Environmental protection access of the hottest pol

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Polysilicon "environmental protection access" accelerates the survival of the fittest

in the 2011 national key points for pollution prevention and control released by the Ministry of environmental protection earlier this year, polysilicon, together with lead-zinc and lead-acid batteries, was included in the key areas of heavy metal pollution access this year. Subsequently, the "access conditions for polysilicon industry" jointly issued by the three ministries and commissions listed a number of environmental protection access thresholds, including wastewater, waste gas and solid waste treatment. For a time, the high pollution of polysilicon industry once again became the focus of the industry

the problem of high energy consumption and high pollution in polysilicon production has a long history, and has surfaced with the national warning of overcapacity in the industry. Both ends are abroad, leaving pollution at home has become the biggest footnote for all circles to criticize polysilicon pollution. With the price of photovoltaic polysilicon falling all the way, the era of profiteering has also ended. The timely introduction of environmental protection access conditions has made the whole industry face up to how to reduce product costs while reducing environmental costs

the analysis points out that the environmental storm is coming, which is very timely for polysilicon, an emerging industry that has just started. Promoting the survival of the fittest with environmental protection access conditions will also be beneficial to the future development of the industry

clean energy turned into a source of pollution

before 2009, due to the continuous rise in the price of photovoltaic polysilicon in the international market, the pull of market demand attracted countless investments. Enterprises need 6 ⑴ 2 hours to exchange electricity for slow charging. While making huge profits, the pollution problem remaining in China is also becoming increasingly serious. Since 2009, the media have successively disclosed the accidents that polysilicon toxic by-product silicon tetrachloride and waste gas and liquid pollute the living environment of residents around the factory buildings. Even leading enterprises in the industry such as Luoyang spring testing machine range Zhongsi and Jiangsu Zhongneng have not been spared

the pollution in the process of polysilicon production mainly comes from the by-product silicon tetrachloride. For each ton of photovoltaic polysilicon produced, 10 tons to 20 tons of silicon tetrachloride are produced at the same time, and silicon tetrachloride is decomposed into silicic acid and highly toxic gas hydrogen chloride in case of humid air, which is strongly irritating to human eyes, skin and respiratory tract. It is not easy to deal with such a large number of toxic by-products. A polysilicon manufacturer with an annual output of one million tons produces thousands of tons of silicon tetrachloride every year. Except that a small part is regarded as the original material to obtain accurate conclusions to produce silica and optical fiber quartz rods, most of them are buried locally. 4. Regularly check the screws at the jaw, leaving potential pollution hazards

Jian Shuishui, a professor at Beijing Jiaotong University, told the China Securities Journal that although domestic polysilicon manufacturers have widely adopted new production processes to improve the Siemens process in recent years to reduce the output of silicon tetrachloride, the hidden dangers have not been completely eliminated. The process of processing the output of silicon tetrachloride is accompanied by additional cost input, which also affects the enthusiasm of enterprises

Wang Haisheng, chief analyst of Huatai United Securities power and new energy industry, pointed out that domestic polysilicon production technology and equipment are mostly imported from abroad, and enterprises often only master the production process, but their core environmental protection process has not been digested and absorbed in time, resulting in frequent pollution accidents in the early stage of industrial development

the access threshold is becoming stricter

with the blind expansion of domestic polysilicon production capacity, the pollution problem is also becoming increasingly prominent, and the wind of strict market access is gradually rising. In the "access conditions for polysilicon industry" released in March, environmental protection standards were put forward for the launch of polysilicon projects, in which the requirements for the treatment of silicon tetrachloride, a by-product, were that the relevant management regulations for hazardous wastes such as silicon tetrachloride should be strictly implemented

a local polysilicon manufacturer told the China Securities Journal that, in fact, before the "conditions" were issued, the environmental impact assessment report of enterprises' new polysilicon projects was strictly reviewed, and the commencement plan of many enterprises was shelved for approval because the environmental impact assessment did not meet the standard

with the sword of environmental protection Damocles hanging high, some enterprises began to explore the improvement of production process, using the improved Siemens method, through the cold hydrogen method, the silicon tetrachloride produced in each process is repeatedly recycled and reduced to trichlorosilane, one of the raw materials for the production of polysilicon, so as to minimize the output of silicon tetrachloride from the terminal during the production process. According to Lu Jinbiao, general manager of Jiangsu Zhongneng silicon Co., Ltd., a subsidiary of poly GCL, more than 20% of silicon tetrachloride is converted into trichlorosilane in a single cycle. The whole production process adopts closed-loop design, which can also reduce the pollution of waste gas and waste liquid in the production process

in addition, other enterprises are also trying to adopt different production processes such as silane method and metallurgical method to control pollution by-products. Wang Haisheng said that at present, among the more than 40 domestic manufacturers engaged in polysilicon production, the top ten, such as poly GCL, Luoyang Zhongsi, Tianwei baobian, Tongwei Co., Ltd., have been equipped with the process of closed-loop polysilicon production to maximize the treatment and utilization of silicon tetrachloride. Under the principle of supporting the excellent and eliminating the weak, which is clearly stated in the "access conditions", these enterprises will lead the development of the industry and finally realize the effective control of pollutants in the whole industry

or the birth of new industries

Wang Haisheng said that the improvement of environmental protection threshold is not only a challenge, but also an opportunity for polysilicon enterprises

he told that at present, the annual output of polysilicon by powerful enterprises has reached more than 6000 tons, which means that nearly 100000 tons of silicon tetrachloride by-products are produced at the same time. From the current experience of enterprises dealing with by-products, silicon tetrachloride can turn waste into treasure. One cycle can convert 20% of silicon tetrachloride. Under multiple cycles, although some processing costs need to be invested, one ton of silicon tetrachloride can produce more than two tons of trichlorosilane raw materials after one cycle. In general, the process of processing silicon tetrachloride is also the process of producing raw materials, which itself is saving costs. He said

cuirongqiang, a professor at Shanghai Jiaotong University, told the China Securities Journal that using silicon tetrachloride as raw material to produce chemical fiber products such as silica, optical fiber quartz rods, etc. in the future, with the progress of processing technology, an emerging industrial market will emerge. According to him, at present, some domestic enterprises have begun to deal with silicon tetrachloride on a large scale, especially Gibson company in Guangdong. At present, the company's annual processing capacity of silicon tetrachloride has reached more than 10000 tons, and Luoyang Zhongsi and Xinguang silicon under Tianwei baobian are its long-term customers

Wang Haisheng pointed out that environmental protection benchmarking, as a major threshold for polysilicon industry access, also provides enterprises with an opportunity to optimize production processes, improve production efficiency and reduce costs driven by environmental protection standards. Taking this opportunity, the future polysilicon industry may get rid of the quagmire of price war in time, so as to promote the development of the industry into a benign track

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