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Computational Fluid Dynamics Of Thermally Double Couple Reactor For Hydrogen Production Through Glycerol Reforming Using Heat From Methanol Production From Carbon Dioxide, Sasinun Thirabunjongcharoen
Computational Fluid Dynamics Of Thermally Double Couple Reactor For Hydrogen Production Through Glycerol Reforming Using Heat From Methanol Production From Carbon Dioxide, Sasinun Thirabunjongcharoen
Chulalongkorn University Theses and Dissertations (Chula ETD)
Thermally double coupled reactor (TDCR) consisted of two concentric channels: 1) an inner tube to which CO₂ and H2 were fed as reactants for exothermic MS with Cu/ZnO/Al2O3 at 220°C and 50 bar, and 2) an outer annulus channel through which glycerol and steam were supplied for endothermic APGR with Pt/Al2O3 at 220˚C and 20 bar. The TDCR could operate without external heat supply when two reactions were coupled. A computational fluid dynamic (CFD) model was established to study this TDCR. Heat transfer from the exothermic channel to the endothermic channel helped increasing glycerol conversion when compared with a single …
Modeling Of Zinc-Air Batteries Using Theoretical And Empirical Approach, Woranunt Lao-Atiman
Modeling Of Zinc-Air Batteries Using Theoretical And Empirical Approach, Woranunt Lao-Atiman
Chulalongkorn University Theses and Dissertations (Chula ETD)
Nowadays, an energy storage system (ESS) is attracting widespread research interest. Zinc-air battery (ZAB) is a promising candidate for ESS owing to its high energy density at low cost. Although ZAB has been researched in various aspects, the modeling aspect is still insufficient. Therefore, this work aims to study the modeling of ZAB using both theoretical and empirical approaches. At first, the ZAB system was analyzed using a theoretical approach. The studied system was an integrated system of zinc-air flow battery (ZAFB) and zinc electrolyzer. The zero-dimensional mathematical model was developed in MATLAB and validated against experimental data. The model …
Synthesis, Characteristic And Application Of Mesocellular Foam Carbon (Mcf-C) As Catalyst For Dehydrogenation Of Ethanol, Yoottapong Klinthongchai
Synthesis, Characteristic And Application Of Mesocellular Foam Carbon (Mcf-C) As Catalyst For Dehydrogenation Of Ethanol, Yoottapong Klinthongchai
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research aims to investigate the synthesis of MCF-C as catalyst for dehydrogenation of ethanol. The study was classified into 3 parts. In the first part, the mesocellular foam silica (MCF-Si) was converted to mesocellular foam carbon using a surfactant residue as a carbon source, and followed by testing the dehydrogenation of ethanol to acetaldehyde. Surfactant residue in the inside of MCF-Si could be used as the carbon source for MCF-C synthesis. The obtained material could maintain the meso-structure, and exhibited higher activity for ethanol dehydrogenation in comparison to MCF-Si. For the second part, MCF-C was examined for 12 h …
การเตรียมเเละวิเคราะห์คุณลักษณะของอนุภาคลิโพโซมสำหรับกักเก็บสารอาร์บูตินด้วยเครื่องโฮโมจิไนเซอร์เเรงดันสูง, รัชพล ชูทับ
การเตรียมเเละวิเคราะห์คุณลักษณะของอนุภาคลิโพโซมสำหรับกักเก็บสารอาร์บูตินด้วยเครื่องโฮโมจิไนเซอร์เเรงดันสูง, รัชพล ชูทับ
Chulalongkorn University Theses and Dissertations (Chula ETD)
