Pulping of holm oak wood. Influence of the operating conditions.
This paper reports on the influence of independent variables in the pulping of holm oak wood (Quercus ilex L.) [viz. temperature (135-195 degrees C), cooking time (30-90min) and soda concentration (10-20%)] on the yield, holocellulose content, alpha-cellulose content, brightness and viscosity of the resulting pulp. By using a central composite factorial design, equations relating each dependent variable to the different independent variables were derived that reproduced the experimental results for the dependent variables with errors less than 5-15% in all cases. The highest pulp yield (56.9%) was obtained with the lowest values of the operating variables. However, obtaining the optimum holocellulose content, alpha-cellulose content and viscosity (viz. 94.5%, 78.5% and 1395ml/g, respectively) entailed using values of the independent variables above their mean levels. Also, ensuring optimal brightness (viz. 24.3%) required using higher temperatures and soda concentrations. A compromise that saves equipment immobilized capital and about 25% of soda is using a soda concentration of 15% at 195 degrees C for 30min. The yield thus obtained differs by less than 29.5% from the highest level; also, the resulting holocellulose content, alpha-cellulose content and brightness differ by less than 12% from their respective optimum values.
López
Francisco
F
Department of Chemical Engineering, University of Huelva, Huelva, Spain.
Alaejos
Joaquín
J
Rodríguez
Alejandro
A
Jiménez
Luis
L
D002482:Cellulose / Q000737:chemistry*; D020650:Combinatorial Chemistry Techniques / Q000379:methods*; D003198:Computer Simulation; D007220:Industrial Waste / Q000517:prevention & control*; D008956:Models, Chemical; D010209:Paper; D029963:Quercus / Q000737:chemistry*; D012037:Refuse Disposal / Q000379:methods; D013696:Temperature; D014934:Wood / Q000737:chemistry*
D007220:Industrial Waste; D002482:Cellulose