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2021

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Full-Text Articles in Engineering

วิธีการจัดการของเสียแผงพลังงานแสงอาทิตย์ชนิดผลึกซิลิกอนจากโรงไฟฟ้าพลังงานแสงอาทิตย์ที่เหมาะสมสำหรับประเทศไทย, อิงฉัตร สุภาพยาม Jan 2021

วิธีการจัดการของเสียแผงพลังงานแสงอาทิตย์ชนิดผลึกซิลิกอนจากโรงไฟฟ้าพลังงานแสงอาทิตย์ที่เหมาะสมสำหรับประเทศไทย, อิงฉัตร สุภาพยาม

Chulalongkorn University Theses and Dissertations (Chula ETD)

นับตั้งแต่ปี พ.ศ. 2545 ประเทศไทยเริ่มมีการลงทุนผลิตไฟฟ้าจากแผงพลังงานแสงอาทิตย์ และมีการติดตั้งใช้งานเพิ่มขึ้นต่อเนื่องโดยเฉพาะแผงในกลุ่มผลึกซิลิกอน ในอนาคตประเทศไทยมีแนวโน้มที่จะเผชิญกับปัญหาจากของเสียแผงในปริมาณมาก ดังนั้นงานวิจัยนี้จึงมีวัตถุประสงค์เพื่อการคาดการณ์ปริมาณของเสียแผง และประเมินแนวทางการจัดการของเสียแผงชนิดผลึกซิลิกอน ผลการดำเนินงานพบว่าปริมาณของเสียแผงสะสมที่จะเกิดขึ้น ในปี พ.ศ. 2582 จากทั้ง 2 มุมมอง (1. แผงหมดอายุการใช้งานเมื่อครบ 20 ปี 2. แผงที่ชำรุดรวมกับแผงหมดอายุการใช้งานเมื่อครบ 20 ปี) มีปริมาณอยู่ในช่วง 237,394 - 322,856 ตัน ซึ่งเป็นกระจกมากเกินครึ่งของปริมาณของเสียที่เกิดขึ้นสะสมอยู่ในช่วง 163,921 – 222,932 ตัน สำหรับวัสดุพอลิเมอร์ (วัสดุห่อหุ้ม แผ่นปิดด้านหลัง และซิลิโคน) มีปริมาณรวมกันอยู่ในช่วง 31,384 – 42,682 ตัน และจากการประเมินแนวทางการจัดการทั้ง 3 (1.แนวทางที่ใช้ในปัจจุบัน 2.แนวทางการบดหยาบ 3.แนวทางการอบแยก) พบว่าทุกแนวทางมีรายได้มากกว่าต้นทุนการจัดการเบื้องต้น แสดงให้เห็นถึงความเป็นไปได้ของระบบเศรษฐกิจหมุนเวียน และในแนวทางการอบแยกที่มีการใช้ความร้อนจะทำให้เกิดการสลายตัวของวัสดุพอลิเมอร์ ในรูปค่าความร้อนของเชื้อเพลิง โดยวัสดุห่อหุ้มมีค่าความร้อนมากที่สุดอยู่ในช่วง 38.46 – 40.54 เมกะจูลต่อกิโลกรัม (มีค่าใกล้เคียงกับไบโอดีเซล 40.2 เมกะจูลต่อกิโลกรัม) มีโอกาสที่จะนำเอาพลังงานที่เกิดขึ้นกลับคืนมาใช้ในกระบวนการ เพื่อช่วยลดการใช้เชื้อเพลิง และจากการนำกลับของวัสดุในปริมาณที่มากที่สุด จะช่วยชดเชยผลกระทบทางสิ่งแวดล้อมที่เกิดขึ้น ถือเป็นเครดิตที่เกิดขึ้นจากการประเมินผลกระทบสิ่งแวดล้อม

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Integrating Human And Ecotoxicological Impacts Into Willingness To Pay Evaluation: Transition From Paraquat To Atrazine Use In Sweet Corn Cultivation, Patharanun Toolkiattiwong Jan 2021

Integrating Human And Ecotoxicological Impacts Into Willingness To Pay Evaluation: Transition From Paraquat To Atrazine Use In Sweet Corn Cultivation, Patharanun Toolkiattiwong

Chulalongkorn University Theses and Dissertations (Chula ETD)

