Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 30 of 101
Full-Text Articles in Engineering
Chromatographic Separation Of Free Lutein And Fatty Acids In De-Esterified Marigold Oleoresin And Its Mathematical Modelling, Weerawat Clowutimon
Chromatographic Separation Of Free Lutein And Fatty Acids In De-Esterified Marigold Oleoresin And Its Mathematical Modelling, Weerawat Clowutimon
Chulalongkorn University Theses and Dissertations (Chula ETD)
The petal of marigold flowers has been reported to be the richest source of a xanthophyll, namely lutein which exhibits strong antioxidant and anticancer properties. Although large amount of lutein can be obtained, the compound in the flowers exists as esterified lutein, which is not readily bio-available. As a result, a number of separation and purification steps are required after solvent extraction of marigold flowers. One of the key steps is de-esterification of lutein fatty acid esters in the extract, or namely marigold oleoresin, by the reaction of the oleoresin with alkali solution, e.g., KOH, to obtain free lutein. The …
Co2 Methanation Over Nial2o4 Spinel - Based Catalysts, Chanya Thamma
Co2 Methanation Over Nial2o4 Spinel - Based Catalysts, Chanya Thamma
Chulalongkorn University Theses and Dissertations (Chula ETD)
In the present work, a series of NiO/NiAl2O4 catalysts were prepared by co-precipitation method with molar ratio of Ni/Al equal 1/2 at different precipitation temperatures (30 and 80oC) and calcination temperatures (500, 700, 900, and 1200oC). The catalyst properties were characterized by using N2 physisorption, X-ray diffraction, H2 TPR, SEM, and TEM. The NiO/NiAl2O4 precipitated at 80oC and calcined at 900oC showed the best activity in CO2 methanation at 350oC with conversion 92% and 100% methane selectivity without CO formation. The optimal of NiO and NiAl2O4 composition at 24.7% and 75.3%wt could provide a stabilizing effect preventing the metal …
Analysis Of Biomarkers In Crude Oils, Processed Oils, And Spilled Oils, Pornpetch Hattakijvilai
Analysis Of Biomarkers In Crude Oils, Processed Oils, And Spilled Oils, Pornpetch Hattakijvilai
Chulalongkorn University Theses and Dissertations (Chula ETD)
Oil spills in marine are commonly come from crude oils, fuel oils and lubricating oils by accidental leakages or purposeful discharges to the surroundings. As crude oil and fuel oil which refined from the heavy fraction of crude oil have similar physical properties especially if they were weathering, it is difficult to differentiate that the spill has the origin from crude oil or fuel oil. In this study, five crude oils, two fuel oils, one fresh and one used lube oil that are typically used in Thailand were investigated. All crude oils, fuel oils, and used lube oil were weathered …
การขจัดกำมะถันแบบดูดซับจากน้ำมันดีเซลบนวายซีโอไลต์แลกเปลี่ยนไอออน, อานันท์ ศิลาจันทร์
การขจัดกำมะถันแบบดูดซับจากน้ำมันดีเซลบนวายซีโอไลต์แลกเปลี่ยนไอออน, อานันท์ ศิลาจันทร์
Chulalongkorn University Theses and Dissertations (Chula ETD)
ปัจจุบัน 95 เปอร์เซ็นต์ ของการขนส่งขึ้นกับเชื้อเพลิงซอสซิลโดยเฉพาะอย่างยิ่งน้ำมันดีเซล น้ำมันดีเซลไม่ได้มีส่วนประกอบแค่พาราฟินและโอเลฟินเพียงเท่านั้น ยังมีสารประกอบกำมะถันซึ่งเป็นสาเหตุหนึ่งที่ก่อให้เกิดภาวะฝนกรด การกัดกร่อนอุปกรณ์ที่เกี่ยวข้อง ความเป็นพิษต่อตัวเร่งปฏิกิริยาและก่อให้เกิดปัญหาต่อระบบทางเดินหายใจ เพื่อแก้ไขปัญหาดังกล่าวกระบวนการขจัดกำมะถันโดยการดูดซับถูกนำมาใช้กับน้ำมันดีเซลเพื่อลดปริมาณของกำมะถันในน้ำมันดีเซล อย่างไรก็ตามน้ำมันดีเซลยังคงมีส่วนประกอบอื่นๆ เช่น สารประกอบแอโรแมติกและไนโตรเจนอยู่ด้วย ดังนั้น งานวิจัยนี้เป็นการศึกษาผลของสารประกอบแอโรแมติกและไนโตรเจนต่อการขจัดกำมะถันในรูปของไดเบนโซไทโอฟีนและ 4,6-ไดเมทิลไดเบนโซไทโอฟีน ในน้ำมันจำลองที่มีนอร์มัลออกเทนเป็นตัวทำละลายโดยการดูดซับโดยใช้คอลัมน์แบบเบดนิ่งที่บรรจุตัวดูดซับ ตัวดูดซับที่ใช้ในการศึกษามี 6 ชนิด ได้แก่ ซีโอไลต์ Na-Y, Ni-Y, La-Y, Ce-Y, Ni-La-Y และ Ni-Ce-Y