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Full-Text Articles in Chemical Engineering
Designing Binary Low Ift Surfactant System Using Hld Concept For Oil Recovery, Tukta Jamprakhon
Designing Binary Low Ift Surfactant System Using Hld Concept For Oil Recovery, Tukta Jamprakhon
Chulalongkorn University Theses and Dissertations (Chula ETD)
Surfactant-based microemulsion technology is widely used in tertiary enhanced oil recovery applications (EOR). The formulation of suitable surfactant system is a key success in production and economic feasibility of this technology. The middle phase or Winsor Type III microemulsions, employed for selecting appropriate surfactant system, can offer an optimal salinity at which the high oil solubilization capacity and minimum interfacial tension (IFT) or ultralow IFT (<0.01 mN/m) are obtained. By this technology, more remaining oil in the reservoir can be solubilized and mobilized which leads to an improvement of oil recovery. This study aims to formulate surfactant systems for the oil recovery through microemulsion formulation. The novel mixed anionic surfactant system of a sodium dioctyl sulfosuccinate (AOT) and an internal olefin sulfonates (IOS) with different alkyl chain lengths (C15-18, C19-23, C24-28) were used due to its mixture avoiding the surfactant precipitation. The result found that the binary mixture of AOT and (IOS C15-18 and IOS C19-23) can form the middle phase at the mixing ratios of 5:5 to 9:1 (by molar ratio) with heptane and decane. When the fraction of IOS increased in the mixed AOT/IOS system, the optimal salinity (S*) also increased. For the effects of a carbon tail length of IOS surfactant was observed that the tail length increased with decreasing the optimal salinity. The hydrophilic-lipophilic deviation (HLD) for the mixed surfactant system was investigated to individually determine the K and Cc values for the IOS surfactants. The finding from this work provided a guide for surfactant selection through HLD concept to formulate microemulsion-based surfactant flooding for EOR application.
Design Of Plantwide Control Structure Of Double Effect Water/Lithium Bromide Absorption Chiller, Kris Prasopsanti
Design Of Plantwide Control Structure Of Double Effect Water/Lithium Bromide Absorption Chiller, Kris Prasopsanti
Chulalongkorn University Theses and Dissertations (Chula ETD)
Alternative control structures for a parallel double effect aqueous lithium bromide absorption chiller, operated in two modes of operation, has been designed using Skogastad's plantwide control procedure. In on-demand mode, two complete decentralized control structures with proportional integral (PI) controllers and one structure with a two inputs - two outputs model predictive controller (MPC) were proposed. Their performance was evaluated using MATLAB-Simulink dynamic simulation. The results varied depended on type of disturbance, but overall, the structure with MPC controller provided slightly better results with less liquid holdup changes and faster setting time in average. For on-supply mode, two self-optimizing control …
The Effects Of Tio2 Phase And Sio2 Supports On Methyl Oleate Epoxidation, Nichaphat Sangkanchanavanich
The Effects Of Tio2 Phase And Sio2 Supports On Methyl Oleate Epoxidation, Nichaphat Sangkanchanavanich
Chulalongkorn University Theses and Dissertations (Chula ETD)
This work studies about the epoxidation reaction of methyl oleate with TiO2 or TiO2/SiO2 catalysts and hydrogen peroxide. Study of TiO2 catalysts interests in catalysts from commercial and sol gel method. The highest catalytic activity and selectivity of TiO2 from commercial is TiO2 commercial type B which gives 46.10% and 79.75%, respectively. For sol gel method, the highest catalytic activity at 75.82% and selectivity at 90.85% is TiO2 calcination temperature at 300OC, due to low crystallinity and high surface area. TiO2/SiO2 with different type of SiO2 support (MCM-41, SBA-15, silicalite, silica gel and fumed silica) shows different catalytic activity and …
