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

• Main Authors: Mohammad taghi Asdolah zadeh, Hossein Resalti, Ali Ghasemian
• Format: Article
• Language: fas
• Published: Regional Information Center for Science and Technology (RICeST) 2011-09-01
• Series: تحقیقات علوم چوب و کاغذ ایران
• Subjects: kenaf; pre-extraction; soda-AQ; yield; kappa number
• Online Access: http://ijwpr.areeo.ac.ir/article_117200_f6038eb7514bffe4f44f7b40b5c1d605.pdf
• ISSN: 1735-0913; 2383-112X

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.