ผลการทดลองแสดงในรูปของความจุเบรคทรูและความจุทั้งหมดในการดูดซับสารประกอบกำมะถันซึ่งสามารถคำนวณได้จากเส้นโค้งเบรคทรู พบว่าความจุในการดูดซับไดเบนโซไทโอฟีนและ 4,6-ไดเมทิลไดเบนโซไทโอฟีนในน้ำมันจำลองที่มีสารประกอบแอโรแมติกและไนโตรเจนโดยใช้ตัวดูดซับชนิดต่างๆ ลดลงตามลำดับดังนี้ Na-Y ~ Ni-Ce-Y ~ Ni-Y > La-Y > Ce-Y > Ni-La-Y สารประกอบแอโรแมติกและไนโตรเจนส่งผลให้ความจุการดูดซับสารประกอบกำมะถันลดลงโดยสารประกอบไนโตรเจนส่งผลต่อการลดลงของการดูดซับสารประกอบกำมะถันมากกว่าสารประกอบแอโรแมติก นอกจากนี้ศึกษาการคืนสภาพตัวดูดซับซีโอไลต์ Na-Y ด้วยการสกัดด้วยตัวทำละลายโดยตัวแปรที่ศึกษา ได้แก่ ชนิดตัวทำละลาย อุณหภูมิและอัตราการไหลของตัวทำละลาย พบว่า การคายสารประกอบที่ดูดซับบ่งบอกประสิทธิภาพของการคืนสภาพจะขึ้นกับสภาพขั้วที่เหมือนกันของตัวทำละลายและสารที่ถูกดูดซับ ตัวทำละลายที่มีอุณหภูมิสูงมักจะช่วยให้สกัดสารถูกดูดซับได้ดีขึ้น และการใช้อัตราการไหลต่ำช่วยให้ตัวทำละลายมีเวลามากในการสกัดสารถูกดูดซับ
Improving Fouling Resistance Of Thin Film Composite Membranes By Addition Of Tio2, Palach Kedchaikulrat
Improving Fouling Resistance Of Thin Film Composite Membranes By Addition Of Tio2, Palach Kedchaikulrat
Chulalongkorn University Theses and Dissertations (Chula ETD)
Polyamide thin film nanocomposite (TFN) membranes with the addition of titanium dioxide (TiO2) nanoparticles (NPs) were synthesized via an interfacial polymerization (IP) on polyacrylonitrile (PAN) support. Also, the TFC membranes with addition of individual components in the TiO2 colloidal solution, ethanol, TiO2 NPs and nitric acid, were individually studied. The performances of the fabricated membranes were evaluated in terms of NaCl salt rejection, water permeability and anti-fouling capability. Membranes characterizations were conducted to observe various characteristics of membranes such as morphology, surface roughness, surface chemistry and hydrophilicity. The results revealed that the addition of TiO2 colloidal solution in aqueous amine …
Conversion Of Glucose To Levulinic Acid By Fe/Carbon Nanoparticle Catalyst Synthesized From Lubricant Oil And Ferrocene, Jirarat Kaewngam
Conversion Of Glucose To Levulinic Acid By Fe/Carbon Nanoparticle Catalyst Synthesized From Lubricant Oil And Ferrocene, Jirarat Kaewngam
Chulalongkorn University Theses and Dissertations (Chula ETD)
Currently, production of levulinic acid which is one of promising chemical substances derived from biomass has been intensively investigated. Different catalyst types have been employed to produce levulinic acid from glucose including zeolite, metal phosphate and alumina. However, carbon based catalysts with high thermal stability, ease of surface functionalization and acid-base resistance were not widely studied. In this thesis, carbon nanoparticles synthesized from lubricant oil and ferrocene via co-pyrolysis was fully studied for glucose conversion to levulinic acid. The effect of carbon nanoparticles acid treatment was mainly investigated in terms of glucose conversion and levulinic acid yield. Pristine magnetic carbon …
Effects Of Bead Size And Concentration Of Unstable Asphaltenes Obtained From Different Centrifugation Techniques On Asphaltene Deposition In Packed Bed Apparatus, Kimchhay Lao
Chulalongkorn University Theses and Dissertations (Chula ETD)
Asphaltenes are the heaviest and most polar fraction of petroleum crude oil. They are the collection of components that can be soluble in aromatics solvents such as benzene or toluene, but insoluble in normal alkanes, n-pentane, n-hexane, or n- heptane. Asphaltenes are a class of molecules consisted of grouped aromatic rings with alkane chains. Changing pressure, temperature, composition, and shear rate during transportation can cause precipitation and deposition, resulting in reduced reservoir productivity due to restricted flow lines, fouling and blockages in the pore spaces of the reservoir. The goal of this investigation is to assess validity of two aspects …
