Dissolving pulp obtaining possibilities by organasolv pulp from poplar wood

Dissolving Pulp Obtaining Possibilities by Organosolv Pulp from Poplar Wood. In this study, it was showed that is possible to product of the dissolving pulp from fast growing species such as poplar by using organosolv pulping process with or without catalysts. In order to find optimum cooking conditions, 4 control and 30 different cooking experiments were done. The effects of ethanol ratio, cooking temperature and time as well as catalyst ratio were studied. After cooking, pulps produced were bleached by using chlorite delignification technique, following that the pulp were purified by cold-alkali extraction. The obtained results show that with the catalyst ratio exceeding 0.01 %, the pulp yield reduced to unacceptable level. From this results, it was found that the high catalyst ratio is not suitable for pulp production under studied conditions. The best pulping result was obtained at 180 °C, without catalyst and for 150 minutes. The optimum pulping conditions were obtained with liquor to chips ratio of 8/1, 40 % ethanol ratio at 180 °C for 150 minutes cooking time without catalyst. The chemical properties and yield of the produced pulp are shown as below: - Total yield (according to raw material ) : 30.74 % - Alpha-cellulose : 95.82 % - Viscosity : 677 cm3/g - Brightness : 82.87% -Pentosans : 1.80 % - Copper Number : 0.33 % - Ash Ratio : 0. 14 % Finally, the organosolv pulp of the poplar wood produced under optimum conditions showed acceptable properties required by the cellulose derivatives industry. Key Words: Poplar, organosolv pulping, delignification, ethanol-water cooking, bleaching, cold-alkali extraction, dissolving pulp, alpha-cellulose, viscosity, brightness, pentosans, copper number.