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Full-Text Articles in Engineering
Preparation Of Natural Rubber Powder Modified With Bis(Triethoxysilylpropyl)Tetrasulfide Treated Silica By Spray Drying Process, Intira Boonvisood
Preparation Of Natural Rubber Powder Modified With Bis(Triethoxysilylpropyl)Tetrasulfide Treated Silica By Spray Drying Process, Intira Boonvisood
Chulalongkorn University Theses and Dissertations (Chula ETD)
In polymer industry, Natural rubber powder (NRP) is broadly used because of its stability and useability. Although, NRP is difficult to be produced due to the rubber adhered together. Consequently, silica was used to encapsulated the rubber particle to avoid adhesion of rubber. However, there is a polarity difference between silica and rubber. Silica can be made hydrophobic via surface modification with silane coupling agent, bis[3-(triethoxysilyl)propyl]tetrasulfide (TESPT). This research study aimed to prepare uniform silica-coated NRP via a combination of silane modification and spray drying technique. The effect of the mass ratio of TESPT and silica is 1%, 5%, 8%, …
Modeling Production Of Aromatic From N-Paraffins With Chemical Equilibria, Thidarat Detsut
Modeling Production Of Aromatic From N-Paraffins With Chemical Equilibria, Thidarat Detsut
Chulalongkorn University Theses and Dissertations (Chula ETD)
Chemical Equilibrium models were constructed for modeling and developing the aromatic production model from the normal paraffin at the equilibrium of the reaction with catalysts, i.e. ZSM-5(80) and Mo2C. The models were verified under operating temperatures of 450-500 ° C under atmospheric pressure at 1 atm. By examining the accuracy by comparing the data calculated from each model with the value obtained from the corresponding experiments at the condition that the reaction is balanced. The suitable equilibrium model depends on the type of catalyst used in the system. The accuracy of all equilibrium models could be improved by specifying the …
Ore Reserve Estimation By Using A Geostatistical Tool At Heinda Mine,Tanintharyi Region,Union Of Myanmar, Aye Min Tun -
Ore Reserve Estimation By Using A Geostatistical Tool At Heinda Mine,Tanintharyi Region,Union Of Myanmar, Aye Min Tun -
Chulalongkorn University Theses and Dissertations (Chula ETD)
Heinda mine is one of major tin producers in Myanmar. The mine has been operated for over 100 years. The mine falls at Latitude 14° 8’ N and Longitude 98° 27’ E, approximately about 45 kilometers to the east of Dawei. The ore reserve is the principal factor of mining venture. The aim of this study is to improve the ore reserve estimation by using geostatistical method (ordinary kriging) compared with conventional method (polygonal method) In geostatistical evaluation, it involved variogram analysis, variogram modelling and kriging estimation. The exponential variogram modelling was used to calculate the ordinary kriging estimation. The …
The Production Of Bio-Jet Fuel From Palm Fatty Acid Distiliate Over Covalt And Nickel Supported Hzsm-12 Catalysts, Ariya Eka Alel
The Production Of Bio-Jet Fuel From Palm Fatty Acid Distiliate Over Covalt And Nickel Supported Hzsm-12 Catalysts, Ariya Eka Alel
Chulalongkorn University Theses and Dissertations (Chula ETD)
Aviation sector becomes one of the largest-developing public transportation nowadays, the number of air passangers always increases year by year. However, this number are proportionally related to the enhance of jet-fuel worldwide demand. The conventional jet-fuel are commonly known as a carbon dioxde emission source and the world has more concern to this pollutant due to its contribution to the climate change. The usage of renewable materials to produce jet fuel is more glanced. One of the renewable sources can be used to generate green jet fuel is palm fatty acid distillate (PFAD) which is a by-product of palm oil …
Correlation Development Of Wax Deposition Prediction From Fang Oil Field, Aung Thwin Thu Aye
Correlation Development Of Wax Deposition Prediction From Fang Oil Field, Aung Thwin Thu Aye
Chulalongkorn University Theses and Dissertations (Chula ETD)
In petroleum industry, wax deposition is a critical operational challenge. It occurs in various locations in the petroleum production chain including well tubing. Hexane, chemical inhibitor, is used to prevent the wax problem of oil from Fang oilfield by the measurement of pour point, wax appearance temperature (WAT) and wax deposition. An increasing shear rate can reduce WAT and the deposited amount increases with lowering the temperature in Fang crude oil. Moreover, the non-linear regression analysis of Fang crude oil with and without hexane in different conditions are done for all three tests. Those regression analysis equations can predict WAT …
