The effects of hot water pre-extraction and alkaline catalyzed on soda-AQ pulping of kenaf whole stem

Autor: Mohammad taghi Asdolah zadeh, Hossein Resalti, Ali Ghasemian
Jazyk: perština
Rok vydání: 2011
Předmět:
Zdroj: تحقیقات علوم چوب و کاغذ ایران, Vol 26, Iss 3, Pp 437-453 (2011)
Druh dokumentu: article
ISSN: 1735-0913
2383-112X
DOI: 10.22092/ijwpr.2011.117200
Popis: In the present study the effects of hot water pre-extraction and alkaline catalyzed were evaluated on soda-aq pulping of kenaf whole stem. In this respect, following kenaf chips pre-extraction at various temperature and time conditions, pulp preparation were carried out on oven-dried weight loss levels of 8.5, 11.5 and 14.5 % of the samples, and the reference untreated kenaf chips performed by using Soda-AQ at 3 levels of H-factors ( 983, 1408 and 1832 hours). Results indicated that kenaf chips weight losses increased while the pre-extracted pH decreased as pre-extraction temperature and time increased. The required H-factor for achieving certain level of weight loss was reduced by adding small amounts of alkali (0.15 % on oven dried kenaf) on hot water extraction stage. The Pulp yields were reduced by increasing cooking H-factor and extracted weight loss. Averages comparison indicated that significant differences were observed, at 95% confidence, between the pulp yield and kappa number from reference pulp and pre-extracted pulp samples at levels of about 8.5, 11.5 and 14.5 %, and pulp yields and their kappa number were higher in reference pulps than pre-extracted samples. In addition, pulp yield average was higher in pre-extracted samples by alkaline catalyzed than pre-extracted samples by hot water, however, no significant differences were observed between their kappa number average. Meanwhile, to obtain a certain (similar) kappa number, pre-extracted kenaf chips in comparison with reference untreated kenaf chips require lower H-factor.
Databáze: Directory of Open Access Journals
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