Hydrogen Production From Sorption Enhanced Chemical Looping Steam Ethanol Reforming Using Calcium Oxide/ Copper Oxide/ Nickel Oxide Multifunctional Catalyst, Talita Nimmas
Chulalongkorn University Theses and Dissertations (Chula ETD)
Multifunctional catalyst was developed for hydrogen production via sorption enhanced chemical looping ethanol steam reforming. Calcium acetate (Ca2Ac) and calcium chloride (CaCl) were used as calcium precursor. Sodium carbonate (Na2CO3) and urea (CO(NH2)2) were used as carbonate precursor. The NiO/CaOAc-Urea-Ca12Al14O33 showed the longest pre-breakthrough period of 60 min and 88% of hydrogen purity at steam to ethanol molar ratio (S/E) of 4:1, temperature 600 ﹾC. Stability of NiO/CaOAc-Urea-Ca12Al14O33 was tested over 10 cycles and the results showed hydrogen purity can be maintained at 90% during pre-breakthrough period. The effect of synthesis method: sol-mixing and sol-gel, on hydrogen production was compared …
The Surface Modification Of Zeolite Y In Composite Selective Layer Of Hollow Fiber Membrane For Separation Of Co2/Ch4 Mixture, Thakorn Wichaidit
The Surface Modification Of Zeolite Y In Composite Selective Layer Of Hollow Fiber Membrane For Separation Of Co2/Ch4 Mixture, Thakorn Wichaidit
Chulalongkorn University Theses and Dissertations (Chula ETD)
This work focused on the fabrication and evaluation of composing hollow fiber mixed matrix membranes (MMMs) incorporated by zeolite Y for CO2/CH4 separation. The effects of surface modification of zeolite Y to improve compatibility of filler and polymer dispersibility of the filler in the polymer matrix on properties and separation performance of the membrane were investigated. A polysulfone (PSF) was used as a support hollow fiber and a selective layer composing of polyether-block-amide (Pebax) and zeolite Y (ZeY) and surface modification of zeolite Y (mo-ZeY) was coated on support. A [3-(2-Aminoethylamino)propyl]trimethoxysilane (AEAPTMS) was used to grafted on surface of pristine …
การพัฒนาฟิล์มบรรจุภัณฑ์บรรยากาศดัดแปรจากสารผสมระหว่างพอลิเอธิลีนชนิดความหนาแน่นต่ำกับเทอร์โมพลาสติกพอลิเอสเทอร์อีลาสโตเมอร์, กันตพงศ์ สักลอ
การพัฒนาฟิล์มบรรจุภัณฑ์บรรยากาศดัดแปรจากสารผสมระหว่างพอลิเอธิลีนชนิดความหนาแน่นต่ำกับเทอร์โมพลาสติกพอลิเอสเทอร์อีลาสโตเมอร์, กันตพงศ์ สักลอ
Chulalongkorn University Theses and Dissertations (Chula ETD)
งานวิจัยนี้เป็นการพัฒนาฟิล์มบรรจุภัณฑ์บรรยากาศดัดแปร (Modified Atmosphere Packaging Film) โดยศึกษาถึงผลของปริมาณสารเทอร์โมพลาสติกพอลิเอสเทอร์อิลาสโตเมอร์ (TPEE) ในสัดส่วน 0 - 50% โดยน้ำหนักที่ถูกผสมเข้าไปในพอลิเอธิลีนชนิดความหนาแน่นต่ำ (LDPE) และสภาวะการขึ้นรูปฟิล์ม ได้แก่ อัตราเร็วในการดึงฟิล์ม (Film Pulling Speed) ช่วง 200 - 240 rpm และอุณหภูมิหล่อเย็นฟิล์ม 15 - 50 องศาเซลเซียสต่อค่าความสามารถในการซึมผ่านแก๊สและไอน้ำของฟิล์มที่ได้ ผลการทดลองพบว่าการเติม TPEE ลงใน LDPE ในปริมาณที่มากขึ้นส่งผลให้ความสามารถในการซึมผ่านไอน้ำและแก๊สของ MAP Film มีแนวโน้มเพิ่มขึ้น เพราะ TPEE มีความสามารถในการซึมผ่านไอน้ำและแก๊สสูงกว่า LDPE นอกจากนี้การเพิ่มอัตราเร็วในการดึงฟิล์มส่งผลทำให้ช่องว่าง (Void) บริเวณรอยต่อระหว่างวัฏภาคของ LDPE กับ TPEE กว้างขึ้น ส่งผลให้อัตราการซึมผ่านของไอน้ำและแก๊สเพิ่มขึ้นตามไปด้วย ในทางกลับกัน การเพิ่มอุณหภูมิหล่อเย็นฟิล์มส่งผลให้เปอร์เซ็นต์ความเป็นผลึกของฟิล์มเพิ่มขึ้น ทำให้อัตราการซึมผ่านของไอน้ำและแก๊สมีแนวโน้มลดลง ส่วนการทำนายเวลาที่แก๊สในถุงบรรจุภัณฑ์เข้าสู่สภาวะคงตัวและปริมาณแก๊สในถุงบรรจุภัณฑ์โดยใช้โปรแกรม MATLAB พบว่า ภายใต้สภาวะที่ศึกษา แก๊สในถุงบรรจุภัณฑ์เข้าสู่สภาวะคงตัวภายในเวลา 24 ชั่วโมง โดยที่ MAP Film ที่มีค่าความสามารถในการซึมผ่านแก๊สออกซิเจนสูงกว่า ทำให้ปริมาณแก๊สออกซิเจนภายในถุงบรรจุภัณฑ์ที่สภาวะคงตัวมีค่าสูงกว่าและในทางกลับกัน MAP Film ที่มีค่าความสามารถในการซึมผ่านแก๊สคาร์บอนไดออกไซด์สูงกว่า ทำให้แก๊สคาร์บอนไดออกไซด์ภายในถุงบรรจุภัณฑ์ที่สภาวะคงตัวมีค่าน้อยกว่า
Simulation Of Water Effect On Biodiesel Production Using Waste Cooking Oil Via Ester-Transesterification In A Reactive Distillation Column, Ajala Anantapinitwatna
