doktorska disertacija
Damjan Lašič Jurković (Author), Andrej Pohar (Mentor), Igor Plazl (Thesis defence commission member), Matjaž Krajnc (Thesis defence commission member), Miran Mozetič (Thesis defence commission member)

Abstract

CH4 in CO2 sta najvplivnejša toplogredna plina. Njuno koncentracijo v atmosferi bi lahko znižali preko pretvorbe tako na mestu izpusta kot tudi zajetih plinov iz ozračja. Zato je nujno potreben razvoj novih procesov in tehnologij, ki bi omogočale tovrstno pretvorbo z visoko energetsko učinkovitostjo in sintezo uporabnih produktov z dodano vrednostjo. Doktorsko delo je razdeljeno na tri sklope, kjer se v vsakem od njih preučuje določen tovrstni proces: Povratno reakcijo vodnega plina, suhi reforming metana in delno oksidacija metana. V sklopu povratne reakcije vodnega plina je bila narejena sinteza petih bakrovih katalizatorjev na različnih nosilcih, ki so bili preučeni z različnim analitskimi tehnikami, pomerjena pa je bila tudi njihova aktivnost in kinetika reakcije pri različnih obratovalnih temperaturah, tlakih, pretokih in razmerjih reagentov. Razviti so bili tudi trije različni matematični modeli reaktorja, ki so vključevali snovni transport in kinetiko površinske reakcije na katalizatorju. Iz modelov so bili dobljeni novi vpogledi v snovni transport, prilagodile pa so se tudi reakcijske konstante za izboljšanje napovedne moči. V sklopu suhega reforminga metana je bil le-ta preučevan v plazemskem reaktorju z iskro, kjer se je študirala kinetika procesa pri uporabi čiste plazme in souporabi plazme in nikljevih katalizatorjev pri različnih obratovalnih pogojih (temperatura, moč plazme, pretok plina, razmerje reagentov), kjer je imela dodaten poudarek stabilnost obratovanja v prisotnosti nalaganja ogljika. Tudi v tem delu je bil narejen matematični model, ki je upošteval fluidno dinamiko v reaktorju. V zadnjem sklopu se je raziskovala delna oksidacija metana s kisikom v plazemskem reaktorju z dielektrično pregrado, kjer so se formirali tekoči produkti kot so metanol, formaldehid ter mravljinčna in ocetna kislina. Kinetika je bila izmerjena pri različnih pogojih (razmerje reagentov, pretok plina), preučil pa se je tudi širok spekter različnih katalizatorjev v kombinaciji s plazmo, in sicer različnih čistih zeolitov ter katalizatorjev na osnovi kovin kot so Pd, Fe in Mo.

Keywords

toplogredni plini;suhi reforming metana;povratna reakcija vodnega plina;delna oksidacija metana;plazemska kataliza;katalizatorji;matematično modeliranje;reakcijska kinetika;doktorske disertacije;

Data

Language: Slovenian
Year of publishing:
Typology: 2.08 - Doctoral Dissertation
Organization: UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher: [D. Lašič Jurković]
UDC: 66.097:519.673(043.3)
COBISS: 1538525891 Link will open in a new window
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Other data

Secondary language: English
Secondary title: Plasma and catalytic processes for methane and carbon dioxide activation
Secondary abstract: CH4 and CO2 are the most impactful greenhouse gases. Their atmospheric concentration could be lowered via conversion of the gases collected at the emission site or captured from the atmosphere. The development of new technologies for such conversion with high energy efficiency and useful products is crucial. The PhD thesis is divided into three parts, each dedicated to the study of one such promising process: reverse water-gas shift reaction, dry reforming of methane and partial oxidation of methane. In the reverse water-gas shift section, synthesis of five different copper-based catalysts with different supports was carried out. The catalysts were characterised with different analytical techniques and had their activity measured at different operating temperatures, pressure, gas flow rates and reagent ratios. Three different reactor mathematical models were developed, taking into account the mass transport as well as the catalytic surface reactions. New insights regarding mass transport were obtained, and numerical regression of the reaction constants was performed in order to increase the model accuracy. Methane dry reforming reaction was studied in a spark plasma reactor. Reaction kinetics were studied both in pure plasma and plasma-catalytic modes of operation, the latter utilising Ni-based structured alumina foam catalysts, under different operating conditions (temperatures, plasma powers, gas flow rates, reagent ratios) and special attention was paid to stability under coke-deposition conditions. A three-dimensional mathematical model was developed for this process using fluid dynamics. Methane partial oxidation was carried out with different reagent ratios and total gas flow rates. In addition, a multitude of different catalytic materials were coupled with plasma, such as pure zeolites and metal-based catalysts (Pd, Fe and Mo).
Secondary keywords: dry reforming of methane;reverse water-gas shift reaction;partial oxidation of methane;plasma catalysis;mathematical modelling;reaction kinetics;Metan;Disertacije;Ogljikov dioksid;
Type (COBISS): Doctoral dissertation
Study programme: 1000381
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo
Pages: IX, 136 f.
ID: 11383202