| 摘要 |
The invention relates to a process of oxidative delignification for lignocellulose materials including wood, annual plants, by-products from agriculture and forestry and cellulose pulps in the presence of heteropolyanions. The process comprises the treatment of lignocellulose material with a suitable oxidizing agent (oxygen, ozone, hydrogen peroxide, air, organic salts and oxidants) in a liquid medium of suitable composition, including mixtures of water with organic solvents in which the percentage water/organic solvent ratio by volume may vary from 99.9:0.1 to 0.1:99.9 and in which the solvents used are of a protic nature, preferably alcohols, or an aprotic nature, preferably soluble in water, in the presence of a heteropolyanion of the Keggin type of formula [Vk MoWn, (MT)n (ER)oOp]X, where MT is a transition metal, ER is a representative element, K is 011, 1 and 0-11, m is 0-11, K+ 1 + m<IMAGE> 12, n+o<IMAGE>4, and in which p is sufficiently large for x > 0, preferably a vanadium heteropolyanion of formula (PM12-yVyO40) - (3+y) where y is 1-6, under conditions in which the heteropolyanion is reduced and reoxidized in the same stage and delignification of the material takes place through oxidation of the lignin. This invention has its main field of application in the production of raw and bleached cellulose pulps (cooking and bleaching).
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