Title:
SHORT-PROCEDURE ECF BLEACHING PROCESS X/D-Z-P(X/Z-D-P) FOR SULFATE WOOD PULP
Document Type and Number:
WIPO Patent Application WO/2022/028385
Kind Code:
A1
Abstract:
The present invention belongs to the technical field of pulping and papermaking, and relates to a short-procedure ECF bleaching process X/D-Z-P (or X/Z-D-P) for sulfate wood pulp. The process comprises the following steps: (1) sequential bleaching (X/D): performing X/D sequential bleaching on sulfate wood pulp subjected to oxygen delignification without washing between X and D; (2) ozone bleaching (Z): performing ozone bleaching on the paper pulp subjected to X/D sequential bleaching; (3) hydrogen peroxide bleaching (P): finally performing hydrogen peroxide bleaching on the paper pulp subjected to ozone bleaching, so as to obtain fully bleached paper pulp (88% ISO); and (4) the positions of D and Z in the bleaching procedure can be exchanged, and changing the process from X/D-Z-P to X/Z-D-P does not affect the final bleaching result. Compared with a traditional D-E0-D-D bleaching sequence, the X/D-Z-P (or X/Z-D-P) bleaching sequence is reduced from four stages to three stages, and an ozone and a hydrogen peroxide green bleaching agent are used, having only one chlorine dioxide bleaching stage. Therefore, in the bleaching method provided in the present invention, the water usage for bleaching and wastewater toxicity are greatly reduced, and under the same whiteness of the final paper pulp, the chlorine dioxide usage is reduced by 50% or more, and the water usage is reduced by 20% or more.
Inventors:
YANG GUIHUA (CN)
ZHANG KAI (CN)
TIAN ZHONGJIAN (CN)
JI XINGXIANG (CN)
CHEN JIACHUAN (CN)
WANG QIANG (CN)
GAO QICHAO (CN)
ZHANG KAI (CN)
TIAN ZHONGJIAN (CN)
JI XINGXIANG (CN)
CHEN JIACHUAN (CN)
WANG QIANG (CN)
GAO QICHAO (CN)
Application Number:
PCT/CN2021/110189
Publication Date:
February 10, 2022
Filing Date:
August 03, 2021
Export Citation:
Assignee:
UNIV QILU TECHNOLOGY (CN)
International Classes:
D21C9/153; D21C9/16
Foreign References:
| CN111979823A | 2020-11-24 | |||
| CN108474173A | 2018-08-31 | |||
| CN106460329A | 2017-02-22 | |||
| CN1630756A | 2005-06-22 | |||
| CA2031848A1 | 1991-06-30 | |||
| CN103321080A | 2013-09-25 |
Attorney, Agent or Firm:
BEIJING FINELAND IP FIRM (CN)
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