The paraquat ban has led to a shift in the use of pesticides in sweet corn cultivation, atrazine as one of the alternative pesticides. This change has led to altered human-ecological impacts that have yet to be explored. The related monetary values of farmers as reflected through their willingness to pay is unknown. This study assessed the health and freshwater ecotoxicity impacts of paraquat and atrazine in soil cultivation using the USEtox 2.12 model. The value of farmers on the impact of the change was explained by willingness to pay (WTP). The theory of planned behavior (TPB) factors, a psychological …

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การเตรียมบล็อกปูทางเท้าพรุนน้ำจากเศษเซรามิกโดยใช้เคลือบเซรามิกเป็นวัสดุเชื่อมประสาน, พิมพ์รัมภา กิติธรากุล Jan 2021

การเตรียมบล็อกปูทางเท้าพรุนน้ำจากเศษเซรามิกโดยใช้เคลือบเซรามิกเป็นวัสดุเชื่อมประสาน, พิมพ์รัมภา กิติธรากุล

Chulalongkorn University Theses and Dissertations (Chula ETD)

ปัญหาน้ำท่วมขังหลังจากที่เกิดฝนตกหนัก มักเป็นปัญหาใหญ่สำหรับพื้นที่ในเขตเมืองหลวง ซึ่งส่งผลกระทบโดยตรงกับผู้คนที่สัญจรบนท้องถนน การนำบล็อกพรุนที่มีความสามารถในการระบายน้ำได้มาใช้ทำเป็นพื้นสำหรับทางเดินสามารถแก้ไขปัญหาดังกล่าวได้ โดยทั่วไปแล้วบล็อกพรุนที่มีความสามารถในการระบายน้ำที่สูงมักจะทำให้ค่าความแข็งแรงต่ำ เนื่องจากมีรูพรุนอยู่ในโครงสร้างของชิ้นงานมาก ดังนั้นในงานวิจัยนี้จึงสนใจนำเศษเซรามิกเนื้อสโตนแวร์ ที่แตกหักเสียหายจากอุตสาหกรรมเซรามิกประเภทเครื่องใช้บนโต๊ะอาหารที่ผ่านการบดและคัดขนาด 2 - 5 มิลลิเมตร มาใช้เป็นมวลรวมหยาบสำหรับการทำบล็อกพรุนและเลือกใช้เคลือบเซรามิกขาวทึบมาเป็นวัสดุเชื่อมประสาน โดยใช้กระบวนการขึ้นรูปด้วยมือในแม่พิมพ์ และได้ศึกษาปัจจัยที่ส่งผลต่อสมบัติทางกายภาพของบล็อกพรุน พบว่ามีปัจจัยหลัก 4 ที่ส่งผลต่อสมบัติทางกายภาพของบล็อกพรุน ได้แก่ อุณหภูมิที่ใช้ในการเผาบล็อกพรุน อัตราส่วนระหว่างมวลรวมและวัสดุเชื่อมประสาน ขนาดของเศษเซรามิกที่ใช้เป็นมวลรวม และความเข้มข้นของเคลือบที่ใช้เป็นวัสดุเชื่อมประสาน นอกจากนี้ยังได้หาเงื่อนไขที่เหมาะสมต่อการขึ้นรูปบล็อกพรุนที่ให้อัตราการไหลซึมผ่านของน้ำและค่าความแข็งแรงที่เหมาะสม ซึ่งพบว่าบล็อกพรุนปูทางเท้าที่ประกอบด้วยเศษเซรามิกขนาด 2 – 5 มิลลิเมตร ปริมาณร้อยละ 80 โดยน้ำหนัก วัสดุเชื่อมประสานปริมาณร้อยละ 20 โดยในวัสดุเชื่อมประสานประกอบด้วยสัดส่วนผงเคลือบแห้งต่อน้ำ ร้อยละ 71.43 : 28.57 โดยน้ำหนัก และเผาที่อุณหภูมิ 1200 °C ซึ่งให้ค่าความแข็งแรงต่อแรงอัดที่ 24.57 MPa ความหนาแน่น 1.64 g/cm3 ค่าความพรุนตัว 30.43% และอัตราการไหลซึมผ่านของน้ำ 897.74 L/m2·min

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Investigation Of Pm2.5 Dispersion In Din Daeng District, Bangkok Using Computational Fluid Dynamics Modeling, Amintra Tancharoen Jan 2021