Pre-Feasibility Study On Granite Quarry For Aggregate: A Case Study At Kanchanaburi Province, Thailand, Bee Ziyivang
Pre-Feasibility Study On Granite Quarry For Aggregate: A Case Study At Kanchanaburi Province, Thailand, Bee Ziyivang
Chulalongkorn University Theses and Dissertations (Chula ETD)
This study aims to develop long term mine planning and design, equipment requirement calculation, and financial model analysis of mining and crushing plant. The ore reserve estimation and pit design carried out by using MineSight software (Ver. 9.50). A discounted cash flow model (DCF) and sensitivity analysis used to evaluate the financial project. Based on our study, the open-pit mining method was advisable for mine planning and design. Ore reserve estimated to 48.4 Mtons under the mining operation of 2.4 Mtos per year. The project time frame is 22 years which spends 21 years for operation and one year for …
Pre-Feasibility Study Of Improving Quality Of Low-Grade Fluorite. A Case Study At Phanomthuan Deposit, Kanchanaburi, Thailand, Keosaychai Souvannavong
Pre-Feasibility Study Of Improving Quality Of Low-Grade Fluorite. A Case Study At Phanomthuan Deposit, Kanchanaburi, Thailand, Keosaychai Souvannavong
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this study was presented the pre-feasibility study of improving quality of low-grade fluorite from Phanomthuan deposit, Kanchanaburi province, Thailand. The purpose of this study aims to explore the optimal condition in order to remove the impurities which contained high SiO2, CaCO3 and other minerals, also evaluate the project in term of economic. Therefore, the improvement quality of fluorite by using froth flotation techniques was reach the ceramic grade. The raw material characterization contains CaF2 = 29.4 Wt.%, SiO2 = 43.9 Wt.% and CaCO3 = 6.9 Wt.%. After flotation process the optimal condition result which contains CaF2 = 96.46 Wt.%, …
Geomechanical Modeling Of Salt Cavern Stability For Carbon Dioxide Storage In The Maha Arakham Formation, Northeastern Thailand, Narumas Pajonpai
Geomechanical Modeling Of Salt Cavern Stability For Carbon Dioxide Storage In The Maha Arakham Formation, Northeastern Thailand, Narumas Pajonpai
Chulalongkorn University Theses and Dissertations (Chula ETD)
In Thailand, CO2 emissions quadrupled over the past three decades since 1989, with the power generation sector as the main contributor by burning fossil fuels to produce electricity. Therefore, the power generating industry has come under scrutiny and been pressed by society to take responsibility. Carbon Capture and Storage (CCS) is one of the many methods to deal with CO2 emissions. Generally, CO2 is captured and stored in geological formations, e.g. rock salt deposits. Salt caverns have been intensively studied regarding their usage for CO2 storage because of their favourable characteristics. In this research, the Finite Element Method (FEM, ANSYS …
The Study Of Sulfur Compounds For Oils Fingerprinting Application, Titiparn Prasantongkolmol
The Study Of Sulfur Compounds For Oils Fingerprinting Application, Titiparn Prasantongkolmol
Chulalongkorn University Theses and Dissertations (Chula ETD)
Oil spills are one of the serious problems to marine and coastal environment worldwide. Besides the known incidents, a number of oil spills are unknown, which may come from both accident and unauthorized drainage. Moreover, the spills cause tarball to arise on the beach and the origin of tarballs are still subtle. Thus, the development of oil fingerprinting is important in order to identify the origin of oil spills and tarballs. Generally, the current standard technique is using GCxGC-TOFMS to analyze the biomarker compounds in oil such as hopane groups. However, this technique is expensive and requires long time for …
Removal Of Trace Olefins From Aromatics With Modified Usy Zeolite And Clays, Sirawit Lertprapaporn
Removal Of Trace Olefins From Aromatics With Modified Usy Zeolite And Clays, Sirawit Lertprapaporn
Chulalongkorn University Theses and Dissertations (Chula ETD)
Naphtha reforming is an important raw material for aromatic hydrocarbon products in petrochemical processes. However, aromatic hydrocarbon streams obtained from refinery contain unavoidable trace amounts of olefins as an impurity. The trace olefins must be removed because these undesirable olefins are harmful to the following separation processes. Alkylation reaction has been used to remove olefins with acid catalysts. In this study, clays and zeolites were screened for further modification in order to enhance the catalytic activity of olefins removal. The catalytic activity testing was studied in a batch reactor at 195 ℃ for 6 h under 12 barg. USY was …