Simulation Of Water Effect On Biodiesel Production Using Waste Cooking Oil Via Ester-Transesterification In A Reactive Distillation Column, Ajala Anantapinitwatna
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research investigated the effect of water content in waste cooking oil (WCO) on the performance of a reactive distillation column for biodiesel production via ester-transesterification. A mixture of triolein and oleic acid was used as a WCO model compound. Amberlyst-15 was used to catalyze esterification while CaO was used for transesterification. From Langmuir-Hinshelwood-Hougen-Watson (LHHW) kinetic model taking into account water absorption for esterification of oleic acid (FFA), biodiesel yield was decreased with increasing of water content in WCO feedstocks. On the other hand, the initial rate of transesterification was increased with increase of amount of water in WCO feedstocks …
Synthesis Of Activated Carbons From Coffee Ground Residues And Their Application As Catalysts For Ethanol Dehydrogenation, Jeerati Ob-Eye
Synthesis Of Activated Carbons From Coffee Ground Residues And Their Application As Catalysts For Ethanol Dehydrogenation, Jeerati Ob-Eye
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this present study, characteristics and catalytic properties of activated carbon derived from coffee ground residue, cobalt metal (Co) supported-activated carbon and various metals (Ce, Co, Cu and Ni) supported-commercial activated carbon were determined and characterized. This study was divided into three parts. Regarding to the first part, the synthesis of activated carbon catalysts derived from coffee ground residues with different methods of physical activation was investigated. The results showed that the catalyst with physically activated by CO2 for 4 hours, exhibited the best catalytic activity of ethanol dehydrogenation to acetaldehyde. In the second part, the best catalyst from the …
Simulation And Evaluation Of Butadiene Production From Ethanol Via One-Step Reaction, Jirawat Imsaard
Simulation And Evaluation Of Butadiene Production From Ethanol Via One-Step Reaction, Jirawat Imsaard
Chulalongkorn University Theses and Dissertations (Chula ETD)
1,3-butadiene is an important compound produced from the steam cracking process. Raising demand for alternatives to fossil fuels has led to an increase in bio-derived ethanol production, which can also be used as a feedstock for 1,3-butadiene synthesis. This research investigated the simulation of 1,3-butadiene production from ethanol using one-step process with 1.AI2O3/ZnO (60:40), 2.MgO-SiO2-Na2O (1:1)(0.1%) and 3.Hf2.5ZM1.6/SiO2 as heterogeneous catalysts. The process simulation was carried out using commercial Aspen plus 8.0 program and the heat utilization efficiency was evaluated by Aspen energy analyzer software. The process optimal condition sequences were identified by adjusting the separation distillation parameters which include …
Effects Of Tio2 Support And Co Addition On Ni/Tio2 Catalysts In Selective Hydrogenation Of Furfural To Furfuryl Alcohol, Kittithad Wonglekha
Effects Of Tio2 Support And Co Addition On Ni/Tio2 Catalysts In Selective Hydrogenation Of Furfural To Furfuryl Alcohol, Kittithad Wonglekha
Chulalongkorn University Theses and Dissertations (Chula ETD)
Furfuryl alcohol is an important chemical intermediate that can be converted into many value-added derivative molecules. It is typically produced by the hydrogenation of furfural using supported metal catalysts. In this work, 15%wt Ni catalysts supported on titania (TiO2) were prepared by incipient wetness impregnation method. The effects of phase composition and average crystallite sizes of TiO2 and Co addition in the range of 1-3 wt% on the catalytic properties of 15 wt%Ni/TiO2 were investigated in the selective hydrogenation of furfural to furfuryl alcohol at 50°C, 20 bar of H2, and 2 h reaction time. It was found that Ni …
Hydrothermal Carbonization Carbon-Based Acid Catalyst For Biodiesel Production, Laddawan Tumkot
