| 摘要 |
A process is provided for reducing carbohydrate losses in the sulphate pulping of wood using sodium hydroxide and sodium sulfide, by pretreating the wood in the presence of water with oxygen gas and nitrogen oxide such as NO2 and/or NO and/or polymeric oxides and double molecules thereof, for example, N2O4 or N2O3, for from about 3 to about 110 minutes at a temperature within the range from about 25 DEG to about 100 DEG C., the amount of nitrogen oxide charged, calculated as monomers, being within the range from about 0.05 to about 1 kilomole per 1000 kg bone-dry wood, resulting in one or several of the following advantages: an improved yield of pulp, an improved viscosity, and a reduced requirement for bleaching chemicals in any subsequent bleaching stages. |
