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

The hydrogenation of carbon dioxide (CO2) to methanol is a promising approach for CO2 utilization. However, conventional methanol synthesis is thermodynamically limited at high temperatures. Alcohol-assisted methanol synthesis has emerged as a novel low-temperature method, using alcohol as a catalytic solvent to alter reaction pathways. Equilibrium analysis using Gibbs free energy minimization in Aspen Plus showed that increasing ethanol enhanced CO2 conversion and methanol yield. At high ethanol concentrations, ethanol remained in the liquid phase. This study investigated ethanol-assisted CO2 hydrogenation in a trickle-bed reactor using a commercial Cu/ZnO/Al2O3 catalyst. CO2 and H2 were introduced in gaseous form, while ethanol …

Simulation Study For Enhancing Thermal Performance Of Cotton Facemasks Through Integration Of Organic Phase Change Materials, Poptham Chaviengpop

Chulalongkorn University Theses and Dissertations (Chula ETD)

Climate change has caused temperature extremities around the world. Maintaining body temperature against cold temperatures is important for preventing long term health risks. PCM incorporated facemasks offers the solution to this problem. In this study, computational fluid dynamics utilizing laminar flow of air in a simulated wind chamber is used to model the human breathing cycle in cold environments (0-10°C) through four different types of PCM incorporation facemasks (random, coating, hollow fiber, and lamination) used in the industry and three separate PCM candidates (n-octadecane, capric acid, and PEG-600). The findings indicates that the facemask utilizing the coating PCM incorporation method …

Photocatalytic Activity Of N, S-Cqds/Tio2 Composites For The Degradation Of Methylene Blue Under Light Irradiation, Thanyapak Akkharaamnuay

Chulalongkorn University Theses and Dissertations (Chula ETD)

Water pollution from synthetic dyes like methylene blue (MB), especially from textile industries, poses serious environmental challenges due to their resistance to conventional treatment. This study focuses on the develops nitrogen and sulfur co-doped carbon quantum dots (N, S-CQDs) incorporated into titanium dioxide (TiO2) for the degradation of methylene blue under light irradiation. The composites were calcined at 400 °C and 500 °C to investigate the effect of calcination temperature on photocatalytic performance. Characterization was conducted using techniques such as XRD, SEM-EDX, TEM, FT-IR, UV–Vis spectroscopy, Photoluminescence, and BET analysis. The results revealed that increasing the calcination temperature enhanced crystallinity, …

Regeneration Of Carbon Dioxide-Rich Amines Via Mineralization, Tanasorn Thumpanisakool

Chulalongkorn University Theses and Dissertations (Chula ETD)

Carbon dioxide (CO2) a major driver of the increasing greenhouse effect, making the development of CO2 capture and utilization technologies. Although monoethanolamine (MEA) is a highly efficient sorbent, the energy cost of its thermal regeneration remains a significant challenge. This thesis investigates a low-energy regeneration route for MEA based on mineralized CO2. Especially, the study systematically investigates the effects of MEA concentration, calcium source selection, and amine regeneration mechanisms. A 5 M MEA solution achieved a CO2 loading capacity up to 2.9 mol/L. However, mineralization with CaSO4 alone resulted in irreversible MEA protonation and poor reusability. Mechanistic analysis revealed that …

Design And Development Of A Sustainable Ethylene Glycol Production Process Via Electrochemical Co2 Reduction, Nichapat Leelalertwong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Addressing the critical issue of rising atmospheric CO2 concentrations and their impact on climate change necessitates innovative technological solutions. This study presents a novel and sustainable method for producing ethylene glycol, commonly used in antifreeze, polyester, and various industrial applications, through electrochemical CO2 reduction, offering a lower environmental impact compared to conventional coal-based or biomass-based processes. This process is known as the "OCEAN" technique, which utilizes oxalic acid as a key intermediate to enhance efficiency and minimize unwanted byproducts. The process was simulated in Aspen Plus to evaluate both technological performance and environmental impact. CO2 is converted to oxalic acid …

Xylan Fast Pyrolysis: An Experimental And Modelling Study Of Particle Changes And Volatiles Release, F Cerciello, E Freisewinkel, A Coppola, C Ontyd, D Tarlinski, Martin Schiemann, Osvalda Senneca, Pierro Salatino, C Allouis, Victor Scherer, Thomas H. Fletcher

Faculty Publications

Biomass char particles produced by pyrolysis may have different morphologies, which has important implications on burning mode, conversion rate and boiler efficiency. These features are difficult to address due to the complexity of biomass structure and pyrolysis reaction models. The present work reports preliminary results on the morphological changes and volatile release that solid particles of Xylan experience upon fast heating in a Drop Tube Reactor (DTR) and in a Heated Strip Reactor (HSR) in a range of temperature between 1100 and 1573 K under inert atmosphere with heating rate in the order of 10³ K/s. Two different Xylan …

Aerosol Jet Printing Of Surface Acoustic Wave Microfluidic Devices, Joseph Rich, Brian Cole, Teng Li, Brandon Lu, Hanyu Fu, Brittany N. Smith, Jianping Xia, Shujie Yang, Ruoyu Zhong, James L. Doherty, Kanji Kaneko, Hiroaki Suzuki, Zhenhua Tian, Aaron D. Franklin, Tony Jun Huang