Natural Gas Storage Using Clathrate Technology : Enhanced Formation At High Temperature, Kan Jeenmuang
Natural Gas Storage Using Clathrate Technology : Enhanced Formation At High Temperature, Kan Jeenmuang
Chulalongkorn University Theses and Dissertations (Chula ETD)
Solidified natural gas (SNG) by storing natural gas in the hydrate form, which is safe and easy to recover stored gas compared to other methods. However, to make this technology competitive, storing natural gas at a higher temperature, lower pressure with faster formation is needed. Tetrahydrofuran (THF) is a well-known thermodynamic promoter used to increase the hydrate formation temperature. However, increasing the hydrate formation temperature has a drawback on decreasing the formation rate. Nonpolar amino acids have been used as a secondary promoter, which increases the hydrate formation kinetics. This work used 5.56 mol% THF cooperated with different concentrations of …
Stochastic Supply Chain Optimization For Ammonia And Urea Processes, Seangplang Srisamut
Stochastic Supply Chain Optimization For Ammonia And Urea Processes, Seangplang Srisamut
Chulalongkorn University Theses and Dissertations (Chula ETD)
To support the demand growth in the agriculture sector from increasing population, ammonia and urea productions have been continuously increasing. Methane from natural gas can be used as feedstock in the production process. Nevertheless, the conventional plant using natural gas feedstock produces carbon dioxide as a by-product of the process. This proposed plant contains two processes, producing ammonia and urea can be more efficient in the production, where the byproducts of CO₂ can be used to produce more urea and reduce CO₂ emission. This research proposes ammonia and urea synthesis process using PROII software to simulate workflow and estimate the …
Ethanol Dehydration Over Wo3/Tio2 Catalysts Using Titania Derived From Sol-Gel And Solvothermal Methods With Palladium Modification, Anchale Tresatayawed
Ethanol Dehydration Over Wo3/Tio2 Catalysts Using Titania Derived From Sol-Gel And Solvothermal Methods With Palladium Modification, Anchale Tresatayawed
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this research, the characteristics and catalytic activity of WO3/TiO2 prepared by sol-gel and solvothermal and their metal modified were investigated. The research was divided into two parts. In the first part, the catalyst performance of WO3/TiO2 catalysts using titania derived from sol-gel and solvothermal methods over ethanol dehydration reaction was examined. The results showed that the different preparation methods essentially altered the physicochemical properties of TiO2 supports. It revealed that the titania derived from solvothermal method denoted as TiO2-SV exhibited higher surface area and pore volume, and larger amounts acid sites than the one obtained from sol-gel method (TiO2-SG). …
Solar Energy Management System For Stand-Alone Application : Analysis Of Power Management Strategies Under Different Solar Irradiance Profiles, Chacrit Lerdwithayaprasit
Solar Energy Management System For Stand-Alone Application : Analysis Of Power Management Strategies Under Different Solar Irradiance Profiles, Chacrit Lerdwithayaprasit
Chulalongkorn University Theses and Dissertations (Chula ETD)
Clean power generation from various renewable energy sources has been gaining much attention due to sustainable and environmental reasons. As renewable energy sources and power demand vary, a hybrid power system and proper energy management are required. This study is focused on the development of an energy management system (EMS) in the hybrid renewable energy system consisting of photovoltaic cell (PV), proton exchange membrane fuel cell (PEMFC), and proton exchange membrane electrolysis cell (PEMEC). A vanadium redox flow battery (VRFB) as energy storage for long-term operation is integrated into such a hybrid system. The models of each subsystem are developed …
Mechanism And Reaction Pathways Of Co2 And Hco3-Photoreduction To Hydrocarbons, Duangthip Sattayamuk
Mechanism And Reaction Pathways Of Co2 And Hco3-Photoreduction To Hydrocarbons, Duangthip Sattayamuk
Chulalongkorn University Theses and Dissertations (Chula ETD)
CO2/HCO3- photocatalytic reductions in water, using P25 Titanium dioxide, produce gas products at the order of the following rate: CO>H2>CH4, using bicarbonate as a substrate, reduction rates are ca. 5 times faster than using CO2 due to the adsorption constant of CO2 on the TiO2 surface is smaller than the bicarbonate. Langmuir-Hinshelwood kinetic model was used to describe the mechanism; therefore, adsorption constant (K) and the rate of maximum substrate coverage (k) at different charges of P25-surface were readily obtained. The K constant of TiO2-adduct formation favors no charge surface but k constant favors positive charge surface. Most …