Adsorptive Bubble Separation For Oil Removal, Paweena Kanokkarn
Adsorptive Bubble Separation For Oil Removal, Paweena Kanokkarn
Chulalongkorn University Theses and Dissertations (Chula ETD)
This present work emphasized on the current knowledge regarding (i) feasibility of multi-stage forth flotation operation for oil removal, and (ii) comprehension of dynamic surface tensions of surfactant solutions in relation to foam characteristics. A multi-stage forth flotation efficiency depends on the enhancement of interfacial adsorption and the number of bubble caps and tray. The operational parameters including foam height, air flow rate and feed flow rate were controlled to obtain the optimum process performance. Under the optimum conditions—a number of trays of 4, a foam height of 60 cm, an air flow rate of 40 L/min, a feed flow …
Study On Energy Storage Ability Of Zno/Tio2 For Photocatalytic Degradation Of Isopropanol, Ratchawan Jarumanee
Study On Energy Storage Ability Of Zno/Tio2 For Photocatalytic Degradation Of Isopropanol, Ratchawan Jarumanee
Chulalongkorn University Theses and Dissertations (Chula ETD)
The photocatalytic degradation of isopropanol under UV irradiation was studied by using p-n junction of ZnO/TiO2 photocatalysts prepared by sol-gel technique. Their energy storage ability was tested with their photocatalytic activity where there was no UV illumination. That was investigated by illumination the system with UV light for 2 h and off for 2 h until 8 h. The composition and surface structure of the catalyst were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), surface area analysis, and particle size analysis. The change in the isopropanol concentration was observed by using gas chromatography. The result showed that the …
Microemulsion Formation Of Vegetable Oils Using Mixed Extended Surfactant For Cleaning Applications, Siriluk Jariyawattanarat
Microemulsion Formation Of Vegetable Oils Using Mixed Extended Surfactant For Cleaning Applications, Siriluk Jariyawattanarat
Chulalongkorn University Theses and Dissertations (Chula ETD)
Some vegetable oils and animal fats can form semi-solid crystalline. The formation of semi-solid fats or waxy soils results in weak interactions between the oil and surfactant during the cleaning process. In this study, the anionic extended surfac-tant (C14-15, 8PO-SO4) systems were employed to form a middle phase microemul-sion with various vegetable oils (coconut, palm and soybean oil). The addition of nonionic extended surfactant (C16-18, 2PO-4EO-OH) in the mixed surfactant systems was also evaluated to observe the solubility enhancement of oil and water phase. The IFT value of formulated surfactant systems was measured to determine the optimum salinity. The Hydrophilic-Lipophilic …
Use Of Anionic Surfactant In Regeneration Of Spent Activated Carbon, Buch Kallapadee
Use Of Anionic Surfactant In Regeneration Of Spent Activated Carbon, Buch Kallapadee
Chulalongkorn University Theses and Dissertations (Chula ETD)
Surfactant-enhanced carbon regeneration (SECR) is a regeneration process that utilizes surfactant solution to dissolve adsorbed organic from spent activated carbon. Sodium dodecyl sulfate (SDS) and methyl ester sulfonate (MES) are anionic surfactants that are used in this investigation. The study is done in 3 steps: sample characterization, regeneration and water flushing step. The proximate analysis of spent activate carbon contains 27.5% moisture, 27.2% volatile matter content, 10% total ash content. The spent activated carbon also contains 18.4% benzene. In regeneration step, the benzene removal by SDS and MES solution were compared. The effect of concentration, solution flow rate and temperature …
Conversion Of Palm Fatty Acid Distillate To Biojet Fuel Over Ni/Hy-Pditioz Core-Shell Catalyst, Chanakran Homla-Or
