THE REACTIVITY OF PREHYDROLYZED SOFTWOOD KRAFT PULPS AFTER PROLONGED COOKING FOLLOWED BY CHLORITE DELIGNIFICATION
In a laboratory study high-quality spruce chips were prehydrolyzed to remove hemicelluloses and then kraft cooked to different kappa numbers by varying the cooking time. Each pulp sample was then chlorite delignified to selectively remove the remaining lignin. The reactivities of the pulp samples be...
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North Carolina State University
2011-05-01
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doaj-3df9cd7432b942faa9b014c8d2fde5ac2020-11-24T23:51:50ZengNorth Carolina State UniversityBioResources1930-21262011-05-016325812591THE REACTIVITY OF PREHYDROLYZED SOFTWOOD KRAFT PULPS AFTER PROLONGED COOKING FOLLOWED BY CHLORITE DELIGNIFICATIONUlf GermgardMuhammad Asif JavedIn a laboratory study high-quality spruce chips were prehydrolyzed to remove hemicelluloses and then kraft cooked to different kappa numbers by varying the cooking time. Each pulp sample was then chlorite delignified to selectively remove the remaining lignin. The reactivities of the pulp samples before and after chlorite delignification were determined by Fock’s test, which is supposed to measure the pulp’s reactivity in the conventional viscose process. A number of analyses were carried out to determine which parameters affected pulp reactivity, as, for example: intrinsic viscosity, kappa number, pulp yield, carbohydrate composition, levelling-off degree of polymerization (LODP), and alkali solubility. The results of the study showed that the pulp reactivity increased with decreasing kappa number, and the highest reactivity was obtained after total lignin removal using chlorite delignification. It was also found that the carbohydrate composition had no influence on the pulp reactivity, but lower intrinsic viscosity either obtained by prolonged cooking or chlorite delignification correlated with higher pulp reactivity. Finally, lower alkali solubility, i.e. higher R18, reduced the reactivity.http://www.ncsu.edu/bioresources/BioRes_06/BioRes_06_3_2581_Javed_G_Reactivity_Prehyd_Kraft_Chlorite_Delig_1652.pdfAlkali solubilityCarbohydrate compositionChlorite delignificationLevelling-off degree of polymerizationPulp reactivityR18S18 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Ulf Germgard Muhammad Asif Javed |
spellingShingle |
Ulf Germgard Muhammad Asif Javed THE REACTIVITY OF PREHYDROLYZED SOFTWOOD KRAFT PULPS AFTER PROLONGED COOKING FOLLOWED BY CHLORITE DELIGNIFICATION BioResources Alkali solubility Carbohydrate composition Chlorite delignification Levelling-off degree of polymerization Pulp reactivity R18 S18 |
author_facet |
Ulf Germgard Muhammad Asif Javed |
author_sort |
Ulf Germgard |
title |
THE REACTIVITY OF PREHYDROLYZED SOFTWOOD KRAFT PULPS AFTER PROLONGED COOKING FOLLOWED BY CHLORITE DELIGNIFICATION |
title_short |
THE REACTIVITY OF PREHYDROLYZED SOFTWOOD KRAFT PULPS AFTER PROLONGED COOKING FOLLOWED BY CHLORITE DELIGNIFICATION |
title_full |
THE REACTIVITY OF PREHYDROLYZED SOFTWOOD KRAFT PULPS AFTER PROLONGED COOKING FOLLOWED BY CHLORITE DELIGNIFICATION |
title_fullStr |
THE REACTIVITY OF PREHYDROLYZED SOFTWOOD KRAFT PULPS AFTER PROLONGED COOKING FOLLOWED BY CHLORITE DELIGNIFICATION |
title_full_unstemmed |
THE REACTIVITY OF PREHYDROLYZED SOFTWOOD KRAFT PULPS AFTER PROLONGED COOKING FOLLOWED BY CHLORITE DELIGNIFICATION |
title_sort |
reactivity of prehydrolyzed softwood kraft pulps after prolonged cooking followed by chlorite delignification |
publisher |
North Carolina State University |
series |
BioResources |
issn |
1930-2126 |
publishDate |
2011-05-01 |
description |
In a laboratory study high-quality spruce chips were prehydrolyzed to remove hemicelluloses and then kraft cooked to different kappa numbers by varying the cooking time. Each pulp sample was then chlorite delignified to selectively remove the remaining lignin. The reactivities of the pulp samples before and after chlorite delignification were determined by Fock’s test, which is supposed to measure the pulp’s reactivity in the conventional viscose process. A number of analyses were carried out to determine which parameters affected pulp reactivity, as, for example: intrinsic viscosity, kappa number, pulp yield, carbohydrate composition, levelling-off degree of polymerization (LODP), and alkali solubility. The results of the study showed that the pulp reactivity increased with decreasing kappa number, and the highest reactivity was obtained after total lignin removal using chlorite delignification. It was also found that the carbohydrate composition had no influence on the pulp reactivity, but lower intrinsic viscosity either obtained by prolonged cooking or chlorite delignification correlated with higher pulp reactivity. Finally, lower alkali solubility, i.e. higher R18, reduced the reactivity. |
topic |
Alkali solubility Carbohydrate composition Chlorite delignification Levelling-off degree of polymerization Pulp reactivity R18 S18 |
url |
http://www.ncsu.edu/bioresources/BioRes_06/BioRes_06_3_2581_Javed_G_Reactivity_Prehyd_Kraft_Chlorite_Delig_1652.pdf |
work_keys_str_mv |
AT ulfgermgard thereactivityofprehydrolyzedsoftwoodkraftpulpsafterprolongedcookingfollowedbychloritedelignification AT muhammadasifjaved thereactivityofprehydrolyzedsoftwoodkraftpulpsafterprolongedcookingfollowedbychloritedelignification AT ulfgermgard reactivityofprehydrolyzedsoftwoodkraftpulpsafterprolongedcookingfollowedbychloritedelignification AT muhammadasifjaved reactivityofprehydrolyzedsoftwoodkraftpulpsafterprolongedcookingfollowedbychloritedelignification |
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