การกักเก็บสารสำคัญในรูปแบบของอนุภาคลิโพโซม เป็นวิธีการที่ได้รับความนิยมเป็นอย่างมาก เนื่องจากอนุภาคลิโพโซมมีส่วนประกอบที่สามารถเข้ากับร่างกายได้ ไม่มีความเป็นพิษ และสามารถย่อยสลายได้เอง รวมไปถึงช่วยเพิ่มเสถียรภาพของสารที่นำมากักเก็บให้ดีขึ้น วิธีการเตรียมอนุภาคลิโพโซมเพื่อกักเก็บสารเป็นหนึ่งปัจจัยที่จะต้องคำนึงถึง เพราะจะส่งผลต่อการกระจายตัวและขนาดของอนุภาค รวมไปถึงอัตราการปลดปล่อยของสารและเสถียรภาพความคงตัวของอนุภาคลิโพโซมด้วย งานวิจัยนี้มีความสนใจที่จะศึกษาการเตรียมอนุภาคลิโพโซมสำหรับกักเก็บสารอาร์บูตินด้วยเครื่องโฮโมจิไนเซอร์แรงดันสูง เนื่องจากอาร์บูตินเป็นสารที่มีเสถียรภาพต่ำการกักเก็บสารในรูปแบบของอนุภาคลิโพโซมมีความเป็นไปได้ที่จะช่วยเพิ่มเสถียรภาพให้กับสารอาร์บูติน การเตรียมอนุภาคด้วยเครื่องโฮโมจิไนเซอร์แรงดันสูงเป็นวิธีที่สะดวกและรวดเร็ว สามารถเตรียมอนุภาคลิโพโซมได้ในปริมาณที่มาก อีกทั้งยังมีความต่อเนื่องของกระบวนการโดยไม่ต้องผ่านหลายขั้น โดยวัตถุประสงค์ของงานวิจัยต้องการศึกษาปัจจัยต่างๆ ได้แก่ อัตราส่วนระหว่างฟอสโฟลิพิด คลอเรสเตอรอล และสารอาร์บูติน อัตราการปลดปล่อยของสารอาร์บูตินและเสถียรภาพความคงตัวของอนุภาคลิโพโซม รวมไปถึง สภาวะของเครื่องโฮโมจิไนเซอร์แรงดันสูง ได้แก่ ความดันและจำนวนรอบ ที่ใช้ในการเตรียมอนุภาคลิโพโซมเพื่อกักเก็บสารอาร์บูติน จากการศึกษาพบว่า การเตรียมอนุภาคลิโพโซมที่กักเก็บสารอาร์บูตินด้วยเครื่องโฮโมจิไนเซอร์แรงดันสูง ทำให้ได้ลิโพโซมขนาดเล็กที่มีผนังสองชั้นเพียงชั้นเดียว ซึ่งจะมีขนาดของอนุภาคลดลงอย่างมีนัยสำคัญเมื่อเพิ่มความดันและจำนวนรอบของเครื่องโฮโมจิไนเซอร์แรงดันสูง โดยมีขนาดเฉลี่ยอยู่ระหว่าง 150 ถึง 200 นาโนเมตร ผลการทดลองความเข้มข้นของลิพิดต่อความสามารถในการกักเก็บสารอาร์บูติน พบว่า เมื่อเพิ่มความเข้มข้นโดยรวมของลิพิด ประสิทธิภาพการกักเก็บสารมีค่าเพิ่มขึ้น ซึ่งมีค่าประสิทธิภาพการกักเก็บสารเฉลี่ยสูงสุดอยู่ที่ 74.29 เปอร์เซ็นต์ นอกจากนั้น ผลการทดลองยังแสดงให้เห็นว่าการกักเก็บสารสำคัญไว้ในรูปแบบของอนุภาคลิโพโซมและมีการเติมสารคลอเรสเตอรอลลงไปจะสามารถช่วยควบคุมอัตราการปลดปล่อยของสารสำคัญได้ รวมไปถึงช่วยเพิ่มเสถียรภาพความคงตัวให้กับอนุภาคลิโพโซมได้อีกด้วย ดังนั้น สภาวะของเครื่องโฮโมจิไนเซอร์แรงดันสูงและสัดส่วนระหว่างฟอสโฟลิพิดกับคลอเรสเตอรอลที่เหมาะสมในการเตรียมอนุภาคลิโพโซมสำหรับกักเก็บสารอาร์บูติน คือ ความดัน 1000 บาร์ จำนวน 3 รอบ ที่ความเข้มข้นโดยรวมของลิพิดร้อยละ 2 โดยน้ำหนัก อัตราส่วนระหว่างฟอสโฟลิพิดกับคลอเรสเตอรอล 10:2 โดยน้ำหนัก และสภาวะอุณหภูมิในการเก็บรักษาที่ 4 องศาเซลเซียส
Enhanced Methane Hydrate Formation Using Promoters For Natural Gas Storage And Transportation Application, Katipot Inkong
Enhanced Methane Hydrate Formation Using Promoters For Natural Gas Storage And Transportation Application, Katipot Inkong
Chulalongkorn University Theses and Dissertations (Chula ETD)
Solidified natural gas (SNG) is an alternative technology for natural gas storage and transportation in the clathrate hydrate formed. It has higher volumetric energy storage with the ease to handle not to mention its safety. Effects of different hydrate promoters, including methyl ester sulfonate (MES), tetrahydrofuran (THF), hollow silica (HS), and sodium dodecyl sulfate (SDS), on the methane hydrate formation was investigated. All experiments were performed in an unstirred tank reactor at desired experimental conditions. The results indicated that all promoters significant enhanced the hydrate formation both kinetics and methane uptake compared with pure water. The increase in the MES …
Synthesis Of Mwcnts By Chemical Vapor Deposition From Methane Using Femo/Mgo Catalyst : Role Of Hydrogen And Kinetic Study, Chawalkul Chotmunkhongsin
Synthesis Of Mwcnts By Chemical Vapor Deposition From Methane Using Femo/Mgo Catalyst : Role Of Hydrogen And Kinetic Study, Chawalkul Chotmunkhongsin
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this study, carbon nanotubes (CNTs) were synthesized by chemical vapor deposition (CCVD) of methane over FeMo/MgO catalyst in a fixed-bed reactor. The role of hydrogen on CNTs synthesis and kinetics of CNTs formation were experimentally investigated. The study revealed that hydrogen in the catalyst reduction process plays an important role in the structural changes of FeMo/MgO catalyst. The catalyst structure fully transformed into metallic FeMo, resulting in the increased yield of 5 folds higher than the non-reduced catalyst. However, the slightly larger diameter and lower crystallinity ratio of CNTs was obtained. The hydrogen co-feeding during the synthesis can slightly …
Deposition Of Tio2-Coated Cspbbr3 Perovskite Heterostructure Thin Film, Chutikan Sairot
Deposition Of Tio2-Coated Cspbbr3 Perovskite Heterostructure Thin Film, Chutikan Sairot
