Open Access. Powered by Scholars. Published by Universities.®

Chemical Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 5251 - 5280 of 14266

Full-Text Articles in Chemical Engineering

การจำลองกระบวนการการปรับปรุงแก๊สซิฟิเคชันชีวมวลร่วมกับการดักจับคาร์บอนไดออกไซด์ แบบแคลเซียมลูปปิงสำหรับการผลิตไฮโดรเจน, อรัญกร สัมภวะผล Jan 2019

การจำลองกระบวนการการปรับปรุงแก๊สซิฟิเคชันชีวมวลร่วมกับการดักจับคาร์บอนไดออกไซด์ แบบแคลเซียมลูปปิงสำหรับการผลิตไฮโดรเจน, อรัญกร สัมภวะผล

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้ได้นำเสนอเกี่ยวกับการวิเคราะห์สมรรถนะของการปรับปรุงกระบวนการแก๊สซิฟิเคชันชีวมวลร่วมกับการดักจับคาร์บอนไดออกไซด์ด้วยวิธีแคลเซียมลูปปิงสำหรับการผลิตไฮโดรเจนที่มีความบริสุทธิ์สูง โดยใช้ทางปาล์มเป็นวัตถุดิบและใช้แคลเซียมออกไซด์เป็นตัวดูดซับคาร์บอนไดออกไซด์ การจำลองกระบวนการจะถูกพัฒนาโดยใช้แบบจำลองแอสเพนพลัส (Aspen Plus simulator) และใช้ในการวิเคราะห์ผลกระทบของตัวแปรดำเนินการที่ศึกษา เช่น อุณหภูมิแก๊สซิฟิเคชัน อัตราส่วนไอน้ำต่อชีวมวล (S/B) อัตราส่วนแคลเซียมออกไซด์ต่อชีวมวล (CaO/B) และอุณหภูมิไรเซอร์ ต่อประสิทธิภาพของกระบวนการ ผลการศึกษาแสดงให้เห็นว่าการเพิ่มขึ้นของอุณหภูมิแก๊สซิฟิเคชันส่งผลดีตต่อการผลิตไฮโดรเจน ปริมาณไอน้ำที่เพิ่มขึ้นส่งผลกระทบอย่างมากต่อการผลิตไฮโดรจน การเพิ่มขึ้นของแคลเซียมออกไซด์ที่ใช้เป็นตัวดูดซับมีบทบาทอย่างสูงต่อการลดการผลิตคาร์บอนไดออกไซด์และสนันสนุนการผลิตไฮโดรเจนให้เพิ่มสูงขึ้น อุณหภูมิไรเซอร์ที่อุณหภูมิต่ำส่งเสริมการผลิตไฮโดรเจน ความเข้มข้นของไฮโดรเจนที่สูงที่สุดคือ 99 % สามารถทำได้ภายใต้สภาวะอุณหภูมิของแก๊สซิฟิเคชันที่ 650 °C อัตราส่วนไอน้ำต่อชีวมวล เท่ากับ 1 อัตราส่วนแคลเซียมออกไซด์ต่อชีวมวล เท่ากับ 1.6 และอุณหภูมิไรเซอร์ เท่ากับ 550 °C ประสิทธิภาพเชิงความร้อนของกระบวนการได้ถูกปรับปรุงโดยการออกแบบเครือข่ายแลกเปลี่ยนความร้อนตามหลักการการวิเคราะห์จุดพินช์ เพื่อนำพลังงานความร้อนที่เหลือจากกระบวนการกลับมาใช้ให้เกิดประโยชน์สูงสุด พบว่าประสิทธิภาพเชิงความร้อนรวมของระบบเพิ่มขึ้นจากเดิม 60.20 % ไปเป็น 75.30 %

Go to article

การสังเคราะห์อนุภาคนาโนคอปเปอร์ซิงค์ทินซัลไฟด์ที่ใช้เป็นชั้นขนส่งโฮลสำหรับเซลล์แสงอาทิตย์เพอร์รอฟสไกท์ที่มีเสถียรภาพสูง, อุรัสยา ศิลป์เจริญ Jan 2019

