• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2006.06b
• /
• pp.291-294
• /
• 2006

Studies of the effectiveness of anthraquinone (AQ) in kraft-AQ pulping in terms of its mechanism of mass transfer have been conducted. Experiments performed have demonstrated an 'apparent solubility' of AQ in caustic solutions of wood lignin. The adsorption behavior of AQ species was also analyzed. Anthraquinone-2-sulfonic acid (AQ-S), a water-soluble derivative of AQ, showed selective adsorption on wood. A mechanism for the transport of AQ into wood chips during kraft pulping are proposed, and some explanations for previously unexplained observations are addressed.

• Journal of the Korean Wood Science and Technology
• /
• v.29 no.4
• /
• pp.103-110
• /
• 2001

Bio-kraft pulping of Populus alba${\times}$glandulosa pretreated with white-rot fungus, Phanerochaete chrysosporium KCCM 34740, was investigated The biopulping efficiency was evalued based on fungal pretreatment time and properties of bio-kraft pulp (pulp yield, freeness, WRY, kappa number and brightness) in comparison to the controls. Pretreatment of poplar wood chips with Phanerochaete chrysosporium KCCM 34740 for 10days resulted in a some increase in screened yield (by 2%). According to increase of fungal incubation time, decrease in freeness (CSF) and increase in WRY were observed And bio-kraft pulping also led to improvement of physical properties of handsheet. As a result of bio-beating effect, we expect the saving of chemicals in kraft cooking process and energy consumption in beating process.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.44 no.6
• /
• pp.1-8
• /
• 2012

This study was carried out to explore optimum use of the products generated from the National Forest Management Operation (NFMO) as raw materials for kraft pulp. First of all, different wood species from NFMO were randomly mixed, and then they were used to make kraft pulp under the specified condition. All kraft pulps made from the mixed species displayed equal physical properties to those from foreign wood chips used in Moorim P&P Co. Ltd. For optical properties, most of the unbleached pulps had high brightness but the pulp made from wood species containing chestnut tree showed the lowest brightness due to its high kappa number. Finally, the products from NFMO had little negative effects on the properties of kraft pulps. This means that they could be used as complementary raw materials for kraft pulps with foreign wood chips.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.44 no.5
• /
• pp.63-71
• /
• 2012

This study was carried out to investigate pulping properties of the forest biomass arising from the national forest management operation. The forest biomass was collected and classified into many groups according to their species and age. After the chips were made from the forest biomass, the measurement of chip size and chemical analysis were performed. To make the pulps from the forest biomass, the kraft pulping was applied and thereafter the physical and optical properties of kraft pulps were measured. The pulp fibers from the forest biomass had the similar mean fiber length, but their properties became different according to wood species and ages. Differently from the other species, kraft pulps from chestnut wood had the highest kappa number. Acacia, paulownia and chestnut woods made kraft pulps with lower tensile strength and brightness than the others. It could be concluded that acacia, paulownia and chestnut woods must be screened out in order to make a good quality of kraft pulps while being collected during Forest Management Operation.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.46 no.3
• /
• pp.50-57
• /
• 2014

In this study, we investigated the physical properties of kraft pulps made from rice husk, peanut husk and garlic stems. These agricultural byproducts were collected individually, and then various pulps were manufactured from them by controlling active alkali, sulfidity, reaction time and the liquor ratio in the kraft pulping process in order to analyze the applicability of these agricultural byproducts as raw materials for kraft pulps. After kraft pulping, we measured yield, flake content, fiber length, fiber width and freeness of pulps, and the fiber shapes of the pulps were observed by using an optical microscope. When the higher active alkali, longer reaction time and lower liquor ratio were applied in kraft pulping process, reject content decreased and fiber yield increased. The pulp from garlic stems had the longest fiber length and that from rice husk showed the highest intial freeness. All of the pulps from agricultural byproducts showed higher initial freeness, shorter fiber length and the similar fiber width compared to OCC, BCTMP and hardwood BKP. The fibers of the pulps made from agricultural byproducts showed a similar shape to those of commercial pulps. It was concluded that these agricultural byproducts had a potential as raw materials to produce an alternative pulp to the commercial pulps.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.30 no.1
• /
• pp.44-58
• /
• 1998