Chulalongkorn University Theses and Dissertations (Chula ETD)
All-inorganic lead halide perovskite quantum dots have been emerged in recent years for optoelectronic and photovoltaic devices due to their excellent optical properties. In this work, surface coating was carried out by titanium dioxide (TiO2) to coat on the surface of CsPbBr3 PQDs to improve the stability and charge separation property. The FTIR spectra confirmed the formation of TiO2 with an amorphous phase (am-TiO2). The crystallite size of CsPbBr3/am-TiO2 QDs composite was increased to be 13.30 nm from 12.65 nm of CsPbBr3. A slightly decrease of energy bandgap was found compare to CsPbBr3 QDs owing to quantum confinement effect. The …
Preparation And Characterization Of Sequential Curing With Off-Stoichiometric Amine-Diglycidyl Ether Of Bisphenol A /Novolac Epoxy Blended Systems, Pakawat Suttitham
Preparation And Characterization Of Sequential Curing With Off-Stoichiometric Amine-Diglycidyl Ether Of Bisphenol A /Novolac Epoxy Blended Systems, Pakawat Suttitham
Chulalongkorn University Theses and Dissertations (Chula ETD)
B-stage epoxy adhesives are used in many applications such as electronic devices and prepreg composites. The most common available form is in the film form, rolls, sheets, or custom preforms. In this work, B-staged epoxy adhesives were prepared by using sequential curing with off-stoichiometric amine technique. Diethylenetriamine (DETA) was used as the curing agent for the first curing step. While dicyandiamide (DICY) was used as the latent curing agent for the second curing step and 3-(3,4-dichlorophenyl)-1,1dimethylurea (DIURON) as accelerator for reducing the curing temperature of DICY. Novolac epoxy was blended in diglycidyl ether of bisphenol A (DGEBA) with various ratio …
Electrode Improvement And Neural Network-Based Dynamic Optimization Of Vanadium Redox Flow Battery, Apisada Chutimasakul
Electrode Improvement And Neural Network-Based Dynamic Optimization Of Vanadium Redox Flow Battery, Apisada Chutimasakul
Chulalongkorn University Theses and Dissertations (Chula ETD)
The performance improvement of a vanadium redox flow battery (VRFB) was focused on this study. The two objectives of this study were (1) to investigate the effect of the operating temperatures of the Atmospheric Pressure Plasma jets (APPJs) process on the energy efficiency of the VRFB and (2) to determine the optimal electrolyte flow rate of the VRFB by solving a dynamic optimization based on a neural network model of the VRFB. The APPJs graphite felt electrode treatment temperature providing the highest energy efficiency of the VRFB was 550°C, explained by the Energy Dispersive X-ray Spectrometry (EDX) and X-ray photoelectron …
A Comparative Simulation Of Glycerol Steam Reforming With Foam And Conventional Pellet Catalysts In Packed Bed Reactor, Chattharika Phitchayakorn
A Comparative Simulation Of Glycerol Steam Reforming With Foam And Conventional Pellet Catalysts In Packed Bed Reactor, Chattharika Phitchayakorn
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research aimed to study the effect of different catalyst structures to the hydrogen production process with glycerol steam reforming in packed bed reactors via the COMSOL Multiphysics program. 2D pseudo-homogeneous steady-state model of a 6-inch diameter adiabatic reactor has been developed to describe a transport phenomenon inside the packed bed reactors with two different catalyst structures of conventional 1-inch pellet catalyst and 10-30PPI foam catalyst. The simulated results show that the novel foam catalyst improved the process performance in terms of pressure drop and hydrogen yield comparing to the conventional 1-inch pellet catalyst. The reactor packed with the conventional …
Property Estimation Of Palmitoylethanolamide And Sucrose Palmitate For Process Design From Methyl Palmitate, Janetiya Wongprathed
