Current situation and development of the hottest b

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Status and development of biomass fiber

biomass fiber can be basically divided into three categories: biomass primary fiber, biomass regenerated fiber and biomass synthetic fiber. The biomass primary fibers represented by cotton, wool, hemp and silk are the traditional dominant varieties in China; Bamboo pulp, hemp pulp fiber, protein fiber, seaweed fiber, chitin fiber, direct solvent cellulose fiber and other biomass regenerated fibers are developing rapidly, which can basically meet the needs of China's economic development and the development of textile industry; PTT, PLA, PBH and other biomass synthetic fibers have broken through key technologies, and the production capacity of some products is world leading

at present, the annual output of biomass fiber that can be directly used has exceeded 30million tons, of which the amount of plant (cellulose) fiber is the largest, about 25million tons of cotton, about 4million tons of various hemps, followed by animal (protein) fiber, such as about 2.1 million tons of wool and about 1.5 million tons of silk. Although this kind of fiber can only be used through certain pretreatment, spinning, weaving and other processes, its technology is relatively mature and has little impact on the environment. However, a large number of biomass raw materials that cannot be directly used need to go through complex processes such as raw material preparation, spinning and strict engineering design to become fibers. Since the invention of viscose method to produce regenerated cellulose fiber at the end of the 19th century, more than 100 years have passed, and various new technologies to produce biomass fiber have been emerging. However, from the perspective of the proportion of fiber output, viscose method still occupies an unshakable dominant position. In 2010, the output of viscose fiber in mainland China was more than 1.8 million tons, while the technology of direct solvent production of cellulose fiber is still in the stage of thousand ton production line and small-scale test line, and its energy consumption and operating costs have seriously affected its further development

natural biomass fiber raw materials have complex composition and structure, and the components and contents that can meet the spinning requirements are also inconsistent. Although it is difficult to summarize the preparation of biomass raw materials that meet the spinning requirements with a unified technology, its essence is to remove the small molecular substances and retain the high molecular substances that meet the spinning requirements. Take cellulose as an example. At present, cellulose raw materials used for spinning generally come from plants, such as cotton linter, wood, bamboo, straw and other agricultural and forestry by-products. Among them, the cellulose content in cotton linter is the highest, more than 95%, while the cellulose content in wood is only 40% - 50%, and the cellulose content in bamboo and straw is lower. Therefore, in order to prepare cellulose raw materials (called pulp in industry) that meet the spinning requirements, the industrial preparation method is to use sulfite solution or alkali solution to cook plant raw materials and remove lignin, hemicellulose and other substances. The pulping black liquor produced in this process is directly discharged, which causes serious environmental pollution. At present, the combination of acidification, biochemistry, neutralization, sedimentation, incineration and burial is adopted, so as to increase the total number of axes to 5, The pollution to the environment cannot be completely eliminated

regenerated fiber 5. Ensure a smooth power supply during the test and operation process. Vitamin fiber is an important category of biomass regenerated fiber according to the selected accessories. Regenerated cellulose fiber refers to the plant resources that can be continuously regenerated, continuously utilized and used to produce fiber in nature. It is harmless or harmful to the environment, and the resources are widely distributed, easy to obtain, suitable for sustainable development and utilization. There are many kinds of regenerated cellulose fiber resources, mainly including cotton linter, wood, bamboo, hemp straw, straw, cotton stalk, reed, straw and so on. According to statistics, at present, the annual circulation of wood in the world has reached 150 million tons, and the materials that can be used for renewable cellulose processing have reached more than 15 million tons; The recycling volume of bamboo reaches 40million tons, and about 5million tons can be used for the processing of regenerated cellulose fibers; The output of cotton fiber reaches about 24million tons, and about 1million tons of cotton linter can be used for the processing of regenerated cellulose; The output of hemp fiber materials has reached more than 3million tons, and hemp and hemp stems, which are difficult to be directly used in textile, can be used as renewable fiber resources. In recent years, the development of renewable cellulose fiber resources in China has made some progress, the output has increased steadily, and the fiber production process and "three wastes" treatment technology are also developing, but the stable supply of resources and other problems also exist objectively. (China Chemical Fiber Industry Association)

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