Investigation Of Pm2.5 Dispersion In Din Daeng District, Bangkok Using Computational Fluid Dynamics Modeling, Amintra Tancharoen

Chulalongkorn University Theses and Dissertations (Chula ETD)

Din Daeng is a small and densely populated district of Bangkok with two major expressways in the area. PM2.5 concentrations in Din Daeng district often exceed both daily and annual standards of the National Ambient Air Quality Standards. Computational Fluid Dynamics (CFD) was applied to investigate the effects of the metropolitan characteristics and traffic volumes on the dispersion of PM2.5 in Din Daeng district. The turbulent flow was analyzed using the Standard k-ε model. There are two scenarios in this simulation study. One is to investigate the consequences of having the expressways and their resulting PM2.5 emissions. The other is …

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Electrochemical Synthesis Of Methoxide For Transesterification Of Palm Oil, Apiruedee Juntuma Jan 2021

Electrochemical Synthesis Of Methoxide For Transesterification Of Palm Oil, Apiruedee Juntuma

Chulalongkorn University Theses and Dissertations (Chula ETD)

Sodium methoxide (NaOCH3) is commonly used as an alkaline homogeneous catalyst in transesterification to produce fatty acid methyl ester (FAME) and glycerol as a by-product. However, this conventional process requires a few steps to remove the homogeneous catalyst from the products by neutralization and washing, creating waste salts to be treated with additional cost. This study investigates the electrochemical synthesis of methoxide. Amberlite IRA402 anion exchange resin is used to adsorb the generated methoxide and subsequently as a heterogeneous catalyst for transesterification to observe its catalytic activity. In contrast to many other similar works, this synthesis was performed with anion-exchange …

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Prediction Of Coke Formation Over A Catalyst Particle For Dry Reforming Of Methane, Chananun Rojanarungruengporn Jan 2021

Prediction Of Coke Formation Over A Catalyst Particle For Dry Reforming Of Methane, Chananun Rojanarungruengporn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, global warming is a significant environmental problem causing various impacts across the globe. Dry reforming of methane (DRM) is one of the reactions that can utilize CO2 effectively. However, the major problem of DRM process is the deactivation of catalysts caused by coke formation over the catalyst particle which mainly occurs from CH4 decomposition reaction. Coke formation leads to a decrease in catalytic performance by blocking the pores and active sites. In this study, the spatial catalyst deactivation caused by coke formation over a spherical alumina-supported nickel catalyst (Ni/Al2O3) particle in dry reforming of methane (DRM) was investigated using …

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Depolymerization Of Kraft Lignin To Phenolic Compounds By Electrochemical Advanced Oxidation In Microreactor, Chawakorn Rittirong Jan 2021

Depolymerization Of Kraft Lignin To Phenolic Compounds By Electrochemical Advanced Oxidation In Microreactor, Chawakorn Rittirong

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research focuses on the depolymerization of kraft lignin to phenolic compounds that are valuable and useful in various industries. Depolymerization is performed using an electrochemical advanced oxidation process with the hydroxyl radicals. In this process, microreactors are used. It consists of a graphite anode and a stainless steel cathode. The results of the variables studied were current density (3.7 and 5.55 A/m2), residence time (100-400 s), base pH (9), the base difference (sodium hydroxide and potassium hydroxide). The experiment found that the major product is octadecamide and the minor product propyl guaiacol is increased when the current increases. On …

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Effect Of Cob Loading Amount In Gc3n4 Nanosheet In Photocatalytic Hydrogen Generation, Chayathorn Prapaitrakool Jan 2021

Effect Of Cob Loading Amount In Gc3n4 Nanosheet In Photocatalytic Hydrogen Generation, Chayathorn Prapaitrakool

Chulalongkorn University Theses and Dissertations (Chula ETD)

Noble metals, such as Pt, Ru, and Ir, have been widely used as expensive catalyst promoters to enhance the photocatalytic hydrogen evolution reaction (HER). In contrast, other cheaper catalyst promoters that can also promote high HER performance have been developed, such as metal phosphides, and metal borides. Recently, nickel boride (NiB) loaded on graphitic carbon nitride nanosheet (gCNS) has exhibited promising HER performance under visible light. Thus, this research attempted to investigate HER performance of cobalt boride (CoB) as a cocatalyst on gCNS and compare to the HER performance of NiB. The amount of CoB loading was varied from 1-11 …

