Aspects on hydrosulphide sorption in the impregnation phase of kraft cooking

摘要

In this study effects of the impregnation liquor concentrations of effective alkali (NaOH) and sodium carbonate (Na_2CO_3) on the hydrosulphide (HS~-) sorption in wood chips was investigated. It was found that the best (highest) HS~--sorption was obtained when EA was not present in the impregnation liquor, but as soon as it was present, even in low concentrations (e.g. 0.1 mo1/L), it reduced the HS~--sorption. It was also observed, in contradiction to earlier findings, that the presence of sodium carbonate did not facilitate HS~--sorption. Cooking experiments clarified that maximum HS~--sorption due to impregnation improved the pulp yield.