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Catalyst accessibility and acidity in the hydrocracking of HDPE: a comparative study of H-USY, H-ZSM-5, and MCM-41 modified with Ga and Al

dc.contributor.authorCosta, Cátia S.
dc.contributor.authorRibeiro, M. Rosário
dc.contributor.authorSilva, Maria João
dc.date.accessioned2024-10-01T07:21:18Z
dc.date.available2024-10-01T07:21:18Z
dc.date.issued2024
dc.description.abstractPlastic pollution is a critical environmental issue due to the widespread use of plastic materials and their long degradation time. Hydrocracking (HDC) offers a promising solution to manage plastic waste by converting it into valuable products, namely chemicals or fuels. This work aims to investigates the effect of catalyst accessibility and acidity on the HDC reaction of high density polyethylene (HDPE). Therefore, a variety of materials with significant differences in both textural and acidic properties were tested as catalysts. These include H-USY and H-ZSM.5 zeolites with various Si/Al molar ratios (H-USY: Si/Al = 2.9, 15, 30 and 40; H-ZSM-5: Si/Al = 11.5, 40, 500) and mesostructured MCM-41 materials modified with Ga and Al, also with different Si/metal ratios (Si/Al = 16 and 30; Si/Ga = 63 and 82). Thermogravimetric analysis under hydrogen atmosphere was used as a preliminary screening tool to evaluate the potential of the various catalysts for this application in terms of energy requirements. In addition, batch autoclave reactor experiments (T = 300 °C, PH2 = 20 bar, t = 60 min) were conducted to obtain further information on conversion, product yields and product distribution for the most promising systems. The results show that the catalytic performance in HDPE hydrocracking is determined by a balance between the acidity of the catalyst and its structural accessibility. Accordingly, for catalyst series where the structural and textural properties do not vary with the Si/Al ratio, there is a clear correlation of the HDPE degradation temperature and of the HDPE conversion with the Si/metal ratio (which relates to the acidic properties). In contrast, for catalyst series where the structural and textural properties vary with the Si/Al ratio, no consistent trend is observed and the catalytic performance is determined by a balance between the acidic and textural properties. The product distribution was also found to be influenced by the physical and chemical properties of the catalyst. Catalysts with strong acidity and smaller pores were observed to favor the formation of lighter hydrocarbons. In addition to the textural and acidic properties of the catalyst, the role of coke formation should not be neglected to ensure a comprehensive analysis of the catalytic performance.pt_PT
dc.description.versioninfo:eu-repo/semantics/publishedVersionpt_PT
dc.identifier.citationCosta CS, Ribeiro MR, Silva JM. (2024) Catalyst Accessibility and Acidity in the Hydrocracking of HDPE: A Comparative Study of H-USY, H-ZSM-5, and MCM-41 Modified with Ga and Al. Molecules 29(17):4248. https://doi.org/10.3390/molecules29174248pt_PT
dc.identifier.doi10.3390/molecules29174248pt_PT
dc.identifier.urihttp://hdl.handle.net/10400.21/17715
dc.language.isoengpt_PT
dc.peerreviewedyespt_PT
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/pt_PT
dc.subjectHydrocrackingpt_PT
dc.subjectMesoporous silicaspt_PT
dc.subjectZeolitespt_PT
dc.subjectAciditypt_PT
dc.subjectAccessibilitypt_PT
dc.titleCatalyst accessibility and acidity in the hydrocracking of HDPE: a comparative study of H-USY, H-ZSM-5, and MCM-41 modified with Ga and Alpt_PT
dc.typejournal article
dspace.entity.typePublication
oaire.citation.issue17pt_PT
oaire.citation.startPage4248pt_PT
oaire.citation.titleMoleculespt_PT
oaire.citation.volume29pt_PT
person.familyNameGomes Ribeiro
person.familyNameSilva
person.givenNameMaria do Rosário
person.givenNameMaria João
person.identifierE-6381-2013
person.identifier.ciencia-id3F1B-A9AE-3FB8
person.identifier.ciencia-id5D1E-8C69-29D5
person.identifier.orcid0000-0003-1704-1362
person.identifier.orcid0000-0003-1017-8315
person.identifier.scopus-author-id35146650100
rcaap.rightsopenAccesspt_PT
rcaap.typearticlept_PT
relation.isAuthorOfPublication376a7113-b766-40c6-aac4-00b4b7b1001c
relation.isAuthorOfPublicationa26ab1ca-f44e-440c-8531-c080f6d7a082
relation.isAuthorOfPublication.latestForDiscoverya26ab1ca-f44e-440c-8531-c080f6d7a082

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