Bleaching of kraft pulp with aqueous highly concentrated ozone solution
| Autor: | Shigeki Nakayama, Toshiro Fujii, Isao Akamatsu, Keisuke Namba, Hiroshi Kamishima |
|---|---|
| Rok vydání: | 1986 |
| Předmět: |
Aqueous solution
Ozone genetic structures Mechanical Engineering Pulp (paper) Inorganic chemistry chemistry.chemical_element Liquid phase General Chemistry engineering.material Pulp and paper industry Oxygen chemistry.chemical_compound chemistry Kraft process Media Technology engineering Pulp bleaching General Materials Science sense organs |
| Zdroj: | JAPAN TAPPI JOURNAL. 40:568-574 |
| ISSN: | 1881-1000 0022-815X |
| DOI: | 10.2524/jtappij.40.568 |
| Popis: | Ozone bleaching of kraft pulp has been investigated for the purpose of developing oxygenbased pulp bleaching process as an alternative to chlorine-containing one which produces unfavourable products. In this paper, liquid phase ozone bleaching has been studied to improve the bleaching rate by the use of aqueous highly concentrated ozone solutions. The results obtained are as follows:1. Aqueous highly concentrated ozone solutions were prepared by the adsorption-desorption method using an apparatus shown in Fig. 1. Acidic and neutral ozone solutions thus prepared contained about 200 mg/l and 100 mg/l, respectively. Ozone degradated slowly in the former, but fastly in the latter.2. With aqueous highly concentrated ozone solutions, bleaching completed within 5 min, and ozone consumption were over 90%. Acidic highly concentrated ozone solutions (pH 2.0) yielded higher viscosity pulps, but needed longer bleaching time than neutral solutions.3. Bleaching sequence consisting of oxygen and ozone with aqueous highly concentrated ozone solutions also resulted in the increase of viscosity of bleached pulp and the reduction of ozone consumption to one-third of bleaching of UKP. Acidic highly concentrated ozone sulutions also produced higher quality pulps, but needed a little longer bleaching time than neutral method. |
| Databáze: | OpenAIRE |
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