| 摘要 |
Lignocellulosic plant materials are treated with a catalyst containing an aqueous lower alcohol solution and converted into fibre possessing superior pulp characteristics. The preferred organic solvent is methanol and the catalyst is supplied in the form of an aqueous alcohol-soluble metal salt, with or without a minor quantity of strong mineral acid in a pressure vessel at temperatures between 130 to 210 DEG C, preferably between 190 DEG C to 200 DEG C for durations from 15 minutes to over one hour. The catalyst salt is a chloride, sulphate, or nitrate of calcium, magnesium or barium, and is used in concentrations between 0.005 to 1.0 molar. A pulp yield of 54 to 56% is easily obtained for a softwood having a Kappa number 35 and a TAPPI (0.5g) viscosity of 20 cP within 45 minutes of cooking whereas aspen can be cooked to a pulp yield of 62% with TAPPI viscosity 22 cP at a Kappa number 25 in less than 30 min. |