Hydrothermal Carbonization Carbon-Based Acid Catalyst For Biodiesel Production, Laddawan Tumkot
Chulalongkorn University Theses and Dissertations (Chula ETD)
This study aims to synthesize the production of biodiesel (oleic acid methyl ester) by esterification in the presence of sulfonated hydrothermal carbon based catalyst under microwave irradiation. The catalyst was prepared by hydrothermal carbonization, followed by sulfonation presenting sulfonic acid group as an active site. The catalyst characterization results confirmed good microwave-absorptivity of the catalyst which can be heated directly and accelerate the reaction immediately at the surface of the catalyst. Esterification of oleic acid (OA) with methanol experiments were optimized by using response surface methodology based on central composite design. Three variables: molar ratio of methanol to OA (2.5:1-7.5:1), …
Graphene Sheets Decorated With Silver Nanoparticles As An Oxygen Reduction Reaction Catalyst For Zinc-Air Battery, Laksanaporn Poolnapol
Graphene Sheets Decorated With Silver Nanoparticles As An Oxygen Reduction Reaction Catalyst For Zinc-Air Battery, Laksanaporn Poolnapol
Chulalongkorn University Theses and Dissertations (Chula ETD)
The aim of this thesis is to develop a catalyst for the cathode of a zinc-air battery and to investigate the effects of reduced graphene oxide decorated with silver nanoparticles on the cathode in the zinc-air battery. First, reduced graphene oxide (AgNPs/rGO) was synthesized using glucose reduction at 60 degrees Celsius. Next, the structure and morphology of AgNPs/rGO were checked using X-ray diffraction (XRD). Then, transmission electron microscopy (TEM) analyzes were carried out. The amount of silver (Ag) decorate in graphene oxide was confirmed by EDX. Next, the synthesized catalysts at 3 concentration, using a rotating disk electrode (RDE), led …
Effect Of Cu Modified Tio2 Catalysts Prepared By Incipient Wetness Impregnation And Sputtering For Photocatalytic Co2 Reduction In Aqueous Solution, Nantiya Jantarasorn
Effect Of Cu Modified Tio2 Catalysts Prepared By Incipient Wetness Impregnation And Sputtering For Photocatalytic Co2 Reduction In Aqueous Solution, Nantiya Jantarasorn
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this work, we investigated the photocatalytic CO2 reduction in aqueous solution and were carried out in a stirred slurry reactor using Cu/TiO2 catalysts synthesized by incipient wetness impregnation and sputtering method. Effects of Cu loading onto titania support enhancing efficiency of the photocatalytic CO2 reduction in aqueous solution under UV irradiation by a band gap energy modification appeared between valence band and conduction band are narrowed. Cu assisted a selective hydrocarbon compound, this is methane. A comparison between Cu/TiO2 catalysts synthesized by incipient wetness impregnation and sputtering method showed that both methods exhibited similar methane selectivity. Sputtered catalysts are …
Reactive Extraction Of Metal Ion And Simultaneous Stripping Using Nanofibers-Supported Liquid Membrane In A Microchannel, Nattakarn Chucherd
Reactive Extraction Of Metal Ion And Simultaneous Stripping Using Nanofibers-Supported Liquid Membrane In A Microchannel, Nattakarn Chucherd
Chulalongkorn University Theses and Dissertations (Chula ETD)
Heavy metals in wastewater resulting from industries have become a prime concern for both environmental and economic reasons. This work intends to recover ions of heavy metal from wastewater using reactive extraction by nanofibers-supported liquid membrane (NSLM) in a microchannel. The use of supported liquid membrane enables simultaneous extraction and stripping (i.e., recovery of the extractant) processes. In this study, the NSLM was applied in a microchannel to minimize mass transfer resistance, hence improving overall performance of the extraction. Copper (II) ion was used as a model ion, while di-2-ethylhexyl phosphoric acid (D2EHPA) dissolved in kerosene was used as the …
