Fight A "Resource Substitution" Protracted War

As long as human beings exist for a day, textile and clothing are indispensable livelihood industries.

To sustain the sustainable development of the industry, the resource problem must be solved.

Only from the current structure of textile raw materials, cotton and chemical fibers occupy half of the territory, and other resources such as wool, linen and silk occupy a small proportion.

The rise and fall of cotton prices and the growing shrinkage of cotton in the world determine that the proportion of cotton in the raw material pattern will gradually decrease. The development of chemical fiber has been strong and timely in the past ten years, but it is fatal that more than 90% of the chemical fiber products depend on oil resources.

In fact, in recent years, the textile and chemical fiber industry has defined a "bright road" supporting the sustainable development of the industry -- biomass fiber and biochemical raw materials industry.

But because the industry itself is at its primary stage, it will take a short time to generate enormous economic and social benefits. Therefore, more extensive force participation is needed.

The two Forum on biomass fiber and biochemical raw materials held in China's Bio Industry Conference has sounded the charge for this industry.

In particular, how to achieve raw material substitution and process substitution within 30 years has been explored deeply and concretely.

The use of cellulose will also remove obstacles.

The ultimate goal of developing biomass fiber and biochemical raw materials is to achieve material substitution and process substitution.

At the same time, the traditional way to realize the differential development of textile chemical fiber products has come to an end. Biochemical technology will bring new breakthroughs in product differentiation.

For this reason, the "30 year development roadmap of biomass fiber and biochemical raw materials technology and industry" (hereinafter referred to as the "30 year roadmap") has been extensively discussed in the forum recently. The textile and chemical fiber industry uses biomass fiber to replace raw material 5% in 2020, reaching 10% in 2030 and 20% in 2040, when the layout of textile materials will become more diversified, and the resource bottleneck will be effectively alleviated.

The data is indeed tempting, but what is the feasible way to support these goals? The industry thinks that developing the raw material pattern of straw, bamboo, linen and other fast growing forest materials and rich viscose fiber and other regenerated cellulose fibers is the first consideration.

The roadmap of the 30 year is as follows:

Cellulose is the most abundant polymer material in nature. It is not only a wide range of sources, but also a renewable resource.

According to scientists, the natural world produces hundreds of billions of tons of cellulose per year through photosynthesis.

However, only about 60 billion tons of cellulose are used by people.

The biggest obstacle in the application and development of cellulose is the high crystallinity of natural cellulose, and a large number of hydrogen bonds exist between molecules and molecules, which make them insoluble in most organic solvents.

Taking straw, straw and other crop straw fibers as an example, their fibers are short and uneven, with less fiber content and more heterozygous cells, with high ash content and large silicon content.

From the commonly used plant materials, the highest content of cellulose in cotton lint is more than 95%, while the cellulose content in wood is only 40% to 50%, and cellulose content in bamboo and straw is lower.

How to separate efficiently and efficiently from natural resources efficiently and cleanliness

Although some progress has been made, the utilization technology of natural resources has yet to be developed.

To this end, the 30 year roadmap has introduced 10 technologies, namely, straw high efficiency and low energy consumption pretreatment technology, biological and French hemp comprehensive treatment technology, high efficiency and low cost cellulosic bacteria and enzyme production technology, ionic liquid new medium, high value product technology in cellulose production, lignin modification processing technology, lignin melt spinning technology, industrial enzyme and biocatalyst, marine biomass comprehensive utilization, biomass fiber high performance technology, biomass biomass full utilization technology integration and ecological industry chain establishment.

Multipath trial instead of viscose method

On the one hand, the research of new technology is to make use of the more extensive natural resources. On the other hand, it is also to make the production process more efficient and clean, and reduce the harm to energy use and environment. That is to say, in the roadmap of 30 years, "biochemical process" is used to achieve "process substitution".

The initial planning for the 30 year road map will reach 5% in 2020, 17% in 2030 and 24% in 2040.

Since the invention of viscose process for regenerated cellulose fibers in the late nineteenth Century, more than 100 years have passed. New technologies for producing biomass fibers are emerging. However, viscose still occupies an unshakable leading position from the proportion of fiber production.

Although the viscose fiber industry has made great efforts in cleaner production and achieved obvious results, the black liquor produced during its pulping process can not completely eliminate environmental pollution.

In order to solve this problem thoroughly, the industry has become more and more brave and has been exploring new ways of environmental protection and efficiency for many years.

At present, there are ways to produce regenerated cellulosic fibers in a certain climate and environment. One is the new solvent method, that is, Lyocell (lysell), which represents Shanghai textile (Holdings) group, the Chinese Academy of textile science and Xinxiang chemical fiber, the two is the son liquid method, and the key is Shandong Hailong; the three is the recent low temperature dissolution method of water system, which is highly concerned by the industry, and is developed by the team led by Professor Zhang Lina of Wuhan University.

Cellulose fibers produced by solvent method have been studied in China for several years, but their progress is slow.

Even if the scale of industrialization has been formed, the economic benefit and technology maturity need more consideration.

The preparation of cellulose by solvent method is all about how to weaken the hydrogen bond between cellulose fractions.

Zhao Qingzhang, consultant of the Chinese Academy of textile science, explained in detail the difficulties of the solvent method: first, the technology has high demand for raw materials and no space for later adjustment; two, the dissolution process is short and the scope of dehydration is narrow and continuous; three, the spinning process must be dry spray wet spinning process, the spinning solution has very high viscosity; four, the NMMO itself has certain instability as solvent, and a series of safety measures need to be taken; five, solvent recovery should meet the requirements of high recovery rate and energy saving, and only when its recovery rate is greater than 99% can it have the economic value of industrial production.

At present, Lenzing is still the only company with large Lyocell fiber production capacity. In 2010, its capacity increased by 10 thousand tons to 140 thousand tons.

Using 7% sodium hydroxide (NaOH) /12% urea aqueous solution, the solvent can cool down to 12 degrees below zero, and can rapidly dissolve cellulose (its molecular weight is below 1.2 * 105). The dissolution time takes only 2 minutes to reach the fastest dissolution rate in the history of cellulose. This is the low temperature dissolution method developed by Professor Zhang Li Na of Wuhan University.

It is understood that this way is better than viscose method.

Synthetic fibers change the traditional polyester image

In the biological family, biomass synthetic fiber has a large volume.

It not only inherits the advantages of traditional synthetic fibers, but also has biodegradable and comfortable properties because of its biological structure.

In the 30 year roadmap plan, the target of biomass synthetic fiber material substitution was 5% in 2020, 10% in 2030 and 20% in 2040; the target of process substitution was 5% in 2020, 10% in 2030 and 15% in 2030.

At present, biomass synthetic fiber mainly includes PTT, PLA, PHBV, PBS fiber and so on, that is, the new polyester fiber usually referred to.

In April this year, PTT series fibers and high