Show simple item record

dc.contributor.advisorNikačević, Nikola
dc.contributor.otherBukur, Dragomir B.
dc.contributor.otherOrlović, Aleksandar
dc.creatorTodić, Branislav
dc.date.accessioned2021-03-10T15:11:44Z
dc.date.available2021-03-10T15:11:44Z
dc.date.issued2015
dc.identifier.urihttp://eteze.bg.ac.rs/application/showtheses?thesesId=3173
dc.identifier.urihttps://fedorabg.bg.ac.rs/fedora/get/o:11518/bdef:Content/download
dc.identifier.urihttp://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=47501583
dc.identifier.urihttp://TechnoRep.tmf.bg.ac.rs/handle/123456789/4622
dc.description.abstractFischer-Tropsch synthesis (FTS) is a heterogeneously catalyzed chemical reaction in which a mixture of hydrogen and carbon-monoxide is converted into an array of hydrocarbon products. These products can be used as synthetic liquid fuels (gasoline, diesel, kerosene) or feedstock for the chemical industry. As such, FTS is a key step in the conversion of coal, natural gas and biomass into liquids in large plants all over the world, including plants in Qatar, Malaysia, South Africa etc. Even though FTS has been commercially used for most of the 20th century, many fundamental aspects of this reaction are unclear. The main objectives of the work included in this thesis were: to study the effect of process conditions on FTS product selectivity and distribution with regards to hydrocarbon chain length, develop a detailed model of FTS kinetics (capable of predicting both reactant disappearance and product formation rates) and apply the detailed kinetic model in modeling and optimization of a multi-tubular fixed-bed reactor for FTS. Most often used catalysts for FTS are iron and cobalt. The experimental data used in this study were obtained in collaboration with Texas A&M University and Center for Applied Energy Research, University of Kentucky, for iron- and cobalt-based catalyst, respectively. The analysis of experimental data for both catalysts showed dependence of product selectivity from process conditions inside the reactor (temperature, pressure, reactant feed ratio and conversion level). These dependences were shown to be related to the chain-growth probability factor (α), which also varies with carbon number. Over the cobalt catalyst, the significant variation of C1 intermediate growth probability (α1) at different process conditions and a lack of the same variations for higher C2+ chain intermediates, was interpreted as evidence for the existence of separate methanation pathways. The same data presented evidence that the secondary 1-olefin readsorption does not play a major part in determining FTS selectivity. For the iron-based catalysts, similar correlations between variations of growth probability with process conditions were found. However, existence of additional pathways for methane formation and relevance of secondary olefin reactions could not be confirmed for that catalyst...en
dc.description.abstractFischer-Tropsch sinteza (FTS) je heterogeno katalizovana hemijska reakcija u kojoj se smeša vodonika i ugljen-monoksida pretvara u niz ugljovodoničnih proizvoda. Ti proizvodi se mogu koristiti kao sintetička tečna goriva (benzin, dizel i kerozin) ili sirovine za hemijsku industriju. Kao takva, FTS je ključni korak u konverziji uglja, prirodnog gasa i biomase u tečnosti u velikim postrojenjima širom sveta, uključujući postrojenja u Kataru, Maleziji, Južnoj Africi itd. Iako je FTS veći deo dvadesetog veka bila u komercijalnoj upotrebi, mnogi fundamentalni aspekti ove reakcije su nejasni. Glavni ciljevi istraživačkog rada u sklopu ove disertacije su bili: ispitivanje efekata procesnih uslova na selektivnost i raspodelu FTS proizvoda u odnosu na dužinu ugljovodoničnog lanca, razvoj detaljnog kinetičkog modela FTS (sposobnog da ujedno predskaže brzine nestajanja reaktanata i nastajanja proizvoda) i primena detaljnog kinetičkog modela u modelovanju i optimizaciji višecevnih FTS reaktora sa pakovanim slojem katalizatora. Najčešće korišćeni katalizatori za FTS su gvožđe i kobalt. Eksperimentalni podaci za gvozdeni i kobaltni katalizator korišćeni u ovoj studiji su dobijeni u saradnji sa Texas A&M Univerzitetom (Texas A&M University) i Centrom za primenjeno istrazivanje energije Univerziteta u Kentakiju (Center for Applied Energy Research, University of Kentucky), respektivno. Analiza eksperimentalnih podataka za oba katalizatora je pokazala zavisnost selektivnosti proizvoda reakcije of procesnih uslova unutar reaktora (temperature, pritiska, odnosa reaktanata u ulaznoj smeši i konverzije reaktanata). Pokazano je da su ove zavisnosti povezane sa verovatnoćom rasta ugljovodoničnog lanca (α), koja se takođe menja sa brojem atoma ugljenika. Značajne varijacije u vrednosti verovatnoće rasta C1 lančanih intermedijera pri različitim procesnim uslovima, zabeležene sa kobaltnim katalizatorom, kao i odsustvo istih varijacija za duže C2+ lančane intermedijere, su interpretirane kao dokaz postojanja dodatnog reakcionog puta za metanaciju. Isti rezultati su poslužili kao dokaz da sekundarne reakcije 1-alkena ne igraju bitnu ulogu u određivanju selektivnosti FTS. Slične korelacije između promena verovatnoće rasta lanca i procesnih uslova su zapažene i sa gvozdenim katalizatorom. Međutim, postojanje dodatnog reakcionog puta za formiranje metana i važnost sekundarnih reakcija alkena nisu potvrđene za taj katalzator...sr
dc.publisherUniverzitet u Beogradu, Tehnološko-metalurški fakultet
dc.rightsopenAccess
dc.subjectFischer-Tropsch sintezaen
dc.subjectkobaltni katalizatoren
dc.subjectgvozdeni katalizatoren
dc.subjectselektivnost proizvoda reakcijeen
dc.subjectraspodela proizvoda reakcijeen
dc.subjectmodelovanje kinetikeen
dc.subjectmehanizam reakcijeen
dc.subjectreactor sa pakovanim slojem katalizatoraen
dc.subjectFischer-Tropsch synthesissr
dc.subjectcobalt catalystsr
dc.subjectiron catalystsr
dc.subjectproduct selectivitysr
dc.subjectproduct distributionsr
dc.subjectkinetic modelingsr
dc.subjectreaction mechanismsr
dc.subjectfixed-bed reactorsr
dc.titleKinetic modeling and oprimization of fixed-bed reactor for Fischer-Tropsch synthesisen
dc.typedoctoralThesis
dc.rights.licenseARR
dc.identifier.fulltexthttp://TechnoRep.tmf.bg.ac.rs/bitstream/id/2148/4619.pdf
dc.identifier.rcubnardus-3015
dc.type.versionpublishedVersion


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record