| 摘要 |
A process is provided for the activation and delignification of cellulose pulp, which comprises: (1) subjecting chemical cellulose pulp to activation by reaction with nitrogen dioxide in the presence of water at a temperature within the range from about 20 DEG to 120 DEG C., while (a) separating gas containing at least 1.2 mml nitrogen oxides, including NO, per liter of gas determined at 25 DEG C. and calculated as nitrogen, reacting nitrogen oxides in said withdrawn gas with oxygen gas in an amount within the range from about 10 to about 200 mole percent, calculated on the amount of NO present, and recycling the reacted gas to the activation; and (b) separating gas containing less than 0.4 mml nitrogen oxides, including NO, per liter of gas determined at 25 DEG C. and calculated as nitrogen from the cellulose pulp and removing said gas from the process; and (2) delignifying the activated cellulose pulp.
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