The objectives of this work were to investigate and improve impregnation of regular (2-8mm thickness range) black spruce wood chips in CMP-AQ pulping. Impregnation and pulping experiments were performed while varying several pulping parameters. Experiments were analyzed in terms of yield, lignin content, percent screen rejects, and strength properties. The goal was to determine optimum pulping conditions that would improve chemical impregnation. Impregnation is a function of percent screen rejects: well impregnated chips have fewer rejects. / Cooking temperature and cooking time were held constant in all experiments at 170$ sp circ$C and 30 minutes, respectively. The liquor pH was adjusted to 7.9 and a liquor-to-wood ratio of 6:1 was used. Presteaming pressure was held constant at 138 kPa and soaking temperature was maintained isothermal at 90$ sp circ$C. / Process variables which can influence the chemical penetration were investigated. These are: wood chip thickness, pre-treatment agents, compression ratio, partial crushing of wood chips, and also pre-steaming and evacuation prior to chemical treatment as a possible method of entrapped air removal. Additional process parameters investigated were the concentration of pulping chemicals and dosage of AQ catalyst. / The advantages provided by the use of thinner wood chips, caustic pretreatment and high compression prex-impregnation were confirmed for improving chemical impregnation. The addition of SAQ catalyst to the CMP pulping process produced pulps of unusually high screened yield for given lignin content. Improvements were also observed in strength properties compared to the control cook where no SAQ was used.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.24070 |
| Date | January 1996 |
| Creators | Rowat, Alison. |
| Contributors | Kubes, G. J. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Engineering (Department of Chemical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001537811, proquestno: MM19880, Theses scanned by UMI/ProQuest. |
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