Conversion Of Palm Fatty Acid Distillate To Biojet Fuel Over Ni/Hy-Pditioz Core-Shell Catalyst, Chanakran Homla-Or
Chulalongkorn University Theses and Dissertations (Chula ETD)
Generally, jet fuel is obtained from the refining of petroleum feedstock in order to powering the aircrafts, hence the world is more confronting a problem with increasing air pollution emission. Therefore, biojet fuel is introduced as an alternative way to solve the problem. Biojet fuel can be derived from bio-based feedstock such as palm fatty acid distillate or PFAD. Which is converted via the deoxygenation reaction in order to remove oxygenated compounds, carboxylic and carbonyl groups in the fatty acid molecules then followed by hydrocracking and hydroisomerization reaction. The heterogeneous catalyst is used to convert PFAD into saturated paraffins in …
Electrical Property-Investigation Of Porous Clay Heterostructures Derived From Naturally-Occurring Clay Minerals For Smart Packaging, Kornkamol Srithammaraj
Electrical Property-Investigation Of Porous Clay Heterostructures Derived From Naturally-Occurring Clay Minerals For Smart Packaging, Kornkamol Srithammaraj
Chulalongkorn University Theses and Dissertations (Chula ETD)
Porous Clay Heterostructure (PCH) is an interesting material to use as entrapping system such as ethylene scavenger, respected to its high surface area with uniform and specific pore size. PCHs have been prepared by the surfactant-directed assembly of mesostructured silica within the two-dimensional galleries of clays. Then, the PCH was synthesized within the galleries of Na-bentonite clay by the polymerization of tetraethoxysilane (TEOS) in the presence of surfactant micelles. In addition, mesoporous clay with organic-inorganic hybrid (HPCH) is modified via co-condensation reaction of TEOS with candidate conductive functional groups (thiol group) and metal loading (silver), designated as MPPCH and Ag-PCH, …
Study The Best Support For Hydrolysis Of Tiger Grass, Kurizara Sayamnikorn
Study The Best Support For Hydrolysis Of Tiger Grass, Kurizara Sayamnikorn
Chulalongkorn University Theses and Dissertations (Chula ETD)
Bioethanol, one of the outstanding biofuels, is not only a renewable bio-based resource, but also interesting to research for improving better properties of the enzyme needed in the hydrolysis process. The purpose of this work is to study how to reuse the enzyme used in the hydrolysis step for bioethanol production by immobilizing Trichoderma reesei (T.reesei) on various silica supports, namely, SBA-15, TUD-1, and MCM-48. The amount of the adsorbed enzymes was determined by UV-visible spectrophotometry. Among those studied supports, SBA-15 showed 100% enzymatic adsorption on the support owing to its larger pore diameter of 6.14 nm, which is large …
การออกแบบไซโคลนโดยจำลองกระบวนการและการพิมพ์สามมิติ, จิรวัฒน์ จึงเจริญสุขยิ่ง
การออกแบบไซโคลนโดยจำลองกระบวนการและการพิมพ์สามมิติ, จิรวัฒน์ จึงเจริญสุขยิ่ง
Chulalongkorn University Theses and Dissertations (Chula ETD)
การเผาไหม้เชื้อเพลิงซากดึกดำบรรพ์ และชีวมวล ภายใต้กระบวนการทางความร้อนในการผลิตไฟฟ้าของอุตสาหกรรมต่างๆ มักพบสารประกอบอนินทรีย์ในเถ้า ซึ่งเป็นมลพิษทางอากาศ ปะปนออกมากับแก๊สผลิตภัณฑ์หลังการเผาไหม้ นักวิจัยจึงพยายามจะหาวิธีแยกเถ้า หรือ อนุภาคของแข็ง เหล่านี้ออกจากแก๊สผลิตภัณฑ์ อุปกรณ์ที่ใช้กันอย่างแพร่หลายคือ ไซโคลน เนื่องจากไซโคลนสามารถสร้างได้ง่าย ค่าใช้จ่ายในการบำรุงรักษาต่ำ โดยใช้แรงเหวี่ยงหนีศูนย์กลางและแรงโน้มถ่วงในการแยกอนุภาคของแข็งออกจากแก๊ส ปัจจุบันมีการพัฒนาไซโคลนให้มีรูปร่างต่างๆ แต่ยังขาดงานวิจัยที่ศึกษาความสัมพันธ์ระหว่างรูปร่างไซโคลนกับประสิทธิภาพการแยกทั้งในเชิงคำนวณและเชิงทดลอง โดยงานวิจัยนี้จะแบ่งการศึกษาออกเป็น 3 ส่วน คือ การหาแบบการจำลองและภาวะที่เหมาะสมสำหรับการจำลองพลศาสตร์ของไหลเชิงคำนวณของไซโคลนในระบบสามมิติจากการทดลองของ Azadi และคณะ เพื่อนำมาศึกษาผลของความดันลด และประสิทธิภาพในการแยกของไซโคลนรูปร่างต่างๆ ที่ปรับเปลี่ยนจากไซโคลนสแตมาน