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Synthesis Of Molybdenum-Based Catalysts On Carbon Support For Partial Hydrogenation Reaction Of Biodiesel, Dolrudee Jaruwat Jan 2021

Synthesis Of Molybdenum-Based Catalysts On Carbon Support For Partial Hydrogenation Reaction Of Biodiesel, Dolrudee Jaruwat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, biodiesel is a renewable energy, which can decrease fossil fuel. It helped reducing air pollution. Partial Hydrogenation is one process which improves the biodiesel quality. In this research, activated carbon was produced from cattail leave via hydrothermal carbonization and chemical activation. The activated carbon was treated with 4 M of potassium hydroxide at 900oC, which exhibits 1323.38 m2g-1 of SBET. Several type of catalysts (Mo, Ni, Ci, Fe, MoNi, MoCu, and MoFe) were studied in this research, which were prepared using a rotary evaporation technique. The experiments reveal that MoNi/C catalyst indicate the highest dispersion of metal particle. The …

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Effects Of Types Of Arylamine Based Benzoxazine Binders In Brake Pads On Thermal Degradation Kinetics, Juntasak Wangrangsimakul Jan 2021

Effects Of Types Of Arylamine Based Benzoxazine Binders In Brake Pads On Thermal Degradation Kinetics, Juntasak Wangrangsimakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aimed to investigate the effect of the alkyl-substituted aromatic amines of polybenzoxazine resins used as binders in the non-asbestos friction composite materials on their thermal degradation and stability. The effects of BA-35x polybenzoxazine resin used as a binder of the brake pad were investigated using thermogravimetric analysis (TGA) under nitrogen atmosphere at various heating rates of 1, 5, 10, 20 and 25 °C/min by applying the model of Advanced iso-conversional method. For the friction composite system using BA-35x as binder, the derivative thermogram exhibited six stages of thermal decomposition reaction. The activation energies of six stages were determined …

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Degradation Of Benzyl Phenyl Ether As Lignin Model Compound By Electrochemical Advanced Oxidation Process In A Microreactor, Kevin Lee Jan 2021

Degradation Of Benzyl Phenyl Ether As Lignin Model Compound By Electrochemical Advanced Oxidation Process In A Microreactor, Kevin Lee

Chulalongkorn University Theses and Dissertations (Chula ETD)

As the world is shifting away from its reliance on fossil fuel, lignocellulosic biomass, which is low cost, renewable and abundant with cellulose, hemicellulose and lignin being its major components. Lignin has high potential to be converted into other value-added chemicals as an alternative to fossil fuel. This research focusses on systematic investigation of degradation of lignin by electrochemical advanced oxidation process (EAOP) in a microreactor, using benzyl phenyl ether (BPE) as a model compound for lignin. The first part of the research investigates the dissolution of BPE in various volume fraction of co-solvent system. The co-solvent system is used …

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Synthesis Of Zinc Sulfide Nanoparticles Using Microemulsion Generated By Hydrodynamic Cavitation Method, Nachapa Choojan Jan 2021

Synthesis Of Zinc Sulfide Nanoparticles Using Microemulsion Generated By Hydrodynamic Cavitation Method, Nachapa Choojan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Zinc Sulfite (ZnS) nanoparticles have attracted attention of researchers as a promising material for semiconductor fabrication. Their optical properties are strongly size-dependent and related to production methodology. A microemulsion technique is simple and requires less energy to produce ZnS nanoparticles. However, this technique usually results in ZnS with a wide size distribution. In this work, microemulsion technique and hydrodynamic cavitation have been effectively combined for synthesis of ZnS nanoparticles with controllable and uniform size distribution. The microemulsion system which consists of water, cyclohexane, hexanol and Triton X-100 surfactant has been prepared by incorporating hydrodynamic cavitation. Experimental results number of passages, …

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Controllable Formation Of Microparticles Via Microfluidic Technique, Narin Paiboon Jan 2021

Controllable Formation Of Microparticles Via Microfluidic Technique, Narin Paiboon

Chulalongkorn University Theses and Dissertations (Chula ETD)

