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2018

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Articles 691 - 703 of 703

Full-Text Articles in Chemical Engineering

Synthesis Of Activated Carbons From Coffee Ground Residues And Their Application As Catalysts For Ethanol Dehydrogenation, Jeerati Ob-Eye Jan 2018

Synthesis Of Activated Carbons From Coffee Ground Residues And Their Application As Catalysts For Ethanol Dehydrogenation, Jeerati Ob-Eye

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this present study, characteristics and catalytic properties of activated carbon derived from coffee ground residue, cobalt metal (Co) supported-activated carbon and various metals (Ce, Co, Cu and Ni) supported-commercial activated carbon were determined and characterized. This study was divided into three parts. Regarding to the first part, the synthesis of activated carbon catalysts derived from coffee ground residues with different methods of physical activation was investigated. The results showed that the catalyst with physically activated by CO2 for 4 hours, exhibited the best catalytic activity of ethanol dehydrogenation to acetaldehyde. In the second part, the best catalyst from the …

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Simulation And Evaluation Of Butadiene Production From Ethanol Via One-Step Reaction, Jirawat Imsaard Jan 2018

Simulation And Evaluation Of Butadiene Production From Ethanol Via One-Step Reaction, Jirawat Imsaard

Chulalongkorn University Theses and Dissertations (Chula ETD)

1,3-butadiene is an important compound produced from the steam cracking process. Raising demand for alternatives to fossil fuels has led to an increase in bio-derived ethanol production, which can also be used as a feedstock for 1,3-butadiene synthesis. This research investigated the simulation of 1,3-butadiene production from ethanol using one-step process with 1.AI2O3/ZnO (60:40), 2.MgO-SiO2-Na2O (1:1)(0.1%) and 3.Hf2.5ZM1.6/SiO2 as heterogeneous catalysts. The process simulation was carried out using commercial Aspen plus 8.0 program and the heat utilization efficiency was evaluated by Aspen energy analyzer software. The process optimal condition sequences were identified by adjusting the separation distillation parameters which include …

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Effects Of Tio2 Support And Co Addition On Ni/Tio2 Catalysts In Selective Hydrogenation Of Furfural To Furfuryl Alcohol, Kittithad Wonglekha Jan 2018

Effects Of Tio2 Support And Co Addition On Ni/Tio2 Catalysts In Selective Hydrogenation Of Furfural To Furfuryl Alcohol, Kittithad Wonglekha

Chulalongkorn University Theses and Dissertations (Chula ETD)

Furfuryl alcohol is an important chemical intermediate that can be converted into many value-added derivative molecules. It is typically produced by the hydrogenation of furfural using supported metal catalysts. In this work, 15%wt Ni catalysts supported on titania (TiO2) were prepared by incipient wetness impregnation method. The effects of phase composition and average crystallite sizes of TiO2 and Co addition in the range of 1-3 wt% on the catalytic properties of 15 wt%Ni/TiO2 were investigated in the selective hydrogenation of furfural to furfuryl alcohol at 50°C, 20 bar of H2, and 2 h reaction time. It was found that Ni …

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Hydrothermal Carbonization Carbon-Based Acid Catalyst For Biodiesel Production, Laddawan Tumkot Jan 2018

Hydrothermal Carbonization Carbon-Based Acid Catalyst For Biodiesel Production, Laddawan Tumkot

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aims to synthesize the production of biodiesel (oleic acid methyl ester) by esterification in the presence of sulfonated hydrothermal carbon based catalyst under microwave irradiation. The catalyst was prepared by hydrothermal carbonization, followed by sulfonation presenting sulfonic acid group as an active site. The catalyst characterization results confirmed good microwave-absorptivity of the catalyst which can be heated directly and accelerate the reaction immediately at the surface of the catalyst. Esterification of oleic acid (OA) with methanol experiments were optimized by using response surface methodology based on central composite design. Three variables: molar ratio of methanol to OA (2.5:1-7.5:1), …

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Graphene Sheets Decorated With Silver Nanoparticles As An Oxygen Reduction Reaction Catalyst For Zinc-Air Battery, Laksanaporn Poolnapol Jan 2018

Graphene Sheets Decorated With Silver Nanoparticles As An Oxygen Reduction Reaction Catalyst For Zinc-Air Battery, Laksanaporn Poolnapol

