Delignifying materials to mfr. cellulose - using alkaline pulping liq. contg. cyclic ketone and aromatic nitro cpd. to increase yield

摘要

Lignocellulose materials (a) are delignified by treatment in a closed reactor with a pulping liq. (b) contg. (1) akali, (2) 0.001-10% based on the wt. of material (a), of a cyclic ketone, viz. naphthoquinone; anthraquinone; anthrone; phenanthrene-quinone; yheir alkyl-, alkoxy-, or amino-derivs.; 6, 11-dioxo-1H-anthra-1,2-c-phyrazole; anthraquinone-1,2-naphthacridone; 7,12-dioxo-7,12-dihydroanthra-1,2-b-pyrazine; 1,2-benzanthraquinone; or 10-methylene-anthrone. Liq. (b) also contains (3) 0.001-10% again based on wt. (a) of an aromatic nitro-cpd. viz. mono- or di- nitrobenzenes, or their amino-, carboxy-, hydroxy-, or methyl-derivs. Treatment is at max. 150-200 degrees C, for 0.5-480 mins. followed by washing with water or an inert aq. liq. to remove liq. (b). Used for delignifying wood, straw, bagasse, e.g. black spruce, forming. cellulose, providing a higher yield and less environmental pollution than conventional processes.