Oksidacija toluena na perovskitnim katalizatorima

undergraduate thesis

• Title (english): Toluene oxidation over perovskite catalysts
• Author: Martina Koren
• Mentor: Vesna Tomašić (mentor)
• Committee member: Vesna Tomašić (predsjednik povjerenstva)
• Committee member: Karolina Maduna (član povjerenstva)
• Committee member: Sandra Babić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2017-09-21, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering; Reaction Engineering

Abstract

Emisija hlapljivih organskih spojeva u atmosferu predstavlja veliki problem u zaštiti okoliša, jer dovodi do ugrožavanja ekosustava, kao i do narušavanja zdravlja ljudi i životinja. Stoga se brojna znanstvena istraživanja odnose na razvoj novih metoda i tehnika kojima bi se smanjile njihove emisije u okoliš. To je sve teže ostvariti zbog sve brojnijih izvora njihovih emisija, a kao jedna od najučinkovitijih metoda ističe se katalitička oksidacija. U teorijskom dijelu ovog završnog rada dan je pregled literature vezane uz temu, s posebnim naglaskom na katalitičku oksidaciju te perovskite kao potencijalne katalizatore koji se koriste za tu svrhu. U eksperimentalnom dijelu rada prikazani su rezultati istraživanja katalitičke oksidacije toluena primjenom praškastih perovskitnih katalizatora (LaFeO3 i LaMnO3). Perovskitni katalizatori pripremljeni su primjenom citratne metode, a mjerenja su provedena u laboratorijskom reaktoru s nepokretnim slojem katalizatora. Toluen je izabran kao predstavnik aromatskih hlapljivih organskih spojeva. Reakcija katalitičke oksidacije toluena na LaFeO3 katalizatoru provedena je pri različitim temperaturama (100-300 °C) i prostornim vremenima. Prostorna vremena mijenjana su promjenom ukupnog protoka reakcijske smjese uz konstantnu masu katalizatora (0,05 g). Sva mjerenja su provedena uz konstantnu početnu koncentracijau toluena (210,43 ppm u dušiku) i konstantan volumni omjer reakcijske smjese i zraka koji je korišten kao oksidans (20:3). U cilju usporedbe aktivnost LaFeO3 uspoređena je s aktivnošću ranije izučavanog LaMnO3 u istom eksperimentalnom sustavu. Nađeno je da oba katalizatora pokazuju zadovoljavajuću aktivnost i stabilnost, međutim LaMnO3 pokazao se boljim katalizatorom, jer se njegovom primjenom mogu postići vrlo velike konverzije već pri relativno niskim temperaturama (< 280 °C).

Abstract (english)

Emission of volatile organic compounds (VOCs) into the atmosphere is a great environmental issue because it has harmful effects on the ecosystems, the human health and animals. Hence, numerous scientific researches relate to the development of new methods and techniques to reduce their emissions into the environment. It is difficult to achieve this goal because of the increasing number of their emissions and catalytic oxidation is one of the most effective methods for this purpose. In the theoretical part of this work a review of literature related to the topic is given with particular emphasis on catalytic oxidation and perovskites as potential catalysts used for this purpose. The experimental part of the paper presents the results of the catalytic oxidation of toluene over an powdered perovskites catalysts (LaFeO3 and LaMnO3). Perovskite catalysts were prepared using citric method, while experimental measurements were done in the laboratory fixed bed reactor. Toluene was chosen as the representative of aromatic volatile organic compounds. Catalytic oxidation of toluene over LaFeO3 as a catalyst was preformed under various temperatures (100-300 °C) and space times. Space times inside the reactor were changed by changing the total flow rate of reaction mixture under constant mass of the catalyst (0.05 g). All measurements were performed at the constant initial concentration of toluene (210.43 ppm in nitrogen) and constant volume ratio of reaction mixture and air which was used as an oxidant (20:3). For comparison purpose, the activity of LaFeO3 was compared to the activity of LaMnO3 which was previously investigated in the same experimental system. It was found out that both catalysts show satisfactory activity and stability. However, LaMnO3 was found to be better catalyst because it allowed very high conversions at relatively low temperatures (< 280 °C).

• Keywords: hlapljivi organski spojevi; katalitička oksidacija; perovskitni katalizatori; LaFeO3; LaMnO3
• Keywords (english): volatile organic compounds; catalytic oxidation; perovskite catalysts; LaFeO3; LaMnO3
• Language: croatian
• URN:NBN: urn:nbn:hr:149:772541
• Study programme: Title: Chemical Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-03-23 10:49:43