Rapid-growth poplar sodium hydroxide anthraquinone pulp biochemical method TCF bleaching process

A sodium hydroxide anthracene, biochemical technology, applied in pulp bleaching, cellulose raw material pulping, textile and papermaking, etc., can solve problems such as large-scale applications that have not yet been realized, and achieve energy saving in beating and fewer beating revolutions. , the effect of improving physical properties

CN103362009AActive Publication Date: 2013-10-23QILU UNIV OF TECH
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2013-10-23

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Abstract

The invention discloses a rapid-growth poplar sodium hydroxide anthraquinone pulp biochemical method TCF bleaching process. The process is characterized in that the process comprises the steps that: (1) steaming is carried out, wherein rapid-growth poplar wood sheets are steamed in a steaming pot, such that an original pulp is obtained; washing and screening are carried out, such that paper pulp is obtained; (2) xylanase pretreatment is carried out; (3) TCF bleaching is carried out, wherein the treated paper pulp is bleached with one of the bleaching sequence selected from OP-Q-P, O1-O2P-Q-P and O1P-O2P-Q-P. According to the invention, paper pulp is pretreated by using xylanase, and bleaching is carried out with one of the three bleaching sequences of XOPQP, XO1O2PQP and XO1PO2PQP, such that paper pulp with higher whiteness and viscosity are obtained. Compared with paper pulp obtained by direct bleaching without xylanase pretreatment, the paper pulp provided by the invention has lower beating whiteness loss. A folding resistance is higher by 30-49 times, a burst index is higher by 0.3-0.6N.m.g<-1>, a breaking length is higher by 0.15-0.36KM, and a tearing index is not significantly changed. When a same or similar beating degree is reached, needed beating revolutions are less, and beating energy consumption can be saved by approximately 17.8%.
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Description

technical field

[0001] The invention relates to a biochemical TCF bleaching process of sodium hydroxide anthraquinone pulp of fast-growing poplar, belonging to the technical field of papermaking. Background technique

[0002] Due to the production of odorous gases such as hydrogen sulfide, methyl mercaptan, methyl sulfide and dimethyl sulfide in the process of kraft pulping and alkali recovery, there are problems of pollution and air odor around the production unit. Therefore, in the open pulping production process of some medium-sized pulp mills, the pulping technology based on the sodium hydroxide anthraquinone method is adopted. Because the chemical used in sodium hydroxide anthraquinone pulping is mainly sodium hydroxide, which also contains a small amount of anthraquinone as a cooking protective agent, these two chemicals are non-toxic and odorless, and no odor is produced during the pulping and cooking process Therefore, this alkaline pulping technology is widely used...

Examples

Embodiment 1

[0032] Example 1 Process optimization of xylanase treatment of fast-growing poplar NaOH-AQ pulp

[0033] There are many studies on the assisted bleaching of hardwood KP pulp by xylanase, and good results have been achieved. According to relevant literature, the main factors affecting the treatment of pulp with xylanase are enzyme dosage, temperature, pH value and time, etc. These factors have varying degrees of influence on the effect of oxygen delignification and subsequent bleaching. At present, since the research on xylanase in the bleaching of fast-growing poplar NaOH-AQ pulp is rarely reported, it is necessary to explore the most suitable process conditions for pretreatment of fast-growing poplar NaOH-AQ pulp with different xylanase preparations, and use a variety of modern instruments It is of great innovative and practical significance to explore the bleaching-assisting mechanism of the new xylanase on NaOH-AQ pulp of fast-growing poplar by using analytical means.

[0...

Embodiment 2

[0106] Example 2 Optimization of bleaching process conditions

[0107] 2.1.1 Raw materials

[0108] The fast-growing poplar chips used in the experiment were mixed fast-growing poplar chips, which were obtained from Shandong Sun Paper Co., Ltd. The length of the wood chips is 15-25mm, the width is 10-20mm, and the thickness is 3-5mm. The qualified rate of the wood chips is over 90%.

[0109] Xylanase X 1 Provided by Novozymes, liquid, without cellulase activity; xylanase X 2 、X 3 All are provided by Shenzhen Lvweikang Biological Co., Ltd., all are white powdery solids, and none of them contain cellulase activity.

[0110] 2.1.2 Cooking experiment

[0111] Cook in a 15L electric heating rotary cooking pot to obtain fast-growing poplar sodium hydroxide anthraquinone puree. The cooking conditions are: the amount of alkali used is 22% (for absolute dry raw materials, based on NaOH), the amount of AQ is 0.05%, the liquid ratio is 1:4, the highest cooking temperature is 165°C,...