Faculty Publications

The addition of surface acoustic wave (SAW) technologies to microfluidics has greatly advanced lab-on-a-chip applications due to their unique and powerful attributes, including high-precision manipulation, versatility, integrability, biocompatibility, contactless nature, and rapid actuation. However, the development of SAW microfluidic devices is limited by complex and time-consuming micro/nanofabrication techniques and access to cleanroom facilities for multistep photolithography and vacuum-based processing. To simplify the fabrication of SAW microfluidic devices with customizable dimensions and functions, we utilized the additive manufacturing technique of aerosol jet printing. We successfully fabricated customized SAW microfluidic devices of varying materials, including silver nanowires, graphene, and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate …

Assessing The Feasibility And Mechanism Of Destructive Removal Of Per- And Polyfluoroalkyl Substances (Pfas) From Water, Kaushik Vinaykumar Londhe

Dissertations

One of the most pertinent challenges faced by the drinking water community is the widespread contamination of per- and polyfluoroalkyl substances (PFAS). These anthropogenic chemicals have been ubiquitously used in everyday products such as carpets, stain repellents, dyes, shampoos, non-stick cookware as well as in aqueous firefighting foams. PFAS are linked with adverse health effects in humans such as thyroid disease, obesity, immunological and reproductive disorders and linked to cancer in adults and low birth weight and developmental defects in infants.

Conventional water treatment technologies have proven to be largely ineffective in PFAS remediation, due to their extreme stability and …

Classification Of Oil Products According To The Nomenclature Of Goods, Kurbankul Mavlankulovych Karimkulov Profesor, Azoda Abdurahmanova

Technical science and innovation

The article analyzes types of vegetable oils. Simple methods of determining their quality using liquid gas chromatography have been developed. Recommendations for improving the classification of foreign economic activity based on commodity nomenclature were developed and recommended for customs operations. “Fats and oils of animal, vegetable or microbiological origin and products of their breakdown; prepared edible fats; waxes of animal or vegetable origin” was called. Animal fats, including pork, beef, sheep, goat, fish and oils of animals such as marine mammals are classified according to the Nomenclature of Foreign Economic Activities of the Republic of Uzbekistan in commodity headings 1501-1506 …

Advancing Polymer Sustainability Through Custom Interpenetrating Polymer Network Synthesis, Processing, And Design, Alexandra Maria Lehman-Chong

Theses and Dissertations

The need for improving polymer sustainability is as ubiquitous as the role of polymers in modern society. Interpenetrating polymer network (IPN) design flexibility offers opportunities for improved polymer sustainability while balancing desired polymer properties for various applications. This work investigates the structure-property-processing relationships of IPNs judiciously designed under the framework of the polymer life cycle. Sustainable polymer design was largely considered at the feedstock and manufacturing stages while considering overall polymer performance. Chemicals from bio-based feedstocks were used to design a full simultaneous polybenzoxazine-epoxy IPN, focusing on the effects of monomer and polymer structure on polymer properties. Processing-property relationships were …

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …

Algorithms For Synthesis Of Adaptive Control Systems With A Customized Model Using The Speed Gradient Method, Jasur Sevinov, Oxunjon Boborayimov

Chemical Technology, Control and Management

Algorithms are considered for the synthesis of adaptive control systems with a customized model based on the speed gradient method. For the synthesis of adaptive control systems, the identification approach is based on obtaining estimates of the unknown parameters in the object. By calculating the speed gradient, identification algorithms with an explicit and implicit customized model were obtained as well as that in sliding modes. A joint solution is given to the interrelated problems of identifying parameters with insufficient current information. The position of an object is about assessing the state with insufficient a priori information about its parameters. This …

Mathematical Models And Calculation Of Parameters Of Optoelectronic Angular Displacement Converters, Yuriy Gennadyevich Shipulin, Azimjon Khusanov

Chemical Technology, Control and Management

The article discusses promising optoelectronic converters (OP) for wide application of angular movements. A methodology and diagram for calculating OP with the transverse movement of a moving element is presented; in order to simplify the calculation, the weight range of angular movements is conventionally divided into three sub ranges. A graph is given of the dependence of the area of the photosensitive surface of a photo resistor made from a single crystal of high-resistivity p-type silicon.

Modeling Of Amine-Based Co2 Capture Process, Zafar Safarovich Turakulov

Chemical Technology, Control and Management

A significant factor influencing climate change is the release of carbon dioxide (CO₂) into the atmosphere as a consequence of human activities such as the combustion of fossil fuels. Climate change can be slowed down by taking action to mitigate industrial-scale CO₂ emissions. Currently, the most advanced technology for capturing CO₂ from industrial flue gases is the post-combustion CO₂ capture based on amine absorption. However, due to the high energy penalties of existing CO₂ capture technologies and insufficient carbon markets, it is necessary to develop methods that compete with these technologies or minimize their …

The Use Of Ultraviolet Radiation As A Means Of Destroying Microorganisms In Cherries, Jasur Safarov, Shaxnoza Sultanova, Pulatov M. Murodjon

Chemical Technology, Control and Management

The article discusses methods for extending the shelf life of cherries, having previously treated it with an ultraviolet ray. The article also presents the results obtained, which prove that the shelf life of cherries exposed to ultraviolet increases. At the same time, the article describes in detail the processing technique and presents the results of research.