1. Application of enzymes in pulping process
Biopulping refers to the pretreatment of lignocellulosic fibers by enzyme-producing microorganisms or enzyme preparations, destroying the structure of lignin or hemicellulose, promoting the rate of shedding during mechanical or chemical pulping, and facilitating the separation of cellulose. At the same time, it can reduce the consumption of energy and chemicals, shorten the pulping time and improve the quality of pulping. White rot fungus is rich in laccase and can effectively decompose lignin in wood fiber. More importantly, white rot fungi, as a filamentous fungus of the Basidiomycetes, can release extracellular enzymes and promote the decomposition of lignin in the pretreatment of raw materials such as wood. White rot fungi have been widely used in the study of biopulping.
2. Application of enzymes in bleaching
Xylanase and laccase are the main enzymes used in the paper industry for biobleaching. In lignocellulosics, lignin is present in combination with xylanase in the form of entangled cellulose. The xylanase and laccase plus bleaching help to improve the dissolution of lignin and reduce the use of laccase and media.
3. Application of enzyme in resin control
The enzyme preparation mainly achieves the purpose of removing the fat-soluble extract of the pulp by acting on the pulp. The use of enzyme preparations for resin control has the characteristics of short acting time and good specificity. Commercially available lipases have been successfully applied to the hydrolysis of cork three vinegar in softwood mechanical pulp.
4. Bio-enzymatic deinking of waste paper
The application of enzyme preparations to deinking waste paper can reduce waste water, water and energy costs. The deinking enzyme acts primarily on the point of attachment of the ink to the pulp. Different enzyme species can be selected depending on the difference in waste paper source and printing ink, including: lipase, xylanase, cellulase and laccase. In order to facilitate the elution of the ink particles from the pulp, it is necessary to add a small amount of a surfactant.
5. The effect of enzyme on the performance of papermaking fiber
The biological modification of pulp fibers by the action of microbial enzymes is beneficial to save energy and reduce the damage of chemicals to fibers.
6. Development and production of paper enzymes
In the paper industry, there are already cases of industrial use of papermaking enzymes in the sections of chemical pulping, such as coarse pulp washing, mechanical pulp bleaching, waste paper beating and deinking, including: cellulase, xylanase, pectin. Enzyme, manganese peroxidase and laccase.
Efficient application of enzymes in the pulp and paper industry can increase production efficiency, improve pulp quality, and reduce energy consumption and water consumption. The collaborative research between bioscientists and paper engineers is the key to promoting the application of biotechnology in pulp and paper.