Reinvestigating the concurring reactions in early-stage cellulose pyrolysis by solution state NMR spectroscopy

dc.contributorAalto-yliopistofi
dc.contributorAalto Universityen
dc.contributor.authorFliri, Lukasen_US
dc.contributor.authorGuizani, Chamseddineen_US
dc.contributor.authorMiranda-Valdez, Isaac Yairen_US
dc.contributor.authorPitkänen, Leenaen_US
dc.contributor.authorHummel, Michaelen_US
dc.contributor.departmentDepartment of Bioproducts and Biosystemsen
dc.contributor.groupauthorBiopolymer Chemistry and Engineeringen
dc.date.accessioned2023-10-11T09:35:27Z
dc.date.available2023-10-11T09:35:27Z
dc.date.issued2023-10en_US
dc.descriptionFunding Information: The authors gratefully acknowledge funding from the Academy of Finland (Project: 348354 ). The authors thank Muhammad Awais for help in the visualization of the results. Publisher Copyright: © 2023 The Authors
dc.description.abstractLow temperature pre-treatments increase the char yield during cellulose carbonization. Although this effect is mostly understood on a kinetic basis, the formed chemical structures leave room for scrutiny. In ongoing ambitions to enhance the char yield of bioderived precursors, the thereby occurring chemistry was reinvestigated. A set of isothermal heating protocols ranging from 150° to 250°C was applied to man-made Ioncell® cellulose fibers and to Avicel® PH-101 microcrystalline cellulose. The prepared cellulosic samples were examined by solution state NMR using a tetra-n-butyl phosphonium acetate ([P4444][OAc]): DMSO-d6 (1:4 wt%) electrolyte as dissolving medium. Complementary, IR spectroscopy, size-exclusion chromatography (SEC) and thermogravimetric analysis coupled with mass spectroscopy (TGA-MS) measurements were performed. The NMR spectra evidenced the formation of levoglucosan end capped moieties as being the first and major occurring reaction during low temperature pre-treatments. In contrast to other mechanistic proposals, no signs for carbonyl or alkene functionalities were discernible in the cellulosic material soluble in the NMR electrolyte, even after treatment at 250 °C for several hours. Thermal cross-linking was observed in SEC already at temperatures not known to significantly influence the overall char yield. In the solution state analytics only partial solubility was observed, owing to the formation of a reluctant fraction previously described as “thermostable condensed phase”. This resulted in analytical blind spots and led to discrepancies between NMR results and FTIR spectra in which carbonyl and alkene vibrations were clearly discernible. Those discrepancies might also imply the co-existence of different fractions in the early stages of cellulose pyrolysis.en
dc.description.versionPeer revieweden
dc.format.extent13
dc.format.mimetypeapplication/pdfen_US
dc.identifier.citationFliri, L, Guizani, C, Miranda-Valdez, I Y, Pitkänen, L & Hummel, M 2023, ' Reinvestigating the concurring reactions in early-stage cellulose pyrolysis by solution state NMR spectroscopy ', Journal of Analytical and Applied Pyrolysis, vol. 175, 106153 . https://doi.org/10.1016/j.jaap.2023.106153en
dc.identifier.doi10.1016/j.jaap.2023.106153en_US
dc.identifier.issn0165-2370
dc.identifier.otherPURE UUID: 7c37ec67-7caf-419b-a9a3-396fead8f9d3en_US
dc.identifier.otherPURE ITEMURL: https://research.aalto.fi/en/publications/7c37ec67-7caf-419b-a9a3-396fead8f9d3en_US
dc.identifier.otherPURE LINK: http://www.scopus.com/inward/record.url?scp=85170407540&partnerID=8YFLogxKen_US
dc.identifier.otherPURE FILEURL: https://research.aalto.fi/files/123840857/CHEM_Fliri_et_al_Reinvestigating_the_concurring_2023_J_Anal_Appl_Pyrol.pdfen_US
dc.identifier.urihttps://aaltodoc.aalto.fi/handle/123456789/123914
dc.identifier.urnURN:NBN:fi:aalto-202310116261
dc.language.isoenen
dc.publisherElsevier Science B.V.
dc.relation.ispartofseriesJournal of Analytical and Applied Pyrolysisen
dc.relation.ispartofseriesVolume 175en
dc.rightsopenAccessen
dc.subject.keywordActive celluloseen_US
dc.subject.keywordCellulose carbonizationen_US
dc.subject.keywordChar yielden_US
dc.subject.keywordLow temperatureen_US
dc.subject.keywordPre-treatmenten_US
dc.titleReinvestigating the concurring reactions in early-stage cellulose pyrolysis by solution state NMR spectroscopyen
dc.typeA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessäfi
dc.type.versionpublishedVersion

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