Chulalongkorn University Theses and Dissertations (Chula ETD)

The aim of this thesis is to develop a catalyst for the cathode of a zinc-air battery and to investigate the effects of reduced graphene oxide decorated with silver nanoparticles on the cathode in the zinc-air battery. First, reduced graphene oxide (AgNPs/rGO) was synthesized using glucose reduction at 60 degrees Celsius. Next, the structure and morphology of AgNPs/rGO were checked using X-ray diffraction (XRD). Then, transmission electron microscopy (TEM) analyzes were carried out. The amount of silver (Ag) decorate in graphene oxide was confirmed by EDX. Next, the synthesized catalysts at 3 concentration, using a rotating disk electrode (RDE), led …

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Reactive Extraction Of Metal Ion And Simultaneous Stripping Using Nanofibers-Supported Liquid Membrane In A Microchannel, Nattakarn Chucherd Jan 2018

Reactive Extraction Of Metal Ion And Simultaneous Stripping Using Nanofibers-Supported Liquid Membrane In A Microchannel, Nattakarn Chucherd

Chulalongkorn University Theses and Dissertations (Chula ETD)

Heavy metals in wastewater resulting from industries have become a prime concern for both environmental and economic reasons. This work intends to recover ions of heavy metal from wastewater using reactive extraction by nanofibers-supported liquid membrane (NSLM) in a microchannel. The use of supported liquid membrane enables simultaneous extraction and stripping (i.e., recovery of the extractant) processes. In this study, the NSLM was applied in a microchannel to minimize mass transfer resistance, hence improving overall performance of the extraction. Copper (II) ion was used as a model ion, while di-2-ethylhexyl phosphoric acid (D2EHPA) dissolved in kerosene was used as the …

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Effect Of Metal Oxides On Zirconia For Ketonic Decarboxylation Of Methyl Stearate, Pawaphat Sartsri Jan 2018

Effect Of Metal Oxides On Zirconia For Ketonic Decarboxylation Of Methyl Stearate, Pawaphat Sartsri

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this research, the effect of characteristics of zirconia and metal oxide modified zirconia catalysts on the catalytic performance were investigated by ketonic decarboxylation of methyl stearate to desired ketone product at the optimal condition (400°C and 1 bar). Zirconia and metal oxide modified zirconia catalysts were characterized by using X-ray diffraction (XRD), Scanning electron microscope (SEM), N2-physissorption, X-ray photoelectron spectroscopy (XPS), and IR spectra of pyridine adsorption (Pyridine-IR). The results indicated that the transition metal oxide group modified zirconia catalysts have higher contents of total Lewis acid site and oxygen vacancies site, and lower content of total Brønsted acid …

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Improving The Efficiency Of Dye-Sensitized Solar Cells With Ultrasonic Spray-Coated Tio2 Electrode That Was Modified By Mno2, Coo, Or Sno2, Supasun Thanadvanichkul Jan 2018

Improving The Efficiency Of Dye-Sensitized Solar Cells With Ultrasonic Spray-Coated Tio2 Electrode That Was Modified By Mno2, Coo, Or Sno2, Supasun Thanadvanichkul

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research investigated the modification of TiO2 electrode by adding the second metal oxide, namely, manganese dioxide (MnO2), cobalt oxide (CoO), or tin dioxide (SnO2) use in for dye-sensitized solar cell (DSSCs). TiO2 and modified TiO2 sols were synthesized via sol-gel methods. The sols were sprayed 500 times onto the fluorine-doped tin oxide glass substrates as a thin film using an ultrasonic spray coater. Finally, the thin film electrode was calcined at 400ºC for two hours. The amount of MnO2, CoO, or SnO2 was varied at 0, 0.1, 0.5, 1.0, and 3.0%wt. The photovoltaic efficiency of DSSCs was measured using …

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Parametric Study Of Copper Zinc Tin Sulfide Thin Films By Convective Deposition Method, Thanawat Anantamongkolchai Jan 2018

Parametric Study Of Copper Zinc Tin Sulfide Thin Films By Convective Deposition Method, Thanawat Anantamongkolchai