Droplet microfluidics is an interesting tool in the encapsulation process due to its potentiality for microparticles and microcapsules fabrication with uniform size and narrow size distribution. The formation of water-in-oil (W/O) emulsion droplets in a microfluidic flow-focusing device for microparticles production were investigated under a wide selection of operating parameters together with liquid materials. Experimental results of 12 data sets from over 100 experiments in two different-sized channels were assessed. The stable narrowing jet and tip streaming regime noticeably created monodisperse droplet formation with high throughput. The droplet size to junction size has been found to correlate with the three …

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Development Of Rotating Tube Reactor For Biodiesel Production From Palm Oil, Narita Chanthon Jan 2021

Development Of Rotating Tube Reactor For Biodiesel Production From Palm Oil, Narita Chanthon

Chulalongkorn University Theses and Dissertations (Chula ETD)

Rotating tube reactor (RTR), one of process intensification technologies, could highly increase the mixing performance and generate sufficient heat for biodiesel production. This research explored the optimum condition, essential characteristics of hydrodynamic regime and residence time distribution inside the rotating tube reactor (RTR) to enhance the biodiesel production rate using alkali-catalyzed transesterification. The operating condition of this RTR was 6:1 methanol-to-oil molar ratio, total flowrate of 30 mL/min and rotational speed of 1,000 rpm at room temperature, giving the highest biodiesel yield of 97.5% with yield efficiency of 3.75 × 10-3 g/J and the quality of biodiesel achieving the ASTM …

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Cathodized Stainless Steel Mesh For Binder-Free Nife2o4/Nife Ldh Oxygen Evolution Reaction Electrode, Natthapon Sripallawit Jan 2021

Cathodized Stainless Steel Mesh For Binder-Free Nife2o4/Nife Ldh Oxygen Evolution Reaction Electrode, Natthapon Sripallawit

Chulalongkorn University Theses and Dissertations (Chula ETD)

Oxygen evolution reaction (OER) is an essential reaction commonly applied in various energy storage and conversion technologies. One of the common issues of OER lies in its low kinetic activity. Therefore, developing durable, low-cost, and high-performance OER catalysts is critical. Recently, many attempts have used stainless steel mesh (SSM) as the substrate for OER electrodes because SSM is abundant, cheap, and durable. Nickel/iron-based materials, i.e., NiFe2O4/NiFe layer double hydroxides (LDHs), are regarded as one of the most excellent OER catalysts in alkaline electrolytes, making them attractive low-cost materials for OER catalysts. However, the synthesis of NiFe2O4/NiFe LDHs directly on the …

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Manganese Dioxide Coated With Tin Oxide As Cathode Material For High-Performance Aqueous Zinc-Ion Battery., Nichakarn Meekaew Jan 2021

Manganese Dioxide Coated With Tin Oxide As Cathode Material For High-Performance Aqueous Zinc-Ion Battery., Nichakarn Meekaew

Chulalongkorn University Theses and Dissertations (Chula ETD)

Rechargeable aqueous zinc-ion batteries (ZIBs) have attracted increasing attention as an energy storage technology due to their high energy density, low cost, and environmental friendliness. However, the application of manganese dioxide as the cathode for aqueous Zn-ion batteries (ZIBs) is restricted by the solubility of manganese dioxide in aqueous electrolytes and the formation of byproducts during the charge/discharge process, causing severe capacity fading and limited cycle life. Surface modification is one of the interesting techniques to improve zinc-ion batteries electrochemical performance. Here, we report an ultrathin SnO2 film as an artificial solid electrolyte interphase (SEI) to modify the surface of …

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Norfloxacin Adsorption By Activated Carbon From Turmeric Waste, Nuttamon Vanichsetakul Jan 2021

Norfloxacin Adsorption By Activated Carbon From Turmeric Waste, Nuttamon Vanichsetakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

In recent years, extensive use of modern medicines and incompetency of conventional wastewater treatment systems have led to contamination of antibiotics in the environment especially in lower income countries. Antibiotics could interact with bacteria in the environment forming resistance to the medicine. Antibiotics also disrupt the balance of ecosystems affecting various lifeforms. Norfloxacin is a common antibiotic in Thailand with reported levels of contamination in Bang Pakong River. Adsorption process is a cheap and effective approach to remove antibiotics from wastewater effluent. Activated carbon is a common adsorbent in adsorption process due to its porous properties. Agricultural waste presents as …

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Electrochemical Tubular Fixed-Bed Reactor For Conversion Of Pressurized Co2 To Co, Pakawat Sengchim Jan 2021