Electrode Improvement Using Diamond-Like Carbon For Electrochemical Advanced Oxidation In Diuron Degradation, Nimit Kantiyawong
Electrode Improvement Using Diamond-Like Carbon For Electrochemical Advanced Oxidation In Diuron Degradation, Nimit Kantiyawong
Chulalongkorn University Theses and Dissertations (Chula ETD)
Diuron is one of the pesticides. Its residual can contaminate natural water resource resulting in environmental and human health problems. Several processes have been used to remove diuron contamination. Nowadays, an electrochemical advanced oxidation process (EAOP) in a microchannel reactor is used to degrade diuron owing to its high efficiency. In this research, the diamond-like carbon (DLC) thin film was used as an electrochemical electrode because it has superior hardness and electrical conductivity. In this research, we have successfully synthesized the DLC thin films using graphite as target material on the surface of 304 stainless steel substrate by the direct …
Computational Fluid Dynamics Modeling Of The Climate Inside A Chicken House, Nuttaphon Kanjanaudomsuk
Computational Fluid Dynamics Modeling Of The Climate Inside A Chicken House, Nuttaphon Kanjanaudomsuk
Chulalongkorn University Theses and Dissertations (Chula ETD)
Nowadays, most of chicken products are from a closed house system. Climate inside such chicken house can significantly affect chicken welfare and its productivity. Moreover, Thailand is in a tropical region where thermal stress is easily occurred. Suitable operating condition and chicken house design can help improve interior climate which can be evaluated by computational fluid dynamics (CFD) modeling technique. In this study, realizable k-ε model, energy conservation and species transport equations were applied to simulate the air velocity, temperature and relative humidity, respectively, inside the chicken house. The model was validated with measured air velocity, temperature and relative humidity …
The Development Of Pt/Wox/Al2o3 For 1,3-Propanediol Production From Glycerol, Parama Uttraporn
The Development Of Pt/Wox/Al2o3 For 1,3-Propanediol Production From Glycerol, Parama Uttraporn
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this work, the researcher studied the hydrogenolysis of glycerol to 1,3-propanediol, by compared the catalytic activity between AlOOH (boehmite) and g-Al2O3. The catalysts were prepared by wet impregnation method. To investigate the properties, catalysts were characterized by XRD, XPS, BET, H2-TPR, H2-TPD, H2-TPR, SEM-EDX, Py-IR, NH3-IR, and XAS. The type of support showed to be of significance in deciding the activity and the selectivity to 1,3-propanediol. It was found that 2%Pt/WOx/g-Al2O3 gave higher activity and selectivity of 1,3-propanediol, which due to a large amount of active site and Brønsted acid site in the catalyst. The effects of H2 pressure, …
Effect Of Metal Oxides On Zirconia For Ketonic Decarboxylation Of Methyl Stearate, Pawaphat Sartsri
Effect Of Metal Oxides On Zirconia For Ketonic Decarboxylation Of Methyl Stearate, Pawaphat Sartsri
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this research, the effect of characteristics of zirconia and metal oxide modified zirconia catalysts on the catalytic performance were investigated by ketonic decarboxylation of methyl stearate to desired ketone product at the optimal condition (400°C and 1 bar). Zirconia and metal oxide modified zirconia catalysts were characterized by using X-ray diffraction (XRD), Scanning electron microscope (SEM), N2-physissorption, X-ray photoelectron spectroscopy (XPS), and IR spectra of pyridine adsorption (Pyridine-IR). The results indicated that the transition metal oxide group modified zirconia catalysts have higher contents of total Lewis acid site and oxygen vacancies site, and lower content of total Brønsted acid …
Regeneration Of Zinc Particles For Zinc-Air Battery By Spouted-Bed Electrochemical Reactor, Peerawat Puengthaijaroen