การสังเคราะห์อนุภาคนาโนคอปเปอร์ซิงค์ทินซัลไฟด์ที่ใช้เป็นชั้นขนส่งโฮลสำหรับเซลล์แสงอาทิตย์เพอร์รอฟสไกท์ที่มีเสถียรภาพสูง, อุรัสยา ศิลป์เจริญ

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้เป็นการสังเคราะห์อนุภาคนาโนคอปเปอร์ซิงค์ทินซัลไฟด์ เพื่อนำมาใช้เป็นชั้นขนส่งโฮลในเซลล์แสงอาทิตย์เพอร์รอฟสไกท์ สมบัติของชั้นขนส่งโฮลจำเป็นต้องอยู่ในรูปของฟิล์มบางคอปเปอร์ซิงค์ทินซัลไฟด์ที่ประกอบไปด้วยอนุภาคที่มีขนาดใกล้เคียงกัน มีความบริสุทธิ์สูงและอยู่ในเฟสเคสเตอไรท์ (kesterite phase) เนื่องจากคุณลักษณะเหล่านี้ส่งผลต่อสมบัติทางแสงและไฟฟ้า และประสิทธิภาพการแปลงพลังงานแสงอาทิตย์เป็นพลังงานไฟฟ้า โดยงานวิจัยนี้ศึกษาการสังเคราะห์อนุภาคนาโนคอปเปอร์ซิงค์ทินซัลไฟด์ด้วยวิธีไฮโดรเทอร์มอลที่อุณหภูมิ 220 170 และ 120 องศาเซลเซียส และวิธีโซล-เจลที่อุณหภูมิ 300 250 และ 200 องศาเซลเซียส ซึ่งการสังเคราะห์ด้วยอุณหภูมิที่แตกต่างกันนั้นส่งผลต่อขนาด ความเป็นผลึกและความบริสุทธิ์ของผลึก การสังเคราะห์ด้วยวิธีไฮโดรเทอร์มอลที่อุณหภูมิ 220 องศาเซลเซียส ผลึกของคอปเปอร์ซิงค์ทินซัลไฟด์ที่ได้มีขนาดใกล้เคียงกันโดยมีค่าเฉลี่ยประมาณ 23 นาโนเมตรจากการคำนวณด้วยสมการเชอร์เรอร์ นอกจากนี้ยังมีคุณภาพในด้านความเป็นผลึกและความบริสุทธิ์ของผลึกคอปเปอร์ซิงค์ทินซัลไฟด์ที่สูงที่สุด และสูงกว่าการสังเคราะห์ด้วยวิธีโซล-เจล ในขณะที่อนุภาคคอปเปอร์ซิงค์ทินซัลไฟด์ที่สังเคราะห์ด้วยวิธีโซล-เจลที่อุณหภูมิต่างๆไม่ส่งผลต่อขนาดและความบริสุทธิ์ของผลึกอย่างเด่นชัด อีกทั้งพบว่ามีค่าช่องว่างระหว่างแถบพลังงานประมาณ 1.48 อิเล็กตรอนโวลต์ ซึ่งเหมาะสมในการนำมาใช้เป็นชั้นขนส่งโฮล เมื่อนำอนุภาคคอปเปอร์ซิงค์ทินซัลไฟด์มาเคลือบเป็นฟิล์มบางด้วยวิธีหมุนเหวี่ยง (spin coating) ด้วยอัตราหมุน 4,000 รอบต่อนาที เพื่อใช้เป็นชั้นขนส่งโฮลด้วยตัวทำละลายที่เหมาะสมต่อการกระจายตัวของอนุภาคคอปเปอร์ซิงค์ทินซัลไฟด์คือไอโซโพรพิลซัลไฟด์ เมื่อประกอบเป็นเซลล์แสงอาทิตย์เพอร์รอฟสไกท์ที่สมบูรณ์พบว่าสามารถคงไว้ซึ่งความเสถียรภาพของเซลล์แสงอาทิตย์ได้เป็นระยะเวลาประมาณ 1,344 ชั่วโมง