Electrochemical Tubular Fixed-Bed Reactor For Conversion Of Pressurized Co2 To Co, Pakawat Sengchim

Chulalongkorn University Theses and Dissertations (Chula ETD)

Electrochemical CO2 reduction reaction (CO2RR) can be used for activating the stable CO2 molecule to the more active CO for downstream purposes. Usually, this process is carried out in CO2-saturated aqueous solutions. The low solubility of CO2 in water of 0.033 M at 1 bar of CO2 and room temperature hinders both kinetics and mass transfer. In this study, a novel electrochemical tubular reactor for electrochemical CO2RR is proposed. The design was made with ease of scale-up in mind. A reactor can contain multiple electrochemical cells connected in series. Each cell consists of 3 main parts: porous anode, porous solid …

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Tetracycline Sorption By Magnetic Biochar Derived From Watermelon Rind: Performance And Influential Factors, Phisit Thairattananon Jan 2021

Tetracycline Sorption By Magnetic Biochar Derived From Watermelon Rind: Performance And Influential Factors, Phisit Thairattananon

Chulalongkorn University Theses and Dissertations (Chula ETD)

Tetracycline (TC) antibiotic is one of emerging contaminants in water reservoirs that causes undesirable effects on environment and human health. Magnetic biochar (MBC) is considered a promising sorbent in adsorption process for removal of contaminants with highly efficient and facile operation. In this work, MBC was synthesized by pyrolysis of watermelon rind impregnated with FeCl3 at different pyrolysis temperatures in a range of 600-900 °C prior to applying for TC adsorption. Characteristics of MBC were analyzed by scanning electron microscopy, elemental analyzer, N2 adsorption/desorption, Fourier-transform infrared spectroscopy, Raman spectroscopy, vibrating sample magnetometry, and X-ray diffractometry. The adsorption kinetics, isotherm, effect …

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Process Of Pretreatment And Hydrolysis Of Lignocellulose From Palm Empty Fruit Bunch For Xylose And Glucose Production, Pitchaya Teerakulkittipong Jan 2021

Process Of Pretreatment And Hydrolysis Of Lignocellulose From Palm Empty Fruit Bunch For Xylose And Glucose Production, Pitchaya Teerakulkittipong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Oil palm empty fruit bunch is an interesting lignocellulose feedstock for sugar production. However, lignin prohibits chemicals from accessing the hemicellulose and cellulose, which is the source of sugar. Therefore, the overall process requires pretreatment to remove lignin and hydrolysis to convert hemicellulose and cellulose to sugar. In this research, the aim is to design a process model of sugar production using different pretreatment chemicals, including alkaline (NaOH) and acid (H2SO4), and compare the other necessary following process. Moreover, capital investment is also estimated. According to the results, different pretreatment chemicals results in a different change of lignocellulose structure and …

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The Prediction Of Pm2.5 Dispersion In Bangkok (Pathumwan District)Using Cfd Modeling, Punyisa Chaisri Jan 2021

The Prediction Of Pm2.5 Dispersion In Bangkok (Pathumwan District)Using Cfd Modeling, Punyisa Chaisri

Chulalongkorn University Theses and Dissertations (Chula ETD)

City configuration, meteorological conditions and emission source are the important factors affecting the concentration and dispersion of pollutants within urban street canyon. The dispersion of PM2.5 in Pathumwan district, Bangkok which has a characteristics of street canyon was predicted using a Computational Fluid Dynamics (CFD) model. Flow and dispersion of PM2.5 were analyzed using standard k-ε turbulence model. The concentrations of PM2.5 were investigated under different conditions to demonstrate the effect of city configuration in study area, meteorological characteristics, and lockdown due to COVID-19 on PM2.5 concentration. The numerical model was validated with the measured data from the air quality …

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Effect Of Bismuth (Bi) Concentration On Bi/Sn Electrodes Prepared By Electrodeposition In Electrochemical Reduction Of Co2 To Toward Solid Carbon Products, Sarita Phupaichitkun Jan 2021

Effect Of Bismuth (Bi) Concentration On Bi/Sn Electrodes Prepared By Electrodeposition In Electrochemical Reduction Of Co2 To Toward Solid Carbon Products, Sarita Phupaichitkun

Chulalongkorn University Theses and Dissertations (Chula ETD)

