The hottest UV photolysis industry urgently needs

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The report of the 19th National Congress of the Communist Party of China pointed out that an all green and low-carbon economic system should be established, pollution emission standards should be raised, and environmental protection credit evaluation, mandatory information disclosure, severe punishment and other systems should be improved

nowadays, VOCs emission has been listed as an important object of supervision and inspection by China's environmental protection departments. As a terminal deodorization technology widely used in the waste gas treatment of industrial enterprises in China, UV (ultraviolet) photolysis technology is most widely used in the waste gas treatment of small and medium-sized enterprises

Zheng Liang, an application professional in the UV industry and chairman of Guangdong bright moon Photoelectric Technology Co., Ltd., introduced that through the effective combination of UV photolysis technology, ion catalytic oxidation technology, pulse corona oxidation technology, adsorption oxidation technology and air filtration technology, low and medium concentration odor gases can be effectively removed, and ultra-low emissions of VOCs generated in the production and operation process can be achieved. However, as UV photolysis technology is a rapidly developing emerging application, the industry has not yet formed technical specifications and standards, resulting in some chaos in the current market

market chaos: UV photolysis is advertised as "omnipotent light"

the components of VOCs are very complex. According to the definition of the World Health Organization, volatile organic compounds (VOCs) refer to various organic compounds with boiling points of 50 ℃ - 260 ℃ at room temperature. VOCs can be further divided into alkanes, aromatics, esters, aldehydes, etc. according to their chemical structures. At present, more than 300 kinds of VOCs have been identified, which brings great challenges to the existing waste gas treatment technology

"UV photolysis technology is a relatively novel VOCs treatment technology, which benefits from strict environmental protection policies and has been widely used in the market." Zheng Liang introduced that compared with other waste gas recommended corresponding mold manufacturers, injection molding plants and other materials, the treatment cost of UV photolysis technology is relatively low, which is favored by many small and medium-sized enterprises

Zheng Liang said that in order to meet the rapid and urgent project needs of the market, some environmental protection companies are eager for success. They do not consider the specific composition and concentration of the treated waste gas. They directly connect UV photolysis equipment without even spray tower, dust collector and other preliminary pretreatment facilities. Some environmental protection companies even publicize ultraviolet light as "universal light", saying that it can be applied to all waste gas treatment

"at present, it is used in all industries, but UV photolysis technology is not omnipotent." Zheng Liang believes that the phenomenon that UV photolysis technology is not standardized in application is relatively serious. UV photolysis can treat 150ppm-200ppm low concentration organic waste gas. High concentration organic waste gas exceeds its treatment capacity and needs to be treated by adsorption, catalytic combustion, biological method and other methods. Due to the professionalism of the technology and the influence of many market factors such as the cost of wdw-yaw series widely used in the pressure test of concrete, bricks and tiles and other materials, the UV photolysis lamp market is mixed, and the quality of lamps used in some equipment is uneven

under the current market conditions, some industry enterprises began to question UV photolysis technology

what worries the insiders even more is that there is still a reduction in work and materials in the market. Some environmental protection enterprises use 10000 air volume UV photolysis equipment to deal with 20000-30000 air volume projects, and some enterprises do not have post maintenance, and fail to clean and replace UV photolysis tubes in time, resulting in low purification efficiency of equipment in some areas

Zheng Liang introduced that the core ability of UV photolysis technology is deodorization and peculiar smell, but the effect on the purification rate of large air volume and ultra-high concentration waste gas in medical, petrochemical and other industries is not obvious. For example, UV photolysis technology has excellent exhaust gas purification effect in spraying, surface coating, plastics, garbage stations and other fields, but it has no effect on the treatment of dust and oil pollution

vocs industrial treatment photolysis photocatalysis combination is the most effective

the person in charge of Shenzhen environmental governance photoelectric industry Co., Ltd. introduced that at present, the high-energy UV photolysis technology uses ultra ultraviolet light with high energy of 185nm, whose energy is equivalent to 6.8ev to remove the organic matter with a deeper understanding. Benzene, xylene, non methane total hydrocarbons and many other organic substances will be destroyed at 185nm wavelength. However, due to the short wavelength of 185nm, higher requirements are put forward for the structural design of waste gas treatment equipment

Qiu Wenfeng and other relevant experts from Suzhou Institute of nanotechnology and nano bionics, Chinese Academy of Sciences used photolysis and photocatalysis to study the degradation of VOCs in the straight through test chamber model. The results showed that under the conditions of air volume of 1000m3/h and toluene concentration of 120ppm, when the photolysis intensity was 5.1kw, photocatalysis was 5 layers (1.44m2) and photocatalysis intensity was 7.2kw, the degradation rate of toluene was the highest, up to 85%. Qiu Wenfeng said that the theoretical simulation results of the straight through test chamber and the degradation experiments of toluene showed that the combination of photodegradation and photocatalysis was the simplest and most effective way to treat VOCs in the industry, which was characterized by low operating costs, complete degradation of pollutants into carbon dioxide and water, and no secondary pollution

the national authorities have also recognized this problem. In September 2016, the first pilot project of the national key research plan "Research on the causes and control technology of air pollution" was launched, "Research on the technology of high-energy ultraviolet photolysis catalytic oxidation synergistic purification of low concentration VOCs". Professor Huang Haibao, School of environmental science and engineering, Sun Yat sen University, said: "if this research project is realized, the high-tech and equipment of photodegradation catalytic oxidation collaborative purification of low concentration VOCs organic waste gas with independent intellectual property rights can make the primary removal rate of VOCs greater than 95%, and the pollutant emission will be better than the latest national standards, without secondary pollution."

it is urgent to standardize the industry standard

since the implementation of the action plan for the prevention and control of air pollution, China's atmospheric environment has been improved. However, the emission of VOCs, the key precursor of fine particulate matter (PM2.5) and ozone (O3), has shown a rapid growth trend

in order to further improve the ambient air quality, it is particularly urgent to comprehensively strengthen the prevention and control of VOCs Pollution

the report of the 19th CPC National Congress clearly pointed out that we should adhere to the joint governance of the whole people and the prevention and control of the source, continue to implement the action of air pollution prevention and control, and win the battle of blue sky defense

this also indicates that China's VOCs Pollution will enter the era of comprehensive treatment, and building a beautiful China with environmental protection technology will become a long-term national policy

Ye Daiqi, Dean of the school of environment and energy of South China University of technology and director of the National Engineering Laboratory for volatile organic compounds pollution control technology and equipment, believes that China lacks sophisticated technology for VOCs control, equipment and supporting materials are backward, and the treatment efficiency is uneven due to different industries or processes. Various industries lack scientific technical standard system and authoritative technical evaluation system in the selection of control technology; There is a lack of technical specifications for equipment manufacturing and project implementation, and the equipment produced by various manufacturers is mixed

Zheng Liang said: "the key to the controversy over UV photolysis technology in the market now is that there is no correct understanding and scientific use of this technology, which makes it a good experience, but it is bad." He hoped that relevant competent departments and industry experts could issue corresponding technical specifications and national standards, promote the research and development of new catalytic materials and the use of high-quality products, so that UV photolysis technology can play a greater role

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