This study was carried out to bleach the Oakwood kraft pulp without the elemental chlorine using the xylanase or wastewater(We : wastewater enzymes) effluented from the submerged biofilter reactor containing the fungi, Phanerorhaete sordida YK-624. So in this research, the proper treatment conditions (pH, temperature, dosage and time) were investigated respectively. And after the various kinds of multistage bleaching of pulps, the properties of pulps were tested. From the experimental results, we can conclude as follows. In the treatments of Oakwood kraft pulps with xylanase, the proper pH, temperature, enzyme dosage and time were 8.0, $35^{\circ}C$ , 400 EXU/kg and 1 hr. respectively. And in the case of treatment with a wastewater(We) effluented from the submerged biofilter reactor, the proper pH, temperature and time were 5.5, $37^{\circ}C$ and 2 hr. respectively. On the other hand, Oakwood kraft pulps were bleached by the method of a multistage bleaching using xylanase or We instead of elemental chlorine Consequently the strengthes and brightnesses of pulps bleached by the method mentioned above were lower than those of pulp bleached by the conventional method using the elemental chlorine. But it is possible to improve the brightnesses through the increase of chlorine dioxide dosage or use of hydrogen peroxide in the final bleaching stage.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.30 no.3
• /
• pp.84-96
• /
• 1998

This study was carried out to bleach the Pinewood kraft pulp without the elemental chlorine using the xylanase or wastewater(We:wastewater enzymes) effluented from the submerged biofilter reactor containing the fungi, Phanerochaete sordida YK-624. So in this research, the proper treatment conditions(pH, temperature, dosage and time) were investigated respectively. And after the various kinds of multistage bleaching of pulps, the properties of pulps were tested. From the experimental results, we can conclude as follows. In the treatments of Pinewood kraft pulps with xylanase, the proper pH, temperature, enzyme dosage and time were 8.0, $35^{\circ}C, 400EXU/kg and 3 hr. respectively. And in the case of treatment with a wastewater(We) effluented from the submerged biofilter reactor, the proper pH, temperature and time were 5.0, $37^{\circ}C and 3 hr. respectively. On the other hand, Pinewood kraft pulps were bleached by the method of a multistage bleaching using xylanase or We instead of elemental chlorine. Consequently, the strengthes and brightnesses of pulps bleached by the method mentioned above were lower than those of pulp bleached by the conventional method using the elemental chlorine. But it is possible to improve the brightnesses through the increase of chlorine dioxide dosage or use of hydrogen peroxide in the final bleaching stage.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.37 no.3
• /
• pp.33-40
• /
• 2005

In this study, a nano-colloidal silica sol was applied to control the anti-slip property by spraying on kraft paper. Two kinds of nano-colloidal silica sol which have cationic and anionic charge were applied in kraft paper, and the friction and physical strength properties of kraft paper were investigated. The application of colloidal silica sol on wet web in wet-end process by spraying method was tried to improve the friction property and to avoid the general problems of machine contaminations caused by the scattering of sprayed silica particles in dryer part. The physical properties of sheet were also improved by the application of wet web spraying method, and the optimum conditions of wet web spraying operation were closely related with the conditions of pH and electrical charge of wet web and silica sol.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2006.06b
• /
• pp.317-321
• /
• 2006

The investigation of the formation of organic sulfur compounds (i.e., odor species), mainly methyl mercaptan and demethyl suifide, during kraft pulping has been conducted, in which both hardwood and softwood species were used. It was discovered that there is an organic sulfur compounds formation phase transition point with respect to delignification extent. The transition point occurs at a kappa number of approximately 35 and 20 for softwoods and hardwoods, respectively. The results also showed that both low sulfidity and anthraquinone (AQ) addition are helpful to control the formation of theses organic sulfur compounds during kraft pulping. Whereas Hexenuronic acid (HexA) has contribution to Kappa number, the extended delignification not only lead to low pulp yield, but also be adverse to odor control. A significant in-digester odor reduction can be achieved if the pulping is to be terminated before phase transition point and combined with AQ addition.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.31 no.2
• /
• pp.8-14
• /
• 1999

A screening has been performed to find hyper-ligninolytic fungi, which degtrade beech and pine lignin extensively in order to broaden the understanding of the ligninolytic enzymes elaborated by various white-rot fungi. One hundred and twenty two ligninolytic strains were selected from decayed woods with a selective medium for screening ligninolytic wood-rotting fungi. Two of them, Phanerochaete sordida YK-624 and YK-472, showed much higher ligninolytic activity and selectivity in beech-wood degradation than typical lignin-degrading fungi, phanerochaete chrysosporium and Coriolus versicolor. They also degraded birch dioxane lignin and residual lignin in unbleached kraft pulp(UKP) much more extensively than P. chrysosporium and C. versicolor. During fungal treatment of beech wood-powder, the fungus strain P. sordida YK-624 showed higher activity of extracellular manganese peroxidase (MnP) in the medium than P. chrysosporium. It also showed MnP activity, which would not be lignin peroxidast during treatment of oxygen-bleached kraft pulp(OKP) and under enzyme-inducing conditin.