Technology Status Of Energy Saving And Emission Reduction In Textile Printing And Dyeing Industry

In recent years, the textile industry has maintained a two digit growth rate. In 2006, the gross output value of textile industry was 2 trillion and 501 billion 689 million yuan, accounting for 15.18% of the whole country, and the export volume of textile and clothing reached 165 billion 136 million dollars, accounting for 72.71% of the total proportion of the whole country.

While the textile industry has made great progress, the implementation of cleaner production and energy conservation and emission reduction have also achieved some success. The advanced treatment technology and equipment have been applied to promote the application of textile printing and dyeing wastewater treatment technology, and the rate of wastewater treatment and the rate of compliance have been greatly improved.

However, with the increasingly shortage of water resources and the worsening of environmental pollution, resources and environment are restricting the healthy and sustainable development of the textile industry.

At present, the development trend of international textile technology is guided by the production of ecological textiles and green manufacturing technology, starting from various channels such as technology, auxiliaries, equipment, etc., to seize the source, pay attention to the ecological problems in every link of the production process, and strive to optimize the textile technology, reduce the consumption of chemicals, water and energy, so as to achieve the goal of high efficiency, high speed and environmental protection.

Foreign countries have invested heavily in developing environment-friendly dye auxiliaries, new technologies and new equipment for water saving, energy saving and emission reduction. They have made great progress in printing and dyeing of water and less water, as well as textile and energy saving, water saving and practical new technologies.

Textile printing and dyeing wastewater is one of the key sources of pollution in China's industrial system. According to the State Environmental Protection Administration, the total amount of printing and dyeing wastewater discharged by the printing and dyeing industry is fifth of the total industrial sector.

In 2004, the total industry displacement was 1 billion 360 million cubic meters, while the total amount of pollutants (COD) was sixth in various industrial sectors.

Printing and dyeing wastewater is an organic wastewater containing a certain amount of refractory biodegradable substances. Its pollutant concentration is high (COD) and its chroma is deep. It is one of the refractory industrial wastewater.

Different dyes and auxiliaries are used in fiber. The properties of wastewater are very different. The main pollutants include soluble organic compounds, toxic substances, chromaticity, acids, alkalis and oils. Pollutants are mostly biodegradable substances, and the biodegradability of wastewater is poor. Therefore, the treatment is difficult.

The solid waste discharged from the printing and dyeing industry, including the sludge produced by water treatment, has not been effectively treated. In some places, a simple open piling is carried out because of no treatment, which has become the root of the pollution accident.

Compared with foreign countries, China's printing and dyeing enterprises have 2-3 times more water than the developed countries, and energy consumption is about 3 times.

In general, the energy consumption of dyeing and printing accounts for more than 30% of the energy consumption of the textile product chain, while the energy efficiency of the printing and dyeing links is very low. At present, only a small number of enterprises adopt the technology of waste heat recovery and utilization, while the large quantity of thermal waste gas and hot waste water discharged directly, and the equipment control does not have energy-saving devices.

During the "11th Five-Year" period, the development goal of textile energy saving and emission reduction technology is to focus on the key tasks and development goals of our textile industry in the new era, take textile printing and finishing as a breakthrough point, improve our textile printing and dyeing finishing technology level, and enhance the international competitiveness of our products, at the same time, we should save water resources from the source, reduce pollution emissions, and gradually achieve the coordinated development of production and environment.

Through joint tackling and new technology popularization and application, we have made breakthroughs in key technologies of printing and dyeing production, such as water less, less water consumption, consumption reduction, emission reduction and eco-environmental protection. We also have a number of independent intellectual property rights technologies and equipment. At the end of 11th Five-Year, we achieved the goal of national energy conservation and emission reduction of "energy consumption of 10000 yuan added value decreased by 20% and tons of fiber consumption decreased by 20%".

During the "11th Five-Year" period, the main tasks of key technology development were: first, readjust the industrial structure and product mix, and eliminate low-grade products; two, develop, apply and popularize new textile processing technologies for energy saving, water saving and consumption reduction; three, develop new, efficient, water-saving and energy-saving new products; four, adopt efficient, environmentally friendly, safe dyes and textile auxiliaries that meet the needs of safety and ecological textile production; five, promote and apply new technologies of energy saving and water saving.

During the "11th Five-Year" period, the key technologies developed were:

A high efficiency, bleaching, bleaching and short flow pretreatment technology for textile dyeing and printing

At present, a general unit and its optimized combination technology, such as rolling, washing, drying and steaming, which are suitable for short process pre-treatment technology, have been developed, and the control of synchronization and fabric tension has been well solved. The continuous production and processing of dyeing, desizing, boiling and bleaching can be realized. The domestic cooking and bleaching equipment can be applied to all kinds of fabrics, but there is still a certain gap with the advanced technology level of foreign countries.

Two pretreatment technology of dyeing and finishing with anhydrous plasma

The plasma pre-treatment technology improves the surface characteristics of fabrics by voltage differential under conditions of no need of water or chemicals.

The results are as follows: improving the hydrophilic properties of the fabric surface, improving the adhesion of fabric coating, impregnation, gluing and condensation, improving the dyed color, color fastness and the quality of printed fabric.

During the "fifteen" period, the biggest advantage of plasma processing prototype developed in China is that continuous plasma treatment can be carried out under atmospheric pressure, which reduces the difficulty of manufacture and control. This technology can be further applied after the technology and equipment are finalized.

Three new technology and technology for dyeing and printing of anhydrous coatings

Pigment printing and dyeing is suitable for all textile fibers. It has the advantages of simple process, convenient collocation, energy saving, water saving, low cost and less environmental pollution, which is conducive to the implementation of cleaner production.

Pigment printing and dyeing occupies an important position in the world's printing and dyeing industry. The printing and dyeing of foreign developed countries has exceeded 50%, while China has less than 30%.

During the "11th Five-Year" period, on the basis of the progress of dyed dyed light coloured paints in the past, the development of medium thick fabric deep coloured pigment dyeing and light weight fabric printing technology was mainly developed to improve the adaptability of pigment dyeing and printing technology to varieties and improve the grade of dyed and printed products.

Four key technologies for dyeing less water, high efficiency, environmental protection and energy saving

1 cold pad batch dyeing technology

Low temperature dyeing can save energy and further script src=>