Carbon dioxide (CO2) is the main greenhouse gas that contributes to climate change. The electrochemical carbon dioxide reduction (CO2RR) is an interesting and low-cost CO2 conversion technology using renewable electricity as an energy source. Herein, CO2RR to solid carbon products was studied on bismuth/tin (Bi/Sn) electrodes synthesized by electrodeposition method. Different Bi concentration (0.01 M,0.03 M, 0.05 M,0.07 M and 0.1 M) were used to prepare the electrodes by electrodeposition method. The SEM-EDX and EIS results which reveal that the Bi/Sn electrode prepared in 0.05 M Bi 3+ had the lowest charge transfer resistance and was indicated as a CO2RR …

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Preparation Of Nickel Phyllosilicate Catalysts By One-Step Modified Spherical Silica Synthesis In Carbon Dioxide Hydrogenation And Selective Hydrogenation Of Furfural To Furfuryl Alcohol, Sasithorn Kuhaudomlap Jan 2021

Preparation Of Nickel Phyllosilicate Catalysts By One-Step Modified Spherical Silica Synthesis In Carbon Dioxide Hydrogenation And Selective Hydrogenation Of Furfural To Furfuryl Alcohol, Sasithorn Kuhaudomlap

Chulalongkorn University Theses and Dissertations (Chula ETD)

Spherical silica derived nickel phyllosilicate catalysts were prepared via a one-step modified spherical silica synthesis under room temperature. For 10wt% Ni loading, the loading sequence of Ni and Si sources during spherical silica synthesis was found to affect the characteristics and catalytic properties in CO2 methanation. The stronger interaction between Ni and silica in the form of nickel phyllosilicate revealed the better catalytic performances than the impregnation method. The highest CO2 methanation activity and methane selectivity were obtained over the catalyst prepared by alternate loading between Ni and Si (Ni_Alt_Si) due to high electron density of nickel on the surface, …

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Liquid-Phase Selective Hydrogenation Of Furfural To Furfuryl Alcohol Over Pt- And Ptfe-Incorporated Mesoporous Carbon, Sureeporn Saknaphawuth Jan 2021

Liquid-Phase Selective Hydrogenation Of Furfural To Furfuryl Alcohol Over Pt- And Ptfe-Incorporated Mesoporous Carbon, Sureeporn Saknaphawuth

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aims to investigate the liquid-phase selective hydrogenation of furfural to furfuryl alcohol in a batch reactor at 50ºC, 20 bar H2 using water and methanol as the solvent. This study has been divided into two sections. The characteristics and catalytic properties of OMC-supported Pt catalysts (Pt/OMC-one-pot) prepared by one-step modified soft-template self-assembly method were compared with the Pt impregnated on OMC, activated carbon (AC), and non-uniform meso/macroporous carbon (MC) in the first section. Larger Pt particle size (~4 nm) was obtained on the Pt/OMC-one-pot comparing to all the impregnated ones, in which the Pt particle sizes were in …

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Electrochemical Reduction Of Carbon Dioxide On Copper-Based Cathodes In Electrochemical Tubular Fixed Bed Reactor, Kanjira Janya Jan 2021

Electrochemical Reduction Of Carbon Dioxide On Copper-Based Cathodes In Electrochemical Tubular Fixed Bed Reactor, Kanjira Janya

Chulalongkorn University Theses and Dissertations (Chula ETD)

CO2 electrochemical reduction reaction (CO2ERR) has been investigated with an aim to eventually become a means to decrease the concentration of CO2 in the atmosphere to hydrocarbons by proton and electron transfer. The product distribution strongly depends on cathode materials. Copper is a unique metal in its ability to catalyze the electrochemical reduction of CO2 to various hydrocarbons including ethylene, but the main problems are the poor solubility CO2 in aqueous solutions. In this study, the performance of CO2ERR is improved by increasing pressure. The ionomer copper foam is used as a cathode in the electrochemical tubular fixed bed reactor …

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Synthesis Of Magnetic Carbon Nanotubes Via Co-Pyrolysis Of Eucalyptus Oil With Bimetallic Ni-Fe Catalyst, Tanapat Rodruangnon Jan 2021

Synthesis Of Magnetic Carbon Nanotubes Via Co-Pyrolysis Of Eucalyptus Oil With Bimetallic Ni-Fe Catalyst, Tanapat Rodruangnon