Property Estimation Of Palmitoylethanolamide And Sucrose Palmitate For Process Design From Methyl Palmitate, Janetiya Wongprathed
Chulalongkorn University Theses and Dissertations (Chula ETD)
Methyl palmitate is the primary component of palm oil-based biodiesel. It is a saturated fatty acid methyl ester which has a high melting point that results in low cold flow properties of biodiesel. Besides, lack of government support may affect the revenue of biodiesel business. For that reason, the producers turn attention to using biodiesel as a raw material for the production of value-added chemicals. Initially, we selected the studied products based on the gross profit margin, production process, market demand and application. This work simulated the production of palmitoylethanolamide, sucrose palmitate and normal alkanes from methyl palmitate using Aspen …
Production Of Γ-Valerolactone (Gvl) From One-Pot Cascade Transformation Of Furfural Over Pt/Zeolite-Based Catalysts, Jukkapan Saengin
Production Of Γ-Valerolactone (Gvl) From One-Pot Cascade Transformation Of Furfural Over Pt/Zeolite-Based Catalysts, Jukkapan Saengin
Chulalongkorn University Theses and Dissertations (Chula ETD)
γ-valerolactone (GVL) is a green renewable resource, which can be used as fuel additives, organic solvent in food industries, pharmaceutical intermediates. The direct production of GVL from furfural in a one-pot transformation is highly desirable in order to minimize the use of solvents, the number of unit operations, and the production cost. The cascade reaction was carried out in a single reactor, using a secondary alcohol as the hydrogen donor with acid catalysts (so-called Meerwein–Ponndorf–Verley reaction). In this work, the transfer hydrogenation of furfural with 2-propanal as a hydrogen donor was investigated on various zeolites including of HY with Si/Al …
Electrochemical Reduction Of Carbon Dioxide To Formate On Bi And Bisn Electrodes Prepared By Electrodeposition On Copper Foil, Jutamas Wasombut
Electrochemical Reduction Of Carbon Dioxide To Formate On Bi And Bisn Electrodes Prepared By Electrodeposition On Copper Foil, Jutamas Wasombut
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this study, The Bix/Cu electrocatalysts were prepared by electrodeposition of Bi on Cu foil, and the BixSny/Cu electrocatalysts were prepared by electrodeposition of Bi and Sn on Cu foil in deposition solution bath with different Bi3+ ion concentrations of 0.05, 0.1, and 0.2 M (Bi0.05/Cu, Bi0.1/Cu, Bi0.2/Cu), while the Sn2+ ion concentration was constant at 0.025 M (Bi0.05Sn0.025/Cu, Bi0.1Sn0.025/Cu, Bi0.2Sn0.025/Cu). The electrocatalysts were characterized by SEM-EDX, XRD, and XPS and tested in the electrochemical CO2 reduction reaction. The results demonstrate that the Bi concentrations in the deposition bath affect the structure of Bi into different forms, including bulky structure …
Selective Hydrogenation Of Acetophenone To 1-Phenylethanol On Pt/ Tio2 Catalysts Prepared By Pulsed Dc Magnetron Sputtering, Khunarnon Ditsataporncharoen
Selective Hydrogenation Of Acetophenone To 1-Phenylethanol On Pt/ Tio2 Catalysts Prepared By Pulsed Dc Magnetron Sputtering, Khunarnon Ditsataporncharoen
Chulalongkorn University Theses and Dissertations (Chula ETD)
1-Phenylethanol (PHE) is a high-value chemical with various applications in fragrance and pharmaceutical industries. It is extensively used as strawberry fragrance additives in yogurts and chewing gums and an intermediate of anti-inflammatory drugs such as Ibuprofen. In this study, selective hydrogenation of acetophenone (AP) to PHE was investigated using platinum catalysts supported on different types of titanium dioxide including PC500 (pure anatase) and P25 (anatase mixed rutile). Pt was deposited on the titanium dioxide supports by pulsed direct current magnetron sputtering (PDC-MSD) method with deposition time spent on Pt coating at 3, 6, and 9 minutes. For comparison purposes, Pt/TiO2 …
