In recent years, under the development of industrial biotechnology, new enzyme molecules have been excavated, and the level of production and application of high-efficiency enzyme preparations has also increased. The application of enzyme preparations in the pulp and paper industry more efficiently saves costs and reduces pollution, and has gradually become the focus of attention in various fields. The in-depth development and application of enzyme preparations will further promote the green manufacturing of the pulp and paper industry.
1. Application in pulp cooking
Laccase is present in white rot fungi, which can decompose lignocellulosic lignin. White rot fungus belongs to the basidiomycete steel-like fungus, which can be penetrated by pretreatment in the mixed culture of wood raw materials, and the extracellular enzyme is released to realize the decomposition of lignin. However, the growth rate of white rot fungi is relatively slow, so the cycle of pulping is long. At the same time, white rot fungus consumes a large amount of polysaccharide during growth, which has a certain influence on the pulping yield. In addition, an enzyme or a commercial enzyme preparation secreted by white rot fungi is used for assisting biopulping, and is affected by the low permeability of the enzyme itself, resulting in an unsatisfactory result. In this case, the synergistic mechanism allows the enzyme preparation to be fully enhanced.
2. Application in pulp bleaching
The chlorine emission of the paper industry has a great negative impact on the ecological environment, and it is necessary to actively develop a chlorine-free bleaching process. Among them, the development prospect of pulp biological enzyme bleaching is very broad, and it belongs to the main way of chlorine-free bleaching. In the paper industry, the main enzymes for biobleaching are laccase and xylanase. Its synergistic bleaching has a positive effect on the improvement of lignin dissolution, and the amount of laccase and medium used can be appropriately reduced.
3. Application in the control of papermaking resin
For wood raw materials, many fat-soluble substances are in the three scattering lines of wood and resin channels. Some of the fungi use fatty acids, triglycerides, etc. during the growth process, and use them as carbon sources. The wood chips are pre-treated to achieve the purpose of controlling the resin.
Currently, commercial lipases are widely used in the hydrolysis of softwood mechanical pulp triglycerides. In recent years, the oxidase report indicates that laccase formed by white rot fungi can act on resin acids, fatty acids, and triglycerides in the presence of a medium.
4. Application in the deinking of waste paper
The application of the enzyme preparation to the deinking of waste paper can reduce the discharge of waste water, save water resources and reduce energy consumption. The enzyme species should be reasonably selected according to the difference in the source of the waste paper and the difference in the printing ink, and the surfactant should be appropriately added.
In summary, the rational use of biological enzymes in the paper industry can achieve an overall improvement in production efficiency, while also increasing the quality of pulp, saving energy consumption and water consumption. However, the use cost of the enzyme preparation is relatively high, and the stability is not ideal, and the mixing effect is poor, resulting in unstable quality of the slurry. To this end, molecular evolution and genetic recombination techniques should be studied in depth to further improve enzyme stability and production levels.