Pulp and paper
Mohammad taghi Asdolah zadeh; Hossein Resalti; Ali Ghasemian
Abstract
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 ...
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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.
Pulp and paper
Noraldin Nazarnezhad; Mohammad taghi Asdolahzadeh
Abstract
This study was investigated the effect of Trametes versicolor on chemimechanical pulp (CMP) delignification. CMP were obtained from Mazanderan wood and paper industries. Circle mats were made from CMP (diameter, 7cm; thickness, 1mm) and fortified with 1g/Lit yeast juice. After sterilized, pulp mats were ...
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This study was investigated the effect of Trametes versicolor on chemimechanical pulp (CMP) delignification. CMP were obtained from Mazanderan wood and paper industries. Circle mats were made from CMP (diameter, 7cm; thickness, 1mm) and fortified with 1g/Lit yeast juice. After sterilized, pulp mats were incubated with tow disks punched from mycelium. The duration of incubate were 5, 10, 15 & 20 days as well as temperature and moisture 25oC and 40%, respectively. Standard hand sheets were made from biodelignification pulp, and was measured mechanical and optical properties. The portion of biodelignification pulp was alkaline extracted under condition of pulp consistency, 10%; temperature, 70oC; time, 80min and 2% sodium hydroxide, and then bleached under conditions of pulp consistency, 10%; temperature, 50oC; time, 60min and 4% hydrogen peroxide. Finally, mechanical and optical properties of standard hand sheet were measured. Results showed optimum time was 10 days that decreased 5.9% lignin. Mechanical properties of treated samples were lower than control samples, but statically were not significant. Optical properties of treated samples were lower than control samples but alkaline extraction and then bleaching with sodium peroxide was increase it.