และสร้างไซโคลนสแตมานต้นแบบด้วยเทคโนโลยีการพิมพ์สามมิติซึ่งมีความสามารถในการปรับแต่งรูปร่างสูง พร้อมทั้งเปรียบเทียบผลจากการทดลองไซโคลนต้นแบบกับผลจากการจำลองพลศาสตร์ของไหลเชิงคำนวณ ผลที่ได้พบว่า แบบจำลองที่เหมาะสมต่อการใช้ในการศึกษาพฤติกรรมการไหลของไซโคลนในระบบสามมิติ คือ RNG k-epsilon model ที่มีสัดส่วนโดยปริมาตรของของแข็งเท่ากับ 6×105 และมีความเร็วทางเข้าเท่ากับ 15 เมตรต่อวินาที โดยได้นำมาศึกษาผลของไซโคลนในรูปร่างต่างๆ ดังนี้ ไซโคลนสแตมาน ไซโคลนที่มุมของทางเข้าเพิ่ม 15 องศา ไซโคลนที่มุมของทางเข้าเพิ่ม 30 องศา ไซโคลนที่มุมของทางเข้าเพิ่ม 45 องศา ไซโคลนที่มุมของทางเข้าลดลง 15 องศา ไซโคลนที่มุมของทางเข้าลดลง 30 องศา ไซโคลนที่มุมของทางเข้าลดลง 45 องศา ไซโคลนที่เพิ่มขนาดเส้นผ่านศูนย์กลางทางออกแก๊ส 10% และ ไซโคลนที่ลดขนาดเส้นผ่านศูนย์กลางทางออกแก๊ส 10% ซึ่งมีไซโคลนเพียงรูปแบบเดียวที่ให้ผลของประสิทธิภาพในการแยกสูงกว่าไซโคลนสแตมาน คือ ไซโคลนที่ลดขนาดเส้นผ่านศูนย์กลางทางออกแก๊ส 10% โดยให้ประสิทธิภาพสูงกว่าประมาณ 1.4%
Catalytic Ethanol Dehydration To Diethyl Ether Over Palladium-Modified Phosphorus Gamma Alumina Catalysts, Chakkrit Khaochartchai
Catalytic Ethanol Dehydration To Diethyl Ether Over Palladium-Modified Phosphorus Gamma Alumina Catalysts, Chakkrit Khaochartchai
Chulalongkorn University Theses and Dissertations (Chula ETD)
The gamma alumina (γ-Al2O3) catalyst was modified with phosphorous (P) by acid activation technique and palladium (Pd) by the incipient wetness impregnation technique. The obtained catalysts were characterized with various techniques including X-ray diffraction (XRD), inductively coupled plasma (ICP), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX), N2 physisorption, ammonia temperature-programmed desorption (NH3-TPD), and thermogravimetric analysis (TGA). In addition, these modified catalysts were tested in ethanol dehydration reaction in a fixed-bed microreactor to determine ethanol conversion and product yield at the atmospheric pressure with temperatures ranging from 200-400oC. From the results, the phosphorous modification diminished the amount of …
Effects Of Carbon Fiber And Glass Fiber On Shape Memory Polymers Based On Benzoxazine-Epoxy Binary Systems, Jutamart Plylaharn
Effects Of Carbon Fiber And Glass Fiber On Shape Memory Polymers Based On Benzoxazine-Epoxy Binary Systems, Jutamart Plylaharn
Chulalongkorn University Theses and Dissertations (Chula ETD)
Recovery stress is an important parameter of shape memory polymers. Generally, recovery stress in SMPs can be enhanced by using fiber reinforced composites with suitable reinforcing agents such as carbon fiber or glass fiber. We aim to study effects of carbon fiber and glass fiber on thermal, mechanical, and shape memory properties of benzoxazine-epoxy SMPs, particularly on recovery stress enhancement. The compositions of carbon fiber and glass fiber reinforced benzoxazine-epoxy SMPs were in a range of 30 to 50vol%. The carbon fiber and glass fiber reinforced benzoxazine-epoxy shape memory polymer was compression-molded at 170oC under a pressure of 10 MPa …
Photocatalytic Degradation Of Methylene Blue Over Polydopamine-Ag/Tio2, Kamonthip Tammarakwattana
Photocatalytic Degradation Of Methylene Blue Over Polydopamine-Ag/Tio2, Kamonthip Tammarakwattana
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research investigated the effect of silver and polydopamine (PDA) doping on TiO2 catalysts for the photocatalytic degradation of methylene blue in aqueous phase. Titanium dioxide was synthesized via a sol-gel method and was calcined at 400 °C for two hours. Silver was loaded onto TiO2 by an incipient wetness impregnation method. The amount of Ag was varied from 0.5%wt to 3%wt. Then polydopamine-Ag/TiO2 catalyst was prepared by an impregnation method, using dopamine as a precursor. The amounts of polydopamine were 5%wt and 10%wt. All catalysts were characterized by N2 physisorption, ICP-OES, XRD, FTIR, CO chemisorption, Photoluminescence, and UV-Visible spectrophotometry. …
