Mh. Kucuk et A. Demirbas, DELIGNIFICATION OF AILANTHUS-ALTISSIMA AND SPRUCE-ORIENTALIS WITH GLYCEROL OR ALKALINE GLYCEROL AT ATMOSPHERIC-PRESSURE, Cellulose Chemistry and Technology, 27(6), 1993, pp. 679-686
Wood chips of Ailanthus altissima and Spruce orientalis were delignifi
ed in either glycerol or alkaline glycerol process, at atmospheric pre
ssure, for the production of pulps. For a typical run, increasing the
reaction time and the reaction temperature from 438 to 498 K raises th
e yield of the removed lignin from 56.2 to 87.9% but decreases the yie
ld of the recovered cellulose from 91.0 82.7% by using 10% sodium hydr
oxide catalyst, for a 9 hours reaction time (for Ailanthus altissima).
Without using any catalyst, the same yields were found as 48.7 - 77.4
% for lignin, 96.0 - 92.6 % for cellulose, in the same range of temper
ature and reaction time. Within the range of reaction parameters studi
ed: temperature (438 - 498 K), catalyst (sodium hydroxide or sodium ca
rbonate), amount of catalyst (5.0 - 10.0 wt % of used sample), chip si
ze (0.3 mm x 15 mm x 15 mm or 2 mm x 15 m x 15 mm) and role of the gly
cerol, temperature and chip size were the most important variables. Th
e pulp yield obtained by this method was 52 % and kappa number was 15.
7 (for Ailanthus altissima).