Biological Degumming: Farewell To Traditional "Retting"

Linen textiles are green products with the characteristics of antibacterial, sweat absorbing and ultraviolet protection. Degumming is a necessary link to transform hemp raw materials into hemp fibers. But the most common problem is that the resource consumption and environmental pollution caused by traditional degumming methods have long troubled enterprises, especially in the field of ramie, which is known as "Chinese grass".

Recently, Liu Zhengchu, a researcher at the Institute of hemp research, Chinese Academy of Agricultural Sciences, and so on, won the fifteenth China Patent Excellence Award. The technology has been selected for the first time at home and abroad to produce highly efficient ramie degumming strains, which can replace traditional chemical degumming or bio chemical degumming methods, and significantly reduce the consumption of resources and energy in the process of ramie degumming.

In an interview with reporters, Liu Zhengchu pointed out that biological degumming has the characteristics of energy saving, emission reduction, consumption reduction, efficient utilization of resources, short process, intuitive and reliable quality monitoring, and friendly production environment. Compared with traditional degumming methods such as retting, biological degumming has transformed the production mode from rough type retting to factory degumming, and accelerated the development of the hemp industry.

Ramie Hemp degumming "killer"

Degumming refers to the process of extracting cellulose from hemp fiber agricultural products by stripping non cellulose. According to Liu Zhengchu, hemp degumming methods can be divided into four categories: retting, chemical degumming, bio chemical degumming and biological degumming.

In the Book of Songs, it is mentioned that "the pond of Dongmen can be used to retting ramie". Retting has become the most traditional rugged degumming technology in China, but it is not suitable for industrial production. With the development of Ramie processing industry, chemical degumming has become a popular technology in recent years. However, the technology has the disadvantages of consuming a lot of chemical reagents and energy sources and serious environmental pollution.

In order to achieve the effect of energy saving and emission reduction, bio chemical degumming, which is known as "biological pretreatment", came into being. However, this technology has not yet taken the "bacteria fermentation" and "enzyme degradation" as the main body to peel off non cellulose. There are also some problems such as complex process technology, preparation of microbial agent Cheng Chang, high cost of enzyme preparation, and no way to get rid of the side effects of chemical methods.

In Liu Zhengchu's view, the key technology to truly realize the greening of ramie industry is biological degumming, that is, the use of complex enzymes secreted by microorganisms to cleavage the intercellular layer, and cut off the chemical bonds between cellulose and non cellulose, so as to peel off the non cellulosic process in the raw materials of linen fiber.

In order to better adapt to industrial production, Liu Zhengchu team has obtained an efficient strain cgmcc5522 through isolation, screening and gene manipulation. It has the characteristics of rapid propagation, rough cultivation conditions, and marked maturity. After the bacteria were diluted with high efficiency bacteria in the surface water, they were inoculated on the raw materials for fermentation for 5~7 hours. After being inactivated and washed, the natural hemp fibers could be obtained.

Liu Zhengchu said that after testing, biological degumming can save 76.4% of raw coal, reduce water consumption by 62.6%, reduce the consumption of processing auxiliary materials by 93.1%, reduce production costs by 20.5%, increase fiber resources utilization rate and enterprise profit rate by 47% and 58% in turn, and reduce inorganic and organic pollutants by 95.9% and 58.3% from the source respectively.

　 Obstacles to technology extension

As early as 2006, the 10 ministries and commissions of the national development and Reform Commission gave priority support to the "ramie bio degumming project" in the special fund of "textile industry adjustment and transformation mode of growth mode", and many enterprises were also supported by national special funds, which promoted ramie textile technology progress and industrial upgrading.

Today, the industrial application of biological degumming technology has also made many achievements. Take the Institute of hemp of the Academy of Agricultural Sciences as an example, the Limited by Share Ltd of Hunan Yuanjiang star hemp industry jointly undertakes the national "863" project, and builds the "high-efficiency, energy saving and clean ramie degumming demonstration project" which is 8000 tons of adult ramie. The annual production capacity of Ramie will reach 30 thousand tons in the future. The Tianyuan Textile Co., Ltd. of Hubei also signed the "contract for the implementation of ramie biological degumming license" with the Institute. At present, 20 thousand tons of ramie demonstration project has been built.