Effects Of Fillers On The Properties Of Polypropylene For Fused Deposition Modeling-Based 3d Printing Technique, Chomphoonut Buaprommee
Effects Of Fillers On The Properties Of Polypropylene For Fused Deposition Modeling-Based 3d Printing Technique, Chomphoonut Buaprommee
Chulalongkorn University Theses and Dissertations (Chula ETD)
The objective of this research was to study the influence of filler contents and filler types on the tensile properties and shrinkage behavior of polypropylene composites to develop the properties of polypropylene (PP) to be a raw material for fused deposition modeling (FDM) technique. PP was compounded with three fillers, i.e., talc and milled glass fiber with aspect ratio 5.4 and 15.4, at various contents of 10, 20 and 30 wt%. The test specimens were fabricated by FDM and injection molding techniques for tensile and shrinkage tests. The findings showed that the increase of filler contents into PP matrix tended …
Performance Comparison Of Different Membrane Micro-Channel Reactors For Methanol Production From Biogas And Hydrogen, Khunnawat Ountaksinkul
Performance Comparison Of Different Membrane Micro-Channel Reactors For Methanol Production From Biogas And Hydrogen, Khunnawat Ountaksinkul
Chulalongkorn University Theses and Dissertations (Chula ETD)
In order to integrate simultaneous methanol production with biogas upgrading in a single unit, the computational fluid dynamics (CFD) models of a triple pipe tubular membrane reactor (TMR) and a planar membrane micro-structured reactor (MMR) were established via COMSOL Multiphysics 5.3a and compared their effect on reactor performance under predetermined condition. For the conceptual design of these reactors, the channel inside the reactors can be divided into three parts; biogas channel (BC), reaction channel (RC) and sweep gas channel (SC). The CO2 in biogas entering into BC is separated through CO2 selective membrane to produce methanol inside RC. Afterwards, water …
Computational Fluid Dynamic Study Of Sorption Enhanced Steam Reforming Of Methane/Ethanol In Circulating Fluidized Bed System, Kiattikhoon Phuakpunk
Computational Fluid Dynamic Study Of Sorption Enhanced Steam Reforming Of Methane/Ethanol In Circulating Fluidized Bed System, Kiattikhoon Phuakpunk
Chulalongkorn University Theses and Dissertations (Chula ETD)
Two-dimensional fluid dynamic models were used to optimize and design a proper pilot-scale system for sorption enhanced steam methane reforming (SESMR) and sorption enhanced steam reforming of ethanol (SESRE) in a circulating fluidized bed reactor (CFBR) using Ni-based catalyst and dolomite as sorbent. The CFBR system was separately designed as 3 parts: including a SESMR riser, a SESRE and a regenerator. The SESMR riser could get H2 purity reached equilibrium of 98.58% in dry basis with the highest H2 flux of 0.301 kg/m2s when operating with steam to carbon ratio of 4 mol/mol, gas velocity of 6 m/s, inlet temperature …
Nanocomposite Membranes Incorporated With Graphene Oxide For Co2/Ch4 Separation, Nadia Norahim
Nanocomposite Membranes Incorporated With Graphene Oxide For Co2/Ch4 Separation, Nadia Norahim
Chulalongkorn University Theses and Dissertations (Chula ETD)
Biogas is an alternative energy produced by anaerobic digestion of organic matter. Generally, raw biogas consists of methane (CH4), carbon dioxide (CO2), few amount of hydrogen sulfide (H2S) and traces of water vapor. Nowadays, upgrading raw biogas is required in order to achieve higher calorific value and meet fuel standard by removal of CO2. In this study, composite membranes of PEG 400/Pebax 1657 blended polymer with graphene oxide (GO) and amine functionalized graphene oxide (Fn-GO) were successfully developed for CO2/CH4 gas separation. The effects of graphene oxide, amine functionalized graphene oxide and PEG 400 additions on CO2/CH4 separation performance were …
