Niskotemperaturna katalitička oksidacija toluena u metalnom monolitnom reaktoru

master's thesis

• Title (english): Low temperature catalytic oxidation of toluene in the metal monolithic reactor
• Author: Tanja Zmijanac
• Mentor: Vesna Tomašić (mentor)
• Committee member: Vesna Tomašić (predsjednik povjerenstva)
• Committee member: Vanja Kosar (član povjerenstva)
• Committee member: Mirela Leskovac (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2017-07-12, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering; Reaction Engineering

Abstract

Onečišćenje okoliša kao posljedica urbanizacije i sve brže industrijalizacije postaje sve veći problem u svijetu. Hlapljivi organski spojevi (VOC) su velik izvor onečišćenja zraka i dovode do značajnog ugrožavanja ekosustava kao i do ozbiljnog narušavanja zdravlja ljudi. Iako u današnje vrijeme postoje različite tehnologije koje se primjenjuju u cilju smanjenja emisija hlapljivih organskih spojeva u atmosferu, još uvijek postoji potreba za razvojem novih, inovativnih tehnologija kao i za unaprjeđenjem postojećih. Jedna od obećavajućih tehnologija je katalitička oksidacija VOC-a u manje problematične produkte (CO2 i H2O). U ovom radu provedena je katalitička oksidacija modelne VOC komponente (toluen) primjenom napredne izvedbe monolitnog katalizatora/reaktora. Istraživanje je obuhvaćalo pripremu metalnog Mn-Cu (1:1) monolitnog katalizatora te izučavanje njegovih katalitičkih značajki pri različitim uvjetima provedbe procesa. Kao modelna komponenta izabran je toluen s obzirom da je on uobičajeni predstavnik aromatskih hlapljivih organskih spojeva, koji su vrlo stabilni i predstavljaju velik problem u zaštiti okoliša. Katalitička oksidacija toluena izučavana je u metalnom monolitnom reaktoru pri izotermnim uvjetima provedbe procesa, provedbom reakcije pri različitim temperaturama (100°C–250°C). Kao oksidans primjenjivan je sintetski zrak. Provedene su tri serije eksperimenata: 1) katalitička oksidacija toluena pri različitim temperaturama i početnim koncentracijama toluena odnosno pri različitim ukupnim protocima reakcijske smjese, 2) pri konstantnom ukupnom protoku reakcijske smjese (150 ml/min) uz promjenu početne koncentracije toluena, 3) pri konstantnoj početnoj koncentraciji toluena (869,57 ppm) uz karakteristične promjene protoka pri različitim temperaturama. Sve reakcije katalitičke oksidacije toluena provedene su uz konstantnu masu katalizatora (0,0024 g) te u uvjetima značajnog suviška oksidansa (sintetski zrak). Metalni monolitni Mn-Cu/Al-Al2O3 katalizator pokazivao je prihvatljivu stabilnost i aktivnost tijekom provedbe katalitičke oksidacije toluena. Potpune konverzije toluena postignute su već pri relativno niskim temperaturama (cca. 250°C), zavisno o ostalim uvjetima provedbe procesa. S obzirom na dobivene rezultate zaključeno je da metalni monolitni katalizator (Mn-Cu/Al-Al2O3) može poslužiti kao zamjena za uobičajene katalizatore na bazi plemenitih metala. To je od velike praktične važnosti, jer se na taj način može značajno utjecati na ekonomičnost izučavanog procesa.

Abstract (english)

Environmental pollution as a result of urbanization and industrialization is rapidly becoming an increasing problem in the world. Volatile Organic Compounds (VOCs) are a major source of air pollution and lead to significant ecosystem endangering as well as severe human health disturbances. Although today there are different technologies which can be applied to reduce volatile organic compounds emissions into the atmosphere, there is still a need to develop new, innovative technologies as well as to improve the existing ones. One of such promising technologies is the catalytic oxidation of VOCs into less problematic products (CO2 and H2O). In this work the catalytic oxidation of the model VOC components (toluene) was carried out using the advanced performance of the monolithic catalyst/reactor. The study included the preparation of a metal Mn-Cu (1:1) monolithic catalyst and the study of its catalytic properties at different process employed conditions. Toluene was chosen as a model component, as it is a common representative of aromatic volatile organic compounds, which are very stable and represent a major environmental problem. Catalytic oxidation of toluene was studied in a metal monolithic reactor under isothermal conditions by performing the reaction at various temperatures (100°C-250°C). Synthetic air was used as the oxidant. Three series of experiments were carried out: 1) catalytic oxidation of toluene at different temperatures and initial concentrations of toluene; 2) at constant total flow of the reaction mixture (150,00 ml/min) with a change in toluene concentration; 3) at constant initial concentration of toluene (869.57 ppm) with characteristic changes in the characteristic flow rates at different temperatures. All reactions of toluene oxidation were carried out with constant catalyst mass (0.0024 g) and under conditions of significant excess of oxygen (synthetic air). The metal monolithic Mn-Cu/Al-Al2O3 catalyst showed acceptable stability and activity during the catalytic oxidation of toluene under working conditions employed in this study. Complete toluene conversion has been achieved at relatively low temperatures (cca. 250°C), depending on the other process conditions. Based on the obtained results, it was concluded that the metal monolithic catalyst (Mn-Cu/Al-Al2O3) could serve as a substitute for ordinary precious metal based oxidation catalysts. This is of great practical importance because it can significantly affect the process economics.

• Keywords: hlapljivi organski spojevi; toluen; katalitička oksidacija; metalni monolitni reaktor; metalni monolitni Mn-Cu/Al-Al2O3 katalizator
• Keywords (english): volatile organic compounds; toluene; catalytic oxidation; metal monolithic reactor; metal monolithic Mn-Cu/Al-Al2O3 catalyst
• Language: croatian
• URN:NBN: urn:nbn:hr:149:570601
• Study programme: Title: Environmental Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka ekoinženjerstva (magistar/magistra inženjer/inženjerka ekoinženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-11-19 08:18:30