Regeneration Of Zinc Particles For Zinc-Air Battery By Spouted-Bed Electrochemical Reactor, Peerawat Puengthaijaroen
Chulalongkorn University Theses and Dissertations (Chula ETD)
Zinc-air batteries are a promising energy storage system due to its high energy density, low toxicity, and low flammability. They are currently used commercially in low-current devices. Batteries for high-current applications are constructed with zinc particles for increased specific surface areas. Nevertheless, the regeneration of zinc particles from dissolved zincate ions in spent electrolytes has been relatively neglected. We fabricate and study a spouted-bed electrochemical reactor for the regeneration of zinc particles from spent electrolytes. The reactor measures 220 mm high and 130 mm wide with copper as a cathode and stainless steel as an anode. The reactor is separated …
Dual-Electrolyte System For Suppressing Corrosion Of Aluminum Electrode In Aluminum-Air Flow Battery, Pemika Teabnamang
Dual-Electrolyte System For Suppressing Corrosion Of Aluminum Electrode In Aluminum-Air Flow Battery, Pemika Teabnamang
Chulalongkorn University Theses and Dissertations (Chula ETD)
Aluminum-air batteries have received considerable attention as an electrical power source due to their theoretical specific capacity reaching 2.98 Ah/g. Further, Al-air batteries are abundant and low cost. On the other hand, the aluminum in the batteries has a problem, such that it is subject to self-corrosion in alkaline. Herein, this work concentrates on the aluminum's corrosive behavior and self-corrosion in methanol-3M KOH mixed solution containing different percentages of deionized water i.e. (0, 5, 10 and 20)%wt, using electrochemical (half-cell testing). The aluminum-air battery consists of: aluminum anode | anolyte | anion exchange membrane | catholyte | air cathode. The …
Reaction Mechanism And Pathway For The Selective Photocatalytic Hydrogenation Of Nitroaromatics Over Tio2 In Alcohols, Pimchanok Nakchuai
Reaction Mechanism And Pathway For The Selective Photocatalytic Hydrogenation Of Nitroaromatics Over Tio2 In Alcohols, Pimchanok Nakchuai
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research investigated the mechanism and photocatalytic performance of the selective photocatalytic hydrogenation of different nitroaromatics (Ar-NO2) in several alcohols under UV light using P25-TiO2 at room temperature and atmospheric pressure. The effect of Pt-deposited P25-TiO2 on the photocatalytic performance was also studied. Ar-NO2 was converted to aminoaromatics (Ar-NH2) with high Ar-NO2 conversion and Ar-NH2 selectivity at nearly 100%. The amounts of Ar-NH2 were proportional with carbonyl compounds at the ratio around 1:3. Acetaldehyde, acetone, and butanone were produced by oxidation of ethanol, 2-propanol, and butanol, respectively. Ethanol exhibited the fastest completed Ar-NO2 conversion due to the most efficient formation …
Oxidative Dehydrogenation Of Ethanol To Acetaldehyde Over Magnesium Aluminium Layered Double Hydroxides Catalyst, Piriya Pinthong
Oxidative Dehydrogenation Of Ethanol To Acetaldehyde Over Magnesium Aluminium Layered Double Hydroxides Catalyst, Piriya Pinthong
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this research, the characteristic and catalytic activity of Mg-Al LDH and their metal-modified mixed oxide were investigated. This research was divided into three parts. In the first part, the effect of calcination temperature on catalytic performance via oxidative dehydrogenation of ethanol was elucidated. The results showed that calcination temperature affected the characteristic of Mg-Al LDH, especially basicity. Moreover, the calcination temperature also affected the catalytic performance on oxidative dehydrogenation of ethanol over Mg-Al LDH. The result was consistent with the basicity of catalysts. In the second part, the Mg-Al mixed oxide derived from calcination of Mg-Al LDH was modified …
Effects Of Immobilization Of Methylalumoxane On Cellulose Support On Ethylene Polymerization Behaviors., Praonapa Tumawong