Electrochemical Reduction Of Co2 To Co On Zn Electrodes Prepared By Electrodeposition Method, Krongkwan Poonbun
Electrochemical Reduction Of Co2 To Co On Zn Electrodes Prepared By Electrodeposition Method, Krongkwan Poonbun
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this work, the effect of substrates including Cu and Ti on the catalytic activity of Zn electrocatalysts prepared by electrodeposition method was investigated in the electrochemical reduction of CO2 (CO2ER). As analyzed by SEM-EDX and XRD results, it indicated that the different substrates did not have any influence on the morphologies of catalysts and the conductivity of substrate was the main factor on the CO2ER performance. The effect of Zn precursor concentration in the range of 0.025 M to 0.4 M was further studied on the characteristics and the activity of Zn/Cu catalysts in the CO2ER. . At low …
Comparative Study Of Gross Split And Cost Recovery Production Sharing Contracts In Indonesia, Mohammad Ubaidillah
Comparative Study Of Gross Split And Cost Recovery Production Sharing Contracts In Indonesia, Mohammad Ubaidillah
Chulalongkorn University Theses and Dissertations (Chula ETD)
In upstream oil and gas business, Indonesian has introduced Production Sharing Contract Cost Recovery (PSC CR) in 1966 and still implementing that fiscal system until nowadays. In January 2017, The Indonesian Minister of Energy and Mineral Resources (MEMR or ESDM) introduce new PSC system called Production Sharing Contract Gross Split (PSC GS) following with three amendments until 2019. Ministries believe this new Fiscal regime can attract more investor to invest Oil & Gas business in Indonesia by delivering three main values which are certainty, efficiency, and simplicity policies. This study evaluates and compares the financial aspect of new Indonesian fiscal …
Effect Of Single Metal Loading On Cao/Al2o3 Pellet Catalyst For Biodiesel Production, Nattawadee Munbupphachart
Effect Of Single Metal Loading On Cao/Al2o3 Pellet Catalyst For Biodiesel Production, Nattawadee Munbupphachart
Chulalongkorn University Theses and Dissertations (Chula ETD)
Biodiesel is a sustainable biofuel mainly derived from transesterification of vegetable oil or animal fat. Transesterification is increasingly being catalyzed by heterogeneous catalysts in recent years. As a result of a high-pressure drop, solid base catalysts in a powder form are not suitable for a continuous process. A pellet catalyst is more convenient, but it has lower surface per volume as well as lower in its catalytic activity for transesterification. This research aims at studying the effect of metal oxides loading on CaO/Al2O3 pellet catalyst for improvement of catalytic activity of transesterification. The 20 wt.% single metal loading of metal …
Preparation And Characterization Of Nanopaper From Regenerated Cellulose, Nattorn Paijit
Preparation And Characterization Of Nanopaper From Regenerated Cellulose, Nattorn Paijit
Chulalongkorn University Theses and Dissertations (Chula ETD)
Cellulose nanopapers (RCNP) were prepared from regenerated cellulose (RC) via the solvent casting method. RC was prepared by dissolution of bleached eucalyptus cellulose pulp (BEP) with 85% H3PO4 at -20oC. Water was applied as anti-solvent in the regenerated process. Effects of storage time after dissolution on fiber solubility were investigated at 0, 20, 40, 60 min, 1, and 2 days. ATR FT-IR spectra and crystalline index proved that regenerated cellulose was obtained. The crystalline index of the fiber became stable at 60 min, indicating the fibers were completely dissolved at 60 min. The results from thermogravimetric analysis showed that after …
Sodium Doping Effects On Properties Of Czts Thin Filmsfabricated By Sol-Gel Convective Deposition Technique, Orawan Sukchoy
