【Ten Years of Rapid Development in Chemical Engineering Equipment】New Process Technologies for High-Purity Silicon in Photovoltaic Electronic Materials from 1970 to 2022 and Their Industrial Application
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Witnessing the decade-long rapid development of chemical engineering equipment; praising the prosperity and strength of modern China. Replies will be rewarded; discussions are welcome. -------------------------------------------------- On December 16, 2022, the \"new process technology for high-purity crystalline silicon in photovoltaic electronic materials and its industrial application,\" independently developed by Hualu Engineering Technology Co., Ltd., passed the evaluation of scientific and technological achievements organized by the China Petroleum and Chemical Industry Federation. The appraisal committee, headed by Chen Jianfeng, an academician of the Chinese Academy of Engineering, concluded that this technological achievement has broken through foreign technical blockades, filled a gap in domestic research, and is overall at the international leading level. High-purity crystalline silicon is an important material for photovoltaics and semiconductors. As a leading enterprise in the research and development of polysilicon technology as well as in engineering design in our country, Hualu has been actively working in the photovoltaic sector for 15 years. It has pursued innovative approaches in polysilicon technology development, continuously improving and upgrading these technologies. The company has successfully mastered a series of cold hydrogenation techniques for polysilicon production, thereby breaking the situation in which its core technologies were dependent on others. Liu Jisan, chief engineer of the Materials and Energy Division at Hualu Company, explained that the company has developed new technologies and equipment for the efficient large-scale cold hydrogenation of silicon tetrachloride, as well as techniques for the hierarchical utilization of thermal energy in large-scale reduction furnaces, multi-stage coupled precision distillation methods, and advanced technologies for the recovery of high-efficiency chlorosilane slurry and its high-temperature cracking treatment. The one-way conversion rate (reaction efficiency) for silicon tetrachloride reaches 29%–32%, which is among the best levels in the world; a single reactor can handle up to 400,000 tons of silicon tetrachloride per year. These integrated technologies have been put into industrial use by several leading polysilicon manufacturers, with a domestic market share of over 90%. They have significantly reduced investment and costs associated with production facilities, greatly improved the technical level of the industry, and brought about substantial economic and social benefits.
It is reported that the production of 1 ton of polysilicon generates about 20 tons of silicon tetrachloride; effectively converting silicon tetrachloride into trichlorosilane, which is the raw material for polysilicon, is crucial in the entire polysilicon production process. As an advanced global process technology, cold hydrogenation has gradually replaced hot hydrogenation in recent years due to its advantages such as high conversion efficiency, low energy consumption, and low investment costs. The fifth-generation cold hydrogenation technology developed by Hualu Company was used industrially for the first time this year in the 24,000-ton high-purity polycrystalline silicon transformation project carried out by Xinjiang Xinte Crystal Silicon High-Tech Co., Ltd. Since its commissioning in April, the unit has been operating at full capacity steadily and continuously, with key indicators such as silicon tetrachloride conversion rate and energy consumption exceeding the design values as well as those of similar domestic units. The power consumption for trichlorosilane production has been reduced to 145 kWh/ton, achieving the best level in China. Luo Caiping, the chief engineer at Hualu Company, said that the company makes full use of its advantages in translating independently developed technologies into practical applications. Focusing on core products such as polysilicon, which feature high economic efficiency, excellent product quality, and strong market competitiveness, the company has developed a range of polysilicon production technology packages spanning from 3,000 tons to 30,000 tons per year. This has enabled the transition of polysilicon production capacity from thousands of tons to tens of thousands of tons per year. The total production capacity of the polysilicon projects designed by this company accounts for over 90% of the national total, laying a foundation for the rapid development of polysilicon production in China and earning widespread recognition within the industry. Since 2020, Hualu Company has taken on the engineering design for most of the new polysilicon projects launched in China, as well as the general contracting for some of these projects, thereby further enhancing its market brand influence. To date, once all the polysilicon production capacity designed by Hualu Company is brought online, it will result in an annual increase in photovoltaic power generation of approximately 1.35 trillion kWh, with an estimated reduction of carbon emissions of around 1.25 billion tons per year. To date, this technological achievement has resulted in 3 proprietary technologies being approved, 6 Chinese invention patents and 10 utility model patents granted, as well as 1 Australian invention patent.
As early as 2006, leveraging its experience and technical expertise in the synthesis of silicone and trichlorosilane, Hualu Company developed cold hydrogenation technology for polysilicon, filling a gap in China’s polysilicon industry and becoming the fourth company in the world to possess independent intellectual property rights for polysilicon production technology. In December 2007, China’s first polysilicon production facility using cold hydrogenation technology was built and put into operation at Jiangsu Zhongneng Group. Since then, they have continued to make improvements and optimizations; second-generation, third-generation, fourth-generation, and fifth-generation technologies were successively developed, and the reactor of the cryogenic hydrogenation unit was expanded to 4.5 meters. As the production capacity of the facility increases, the manufacturing process is also improved, resulting in a higher conversion rate of silicon tetrachloride and further reduced energy consumption. Compared to the first generation, the power consumption of third-generation trichlorosilane in the fifth-generation technology has been reduced from 1,000 kWh/ton to 150 kWh/ton, which is about half of that of current foreign cold hydrogenation technologies and only 7.5% of that of traditional hot hydrogenation processes.
【Ten Years of Great Development in Chemical Equipment】The summary post is being updated continuously; feel free to join the discussion at https://bbs.hcbbs.com/thread-3576046-1-1.html (Source: Haichuan Network – Chemical Industry Trends)