Effects Of Immobilization Of Methylalumoxane On Cellulose Support On Ethylene Polymerization Behaviors., Praonapa Tumawong
Chulalongkorn University Theses and Dissertations (Chula ETD)
The way to improve the physical properties of polyethylene is done by adding nano-sized filler during the synthetic process. These can be commonly achieved by in situ polymerization. These studies are divided into two parts in this research. Firstly, it investigated the effect of types and amounts of cocatalyst and scavenger of zirconocene catalyst on ethylene polymerization behaviors. In fact, methylalumoxane (MAO) and triethylaluminum (TEA) were used as cocatalyst and scavenger, respectively. The ratios of [Al]MAO/[Zr]cat and [Al]TEA/[Zr]cat were varied during the in situ polymerization of ethylene. The polymerization was performed in a semi-batch autoclave reactor under adiabatic operation at …
Development Of Suture Pad From Silk-Reinforced Polydimethylsiloxane Composite, Radhitya Banuaji Prastowo
Development Of Suture Pad From Silk-Reinforced Polydimethylsiloxane Composite, Radhitya Banuaji Prastowo
Chulalongkorn University Theses and Dissertations (Chula ETD)
The aim of this research is to investigate the mechanical properties of polydimethylsiloxane reinforced with short silk fibers for suture pad application. The effect of aspect ratio and fibers content of the polydimethylsiloxane reinforced with silk fibers on the properties was evaluated. From the results, tensile modulus and tensile strength of polydimethylsiloxane reinforced with different aspect ratio were increased with increasing aspect ratio and fibers content. The composite with the addition of silk fiber produces higher tear resistance with suture thread compared with pure polydimethylsiloxane. Furthermore, the hardness of polydimethylsiloxane reinforced with short silk fibers was improved with the addition …
Design Of Solid Oxide Fuel Cell-Molten Carbonate Fuel Cell Combined System For Power Generation And Carbon Dioxide Emission Reduction, Prathak Jienkulsawad
Design Of Solid Oxide Fuel Cell-Molten Carbonate Fuel Cell Combined System For Power Generation And Carbon Dioxide Emission Reduction, Prathak Jienkulsawad
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research concentrates on the design and performance analysis of a solid oxide fuel cell (SOFC) and a molten carbonate fuel cell (MCFC) integrated system with using methane as fuel. Because SOFCs cannot completely use their fuel, there is remaining fuel leaving the system. In addition, the exhaust gas from an SOFC can be directly fed into an MCFC. The integrated fuel cell system shows an electrical efficiency of 55.22%, which is higher than a single fuel cell system. Fuel utilization of both fuel cells, SOFC temperature dramatically affect the performance of the integrated system. Four configurations were next proposed …
Effect Of Calcination Conditions Of P25-Tio2 On Photocatalytic Selective Hydrogenation Of 3-Nitrostyrene, Saknarin Chaitaworn
Effect Of Calcination Conditions Of P25-Tio2 On Photocatalytic Selective Hydrogenation Of 3-Nitrostyrene, Saknarin Chaitaworn
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this work, we investigated the effect of calcination of nanocrystalline commercial titanium dioxide catalyst (P25) on photocatalytic selective hydrogenation of 3-nitrostyrene. TiO2 supports were calcined under air, hydrogen and nitrogen atmosphere at various temperatures around 600 to 900°C for 5 hours. In order to investigate characteristic and catalytic properties of TiO2 after treatment, treated-TiO2 were analyzed by using X-ray diffraction (XRD), N2-physisorption, X-ray photoelectron spectroscopy (XPS), UV-Vis spectroscopy (UV-Vis), photoluminescence spectroscopy (PL), thermogravimetric analysis (TGA), scanning electron microscope (SEM). Photocatalytic hydrogenation performance of treated-TiO2 were tested under UV light irradiation. The 3-nitrostyrene consumption was linearly related to the photoluminescence …
