Arrisa Ruangmee and Chayanoot Sangwichien

pp. 443 - 450

Abstract

Response surface methodology with central composite design was applied to optimize alkali pretreatment of narrow-leaf
cattail (Typha angustifolia). Joint effects of three independent variables; NaOH concentration (1-5%), temperature (60-100 ºC),
and reaction time (30-150 min), were investigated to evaluate the increase in and the improvement of cellulosic components
contained in the raw material after pretreatment. The combined optimum condition based on the cellulosic content obtained
from this study is: a concentration of 5% NaOH, a reaction time of 120 min, and a temperature of 100 ºC. This result has been
analyzed employing ANOVA with a second order polynomial equation. The model was found to be significant and was able to
predict accurately the response of strength at less than 5% error. Under this combined optimal condition, the desirable cellulosic content in the sample increased from 38.5 to 68.3%, while the unfavorable hemicellulosic content decreased from 37.6 to
7.3%.