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, most of the energy production is from fossil fuel-resources, which is a major source of greenhouse gases. Therefore, several researchers have been looking for the alternative energy that is clean and renewable energy. One of the outstanding alternatives is to utilize solar energy for conversion into electricity. Recently, CZTS (copper zinc tin sulfide, Cu2ZnSnS4) thin film solar cells have received numerous interest because of its decent energy band gap of about 1.4 - 1.6 eV, which matches with the solar spectrum, and its high absorption coefficient. Nevertheless, the manufacture of CZTS solar cells has used sophisticated methods for fabrication …

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Methane And Carbon Dioxide Adsorption On Al-Based And Zr-Based Mofs: Effects Of Amino-Functionalization, Orawee Lamoonkit Jan 2018

Methane And Carbon Dioxide Adsorption On Al-Based And Zr-Based Mofs: Effects Of Amino-Functionalization, Orawee Lamoonkit

Chulalongkorn University Theses and Dissertations (Chula ETD)

For natural gas storage, adsorbed natural gas (ANG) technology has attracted great attention. There is a wide range of porous materials for ANG, but the most promising porous adsorbents for natural gas are metal organic frameworks (MOFs). This study examined adsorption of carbon dioxide and methane gases on aluminium (Al) based MOFs and zirconium (Zr) based MOFs including MIL-53(Al), MIL-53(Al)-NH₂, UiO-66, UiO-66-NH₂ 25%, UiO-66-NH₂ 50%, UiO-66-NH₂ 75%, and UiO-66-NH₂. Experiments were carried out in a static system at 33°C and pressures up to 100 psi. Characterization and structural analysis of the adsorbents were investigated by Fourier transform infrared spectroscopy (FTIR), …

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Kinetics Study For Fischer-Tropsch Synthesis Over Cobalt Catalyst By Kinetic Monte-Carlo Simulation, Nuttawut Pugingna Jan 2018

Kinetics Study For Fischer-Tropsch Synthesis Over Cobalt Catalyst By Kinetic Monte-Carlo Simulation, Nuttawut Pugingna

Chulalongkorn University Theses and Dissertations (Chula ETD)

Kinetic Monte-Carlo simulation was utilized to study the kinetic behaviors of C₁ and C₂ formation in the Fischer-Tropsch synthesis over the cobalt surface by varying reaction conditions. Two reaction models: the carbide mechanism and the CO insertion mechanism were applied to this simulation. The production rates and fractional coverages of each adsorbed species could be calculated under the steady state. Moreover, the combination between carbide and CO insertion mechanism was also studied to suggest the possibility of each reaction mechanism, and compared the results with the reported experimental results under the same conditions. It was ob-served that the C–C bond …

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The Effect Of Mcm-41 Addition To Pva/Pan/Pvp Polymer Electrolyte For Zinc-Air Batteries, Sirinuch Nanthapong Jan 2018

The Effect Of Mcm-41 Addition To Pva/Pan/Pvp Polymer Electrolyte For Zinc-Air Batteries, Sirinuch Nanthapong

Chulalongkorn University Theses and Dissertations (Chula ETD)

A membrane separator is one of the main components in zinc-air batteries playing an important role in controlling the mass transfer for the electrochemical reaction in the battery which determines the battery performance. This work aimed to develop a new membrane separator for the zinc-air battery. Polyvinyl alcohol (PVA), polyacrylonitrile (PAN), polyvinylpyrrolidone (PVP), and their blends were used for the fabrication of separator in this work. In addition, an inorganic nanoparticle with high hydroxide content such as MCM-41 was also applied as the filler for the polymers. The results revealed that the addition of PAN in PVA enhanced the electrolyte …

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Rheology, Morphology And Electronic Properties Of Hybrid Copper Organic Decompose Conductive Ink, Chaiwat Klaewwigkij Jan 2018

Rheology, Morphology And Electronic Properties Of Hybrid Copper Organic Decompose Conductive Ink, Chaiwat Klaewwigkij

Chulalongkorn University Theses and Dissertations (Chula ETD)

Hybrid Metal-Organic Decomposition (HMOD) inks containing alkanol amines copper complex solution with fine copper particles show high potential for flexible printed electronics application. Conductive patterns are fabricated from HMOD inks by screen printing onto a polyimide substrate. This work studies the effects of co-solvent, copper particles loading, and viscosity of the inks on properties of the conductive patterns obtained. Firstly, the effects of co-solvent related to the stability of the HMOD inks and the impact of preparation time related to the crack of the conductive pattern are examined. The HMOD inks are prepared from copper formate (CuF), and alkanol amines …

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