Synthesis Of Cu2znsns4 For Thin Film Solar Cells Prepared By Solution-Based Processes, Napaporn Khothong
Synthesis Of Cu2znsns4 For Thin Film Solar Cells Prepared By Solution-Based Processes, Napaporn Khothong
Chulalongkorn University Theses and Dissertations (Chula ETD)
Copper zinc thin sulphide (Cu2ZnSnS4: CZTS) thin films were synthesized via convective deposition method at various deposit speeds based on sol-gel precursor of 2-methoxyethanol solution with metal chlorides and thiourea. The deposited films were annealed at 340 to 550ºC under N2 atmosphere to yield high quality CZTS films. The compositions, morphology, phase, and optical properties of the CZTS films were characterized by Energy dispersive X-ray analysis (EDX), Scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, and UV-Vis spectrophotometer, respectively. The formation films exhibited in kesterite structure and the band gap was about 1.4-1.5 eV. The CZTS films also applied …
Development Of Conductive Polyimide/Polysulfone Composites As Positive Temperature Coefficient Materials, Noppawat Kuengputpong
Development Of Conductive Polyimide/Polysulfone Composites As Positive Temperature Coefficient Materials, Noppawat Kuengputpong
Chulalongkorn University Theses and Dissertations (Chula ETD)
For positive temperature coefficient (PTC) applications of electrically conductive composites, volume resistivity at room temperature of lower than 104 Ω.cm is one major requirement. Conductive polyimide (PI) PTC with the above level of conductivity value can be achieved by a use of carbon black (CB) as conductive filler. For materials with PTC, there is a change in resistance related to temperature. In order to reduce the amount of CB used in the PTC composites, one of well-known methods is to introduce another polymer into a polymer to generate immiscible blends. When the conductive filler is dispersed in one polymer phase, …
Carbon Nanotube/Polymer Composite Membrane For Co2 Capture, Pacharaporn Yaisanga
Carbon Nanotube/Polymer Composite Membrane For Co2 Capture, Pacharaporn Yaisanga
Chulalongkorn University Theses and Dissertations (Chula ETD)
Membrane gas absorption (MGA) was applied for carbon dioxide capture due to its unique potential, such as independent adjustment of gas and liquid, compact equipment installation, and sizable module. However, a major issue of MGA is membrane wetting, causing lower absorption efficiency and membrane damages. Hydrophobicity is one of the key parameters to improve membrane property for solving such problem. This thesis focused on using carbon nanotubes as the filler to composite with polyacrylonitrile (PAN) or polyvinylidene fluoride (PDVF) via a phase inversion technique to improve membranes hydrophobicity. In case of PAN, the results showed that the addition of CNT …
Novel Shape Memory Polymer From Bio-Based Polybenzoxazine/Bio-Based Epoxy Copolymers, Phakakrong Hombunma
Novel Shape Memory Polymer From Bio-Based Polybenzoxazine/Bio-Based Epoxy Copolymers, Phakakrong Hombunma
Chulalongkorn University Theses and Dissertations (Chula ETD)
Shape memory polymers (SMPs) are known as smart polymer materials which can be deformed and fixed in a temporary shape and can recover to its original shape upon an external stimulus such as temperature which is the main stimulus for general SMPs. In this research, a renewable natural resource based on vanillin-furfurylamine benzoxazine (V-fa) and eugenol-furfurylamine benzoxazine (E-fa) are developed to substitute the use of petroleum based polybenzoxazine. The as-synthesized V-fa and E-fa show the degradation temperature at 5% weight loss to be as high as 343 and 310°C and char content to be 66 and 54%, respectively. Effects of …
Continuous Hydrotreating Process Of Palm Fatty Acid Distillate (Pfad) Over Bimetallic Nicu/Hzsm-5 Catalyst For Bio Jet Fuel Production, Phisit Wirikulcharoen