However, there is still a lot of technical problems and bottlenecks to be tackled in order to popularize biological degumming in the whole industry.

Liu Zhengchu admitted to reporters that although the technology of biological degumming is a new technological invention invented at home and abroad, there is no successful precedent for the matching of process and equipment.

At present, though the patent technology scheme of technological equipment has been formed, no mechanical processing enterprise is willing to trial produce and improve these technological equipment. The research unit of biological degumming technology is restricted by manpower, material resources, financial resources and other factors. It is impossible and impossible to completely solve the following processing technology and equipment matching with biological degumming technology. Liu Zhengchu said.

According to the reporter, current Hemp spinning enterprise They are making use of the processing technology and equipment formed in the 70s and 80s of last century to carry out the meager profit operation on small scale production capacity, and can only barely maintain the present situation of enterprises' survival. Enterprises themselves have neither economic strength nor technical strength to achieve independent innovation involving many processing links.

As Liu Zhengchu said, "even if the enterprises successfully introduce the technology of biological degumming, it is difficult for us to develop new products with special advantages and market potential at the same time.

Because of the high cost of technology promotion and large investment in equipment, many enterprises, especially small and medium-sized enterprises, are hard to accept. In addition, Yao Mu, academician of the Chinese Academy of engineering, also pointed out that biological degumming is not a technology that can easily be grasped by an enterprise.

"Bacteria degumming and enzyme degumming" fibre We should deal with the problem appropriately, and we should not deal with it or deal with it too much. " Yao Mu said that when selecting varieties of bacteria and enzymes, enterprises should choose suitable varieties that can be precisely controlled so as to make the degumming work start in good time and stop at the right time. This also puts forward higher requirements for enterprises in terms of technology.

　 How to popularize "small industry"

In Liu Zhengchu's opinion, biological degumming is the key technology to accelerate the development of the hemp industry. And peer experts headed by Yao Mu also believe that the implementation of bio degumming technology can alleviate the shortage of oil, forest and land resources, improve the ecological environment, and bring a technological revolution to the textile industry and the emerging biomass energy and materials industry.

However, the "Ma" and "silk" ethnic industries with Chinese characteristics have been used as "small industries" in our country and have not received enough attention, which limits the popularization and application of biological degumming technology to a certain extent.

In this regard, Liu Zhengchu believes that in the comprehensive national strength and the development of science and technology of bulk industries to a higher level, it is also necessary to appropriately adjust the science and technology guidance policy.

He suggested the current technology guide. policy The direction should be adjusted as follows: first, under the precondition of ensuring "food security" and "ecological safety", we should "grasp the big and not let the small"; two, we should emphasize the importance of "enterprise as the main body of innovation" and give full play to the role of the original innovation platform of scientific research institutions.

In order to speed up the industrial application of biological degumming, Yao Mu also suggested speeding up research and development and equipped with ramie degumming, new textile equipment, devices and control systems. Strain propagation and enzyme should also be produced by specialized enterprises and close to the degumming base.

In addition, the technology of biological degumming also needs a certain financial support from the state. Liu Zhengchu said that biological degumming belongs to the cross and marginal disciplines and involves the whole process of the industrial chain of hemp. However, it is unthinkable for people of science and technology who are engaged in interdisciplinary or interdisciplinary edge or cross disciplinary research to win scientific research projects and acquire scientific and technological achievements.

To this end, he believes that if the interdisciplinary projects or achievements are independent of the comprehensive evaluation of multidisciplinary and open pleas, the limited research funds should be used for the interdisciplinary subjects badly needed to be subsidized, and the investment in the transformation of revolutionary achievements will be increased, which may play a "finishing touch" role in the promotion of bio degumming technology.