Sodium Doping Effects On Properties Of Czts Thin Filmsfabricated By Sol-Gel Convective Deposition Technique, Orawan Sukchoy
Chulalongkorn University Theses and Dissertations (Chula ETD)
Cu2ZnSnS4 (CZTS) is an interesting candidate for thin-film solar cell applications due to its availability and attractive properties (energy band gap of 1.5 eV and high absorption coefficient). However, CZTS solar cell performance is limited because of the defect formation from small grain size, pinholes, rough surface, and negative defects in CZTS such as CuZn. One of the most possible ways to reduce these negative defects, and to increase solar cell performance is by doping with sodium. In this work, CZTS films were synthesized by sol-gel convective deposition technique and Na was doped in CZTS film using 2 different methods: …
Methanol Synthesis Via Hydrogenation Of Mixed Co/Co2 Over Mn Modified Cu/Zno/Al2o3 Catalyst, Papawin Tunyasitikun
Methanol Synthesis Via Hydrogenation Of Mixed Co/Co2 Over Mn Modified Cu/Zno/Al2o3 Catalyst, Papawin Tunyasitikun
Chulalongkorn University Theses and Dissertations (Chula ETD)
The purposes of this study are to investigate the methanol synthesis by using mixed CO/CO2 hydrogenation on Mn modified Cu/ZnO/Al2O3 catalyst which is prepared by the co-precipitation method and to investigate the overall energy consumption of methanol synthesis based on experimental results through the simulation process using Aspen Plus V.9. The improvement of catalytic activity is performed by a continuous fixed bed microreactor at 250°C under atmospheric pressure for 5 hours on the stream through hydrogenation of different feed composition of CO2/H2, CO/H2, and CO/CO2/H2, and 24000 ml/gcat∙h of GHSV. The physical and chemical properties of the catalysts are measured …
Stability Enhancement Of Cspbbr3 Quantum Dots By Coating Tio2 As A Surface Encapsulation, Parina Nuket
Stability Enhancement Of Cspbbr3 Quantum Dots By Coating Tio2 As A Surface Encapsulation, Parina Nuket
Chulalongkorn University Theses and Dissertations (Chula ETD)
The cesium lead bromide quantum dots (CsPbBr3 QDs) have exhibited the excellent optical properties which have been widely used in the applications of optoelectronic and photoelectrochemical devices. However, the instability of CsPbBr3 QDs against the environment factors has been a major obstacle hindering the commercialization of corresponding devices. Herein, the new encapsulation process, in-situ method, for CsPbBr3/TiO2 was presented to prevent the agglomeration of the particles and improve the stability of CsPbBr3 QDs without heat treatment at high temperature. The CsPbBr3 QDs were coated with TiO2 by using titanium tetraisopropoxide (TTIP) as a titanium source which was injected during the …
Performance Of Carbon Nanotubes As Supports Of Nickel-Iron Catalysts For Carbon Dioxide Methanation, Phanatchakorn Mala
Performance Of Carbon Nanotubes As Supports Of Nickel-Iron Catalysts For Carbon Dioxide Methanation, Phanatchakorn Mala
Chulalongkorn University Theses and Dissertations (Chula ETD)
Nowadays, an increase in CO2 emission is one of the main reasons of global warming. Many studies have tried to solve the problem by developing catalysts to efficiently convert CO2 into CH4. Herein, bimetallic Ni-Fe catalyst was studied to improve the catalyst activity of Ni-based catalyst which has low activity and is easily deactivated. Carbon nanotubes (CNTs) have been identified as one of the most promising nanomaterials with unique electrical, thermal, and mechanical properties. In this thesis, CNTs was synthesized from eucalyptus oil as a renewable carbon source and then employed as catalyst support material in methanation. Variations of synthesis …
Effect Of Cu/Zn Ratios And Zr, Mn Promoters On Cuo/Zno-Based Catalysts For Methanol Synthesis Via Hydrogenation Of Co And Co2, Phapatchaya Phonrat