Synthesis Of Black Titanium Dioxide And Effect Of Calcination Conditions And Reducing Agent On Photocatalytic Degradation Of Methyl Orange, Saran Saensook
Synthesis Of Black Titanium Dioxide And Effect Of Calcination Conditions And Reducing Agent On Photocatalytic Degradation Of Methyl Orange, Saran Saensook
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research studied the synthesis and application of black titanium dioxide in the photocatalytic degradation of methyl orange (MO). First, titanium dioxide was prepared via a sol-gel method. Then sodium borohydride was used as the reducing agent in order to synthesize black titanium dioxide. Thus, a 2x2x3 factorial experimental design was employed to assess the significance of the following three factors: (A) calcination temperature (400 and 500 °C); (B) calcination time (5 and 10 h); and (C) the molar ratio of NaBH4 to TiO2 used (0:1, 0.5:1, and 1:1). The removal of MO under UV and visible light were the …
The Effect Of Mcm-41 Addition To Pva/Pan/Pvp Polymer Electrolyte For Zinc-Air Batteries, Sirinuch Nanthapong
The Effect Of Mcm-41 Addition To Pva/Pan/Pvp Polymer Electrolyte For Zinc-Air Batteries, Sirinuch Nanthapong
Chulalongkorn University Theses and Dissertations (Chula ETD)
A membrane separator is one of the main components in zinc-air batteries playing an important role in controlling the mass transfer for the electrochemical reaction in the battery which determines the battery performance. This work aimed to develop a new membrane separator for the zinc-air battery. Polyvinyl alcohol (PVA), polyacrylonitrile (PAN), polyvinylpyrrolidone (PVP), and their blends were used for the fabrication of separator in this work. In addition, an inorganic nanoparticle with high hydroxide content such as MCM-41 was also applied as the filler for the polymers. The results revealed that the addition of PAN in PVA enhanced the electrolyte …
Application Of Amine-Functionalized Titanium Dioxide Wrapped In Reduced Graphene Oxide In Photocatalytic Degradation Of Methylene Blue, Sirinya Kanjanapanasont
Application Of Amine-Functionalized Titanium Dioxide Wrapped In Reduced Graphene Oxide In Photocatalytic Degradation Of Methylene Blue, Sirinya Kanjanapanasont
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research investigated the effect of reduced graphene oxide (rGO) addition to amine-functionalized titanium dioxide (APTMS-TiO2). The loading amount of rGO was varied from 0 to 0.05 %wt. Also, the effect of the amount of 3-aminopropyltrimethoxysilane (APTMS) was studied. To synthesize TiO2/rGO catalysts, the amount of APTMS was varied at 2.21 and 22.1 mmol. TiO2 catalyst was synthesized via a sol-gel method. Next, the surface of TiO2 was modified with APTMS by refluxing. Then graphene oxide was wrapped around APTMS-TiO2 and was reduced to rGO using hydrazine and ammonia. In the experiment, the catalyst was dispersed in methylene blue solution …
Effect Of Ceo2 And La2o3 Promoters On Ni/Al2o3 Oxygen Carrier Performance In Chemical Looping Steam Reforming Of Ethanol For Hydrogen Production, Supalak Isarapakdeetham
Effect Of Ceo2 And La2o3 Promoters On Ni/Al2o3 Oxygen Carrier Performance In Chemical Looping Steam Reforming Of Ethanol For Hydrogen Production, Supalak Isarapakdeetham
Chulalongkorn University Theses and Dissertations (Chula ETD)
The effects of Ce and/or La on NiO/Al2O3 were studied in chemical looping steam reforming of ethanol. Oxygen carriers (OCs) were prepared by wet impregnation method and characterized by various techniques. The redox test was performed by alternating between fuel feed (FFS) and air feed step (AFS) at 500oC. It was found that Ce- and La-doped improved the OCs' properties. A suitable amount of Ce- and La-doping helped increase carbon tolerance due to oxygen storage capacity and mobility. The solubility limit was found at 50 mol% La in solid solution. At higher La-doping, La2O3 dispersed on the surface and adsorbed …