| Popis: |
Catalyst employment in cooking liquor of 80% aqueous methanol is required for fiber liberation at high yield (50%) and has a remarkable impact on pulp production capability in the alcohol organosolv pulping of spruce wood. In alcohol solution without a suitable catalyst, the softwood fibers cannot be effectively liberated from the wood matrix. The effectiveness of the catalysts tested in this research varied widely. Divalent metal ions were found to be very effective, whereas monovalent cations were incapable of fiber liberation and trivalent cations were found to be too aggressive and hydrolyzed the carbohydrates, causing extensive damage to the fibers. Under the specified pulping conditions, the divalent metal ion catalyzed alcohol organosolv pulping process was capable of producing 60–61% screened pulp. Successful chemical pulp production by the NAEM (Neutral Alkali Earth Metal) catalyzed organosolv pulping process opens access to biorefining and provides value recovery both from the pulp and also from the dissolved wood components from the spent pulping liquor. |