Continuous Hydrotreating Process Of Palm Fatty Acid Distillate (Pfad) Over Bimetallic Nicu/Hzsm-5 Catalyst For Bio Jet Fuel Production, Phisit Wirikulcharoen
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research investigated bimetallic NiCu/HZSM-5 catalyst for the production of bio jet fuel via hydrotreating process. The catalysts with different Ni and Cu ratio were characterized by XRD, NH3-TPD, H2-TPR, SEM-EDX and N2-physisorption techniques. Palm fatty acid distillate (PFAD), nonedible by-product from palm oil refining process, was employed as a low-cost feedstock. For catalyst screening, the reaction was performed in an autoclave reactor under batch operation with operating temperature of 375°C, initial H2 pressure of 50 bars and reaction time of 3 h. The results showed that doping Cu could enhance deoxygenation activity while carbon formation was found to be …
Microwave Heating With Potassium Hydroxide Activation For Converting Water Hyacinth Into Activated Carbon, Purichaya Kuptajit
Microwave Heating With Potassium Hydroxide Activation For Converting Water Hyacinth Into Activated Carbon, Purichaya Kuptajit
Chulalongkorn University Theses and Dissertations (Chula ETD)
Activated carbon was successfully synthesized form dried water hyacinth via KOH activation with microwave irradiation. Resultant activated carbon with large specific surface area can be produced using microwave irradiation for 1 minute which was consumed less time than conventional heating method that consumed 1 hour. Microwave irradiation can be a strategic way to improve uniform and quick heating to prepare porous carbons by inducing dipole rotation in atomic scale and creating a frictional force between atoms and molecules within heated material so that volumetric heating inside the heated material is realized. The BET analysis shown that the activated carbon, derived …
Effect Of Amino Propanol Structure On Carbon Dioxide Absorption, Rossukon Nimcharoen
Effect Of Amino Propanol Structure On Carbon Dioxide Absorption, Rossukon Nimcharoen
Chulalongkorn University Theses and Dissertations (Chula ETD)
Currently, global warming is the main issue on environmental concern due to the higher amount of carbon dioxide (CO2) in the atmosphere.The current technology to remove CO2 effectively is carbon capture and storage or CCS, especially absorption with aqueous amine solutions. The commonly used amine solutions are monoethanolamine (MEA). They have some disadvantages like low capacity. Therefore, a new solvent such as 3-amino-1-propanol (3A1P), 3-dimethylamino-1-proapnol (3DMA1P) and 1-dimethylamino-2-proapnol (1DMA2P) have been designed to be used as alternative solvents for CO2 removal. In this work, the solubility of carbon dioxide in new promising solvents. The effect of solvent concentration is studied …
Development Of Graphite/Graphene/Carbon Nanotubes Filled Benzoxazine Composites For Bipolar Plates In Fuel Cell Applications, Sirawit Witpathomwong
Development Of Graphite/Graphene/Carbon Nanotubes Filled Benzoxazine Composites For Bipolar Plates In Fuel Cell Applications, Sirawit Witpathomwong
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research aims to develop bipolar plate from polymer composite to be used in proton exchange membrane fuel cells. The key properties of bipolar plates include high thermal conductivity, high electrical conductivity, high flexural strength and modulus, and low water absorption. The polybenzoxazine composites having three types of carbon derivatives i.e. graphite, graphene, and carbon nanotubes were prepared using a compression molder with a pressure of 15 MPa and a temperature of 200oC for 2 hours. The effects of carbon nanotube contents varying from 0-2wt% at an expense of graphite with constant content of graphene and benzoxazine at 7.5 and …