Modeling Aromatics Production From Mixtures Of Butanes And Butenes With Chemical Equilibria, Hataipat Sangwattanakul
Modeling Aromatics Production From Mixtures Of Butanes And Butenes With Chemical Equilibria, Hataipat Sangwattanakul
Chulalongkorn University Theses and Dissertations (Chula ETD)
Aromatics production from C4 hydrocarbons is an interesting way to increase economic values and mixed C4 usage alternatives. This study was to model aromatics production from mixtures of butanes and butenes, enabling industrial work to be more developed and actualized by reducing laboratory cost and experimental time. The model was regarded as an equilibrium state in which the forward reaction rate and the reverse reaction rate are equivalent. The catalysts would be Zn loaded on ZSM-5/ZSM-11 under 480 ⁰C and 0.4 MPa and MoC loaded on HZSM-5 under 500 ⁰C and 1 atm. The reactions in the models were from …
Process Synthesis And Design Of Integrated Biorefinery In Pulp And Paper Industry, Ghochapon Mongkhonsiri
Process Synthesis And Design Of Integrated Biorefinery In Pulp And Paper Industry, Ghochapon Mongkhonsiri
Chulalongkorn University Theses and Dissertations (Chula ETD)
Integration of biorefinery into pulp and paper industry has been considered as sustainable development for pulp and paper industry and lignocellulosic biorefinery. High value-added biochemical, biofuel and bioenergy productions could be implemented into existing pulp mills by material and utility integration. A systematic methodology employing a superstructure-based process synthesis, process design and innovation is an effective approach to explore potential pathways for both economic and environmental sustainability with support from computer-aided tools. A superstructure of the multi-product biorefinery process network with the pulp and paper industry is developed and optimized with the objective to maximize profit. The synthesis results project …
Single-Step Conversion Of Xylose To Furfural And Furfuryl Alcohol On Zeolite-Based Catalyst, Jirapat Chatkaweekoon
Single-Step Conversion Of Xylose To Furfural And Furfuryl Alcohol On Zeolite-Based Catalyst, Jirapat Chatkaweekoon
Chulalongkorn University Theses and Dissertations (Chula ETD)
Furfural possesses the potential to be utilized as a platform compound for the synthesis of a wide variety of chemicals, especially furfuryl alcohol, which is an important intermediate used to produce high-value chemicals. In this research, several types of zeolite catalysts in hydrogen form are used as catalysts for conversion of xylose to produce furfural and furfuryl alcohol in one step. The reaction is carried out under 130°C, 30 bar hydrogen pressure, and 2 h reaction time. Acid site types (Lewis and Bronsted) are important for the catalysis and distribution of the product. Bronsted acid sites promote xylose dehydration to …
Development Of Stack Model For Tri-Electrode Rechargeable Zinc-Air Cylindrical Flow Battery, Kanya Bumroongsil
Development Of Stack Model For Tri-Electrode Rechargeable Zinc-Air Cylindrical Flow Battery, Kanya Bumroongsil
Chulalongkorn University Theses and Dissertations (Chula ETD)
Nowadays, the demand for renewable energy is continuously increasing. Therefore, an efficient energy storage system is essential. Zinc-air batteries have received extensive attention because they use low-cost material but offer great safety benefits. This research, therefore, develops a stack model for a tri-electrode tubular designed rechargeable zinc-air flow battery for using in a large scale system. The connection of battery cells in series and parallel is studied. The connection of battery cell with common flowing electrolyte creates a shunt current. A mathematical model is developed and validated against experimental data, which measured both full cell and half cell potentials. The …
A Study On The Deactivation Of Nickel-Based Catalyst For The Dry Reforming Of Methane Via Density Functional Theory, Mongkol Lerdpongsiripaisarn
A Study On The Deactivation Of Nickel-Based Catalyst For The Dry Reforming Of Methane Via Density Functional Theory, Mongkol Lerdpongsiripaisarn
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this work, the stability assessment of catalyst for the dry reforming reaction was investigated through the coke resistance performance and the ability of coke removal. The coke resistance performance was considered via the coke adsorption energy. For surface 100 and 211, NiCo bimetallic catalyst and Ni exhibit weaker bonding between coke and catalyst surface. For surface 111, both catalysts exhibited similar adsorption energy value. NiCo bimetallic catalyst also showed higher adsorption energy for surface 111 and 211 than the noble metal catalyst such as Rh and Pd catalyst which means NiCo catalysts can show the coke resistance performance that …
