Title Analiza i modeliranje keramičkog monolitnog reaktora za oksidaciju BTEX-a Title (english) Analysis and modeling of a ceramic monolithic reactor for BTEX oxidation Author Andrea Matejaš Mentor Vesna Tomašić (mentor)Committee member Vesna Tomašić (predsjednik povjerenstva)Committee member Igor Dejanović (član povjerenstva)Committee member Domagoj Vrsaljko (član povjerenstva)Granter University of Zagreb Defense date and country 2021-09-15, Croatia Scientific / art field, TECHNICAL SCIENCES Abstract Onečišćenje zraka uslijed ubrzane industrijalizacije predstavlja sve veći problem u svijetu i u središtu je brojnih istraživanja. Hlapljivi organski spojevi (engl. volatile organic compounds, VOC) poznati su toksični spojevi koji pridonose onečišćenju zraka, a pri normalnim uvjetima tlaka i temperature vrlo lako isparavaju. Najznačajniji predstavnici hlapljivih organskih spojeva, benzen, toluen, etilbenzen i o-ksilena (BTEX), opasni su po zdravlje ljudi, biljni i životinjski svijet, a ovisno o dugotrajnosti izlaganja uzrokuju akutne i kronične probleme. Postoje brojne metode smanjenja emisija hlapljivih organskih spojeva u okoliš, a pritom se posebno izdvaja katalitička oksidacija kao jedna od najučinkovitijih metoda. Cilj ovog rada je razvoj keramičkog monolitnog katalizatora za katalitičku oksidaciju VOC-a, uz primjenu plinovite smjese benzena, toluena, etilbenzena i o-ksilena (BTEX) kao modelne komponente. Za izradu monolitnog nosača katalizatora upotrijebljena je tehnika aditivne proizvodnje (ili 3D-ispisa). Na monolitne nosače metodom impregnacije nanošene su katalitičke aktivne komponente (kombinacije prijelaznih metala mangana, bakara, željeza). Katalitička oksidacija BTEX-a provedena je pri konstantnoj početnoj koncentraciji modelih komponenti, konstantnom omjeru reaktanta i oksidansa (sintetski zrak) te pri različitim temperaturama i prostornim vremenima. Nađeno je da se tehnologijom aditivne proizvodnje (3D-ispisa), tj. postupkom stereolitografije mogu uspješno izrađivati keramički monolitni nosači katalitički aktivnih komponenti. Ustanovljeno je da konverzija komponenti BTEX smjese raste s porastom temperature reakcije i sa smanjenjem ukupnog protoka reakcijske smjese, odnosno s povećanjem prostornog vremena. Nađeno je dobro slaganje eksperimentalnih rezultata s pretpostavljenim 1D heterogenim modelom reaktora koji uključuje kinetičke modele za reakciju prvog reda za sve komponente BTEX smjese. Procijenjene su vrijednosti ključnih parametara modela, tj. vrijednosti konstanti brzine reakcije, k, energije aktivacije, Ea i značajke frekvencije (Arrheniusove značajki), Ar za oba katalizatora te je zaključeno da je MnCuOx učinkoviti katalizator za oksidaciju BTEX-a od MnFeOx.
Abstract (english) Air pollution due to accelerated industrialization is a growing problem in the world and is at the center of numerous studies. Volatile organic compounds (VOC) are known toxic compounds that contribute to air pollution and evaporate very easily under normal conditions of pressure and temperature. The most important representatives of volatile organic compounds, benzene, toluene, ethylbenzene and o-xylene (BTEX), are dangerous to human health, flora and fauna, and depending on the duration of exposure cause acute and chronic problems. There are numerous methods for reducing emissions of volatile organic compounds into the environment, with catalytic oxidation being singled out as one of the most effective methods. The aim of this work is to develop a ceramic monolithic catalyst for the catalytic oxidation of VOC, using a gaseous mixture of benzene, toluene, ethylbenzene and o-xylene (BTEX) as a model component. The technique of additive production (or 3D-printing) was used to produce the monolithic catalyst carrier. Catalytic active components (combinations of transition metals manganese, copper, iron) were applied to monolithic carriers by the method of impregnation. Catalytic oxidation of BTEX was performed at a constant initial concentration of the model components, a constant ratio of reactant and oxidant (synthetic air) and at different temperatures and space times. It was found that the technology of additive production (3D-printing), i.e. the process of stereolithography, makes it possible to successfully produce ceramic monolithic carriers of the catalytically active components. It was established that the conversion of BTEX components increases with the increase of reaction temperatures and with the decrease of total flow of reaction mixture, that is with the increase of space time. A good matching of the experimental results on the assumed 1D heterogeneous reactor models including the first order kinetic reaction models for all components of the BTEX mixtures is obtained. The values of key model parameters, i.e. values of reaction rate constants, k, activation energy, Ea and significant frequency (Arrhenius characteristics), Ar for both catalysts were estimated and it was concluded that MnCuOx is an effective catalyst for oxidation of BTEX from MnFeOx.
Keywords
hlapljivi organski spojevi
BTEX
katalitička oksidacija
aditivna proizvodnja
monolitni katalizator
Keywords (english)
volatile organic compounds
BTEX
catalytic oxidation
additive manufacturing technology
monolithic catalyst
Language croatian URN:NBN urn:nbn:hr:149:773244 Project Number: IP-2018-01-8669 Study programme Title: Chemical Engineering - Graduate study Type of resource Text File origin Born digital Access conditions Access restricted to students and staff of home institution Terms of use Created on 2023-04-13 11:51:05