Go to article

Review Of Carbonaceous Annealing Effects On O2 And Co2 Coal Reactivity, Troy Michael Holland, Thomas H. Fletcher, Osvalda Senneca Jan 2019

Review Of Carbonaceous Annealing Effects On O2 And Co2 Coal Reactivity, Troy Michael Holland, Thomas H. Fletcher, Osvalda Senneca

Faculty Publications

Coal is, and will remain for the foreseeable future, a critical energy production resource. Advanced models of coal conversion behavior in air and oxy-coal environments enhance the boiler operational efficiency and design optimization. Although coal conversion models have continuously improved over decades of research, not all aspects of coal particle heating and conversion have received equal treatment. Coal particle annealing is one aspect of the coal conversion process that is simultaneously highly sensitive to the conversion environment, exceptionally impactful on coal chemistry, and frequently neglected in coal models. However, the current body of literature has explored numerous aspects of coal …

Go to article

Effects Of Polyaniline Thickness On Photovoltaic Properties Of Pani/Tio2 Photovoltaic Cells, Akkharaphak Auisakul Jan 2019

Effects Of Polyaniline Thickness On Photovoltaic Properties Of Pani/Tio2 Photovoltaic Cells, Akkharaphak Auisakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Polyaniline (PANI) is a cheap conducting polymer that exhibits p-type properties with high conductivity and unique redox properties. In this work, PANI was synthesized directly on TiO2/FTO substrates by electropolymerisation from acidic aqueous solutions of aniline to form PANI/TiO2 p-n junctions with photovoltaic properties. The thickness of the PANI layer was varied by varying electrodeposition time: 15, 30, and 45 min at the same current density of 2 mA cm-2. The thicknesses of the deposited PANI layers were examined with Scanning Electron Microscope (SEM). Short-circuit currents (ISC) and open-circuit voltages (VOC) of fabricated Pt/PANI/TiO2/FTO cells are investigated. It was found …

Go to article

Ethanol Dehydration Over Wo3/Tio2 Catalysts Using Titania Derived From Sol-Gel And Solvothermal Methods With Palladium Modification, Anchale Tresatayawed Jan 2019

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). …

Go to article

Development Of Bioplastic Blown Films To Be Used As A Packaging For Dried Banana, Apinya Wongthanaroj Jan 2019

Development Of Bioplastic Blown Films To Be Used As A Packaging For Dried Banana, Apinya Wongthanaroj

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aimed to study effects of poly(butylene adipate-co-terephthalate) (PBAT) contents on properties of polylactic acid / poly(hydroxybutyrate-co-hydroxyvalerate) / poly (butylene adipate-co-terephthalate) (PLA/PHBV/PBAT) blends to be used as a packaging for solar-dried bananas. The blend of PLA and PHBV (PLA/PHBV) was fixed at weight ratio of 80/20 while the PBAT content was varied from 0-30 wt%. The films were prepared by melt compounding and blown film extrusion. It was found that the addition of PBAT decreased barrier properties of PLA/PHBV film. Gas barrier which is oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) increased with increasing of PBAT …

Go to article

Production Of Activated Carbonaceous Catalyst For Their Application In Bio Jet-Fuel Synthesis, Araya Smuthkochorn Jan 2019

Production Of Activated Carbonaceous Catalyst For Their Application In Bio Jet-Fuel Synthesis, Araya Smuthkochorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Recently, research and development in alternative aviation fuel to replace fossil-based fuel has been of interest for many research works. Hydrodeoxygenation (HDO) is one of the most efficient processes to produce clean fuel. This study involves the synthesis of activated carbon (AC) from heavy fuel oil (HFO) via the carbonization-chemical activation process for utilization as catalyst support. AC with a high surface area of 1527.4 m2/g was obtained from KOH-activation in the ratio of 1:1 and carbonization temperature of 700°C. The molybdenum phosphide (MoP) catalyst impregnated on AC was prepared via the wet impregnation process. The microscopic analysis revealed the …

Go to article

Solar Energy Management System For Stand-Alone Application : Analysis Of Power Management Strategies Under Different Solar Irradiance Profiles, Chacrit Lerdwithayaprasit Jan 2019

