Hydrogen production via reforming of pyrolysis oil aqueous fraction

dc.contributorAalto-yliopistofi
dc.contributorAalto Universityen
dc.contributor.advisorPaasikallio, Ville
dc.contributor.authorAzhari, Ajimufti
dc.contributor.schoolKemian tekniikan korkeakoulufi
dc.contributor.supervisorLehtonen, Juha
dc.date.accessioned2014-08-29T06:54:28Z
dc.date.available2014-08-29T06:54:28Z
dc.date.issued2014-08-19
dc.description.abstractIncrease in energy demands and the need of new and renewable energy sources pushes the development of biomass utilization. One of the new emerging interests is hydrogen production from pyrolysis oil aqueous fraction using catalytic steam reforming. Although it is known firstly as a source of valuable chemicals and sugars, hydrogen production via reforming is indicated to be the most cost-effective way for utilizing pyrolysis oil aqueous fraction. The literature review revealed that wide range of catalysts and process conditions have been tested and main challenges revolved around catalyst stability, feeding system and reactor design. Based on the stability issue, oxidative steam reforming and testing of different types and combinations of reforming catalysts was chosen as a topic of the experimental part master’s thesis. In the experimental part, oxidative steam reforming of pyrolysis oil aqueous fraction from condenser unit in fast pyrolysis of forest thinning was tested using three different catalysts and catalyst combination and four different oxygen concentrations —represented by different O/C ratios. The experiments were carried out in a fixed bed steel reactor with process conditions set up as reaction temperature of 650oC, atmospheric pressure and S/C of 3.84. It was found that combination of zirconia monolith as pre-reformer and commercial nickel catalyst (Reformax) to be the best catalyst combination that enhanced the stability of carbon-to-gas conversions and hydrogen production. With this combination, the carbon-to-gas conversions remained above 80% for 4 hours and hydrogen productions above 70% in any O/C ratio used. This catalyst combination also showed role in suppressing the rate of C2 formation side reactions. It was also found that increase of oxygen fed into in the system benefited to create more stable carbon-to-gas conversions and hydrogen production profiles. The observed main problem with the experiments was carbon coking at the top of the reactor as a result of feed depolymerisation and decomposition during the spraying process.en
dc.format.extent68+19
dc.format.mimetypeapplication/pdfen
dc.identifier.urihttps://aaltodoc.aalto.fi/handle/123456789/13888
dc.identifier.urnURN:NBN:fi:aalto-201408292539
dc.language.isoenen
dc.locationPKfi
dc.programmeMaster’s Degree Programme in Environomical Pathways for Sustainable Energy Systemsfi
dc.programme.majorBiorefineriesfi
dc.programme.mcodeKM3005fi
dc.rights.accesslevelopenAccess
dc.subject.keywordpyrolysis oilen
dc.subject.keywordaqueous fractionen
dc.subject.keywordoxidative steam reformingen
dc.subject.keywordhydrogenen
dc.titleHydrogen production via reforming of pyrolysis oil aqueous fractionen
dc.typeG2 Pro gradu, diplomityöen
dc.type.okmG2 Pro gradu, diplomityö
dc.type.ontasotMaster's thesisen
dc.type.ontasotDiplomityöfi
dc.type.publicationmasterThesis
local.aalto.digifolderAalto_05479
local.aalto.idinssi49667
local.aalto.openaccessyes
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