Priprema keramičkih monolitnih nosača katalizatora na osnovi ZrO2 primjenom tehnologije proizvodnje rastaljenim filamentom

master's thesis

• Title (english): Preparation of ceramic monolithic catalyst supports based on ZrO2 using fused filament fabrication
• Author: Nikolina Zekić
• Mentor: Vesna Tomašić (mentor)
• Committee member: Vesna Tomašić (predsjednik povjerenstva)
• Committee member: Filip Car (član povjerenstva)
• Committee member: Domagoj Vrsaljko (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2023-09-07, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

U ovom diplomskom radu pripremljeni su keramički monolitni nosači katalizatora na bazi cirkonijeva dioksida (ZrO2) primjenom tehnologije proizvodnje rastaljenim filamentom. Na dobivene nosače nanesene su katalitički aktivne komponente postupkom mokre impregnacije. Testiranje aktivnosti pripremljenih katalizatora provedeno je provedbom katalitičke oksidacije smjese aromatskih spojeva, odnosno smjese benzena, toluena, etilbenzena i o-ksilena (BTEX). Određena je učinkovitost pripremljenih monolitnih katalizatora za katalitičku oksidaciju BTEX-a s obzirom na kemijski sastav katalitički aktivne komponente (MnFeOx, MnCuOx i MnNiOx) te s obzirom na geometriju monolitnog nosača (ZDP, Z i M). Prije kinetičkih mjerenja ispitana je dimenzijska stabilnost 3D-ispisanih monolitnih nosača i mehanička stabilnost katalitičkog sloja te je provedena karakterizacija korištenog ZrO2 filamenta. Rendgenskom difrakcijskom analizom utvrđeno je da se keramička faza materijala sastoji od monoklinskog i tetragonskog ZrO2. Laserskom difrakcijskom analizom utvrđeno je da su u uzorku prisutne čestice dimenzija 71 - 3000 μm. Vrijednost medijana veličine čestica (d50) u populaciji iznosila je 540,10 μm, dominantna veličina keramičkih čestica u populaciji (dmode) iznosila je 562,34 μm, a Sauterov promjer (d3,2) čestica 886,25 μm. Simultanom TGA/DTA analizom ispitana su toplinska svojstva ZrO2 filamenta koji je poslužio za pripremu monolitnog nosača. Na temelju izmjerenog odstupanja karakterističnih dimenzija 3D-ispisanih monolitnih nosača od dimenzija predviđenih CAD modelom određen je dimenzijski korekcijski faktor koji je iznosio 1,18. Na temelju testova odstupanja mase 3D-ispisanih nosača utvrđena je jednolika raspodjela čestica keramike ispisanih nosača. Mehanička stabilnost katalitičkog sloja određena je testovima adhezije, odnosno izlaganjem katalizatora ultrazvuku radne frekvencije 37 kHz. Gubitak katalitičkog sloja uslijed djelovanja ultrazvučnih vibracija iznosio je od 0,016 % do 0,051 %, čime je dokazana izvrsna mehanička stabilnost pripremljenih katalitičkih slojeva. Rezultati ispitivanja učinkovitosti katalizatora za oksidaciju BTEX-a pokazali su da je 3D-ispisani model M koji je sadržavao MnFeOx kao katalitički aktivnu komponentu najuspješniji katalizator za oksidaciju BTEX spojeva. Navedeni katalizator omogućava katalitičku oksidaciju svih komponenata BTEX smjese već pri temperaturi od
177 °C.

Abstract (english)

In this work, ceramic monolithic catalyst carriers based on zirconium dioxide (ZrO2) were prepared by fused filament fabrication. The active catalyst components were deposited on the obtained supports by the wet impregnation technique. The activity of the prepared catalysts was tested by carrying out the catalytic oxidation of a mixture of aromatic compounds, including benzene, toluene, ethylbenzene, and o-xylene (BTEX). The efficiency of the prepared monolithic catalysts used for the catalytic oxidation of BTEX was determined with respect to the chemical composition of the catalytically active component (MnFeOx, MnCuOx, and MnNiOx) and with respect to the geometry of the monolithic carrier (ZDP, Z, and M). Prior to the kinetic measurements, the dimensional stability of the 3D-printed monolithic carriers and the mechanical stability of the catalyst layer were investigated. Characterization of the ZrO2 filament used was performed too. X-ray diffraction analysis showed that the ceramic phase of the material consists of monoclinic and tetragonal ZrO2. The size of the ceramic particles was determined by laser diffraction analysis. The results of the analysis showed that the size of the ceramic particles ranged from 71 to 3000 μm. The median value of the particle size (d50) in the population was 540.10 μm. The predominant size of the ceramic particles in the population (dmode) was 562.34 μm, and the Sauter diameter (d3,2) of the particles was 886.25 μm. The thermal properties of the ZrO2 filament used to prepare monolithic carriers were investigated by simultaneous TGA/DTA analysis. The dimensional correction factor was determined by measuring the characteristic dimensions of the 3D-printed monolithic carriers against the dimensions predicted by the CAD model. The value of the dimensional correction factor was 1.18. Based on the measured mass deviation of the 3D-printed carriers, a uniform distribution of the ceramic particles in the printed carriers was observed. The mechanical stability of the catalytic layer was determined by adhesion tests. The catalyst was exposed to ultrasound at a frequency of 37 kHz. The loss of the catalytic layer due to the ultrasonic vibrations was from 0.016% to 0.051%, proving the excellent mechanical stability of the prepared catalytic layers. The results of the efficiency of the prepared monolithic catalysts used for the catalytic oxidation of BTEX showed that the 3D-printed model M, which contained MnFeOx as the catalytically active component, was the most successful catalyst for the oxidation of BTEX compounds. The mentioned catalyst enables catalytic oxidation of all components of the BTEX mixture at a temperature of 177 °C.

• Keywords: aditivna proizvodnja; monolitni katalizator; mokra impregnacija; katalitička oksidacija; benzen; toluen; etilbenzen; o-ksilen (BTEX)
• Keywords (english): additive manufacturing; monolithic catalyst; wet impregnation; catalytic oxidation; benzene; toluene; ethylbenzene; o-xylene (BTEX)
• Language: croatian
• URN:NBN: urn:nbn:hr:149:685872
• Study programme: Title: Chemical Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-09-14 12:49:36