Neutral sulfite semi-chemical (NSSC) pulping of rapeseed residues from Karadj rapeseed growing fields was investigated. Rapeseed residue was collected from the research field at the Agriculture and Natural Resources Campus, University of Tehran located in Karadj. | Research Article Turk J Agric For 34 (2010) 11-16 © TÜBİTAK doi: Neutral sulfite semi-chemical pulping of rapeseed residues Mohammad AHMADI1, Ahmad Jahan LATIBARI2,*, Mehdi FAEZIPOUR1, Sahab HEDJAZI1 1 College of Natural Resources , University of Tehran, Karadj, IRAN 2Agriculture Research Center, College of Agriculture and Natural Resources, Islamic Azad University, Karadj Branch, Karadj, IRAN Received: Abstract: Neutral sulfite semi-chemical (NSSC) pulping of rapeseed residues from Karadj rapeseed growing fields was investigated. Rapeseed residue was collected from the research field at the Agriculture and Natural Resources Campus, University of Tehran located in Karadj. Cellulose, lignin, holocellulose, extractives soluble in alcohol acetone, 1% NaOH solubility, and ash were determined as 42 ± 2%, 17 ± 1%, ± 2%, ± , ± , and 6%, respectively. Fiber length, width, and cell wall thickness were measured as mm, 32 μm, and 4 μm. Three pulping durations of 20, 40, and 60 min and 5 chemical charges of 8%, 10%, 12%, 14%, and 16% active alkali were used. Cooking temperature at 175 °C, Na2SO3 to Na2CO3 ratio of 3:1, and liquor to residue ratio of 8:1 were kept constant. The highest yield (72%) was obtained applying the treatment combination of 20 min pulping time and 8% active alkali and the lowest yield () was observed with 60 min pulping time and 16% chemical. After the pulping study, selected pulps were refined –2 to 375 ± 5 mL CSF and 60 gm handsheets were made. The results of pulping and handsheet evaluation indicated that 12% active alkali, 60 min pulping at 175 °C can be considered as the optimum pulping condition for rapeseed residues. 2 –1 –1 Tear, tensile, and burst indices and breaking length of this pulp were measured as mN m g , N mg , kPa 2 –1 m g , and km, respectively. Key words: Rapeseed, NSSC, yield, strength, optical, fiber length Introduction Paper was invented .
