화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.50, No.4, 1847-1852, 2011
Pulpability and Bleachability of Xylan-Depleted Eucalyptus Wood Chips
Wood autohydrolysis for xylan removal prior to kraft pulping and the consequences of this practice downstream in a kraft pulp mill has been investigated Chip autohydrolysis for 60 min at 165 degrees C removed 61% of the xylans, but subsequent}craft cooking produced a 9.4% lower yield than reference. Pulp from 60 mm autohydrolyzed chips showed 75% efficiency in oxygen delignification compared to 43.6% from the reference, resulting in a subsequent ECP bleaching cost reduction of 36% and significant effluent improvement. The chip autohydrolysis process resulted in a pulp of higher bulk, lower beatability and strength in relation to the reference, and an acid hydrolysate of low xylan concentration. Pulp cellulose and xylan derived from autohydrolyzed chips are less stable during kraft pulping because of their low molecular weight and high polydispersity. Xylan lignin and cellulose lignin complexes from kraft pulps derived from autohydrolyzed chips contain lignin of higher molecular weight than that of regular kraft pulp.