Development Of Zero-Waste Package For Asphalt From Natural Rubber / Ethylene Vinyl Acetate Copolymer Thermoplastic Vulcanizates, Nappaphan Kunanusont
Development Of Zero-Waste Package For Asphalt From Natural Rubber / Ethylene Vinyl Acetate Copolymer Thermoplastic Vulcanizates, Nappaphan Kunanusont
Chulalongkorn University Theses and Dissertations (Chula ETD)
Asphalt is normally delivered in liquid form which was heated all the time. It consumes more energy and need the special truck to deliver it. An alternative way to deliver the asphalt in form of solid covered with package can reduce energy consumption and normal truck can be used to deliver. The objective of this research was to develop the zero-waste package for asphalt that was no waste after use and not harmful to asphalt properties. The research consists of two parts which are (1) development of package from natural rubber (NR) and ethylene vinyl acetate copolymer (EVA) thermoplastic vulcanizates …
Improvement And Economic Analysis Of Bio-Hydrogenated Diesel Production For Producing Bio-Jet Fuel, Nattamon Munkong
Improvement And Economic Analysis Of Bio-Hydrogenated Diesel Production For Producing Bio-Jet Fuel, Nattamon Munkong
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this study, process improvement of bio-hydrogenated diesel (BHD) production to produce jet fuel as an alternative product was carried out. The BHD was produced from palm oil with NiMo/Y-Al2O3 catalyst, while the bio-jet fuel was produced by catalytic cracking of the BHD product using NiAg/SAPO-11 catalyst, followed by appropriate separations. Process simulation by using Aspen Plus program was performed to evaluate the improved process. A comparison with a base case BHD production process was also demonstrated and discussed. It was found that a conventional existing BHD process can be improved by plugging in a hydrocracking/isomerization unit to process. The …
Study Of Co2 And Bi-Reforming Of Methane On Modified Nickel-Based Catalysts, Nichakorn Buasuk
Study Of Co2 And Bi-Reforming Of Methane On Modified Nickel-Based Catalysts, Nichakorn Buasuk
Chulalongkorn University Theses and Dissertations (Chula ETD)
Nowadays, several currently operated industrial factories significantly increase the rate of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) far higher than those that should be normally. Therefore, various mitigation ways to reduce carbon dioxide and methane are increasingly important. The prevailing methods are dry reforming of methane and bi-reforming of methane. Therefore, this research involves the study of the catalytic activity and coke resistance on the Ni-based catalysts with and without a promoter. The activity tests on the dry reforming of methane reaction and bi-reforming of methane reaction were performed in a fixed-bed reactor under atmospheric pressure at …
Development And Characterization Of Natural Rubber-Cellulose Sponge, Nuttapon Suppanucroa
Development And Characterization Of Natural Rubber-Cellulose Sponge, Nuttapon Suppanucroa
Chulalongkorn University Theses and Dissertations (Chula ETD)
Natural rubber (NR) sponges are a renewable biopolymer material derived from milky sap (latex) from rubber trees. In this study, composite sponges of natural rubber and cellulose (NR-C) with various compositions were synthesized. The Dunlop process was employed to prepare the NR-C sponges in various contents of cellulose fibers as reinforcing agent. The cellulose fibers were extracted from the pulp of eucalyptus trees and sodium alginate (SA) was used as dispersing agent. The aim of this work was to develop a green composite sponge with highly porous, flexible, and hydrophilic properties. The effects of cellulose loading on mechanical performance of …
Effects Of Graphite/Partially Carbonized Hemp Hurd Particle Mass Ratios On Tribological Properties Of Polybenzoxazine Composites, Nuttarika Kunaroop
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 …
Improvement Of Screen Printable Anisotropic Conductive Adhesive With Polyethylene Glycol As Diluent, Papitchaya Manduang
Improvement Of Screen Printable Anisotropic Conductive Adhesive With Polyethylene Glycol As Diluent, Papitchaya Manduang
Chulalongkorn University Theses and Dissertations (Chula ETD)
