Electrochemical Reduction Of Co2 To Co On Zn Electrodes Prepared By Electrodeposition Method,
2020
Faculty of Engineering
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,
2020
Faculty of Engineering
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,
2020
Faculty of Engineering
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,
2020
Faculty of Engineering
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,
2020
Faculty of Engineering
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,
2020
Faculty of Engineering
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,
2020
Faculty of Engineering
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,
2020
Faculty of Engineering
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,
2020
Faculty of Engineering
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,
2020
Faculty of Engineering
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,
2020
Faculty of Engineering
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,
2020
Faculty of Engineering
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,
2020
Faculty of Engineering
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,
2020
Faculty of Engineering
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,
2020
Faculty of Engineering
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,
2020
Faculty of Engineering
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 …
Esterification Of Ethanol And Lactic Acid With Wo3 On Montmorillonite Catalysts For Ethyl Lactate Production,
2020
Faculty of Engineering
Esterification Of Ethanol And Lactic Acid With Wo3 On Montmorillonite Catalysts For Ethyl Lactate Production, Suthicha Mukjinda
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research aims to study the characteristics, catalytic properties and stability of tungsten oxide (13.5 wt%) supported on montmorillonite (W/MMT) catalysts prepared by using three different calcination temperatures including 375 (W/MMT375), 475 (W/MMT475) and 575 (W/MMT 575) °C. All catalysts were examined in esterification of ethanol and lactic acid at 80 °C. Characterization studies showed that the W/MMT475 catalyst exhibited the highest acidity, followed by W/MMT375 and W/MMT575, respectively. However, from the surface area result, W/MMT375 exhibited the highest surface area, followed by W/MMT475 and W/MMT575, respectively. When all catalysts were tested in esterification of ethanol and lactic acid, it …
Novel Electrochemical Packed-Bed Reactor For Carbon Dioxide Reduction,
2020
Faculty of Engineering
Novel Electrochemical Packed-Bed Reactor For Carbon Dioxide Reduction, Suwakul Chaiwarit
Chulalongkorn University Theses and Dissertations (Chula ETD)
Electrochemical reduction of carbon dioxide (CO2) is a promising strategy to recycle CO2 into valuable chemical products. Nevertheless, a conventional apparatus which usually utilizes stack design to maximize its surface-to-volume ratio requires many elements and complicated instruction assembly. The stack design often requires feed streams to flow in narrow channels throughout the cell, which is also constrained by membrane size roughly 1 m2 by current manufacture technology. This research focuses on development of a new type of electrochemical reactor that is suitable for industrial-scale applications. The novel electrochemical packed-bed reactor is designed for the electroreduction to covert CO2 into CO …
Effect Of Molecular Sieve Addition On Methanol Synthesis From Co2 And H2 Through Alcohol Assisted Method Over Cu/Zno Catalyst,
2020
Faculty of Engineering
Effect Of Molecular Sieve Addition On Methanol Synthesis From Co2 And H2 Through Alcohol Assisted Method Over Cu/Zno Catalyst, Tanawut Boonamnuay
Chulalongkorn University Theses and Dissertations (Chula ETD)
Low-temperature methanol synthesis from CO2 and H2 was carried out using ethanol as catalytic solvent. The alcohol-assisted method reduced synthesis temperature and enhanced methanol yield (35.8%) at 150 oC (5.0 MPa, Cu/ZnO catalyst). However, ethyl acetate and water were generated as byproducts from the reaction. The byproducts formed azeotrope mixture with methanol and led to a complex product purification. Therefore, in this study, molecular sieves (MS) were introduced to adsorb the byproducts. The effect of different MS (3A and 5A) was studied. It was found that MS helped enhancing methanol yield. The highest methanol yield (42.6%) was obtained when adding …
Process Analysis And Economic Evaluation Of Acetaldehyde Production From Ethanol Via Non-Oxidative Dehydrogenation,
2020
Faculty of Engineering
Process Analysis And Economic Evaluation Of Acetaldehyde Production From Ethanol Via Non-Oxidative Dehydrogenation, Thanakarn Suthirojn
Chulalongkorn University Theses and Dissertations (Chula ETD)
At present, there is an awareness of global warming. The use of combustion fuel in cars is another cause of carbon dioxide emission which can caused global warming. As a result, electric vehicles (EV) have a greater role in the world Including Thailand, resulting in lower fuel consumption. For this reason, the demand for ethanol may decreased. Due to the higher price and wide range of applications, it is interesting to find alternatives to convert ethanol into acetaldehyde in this work. In this research, Aspen plus will be utilized for the process simulation and economic evaluation of two processes by …