Effect Of Cu/Zn Ratios And Zr, Mn Promoters On Cuo/Zno-Based Catalysts For Methanol Synthesis Via Hydrogenation Of Co And Co2, Phapatchaya Phonrat
Chulalongkorn University Theses and Dissertations (Chula ETD)
The aim of this research is to investigate CuO/ZnO/Al2O3 (CZA) catalysts with different Cu/Zn weight ratios including CZA-0.5, CZA-1, CZA-2 and CZA-3.5 catalysts having Cu/Zn weight ratios is 0.5, 1, 2 และ 3.5, respectively. Catalysts were prepared by the co-precipitation method. Catalysts were characterized to determine the physical and chemical properties using various techniques such as N2 adsorption, CO-Chemisorption, SEM-EDX, ICP-MS, XRD, XPS, H2-TPR, CO2-TPD and TGA. The catalysts were tested in CO hydrogenation and CO2 hydrogenation at 250 °C under atmospheric pressure. From reaction test, it was found that CZA-3.5 catalyst exhibited the highest catalytic activity due to the …
Techno-Economic Analysis Of Hydrogen Production From Dehydrogenation And Steam Reforming Of Ethanol For Carbon Dioxide Conversion To Methanol, Phatchayada Khamhaeng
Techno-Economic Analysis Of Hydrogen Production From Dehydrogenation And Steam Reforming Of Ethanol For Carbon Dioxide Conversion To Methanol, Phatchayada Khamhaeng
Chulalongkorn University Theses and Dissertations (Chula ETD)
Decreasing carbon dioxide (CO2) emission by converting to higher-valued product has become of interest. Hydrogen (H2) is an important feedstock required in thermochemical conversion of CO2 to chemicals such as methanol. The cost and availability of H2 affect the cost of CO2 conversion. This study is focused on the process simulation of H2 production from ethanol feedstock. Steam reforming of ethanol is compared with dehydrogenation of ethanol to H2 with valued products including ethyl acetate and acetaldehyde. Form this study, steam reforming of ethanol presents the lowest cost of H2 production at 1.90 USD/kg H2 while dehydrogenation of ethanol presents …
Sulfonated Polyetheretherketone/Polyvinylidene Fluoride Blend Polymeric Cation Exchange Membrane As Separator In Zinc-Iodine Flow Batteries, Pimpen Pusanasuwanasri
Sulfonated Polyetheretherketone/Polyvinylidene Fluoride Blend Polymeric Cation Exchange Membrane As Separator In Zinc-Iodine Flow Batteries, Pimpen Pusanasuwanasri
Chulalongkorn University Theses and Dissertations (Chula ETD)
Zinc-iodine flow batteries (ZIFBs) are very appealing owing to their abundance of active materials, low cost, high safety and environmental friendliness. The cation exchange membrane (CEM) separator contributes a significant part to the cost and determines battery performance. Sulfonated poly (ether ether ketone) (SPEEK) is a promising candidate as a CEM separator. The ionic conductivity of SPEEK CEM can be tuned by adjusting a degree of sulfonation (DS), but the mechanical property of CEM could be deteriorated. Blending poly (vinylidene fluoride) (PVDF) with SPEEK can improve the mechanical strength of SPEEK membrane. Therefore, this study examined the effect of PVDF …
Preparation And Characterization Of Rice Husk Ash Filled Natural Rubber Film: Effect Of Cross-Linking Agents On Mechanical And Electrical Properties, Praewpakun Sintharm
Preparation And Characterization Of Rice Husk Ash Filled Natural Rubber Film: Effect Of Cross-Linking Agents On Mechanical And Electrical Properties, Praewpakun Sintharm
Chulalongkorn University Theses and Dissertations (Chula ETD)
Natural rubber (NR) is one of the most important polymers produced by plants and is widely utilized as raw material for many products due to its excellent flexibility. Rice husk ash (RHA) is one of the major agricultural residues generated from the rice milling plant. In order to add value to NR and RHA, this study aims to use different types of RHA (black rice husk ash (BRHA), white rice husk ash (WRHA) and BRHA treated by acid washing (BRHAT)) as filler in NR composites. By the addition of alginate as a thickening and dispersing agent, a maximum of 100 …