The primary aim of this research is to improve screen printable anisotropic conductive adhesive by reducing the viscosity of anisotropic conductive adhesive which is EPN/PPGDE/CTBN epoxy adhesive with polyethylene glycol 400. This research compared the conductivity of commercial and synthesized silver particles. As a result, the volume resistivity of commercial silver particles was lower than the synthesized silver particle due to silver oxide of silver particles. 1 phr of commercial silver particle was added in anisotropic conductive adhesive in which its volume resistivity was less than 1 Ω·cm. The effect of addition polyethylene glycol in the anisotropic conductive adhesive with …
Development And Characterization Of Solid Oxide Electrolysis Cells Based On Zirconia And Ceria Based Electrolyte For Hydrogen Production From Steam, Parintorn Temluxame
Development And Characterization Of Solid Oxide Electrolysis Cells Based On Zirconia And Ceria Based Electrolyte For Hydrogen Production From Steam, Parintorn Temluxame
Chulalongkorn University Theses and Dissertations (Chula ETD)
Steam electrolysis for hydrogen production is investigated in solid oxide electrolysis cell (SOEC). Sc3+, Ce4+, and Gd3+ are doped in zirconia (SCGZ) and compared with yttria stabilized zirconia (YSZ) and gadolinium doped ceria (GDC) electrolyte. Electrolyte-supported cells are fabricated. The SCGZ and YSZ electrolytes are dense with >95% relative density while GDC is less densified. The activation energy of conduction of the SCGZ electrolyte is the lowest at 65.58 kJ mol-1 although phase transformation is detected after electrolyte fabrication process. Cathode-supported cell having SCGZ electrolyte (Ni-SCGZ/SCGZ/BSCF) shows the highest electrochemical performance. Durability test of the cells in electrolysis mode is …
Effect Of Titania Phase Composition In Wo3/Tio2 Catalysts On Catalytic Properties In Dehydration Of Ethanol To Diethyl Ether, Phatthraporn Termvoratham
Effect Of Titania Phase Composition In Wo3/Tio2 Catalysts On Catalytic Properties In Dehydration Of Ethanol To Diethyl Ether, Phatthraporn Termvoratham
Chulalongkorn University Theses and Dissertations (Chula ETD)
At the present, several agricultural products can be used as raw materials for bio-ethanol production and consequently converted it into many valuable substances such as ethylene and diethyl ether. This can undergo via WO3/TiO2 catalyst in which the anatase phase of titania usually has a better activity on ethanol dehydration to diethyl ether and ethylene than rutile phase. However, pure anatase phase of titania perhaps does not give the best of catalytic properties. So, this study investigates on the effects of tungsten on titania-supported catalysts with different phase composition of titania consisting of anatase and rutile phase with various proportion …
Study Effect Of Catalyst Shape On The Ethylbenzene Dehydrogenation In Fixed Bed Reactor By Using Various Mathematical Models, Pawinee Maithong
Study Effect Of Catalyst Shape On The Ethylbenzene Dehydrogenation In Fixed Bed Reactor By Using Various Mathematical Models, Pawinee Maithong
Chulalongkorn University Theses and Dissertations (Chula ETD)
Nowadays, the chemicals are mostly manufactured by catalytic reactions in fixed bed reactor. Catalyst shape affects to reactor performance and the effect is studied by mathematic models which are varied forms to more realistic. Therefore, the objective of research is to study the effect of catalyst shape on the behavior of reactor for ethylbenzene dehydrogenation to styrene in gas phase by varied form. The simplest model, pseudohomogeneous model (model1), predicts 36.52% ethylbenzene conversion. The more complex model, heterogeneous model accounting for internal mass transfer (model2), predicts 34.49% conversion that equals to the model accounting for internal mass and heat transfer(model3). …
Non-Faradaic Electrochemical Modification Of Catalytic Activity (Nemca) Of Propane Oxidation On Pt/Ysz Thin Film Cell, Wanchana Lelalertsupakul
Non-Faradaic Electrochemical Modification Of Catalytic Activity (Nemca) Of Propane Oxidation On Pt/Ysz Thin Film Cell, Wanchana Lelalertsupakul
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this work, non-Faradaic Electrochemical Modification of Catalytic Activity (NEMCA) of propane oxidation over Pt/yttria-stabilized zirconia (YSZ) thin films on alumina substrates has been studied. YSZ thin films were initially prepared by slurry dip coating and calcined at a relatively lower temperature of 800 oC. Propane oxidation at temperatures in a range of 300-500 oC clearly exhibited NEMCA. The maximum rate enhancement ratio was close to 3 at an applied potential of 1.0 V and a reaction temperature of 400 oC. The maximum faradaic efficiency was higher than 10,000 at an applied potential of 0.2 V and 300oC. However, NEMCA …