Pretreatment with Nitrous Acid for Oxygen Bleaching of Kraft Pulp

硫酸盐纸浆氧漂白的亚硝酸预处理

• 批准号: 06660203
• 负责人: OHI Hiroshi
• 金额: $ 1.28万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06660203/
• 关键词: nitrous acid; oxygen bleaching; kraft pulp; lignin; veratraldehyde; 針葉樹; 酸素漂白; 無塩素漂白; 酸素; 漂白

A pretreatment method with nitrite and nitric acid for oxygen bleaching of kraft pulp has been proposed as one of the possible methods for the reduction of organic chlorine compounds from bleaching process. Effects of the nitrous acid pretreatment were compared with those of the nitrogen dioxide pretreatment proposed by Swedish researchers, and their delignification mechanism was compared to each other on the basis of reactions of lignin model compounds. The problems and advantage of the nitrous acid treatment were discussed to carry out it on an industrial scale in the near future.(1) Softwood (Pinus densiflora Sieb.et Zucc.) kraft pulp was delignified under the conditions at 90ﾟC for 3 hours with nitrite (0.3% on pulp) and nitric acid (4% on pulp), whereas it was slightly done in the absence of the nitrite.(2) Phenolic lignin model compounds were rapidly degraded under the conditions compared with nonphenolic lignin models. However, the nonphenolic models (veratrylglycerol-beta-guaiacyl ether.VG,alpha-ethyl ether of VG : VGE,veratrylglycerol-beta-syringyl ether : VS,alpha-ethyl ether of VS : VSE,dehydrodi-isoeugenol methyl ether : DIM) were distinctly degraded through cleavage of their Calpha-Cbeta bonds giving veratraldehyde.(3) Z-, E-isoeugenol methyl ether, IME was rapidly degraded even at 0ﾟC,giving veratraldehyde. It suggests a possible mechanism involving acid-promoted conversion of the nonphenolic lignin units into ring-conjugated structures, followed by the oxidative cleavage of the Calpha-Cbeta bonds.(4) Compared with the nitrogen dioxide treatment, the nitrous acid treatment has the advantage. The latter does not need the gas-phase chemical and the two-stages treatment, and gives similar results to the former. However, an environmental issue of disposal of the spent liquor including nitrogen compounds may be made. Development of the process which would recover it and regenerate nitrite and nitric acid may solve the problem.

用牛皮纸果肉的一质预交方法和一硝化的钩状粉碎方法是由瑞典研究人员提供的有机氯构成。亚硝酸处理是软木（Pinus densiflora sieb.et Zucc。）IC酸（果肉上的4％），而在没有亚硝酸盐的情况下，它略有完成。 VG的α-乙醚：VGE，Veratrylglycerol-Beta-syringyl-Ether：vse Ha-cbeta键，可为veratradredee（3）Z-，E-异烯醇甲基乙醚迅速降解，即使在0 C中迅速降解将单位促进到环轭结构中，然后将其氧化性裂解，而后者确实需要气体和taes tre，并给予前者可以开发该过程，并将其再生亚硝酸盐和硝酸来解决该问题。

项目成果

H.Ohi and M.Kishino: "Mechanism of Delignification by Nitrous Acid III.Degradation of a nonphenolic beta-5 type lignin model compound" Mokuzai Gakkaishi. (to be published).

H.Ohi 和 M.Kishino：“亚硝酸脱木质素的机制 III.非酚 β-5 型木质素模型化合物的降解”Mokuzai Gakkaishi。

H.Ohi and M.Kishino: "Cleavage of Calpha-Cbeta Bonds of Lignin Model Compounds by Nitrite and Nitric Acid II.Stereospecific reactions of lignin model compounds" Holzforschung. (to be published).

H.Ohi 和 M.Kishino：“亚硝酸盐和硝酸对木质素模型化合物的 Calpha-Cbeta 键的裂解 II。木质素模型化合物的立体特异性反应”Holzforschung。

M.Kishino, H.Ohi, K.Ikegami, A.Yamaguchi: "Mechanism of Delignification by Nitrous Acid II.Degradation of an alpha-alkyl ether of nonphenolic beta-O-4 type lignin model compound" Mokuzai Gakkaishi. Vol.42, No.1. 95-100 (1996)

M.Kishino、H.Ohi、K.Ikegami、A.Yamaguchi：“亚硝酸脱木质素的机制 II.非酚 β-O-4 型木质素模型化合物的 α-烷基醚的降解”Mokuzai Gakkaishi。

H.Ohi and M.Kishino: "Cleavage of Calpha-Cbeta Bonds of Lignin Model Compounds by Nitrite and Nitric Acid" Holzforschung. (in press).

H.Ohi 和 M.Kishino：“亚硝酸盐和硝酸对木质素模型化合物的 Calpha-Cbeta 键的裂解”Holzforschung。

H.Ohi and M.Kishino: "Cleavage of Cα-Cβ Bonds of Lignin Model Compounds by Nitrite and Nitric Acid II.Stereospecific reactions of lignin model compounds" Holzforschung. 「発表予定」.

H.Ohi 和 M.Kishino：“亚硝酸盐和硝酸对木质素模型化合物的 Cα-Cβ 键进行裂解 II。木质素模型化合物的立体特异性反应”Holzforschung“待发表”。