tailieunhanh - Production of dissolving grade pulp from poplar wood by ethanol water process

The possibilities of dissolving grade pulp production from poplar by an ethanol-water process were investigated. The effects of ethanol ratio, cooking temperature and acid catalyst ratio on unbleached, bleached and alkali-purified pulps were studied. It was seen that catalyst ratios exceeding caused serious yield and viscosity losses. | Turk J Agric For 26 (2002) 239-245 © TÜB‹TAK Production of Dissolving Grade Pulp from Poplar Wood by Ethanol-Water Process Hüseyin KIRCI Karadeniz Technical University, Faculty of Forestry, 61080 Trabzon - TURKEY Mehmet AKGÜL Sütçüimam University, Faculty of Forestry, Kahramanmarafl - TURKEY Received: Abstract: The possibilities of dissolving grade pulp production from poplar by an ethanol-water process were investigated. The effects of ethanol ratio, cooking temperature and acid catalyst ratio on unbleached, bleached and alkali-purified pulps were studied. It was seen that catalyst ratios exceeding caused serious yield and viscosity losses. The results showed that with the catalyst ratio to pulping liquor exceeding , pulp yield and viscosity were reduced to an unacceptable level. The best pulping result was obtained at 40% ethanol consistency, 180 ºC pulping temperature and 150 min reaction time without the addition of acid catalyst to the pulping liquor. After bleaching and alkali purification, the pulp obtained had a yield, α-cellulose content, 677 cm3/g viscosity, 83% ISO brightness, residual pentosans, copper number and ash content. However, brightness was increased to ISO level with the application of a multistage bleaching (CEHDED) sequence instead of chlorite bleaching without serious losses in yield or α-cellulose content at normal viscosity levels. It is concluded that these pulps meet dissolving grade pulp quality requirements. Key Words: Poplar, organosolv pulping, ethanol-water pulping, dissolving pulp, alpha-cellulose Etanol-Su Piflirme Yöntemiyle Kavak Odunundan Çözünür Hamur Üretimi Özet: Bu çal›flmada kavak odunundan etanol-su yöntemiyle selüloz türevleri endüstrisinde kullan›lacak çözünür hamur üretimi imkanlar› araflt›r›ld›. Esmer, a¤art›lm›fl ve alkali ile saflaflt›r›lm›fl hamur özellikleri üzerine etanol oran›, piflirme s›cakl›¤› ve asit katalizör oran›n›n etkisi çal›fl›ld›. .