Abstract

The redisposition of lignin to the fiber face after organosolv pre-treatment was studied using two different reactor types. Results from the conventional autoclave reactor suggest that redisposition occurs during the cooling down stage. Redeposited patches appeared to be globular in shape. The size and population viscosity of the patches depends on the attention of organosolv lignin in the cuisine liquor, which is harmonious with the thesis that reprecipitation of lignin occurs when the system is cooled down. The use of a relegation reactor showed that displacing the spent cooking liquor with fresh cuisine liquor helps in reducing the redisposition and the addition of a washing stage with fresh cuisine liquor reduced the reprecipitation of lignin, particularly on the external fiber shells. Redeposition of lignin was still observed on regions that were less accessible to washing liquid, similar as fiber lumens, suggesting that complete forestalment of redisposition wasn’t achieved.