Effect Of Acidity On Hydrolysis And Depolymerization Of Lignocellulose In One-Pot Lignin-First Biorefinery, Rattanaporn Kaewklam
Effect Of Acidity On Hydrolysis And Depolymerization Of Lignocellulose In One-Pot Lignin-First Biorefinery, Rattanaporn Kaewklam
Chulalongkorn University Theses and Dissertations (Chula ETD)
In lignin-first biorefinery, extraction and depolymerization of lignin from lignocellulosic materials provide value-added lignin monomers. In this study, a mixture of acid-containing water and ethylene glycol was introduced to the lignin-fist biorefinery for simultaneously improving lignin cleavage, together with the depolymerization of cellulose and hemicellulose within one-pot. The experiments were conducted at 180-250°C under the hydrogen pressure of 30 bar for 1-6 h using oil palm empty fruit bunch (OPEFB) as a biomass source. The presence of acid and mixed solvent in the reaction provided the lignin oil yield up to 60 wt% comprising of the main monomers such as …
Evaluation Of Cost, Materials, And Safety Of Flow Battery Technologies For Large Scale Energy Storage, Somya Lekcharoen
Evaluation Of Cost, Materials, And Safety Of Flow Battery Technologies For Large Scale Energy Storage, Somya Lekcharoen
Chulalongkorn University Theses and Dissertations (Chula ETD)
New technologies of flow batteries have been developed but the cost, materials, and safety of each of the technologies are still lacking evaluation such as zinc-based flow batteries, so in this work, the cost, materials, and safety of zinc-based flow batteries including zinc air flow battery, zinc iodine flow battery, zinc iron flow battery, zinc manganese dioxide flow battery and vanadium flow batteries are examined for 12 large scale energy storage applications. This work demonstrated that zinc air flow battery is the most cost-effective because of the lowest cost of investment cost and Levelized cost of storage (LCOS) in all …
Mno2/Carbon Material Cathode For Rechargeable Aqueous Electrolyte-Based Zinc-Ion Batteries, Sonti Khamsanga
Mno2/Carbon Material Cathode For Rechargeable Aqueous Electrolyte-Based Zinc-Ion Batteries, Sonti Khamsanga
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research focused on improvement of the electrical conductivity of cathode material by using the MnO2 on carbon material for the rechargeable aqueous electrolyte-based zinc-ion batteries (ZIBs). This study has been divided into two sections. delta-MnO2 with nanoflower structure supported on graphite flake (MNG) was synthesized for cathode material in first section. MNG exhibits a fast insertion/extraction of Zn2+ ions with diffusion scheme and pseudocapacitive behavior. The battery using MNG cathode exhibited a high initial discharge capacity of 235 mA h/g at 200 mA/g specific current density compared to 130 mA h/g which is displayed by the pristine delta-MnO2 cathode …
Techno-Economic Analysis Of Acetaldehyde Production Via Partial Oxidative Dehydrogenation Of Ethanol, Sudarat Sompong
Techno-Economic Analysis Of Acetaldehyde Production Via Partial Oxidative Dehydrogenation Of Ethanol, Sudarat Sompong
Chulalongkorn University Theses and Dissertations (Chula ETD)
Due to the increased attention regarding the battery electric vehicles, the demand for ethanol as a biofuel may be reduced in the future. Therefore, ethanol transformation towards acetaldehyde is conducted in this work, primarily because of the higher selling price and several advantages of acetaldehyde. Regarding the acetaldehyde preparation, acetaldehyde is produced by partial oxidative dehydrogenation of ethanol. According to the economic analysis results, at the same price of acetaldehyde, an annual production capacity of 120,000 tons is the most profitable production size. In addition, the potential process of producing acetaldehyde from ethanol is acetaldehyde production process at 200°C since …