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New catalytic bleaching sequences for kraft pulp

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dc.contributor Aalto-yliopisto fi
dc.contributor Aalto University en
dc.contributor.advisor Afsahi, Ghazaleh
dc.contributor.advisor Vehmaa, Janne
dc.contributor.author Isaza Ferro, Estefania
dc.date.accessioned 2017-09-04T08:37:33Z
dc.date.available 2017-09-04T08:37:33Z
dc.date.issued 2017-08-29
dc.identifier.uri https://aaltodoc.aalto.fi/handle/123456789/27891
dc.description.abstract The modern pulp industry has endeavoured to maximize its efficiency and minimize its environmental impact for decades. The bleaching process has a major impact on the heat, power and chemical consumption of the pulp mill, and hence bleaching constitutes an at-tractive process to be optimized in order to increase the performance of the mill further. Catalytic bleaching is a novel discovery which could decrease the duration of the bleaching processes. So far the catalytic bleaching has been demonstrated to work successfully only in the HcatZP sequence. For this reason, the goal of this thesis was to clarify if new kraft pulp bleaching sequences with initial chlorine dioxide (D) stage and an intermediate Hcat stage could provide fully bleached pulps. In order to design the new catalytic sequences, a literature review was elaborated on diffrerences between softwood and hardwood kraft pulps, the basics of pulp bleaching, the reactions of lignin and carbohydrates during bleaching processes and the ideal operational parameters in these processes. The eucalyptus pulp bleaching sequences studied included D0EHcatP which achieved a final brightness of 88.0% ISO and HcatZ/DP which attained a brightness of 89.2% ISO. Addi-tionally, a reference trial AEOPDP was performed to check the bleachability of the pulp. This sequence achieved a brightness of 88.0% ISO, which suggested that the pulp used was quite hard to bleach. In conclusion, HcatZ/DP was the best sequence for catalytic bleaching of eucalyptus kraft pulp. The softwood bleaching sequence OEOPHcatDP reached a final brightness of 75.2% ISO. en
dc.format.extent 50
dc.language.iso en en
dc.title New catalytic bleaching sequences for kraft pulp en
dc.type G2 Pro gradu, diplomityö fi
dc.contributor.school Kemian tekniikan korkeakoulu fi
dc.subject.keyword kraft pulp en
dc.subject.keyword pulp bleaching en
dc.subject.keyword catalytic bleaching en
dc.subject.keyword Hcat en
dc.subject.keyword hardwood en
dc.identifier.urn URN:NBN:fi:aalto-201709046790
dc.programme.major Biomass Refining fi
dc.programme.mcode CHEM3021 fi
dc.type.ontasot Master's thesis en
dc.type.ontasot Diplomityö fi
dc.contributor.supervisor Vuorinen, Tapani
dc.programme Master's Programme in Chemical, Biochemical and Materials Engineering fi
dc.ethesisid Aalto 9530
dc.location P1


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