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 …

Go to article

Co-Electrodeposition Of Gold Nanoparticle And Reduced-Graphene Oxide In Application Of Achetylcholinesterase Biosensor, Chiranthanin Mahayotheecharak Jan 2019

Co-Electrodeposition Of Gold Nanoparticle And Reduced-Graphene Oxide In Application Of Achetylcholinesterase Biosensor, Chiranthanin Mahayotheecharak

Chulalongkorn University Theses and Dissertations (Chula ETD)

A rapid pesticide detection technique is highly desirable due to the widespread usage of many pesticides in the agricultural industry. An emerging technique that shows promising potential is an electrochemical biosensor. The technique allows sensitive and rapid quantification of an analyte. Due to its simplicity, it could be a potential alternative to traditional method. In this work, we utilised a composite materials consist of partially reduced graphene oxide (rGO) and gold nanoparticle (AuNPs) to fabricate a disposable AChE biosensor on a Screen-Print Carbon electrode. The composite rGO and AuNPs possess high electron conductivity while AuNPs also exhibit desirable biocompatibility. The …

Go to article

Mechanism And Reaction Pathways Of Co2 And Hco3-Photoreduction To Hydrocarbons, Duangthip Sattayamuk Jan 2019

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 …

Go to article

Modeling Aromatics Production From Mixtures Of Butanes And Butenes With Chemical Equilibria, Hataipat Sangwattanakul Jan 2019

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 …

Go to article

Preparation Of Natural Rubber Powder Modified With Bis(Triethoxysilylpropyl)Tetrasulfide Treated Silica By Spray Drying Process, Intira Boonvisood Jan 2019

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%, …

Go to article

Single-Step Conversion Of Xylose To Furfural And Furfuryl Alcohol On Zeolite-Based Catalyst, Jirapat Chatkaweekoon Jan 2019

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 …

Go to article

Iodine Encapsulation Using Anionic Polyelectrolytes For Rechargeable Zinc-Iodine Batteries, Jirapha Pimoei Jan 2019

Iodine Encapsulation Using Anionic Polyelectrolytes For Rechargeable Zinc-Iodine Batteries, Jirapha Pimoei

Chulalongkorn University Theses and Dissertations (Chula ETD)

Rechargeable zinc-iodine batteries are attractive as promising candidates for electrical energy storage due to their abundant resources, low cost, and high safety. However, these batteries still have some problems, such as poor cycling stability and high self-discharge due to the leakage of iodine species from the positive electrode. Anionic polyelectrolytes can be applied as supportive binders to alleviate this issue because these polyelectrolytes can encapsulate iodine species and facilitate the transfer of other active species. In this study, different types of anionic polyelectrolytes, including sodium carboxymethyl cellulose (Na-CMC), sodium alginate (Na-Alg), and sodium polystyrene sulfonate (Na-PSS), were investigated. The batteries …

Go to article

Catalytic Dehydration Of Ethanol With Different Loading Of Wo3 Supported On Activated Carbon And Clay Catalysts, Jirayu Liewchalermwong Jan 2019

Catalytic Dehydration Of Ethanol With Different Loading Of Wo3 Supported On Activated Carbon And Clay Catalysts, Jirayu Liewchalermwong

Chulalongkorn University Theses and Dissertations (Chula ETD)

The catalytic ethanol dehydration is a reaction, which increases the value of ethanol by producing diethyl ether (DEE) or ethylene. The catalysts which have been used for this reaction were tungsten catalysts supported on activated carbon and montmorillonite catalysts, by varying W loading between 2-13.5 wt.%. The catalysts were tested in a fixed bed microreactor under atmospheric pressure and temperature range of 200 to 400˚C. The results showed that Low tungsten on catalyst decreased the total surface acidity. Besides, additional tungsten loading increased the total surface acidity. Low tungsten loading enhanced ethanol dehydrogenation to acetaldehyde. The high content of tungsten …

Go to article

Effects Of Cuo/Zno/Al2o3 Catalyst Modification Using Zr, Mn And Si For Methanol Synthesis Via Co2 Hydrogenation, Kamonlak Pongpanumaporn Jan 2019