Chulalongkorn University Theses and Dissertations (Chula ETD)

Magnetic carbon nanotubes (MCNTs) have been specified one of the most promising nanomaterials. They have been applied in many applications due to special electrical, mechanical, and chemical properties. Additionally, magnetic carbon nanotubes could be easily handled by using magnetic field. There are many production developments for increasing in yield and quality of MCNTs. In this thesis, bimetallic Ni-Fe catalyst was investigated for its possibility to improve MCNT synthesis. Nickel content was impregnated on the surface of ferrocene which is the source of Fe content. The catalyst is called ‘ferrocene impregnated with nickel nitrate’. Eucalyptus oil, which mainly contains eucalyptol, was …

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Development Of Nonaqueous Zinc-Ion Battery Based On Manganese Dioxide Cathode, Wathanyu Kao-Ian Jan 2021

Development Of Nonaqueous Zinc-Ion Battery Based On Manganese Dioxide Cathode, Wathanyu Kao-Ian

Chulalongkorn University Theses and Dissertations (Chula ETD)

Zinc-ion batteries (ZIBs) are considered promising candidates for large-scale applications replacing lithium-ion batteries (LIBs). ZIBs having aqueous electrolytes have many advantages being low-cost, safe, and eco-friendly. However, a number of shortcomings hinder their application e.g. self-corrosion, hydrogen evolution, and Zn dendrite-formation. To mitigate these issues, nonaqueous electrolytes i.e. organic-based and room temperature ionic liquid electrolytes have been proposed. Nevertheless, nonaqueous electrolytes are yet to be elucidated. Herein, this work identifies nonaqueous electrolytes' state of the art and develops a new nonaqueous electrolyte system for ZIBs based on a manganese dioxide (MnO2) cathode. For this purpose, Zn chemistry in nonaqueous electrolytes …

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Structural Optimization Under Limited Natural Frequency Constraints Using Comprehensive Learning Phasor Particle Swarm Optimization, Ei Cho Pyone Jan 2021

Structural Optimization Under Limited Natural Frequency Constraints Using Comprehensive Learning Phasor Particle Swarm Optimization, Ei Cho Pyone

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this research, a phasor particle swarm optimization with comprehensive learning strategy (CLPPSO) is proposed for the optimal design of dome-like truss structures under the limited frequency-constraints. The proposed scheme is a new variant of PSO techniques with the direct combination of both the phasor theory in mathematics and comprehensive learning strategy to the particle swarm optimization. In order to model particle control parameters, a phase angle incorporating the periodic sine and cosine functions is essentially applied through which only the previous best positions of all particles are used to update the exemplar particle’s velocity during the optimization process. This …

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Simultaneous Size And Shape Structural Optimization Using Enhanced Comprehensive Learning Particle Swarm Optimization, Soviphou Muong Jan 2021

Simultaneous Size And Shape Structural Optimization Using Enhanced Comprehensive Learning Particle Swarm Optimization, Soviphou Muong

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study proposes a simultaneous size and shape structural optimization on truss structures using a metaheuristic algorithm, namely Enhanced Comprehensive Learning Particle Swarm Optimization (ECLPSO) which is based on the CLPSO algorithm. CLPSO itself was originated from a famous Particle Swarm Optimization (PSO) that was invented based on behaviour or movement of a bird flock. CLPSO is an improved PSO algorithm which has good exploration ability but is poor in exploitation. Thus, ECLPSO introduces of two enhancements, including perturbation-based exploitation and adaptive learning probabilities, to improve the exploitation ability and to adjust the learning probabilities of each particle, respectively. The …

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A System For Generating Fire Extinguisher Plan And Supporting Fire Evacuation Route In Construction Project, Thiha Nyimin Jan 2021

A System For Generating Fire Extinguisher Plan And Supporting Fire Evacuation Route In Construction Project, Thiha Nyimin

Chulalongkorn University Theses and Dissertations (Chula ETD)

Fires in under-construction threaten worker safety and have a lot of negative impacts on many aspects of construction that were reported the past few years. Due to the dynamic nature of construction, the fire safety plan in construction needed to be reviewed and updated according to construction progress. The conventional approach or manual process to develop the fire safety plan for a construction project can be a time-consuming and enormous labor-intensive task. Furthermore, some of the emergency signs are unclear due to the nature of construction and some are not showing the correct evacuation route because of the structural design …

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