magistrsko delo
Rolando Krivec (Author), Darja Pečar (Mentor), Andreja Goršek (Co-mentor)

Abstract

Namen magistrskega dela je bil sintetizirati, karakterizirati in uporabiti trdni kovinski kislinski katalizator. Učinkovitost sintetiziranega katalizatorja smo preverjali na modelni reakciji esterifikacije maščobne kisline. Sintetiziran kovinsko kislinski katalizator smo dodali k mešanici miristinske kisline in metanola, kjer kot produkt nastane metilmiristat. Reakcije smo jo izvajali v šaržnem reaktorju pri različnih temperaturah, θ = (50, 55, 60 in 64,5) °C, ter pri različnih količinah dodanega katalizatorja, m = (0,125; 0,1; 0,075 in 0,05) g. Reakcije smo izvajali 5 h, vmes smo v časovnih intervalih jemali vzorce. Vzorce smo nato razredčili do ustrezne koncentracije in jih analizirali s pomočjo plinske kromatografije. Iz dobljenih kromatogramov smo s pomočjo predhodno skonstuirane umeritvene krivulje izračunali koncentracijo metilmiristata. Na podlagi dobljenih eksperimentalnih podatkov smo določili kinetiko reakcije esterifikacije miristinske kisline, katalizirane s sintetiziranim kovinsko kislinskim katalizatorjem. Uporabili smo Langmuir-Hinshelwood-Hougen-Watson-ov kinetični model. Za izračun kinetičnih parametrov, vključno s konstanto proizvodnosti, smo uporabili računalniški program Scientist. Katalizator smo karakterizirali z adsorpcijo-desorpcijo dušika (BET), Fourierjevo transformacijsko infrardečo spektroskopijo (FT-IR), dinamično svetlobno sipanje (DLS), diferenčno dinamično kalorimetrijo (DSC) in termogravimetrično analizo (TGA). Iz dobljenih rezultatov smo ugotovili, da z višanjem temperature in mase dodanega katalizatorja,koncentracija nastalega metilmiristata in s tem tudi presnova reakcije naraščata. Rezultati kemijskih analiz so pokazali, da sintetiziran katalizator Fe-SBA-15 vsebuje funkcionalne skupine Si-O-Si in -SO3H, je brez prisotnih primesi in v njem najdemo sledove vezane vode. Volumen por je 0,878 cm3 g-1, velikost por 6,25 nm in BET površina 61,3 m2 g-1.

Keywords

Fe-SBA-15;esterifikacija;kovinski katalizator;miristinska kislina;metanol;kinetični model;magistrske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher: [R. Krivec]
UDC: 543.544.3(043.2)
COBISS: 66732547 Link will open in a new window
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Downloads: 131
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Other data

Secondary language: English
Secondary title: Kinetics of myristic acid esterification using metal catalyst
Secondary abstract: The goal of this master's thesis was to synthesize, characterize and use a solid metal acid catalyst. We tested the efficiency of the synthesized catalyst on a model reaction of esterification of fatty acids. We have accomplished this by adding the synthesized metal acid catalyst to the mix of miristine acid and methanol which produced methyl myristate. The reaction was performed multiple times inside the batch reactor with different temperature settings θ = (50, 55, 60 and 64,5) °C and varying amounts of the added catalyst m = (0,125, 0,1, 0,075 and 0,05) g. Each reaction took 5 h during which we took samples in regular time intervals. The samples were diluted to the appropriate concentration and analyzed by gas chromatography. From the resulting chromatographs, with the aid of constructed calibration curves, we calculated the concentration of methyl myristate. Based on the obtained experimental data, we determined the kinetics of the myristic acid esterification reaction catalyzed by a synthesized metal acid catalyst using the Langmuir-Hinshelwood-Hougen-Watson kinetic model. To calculate the kinetic parameters and the productivity constant we used the Scientist software. To characterize the catalyst we used Nitrogen adsorption-desorption (BET), Fourier transform infrared spectroscopy, (FT-IR), dynamic light scattering (DLS), differentially dynamic calorimetry (DSC) and thermogravimetric analysis (TGA). Based on our findings we concluded that the higher the temperature and mass of the added catalyst is, the higher is the concentration of the formed methyl myristate and thus the metabolism of the reaction. Additional chemical analysis revealed that our synthesized catalyst Fe-SBA-15 is made up from the Si-O-Si and -SO3H functional groups, it is free of impurities and in it we find traces of bound water. Its pore volume is 0,878 cm3 g-1, pore size 6,25 nm and BET surface 61,3m2 g-1.
Secondary keywords: Fe-SBA-15;esterification;metal catalyst;myristic acid;methanol;kinetic model;
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages: XII, 38 f.
ID: 12881367