Effects Of Cuo/Zno/Al2o3 Catalyst Modification Using Zr, Mn And Si For Methanol Synthesis Via Co2 Hydrogenation, Kamonlak Pongpanumaporn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Currently, the estimated CO2 amount has tended to increase interesting of population. One of the most effective utilization ways of CO2 is to convert CO2 to higher valued chemicals. Thus, methanol was chosen to produce via CO2 hydrogenation by using CuO/ZnO/Al2O3 (CZA) catalyst. In the first part, CZA was prepared by co-impregnation method under different pH (7, 8 and 9) during co-precipitation. It was found that the suitable pH was 8 (CZA-PH8) due to high surface area, high basicity, and reducibility. The CO2 conversion and methanol selectivity were 2.6% and 10%, respectively at 250oC under atmospheric pressure. However, it should …

Go to article

Deactivation Of Ti-Based And Γ-Al2o3 Catalysts In Liquid-Phase Methyl Oleate Epoxidation Reaction, Kanokpon Maungthong Jan 2019

Deactivation Of Ti-Based And Γ-Al2o3 Catalysts In Liquid-Phase Methyl Oleate Epoxidation Reaction, Kanokpon Maungthong

Chulalongkorn University Theses and Dissertations (Chula ETD)

To eliminate some drawback of heterogeneous catalysts as a low stability, the deactivation scheme and surface regeneration of TiO2 (P25), TS-1 and γ-Al2O3 catalysts was investigated on the liquid-phase methyl oleate epoxidation reaction at 50 ºC. Based on the results, there are two deactivation effects illustrated on the surface after the reaction: (1) the fouling effects are found the main deactivation on this reaction. There are three types which type 1 is found in P25 and γ-Al2O3, type 2 is uncovered in TS–1 and γ-Al2O3, and type 3 is appeared in γ-Al2O3 only. The FT-IR reveals that are alkane (C–H) …

Go to article

Development Of Stack Model For Tri-Electrode Rechargeable Zinc-Air Cylindrical Flow Battery, Kanya Bumroongsil Jan 2019

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 …

Go to article

A Study On The Deactivation Of Nickel-Based Catalyst For The Dry Reforming Of Methane Via Density Functional Theory, Mongkol Lerdpongsiripaisarn Jan 2019

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 …

Go to article

Study Of Thermal And Mechanical Properties Of Tertiary Blend Of Poly(Lactic Acid), Poly(Hydroxybutyrate-Co-Hydroxyvalerate) And Thermoplastic Starch, Naphat Yampry Jan 2019

Study Of Thermal And Mechanical Properties Of Tertiary Blend Of Poly(Lactic Acid), Poly(Hydroxybutyrate-Co-Hydroxyvalerate) And Thermoplastic Starch, Naphat Yampry

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, single-use plastics such as straws, plastic bags cause plastic waste problems because the majority of these plastics which are petroleum-based plastics are not compostable and difficult to recycle. As a result, biodegradable plastic is a proper option to replace traditional plastic. The objective of this work was to study the morphology as well as the thermal and mechanical properties of tertiary blend of poly(lactic acid) (PLA), poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and thermoplastic starch (TPS). PLA/PHBV at weight ratios of 80/20, 70/30, and 60/40 were prepared to find the optimal ratio. Then the PLA/PHBV at weight ratio of 80/20 was added by …

Go to article

Improvement And Economic Analysis Of Bio-Hydrogenated Diesel Production For Producing Bio-Jet Fuel, Nattamon Munkong Jan 2019

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 …

Go to article

Study Of Co2 And Bi-Reforming Of Methane On Modified Nickel-Based Catalysts, Nichakorn Buasuk Jan 2019

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 …

Go to article

Development And Characterization Of Natural Rubber-Cellulose Sponge, Nuttapon Suppanucroa Jan 2019

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 …

Go to article

Application Of Co-Solvent For Biodiesel Production In Ultrasound-Assisted Reactor, Panidaporn Ritprasert Jan 2019

