Straw pulping and papermaking is a sustainable comprehensive utilization model
In recent years, China's paper industry has made great achievements, but we also need to calmly think about the bottlenecks of resources, structure and environment that need to be solved in order to maintain the sustainable development of China's paper industry. I want to talk about fiber raw materials here. The paper industry is the third largest foreign exchange industry in China. China has become the world's largest importer of pulp and waste paper for many years. How to effectively solve the shortage of fiber raw materials? This is a major problem facing the papermakers.
First of all, we must work hard to further improve the recycling rate of waste paper in China. After years of hard work, China's waste paper recycling industry has made great progress, but there is still potential for improvement. China's waste paper classification work started late, and the quality of waste paper is difficult to control, which brings many difficulties to the production enterprises. It is necessary to attach great importance to the recycling of waste paper, strengthen the supervision of waste paper classification, and strive to improve the efficiency of recycling and utilization of domestic waste paper. Secondly, while continuing to adhere to the forestry-paper integration strategy, we must attach great importance to the use of forestry and the use of agricultural straw. The annual production of various types of lignocellulosic agricultural forestry wastes in China is more than 1 billion tons, and the utilization rate is less than 30%. Therefore, there is huge potential for development. In recent years, the Ministry of Agriculture has asked all localities to explore effective mechanisms to stimulate sustainable straw utilization, such as straw returning, fielding, processing and utilization. It can be seen that the comprehensive utilization of straw is a pressing issue.
Agricultural straw such as wheat straw, cotton stalks, corn stalks, etc., with good fiber quality, is a suitable raw material for pulping and papermaking. Before the 1980s, China's pulp and paper raw materials were mainly straw. Therefore, we have accumulated rich experience in the process of using straw pulping and papermaking. The technical level is in the leading position in the world and produces many high-quality products. Due to the reasons of enterprise ownership and related policies, grass-based pulp and paper enterprises have seriously invested in technological innovation and technological transformation, which has caused environmental protection problems. Technically speaking, the prior art can solve the problem of straw pulping pollution.
There are several models for thinking about the use of agricultural straw pulping: 1 There are large-scale pulp and paper enterprises with OCC as raw materials, and it is possible to adopt a high-yield chemical mechanical pulp technology route to add straw pulping lines for matching with OCC. Copy and produce high-strength corrugated base paper and natural packaging paper, and prepare waste materials into pellet fuel or organic compound fertilizer. The wastewater has good biodegradability and can improve the treatability of OCC wastewater. It can reach the standard discharge through traditional physical and chemical biochemical technology, and can make water balance and water reuse. It can increase production without increasing pollution and increase water consumption. Areas with strict emission requirements, assisted with advanced treatment technology, can also achieve effective treatment of emissions. 2 Mixed fermentation of grass and wood can improve the evaporation and concentration of black liquor and achieve smooth operation on the traditional alkali recovery system. 3 Existing chemical wood pulp enterprises, newly added grass raw material chemical pulp production line, supplemented by silicon retention cooking technology, using MVR technology to pre-concentrate concentrated grass black liquor, and into the wood pulp black liquor alkali recovery system.
At the technical and equipment level, the state and relevant departments should actively organize scientific research to carry out research on technology and equipment. Such as: straw collection, packaging and storage technology and equipment, straw preparation technology and equipment, preparation of solid waste comprehensive utilization technology, large straw pre-dip softening technology and equipment, straw pulp special grinding blade tooth shape optimization design, non-wood pulp waste liquid efficient Extraction and enrichment technology and equipment, short-stage process and reuse technology and equipment.
We have reason to believe that in the near future, there will be a new development in the pulping of grass raw materials. In order to alleviate the contradiction of the shortage of paper fiber raw materials in China, promote the construction of new countryside, increase farmers' income and improve the ecological environment play a positive role.