Application Of Co-Solvent For Biodiesel Production In Ultrasound-Assisted Reactor, Panidaporn Ritprasert

Chulalongkorn University Theses and Dissertations (Chula ETD)

Biodiesel has been a promising alternative energy due to its renewability and lesser emissions of harmful gases such as carbon monoxide in comparison to traditional petroleum diesel fuel. Mostly, biodiesel production via transesterification requires catalyst to achieve faster reaction rate and complete the reaction. However, mass transfer between two immiscible reactants are obstacle to the biodiesel production. In this work, ultrasound-assisted (US) reactor and addition of co-solvent were used to overcome mass transfer limitation. The condition for biodiesel production from transesterification of palm oil using a circulated US reactor and addition of co-solvent was operated at 60°C, 1 atm, calcium …

Go to article

Improvement Of Screen Printable Anisotropic Conductive Adhesive With Polyethylene Glycol As Diluent, Papitchaya Manduang Jan 2019

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 …

Go to article

Development And Characterization Of Solid Oxide Electrolysis Cells Based On Zirconia And Ceria Based Electrolyte For Hydrogen Production From Steam, Parintorn Temluxame Jan 2019

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 …

Go to article

Biodiesel Production From Cooking Palm Oil In The Presence Of Cao/Γ-Al2o3 Catalyst Using Rotating Packed-Bed Reactor, Patcharaporn Sukjarern Jan 2019

Biodiesel Production From Cooking Palm Oil In The Presence Of Cao/Γ-Al2o3 Catalyst Using Rotating Packed-Bed Reactor, Patcharaporn Sukjarern

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis proposed the biodiesel production from cooking palm oil by using rotating pack bed reactor (RPB). The experiments were divided into 3 parts i) preparation of CaO/γ-Al2O3 catalyst and catalytic activity for the transesterification in a conventional mechanical stirrer reactor (MS). ii) study of CaO/γ-Al2O3 heterogeneous catalysts using RPB iii) study of NaOH homogeneous catalysts using RPB by packing inert packing bed. The Response surface methodology (RSM) based on the Central composite design (CCD) was used to reduce the number of experiments. The optimum condition for CaO /γ-Al2O3 catalyst preparation was at calcination temperature of 500ºC and 24%CaO/γ- Al2O3. …

Go to article

Preparation Of Ba0.5sr0.5(Co0.8fe0.2)1-Xtaxo3-Δ Perovskite Anode For Solid Oxide Electrolysis Cell And Comparison Of Electrochemical Performance And Durability With The Basic Anodes, Patthiya Prasopchokkul Jan 2019

Preparation Of Ba0.5sr0.5(Co0.8fe0.2)1-Xtaxo3-Δ Perovskite Anode For Solid Oxide Electrolysis Cell And Comparison Of Electrochemical Performance And Durability With The Basic Anodes, Patthiya Prasopchokkul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Among perovskite anodes in solid oxide electrolysis cell (SOEC), Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) has gained much attention due to its relatively high performance. However, the BSCF still suffers from chemical instability. In this study, partial substituting higher valance Ta5+ (5, 10, 15 and 20 mol%) at the B-site (Co2+/Fe3+) of BSCF was investigated to improve its structural stability. The Ba0.5Sr0.5(Co0.8Fe0.2)1-xTaxO3-δ (BSCFTax, 0 ≤ x ≤ 0.20) were synthesized by citrate-EDTA complexing method. The BSCF and BSCFTa0.05 exhibited the single phase perovskite while segregation of Ta2O5 and Ta3N5 were observed in other samples. The symmetrical half-cell having the yttria stabilized zirconia (YSZ) as …

Go to article

Study Effect Of Catalyst Shape On The Ethylbenzene Dehydrogenation In Fixed Bed Reactor By Using Various Mathematical Models, Pawinee Maithong Jan 2019

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). …

Go to article

Effect Of Titania Phase Composition In Wo3/Tio2 Catalysts On Catalytic Properties In Dehydration Of Ethanol To Diethyl Ether, Phatthraporn Termvoratham Jan 2019

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 …

Go to article

First Prev Next Last