四氯化硅氢化制备三氯氢硅生产工艺研究
发布时间：2018-09-10 13:36
【摘要】：近年来,位于光伏上游的多晶硅产业,因产能过剩遭遇寒潮,国内多晶硅产业受到严重的冲击,除了国外多晶硅生产巨头冲击国内市场的因素外,其根本原因还是自身核心技术不够成熟,导致生产成本过高。降低产业能耗,实现副产物循环利用,成了国内多晶硅行业健康持续发展的关键。改良西门子法是生产多晶硅的主流工艺,每生产1 t多晶硅副产约15 t四氯化硅,如何处理数量庞大的四氯化硅,成为制约多晶硅行业发展的巨大瓶颈。利用四氯化硅氢化技术制备三氯氢硅,实现物料的闭路循环,大幅降低生产成本,开始得到越来越多业内人士的关注。现有的高温氢化工艺和冷氢化工艺中的高能耗和反应转化率低的问题亟待解决。怎么提高四氯化硅转化率,节能降耗成了氢化技术的研究热点。针对该问题,本文对四氯化硅DBD等离子体氢化工艺进行了探索,并将镍基催化剂用于高温氢化反应进行实验研究。主要的研究工作内容和结果如下:(1)提出了DBD等离子体放电用于四氯化硅的氢化反应,并设计等离子体发生器和石英套管反应器,搭建专业实验平台,对DBD等离子体放电条件和四氯化硅氢化反应进行小试试验探索。在DBD低温等离子体中,四氯化硅发生氢化反应生成三氯氢硅,而且在试验功率范围内,随着等离子体电源功率的增大,三氯氢硅收率增大,实验条件下得到三氯氢硅的最大收率为12.1%。(2)DBD等离子体氢化过程中反应进度不易控制,四氯化硅等离子体还原没有停留在生成三氯氢硅这一步,而是继续还原生成了单质硅。高温四氯化硅气体夹带着不定型硅粉,形成导电性的烟雾,改变了原有的放电结构,放电间距大大变小,放电均匀性不好控制。(3)采用浸渍法制备不同的负载镍催化剂,对比了四种催化剂对四氯化硅氢化反应的催化效果,结果表明,Ni/HZSM-5催化性能最佳。最佳反应条件为:镍负载量为10%,反应温度850℃,反应压力0.3 MPa,进料比H_2:SiCl_4为4,空速为5000 h~(-1),在最佳反应条件下,四氯化硅的转化率可以达到16.69%。
[Abstract]:In recent years, the polycrystalline silicon industry located in the upper reaches of photovoltaic has suffered a severe shock due to the cold wave of overcapacity. In addition to the factors that the foreign polysilicon production giants have impacted the domestic market, The fundamental reason is that its core technology is not mature enough, leading to high production costs. Reducing industry energy consumption and realizing recycling of by-products have become the key to the healthy and sustainable development of domestic polysilicon industry. The modified Siemens method is the mainstream process for the production of polysilicon. How to deal with the large quantity of silicon tetrachloride for every 1 ton polysilicon by-product about 15 tons of silicon tetrachloride has become a huge bottleneck restricting the development of polycrystalline silicon industry. The production of trichlorosilicon by hydrogenation of hydrochlorinated tetrachloride can realize the closed-circuit circulation of the material and reduce the production cost greatly. It has been paid more and more attention to by the industry. The problems of high energy consumption and low reaction conversion in the existing high temperature hydrogenation process and cold hydrogenation process need to be solved. How to improve the conversion rate of silicon tetrachloride and save energy and reduce consumption has become the research hotspot of hydrogenation technology. In order to solve this problem, the plasma hydrogenation process of silicon tetrachloride (DBD) was investigated, and the nickel-based catalyst was used in the hydrogenation at high temperature. The main contents and results are as follows: (1) DBD plasma discharge is proposed for hydrogenation of silicon tetrachloride, and plasma generator and quartz casing reactor are designed to build a professional experimental platform. The discharge conditions of DBD plasma and the hydrogenation of silicon tetrachloride were investigated. In DBD low temperature plasma, silicon tetrachloride is hydrogenated to produce trichlorosilicon. In the range of test power, the yield of trichlorosilicon increases with the increase of plasma power. Under the experimental conditions, the maximum yield of trichlorosilicon is 12.1. (2) the reaction progress is not easy to control during the hydrogenation of DBD plasma. The plasma reduction of silicon tetrachloride does not stop at the step of producing trichlorosilicon, but continues to reduce to form elemental silicon. High temperature silicon tetrachloride gas entrainment of amorphous silica fume to form conductive smoke, changed the original discharge structure, discharge spacing greatly smaller, discharge uniformity is not easy to control. (3) different nickel catalysts were prepared by impregnation method. The catalytic effects of four kinds of catalysts for hydrogenation of silicon tetrachloride were compared. The results showed that Ni / HZSM-5 had the best catalytic performance. The optimum reaction conditions are as follows: nickel loading 10, reaction temperature 850 鈩，
本文编号：2234599
[Abstract]:In recent years, the polycrystalline silicon industry located in the upper reaches of photovoltaic has suffered a severe shock due to the cold wave of overcapacity. In addition to the factors that the foreign polysilicon production giants have impacted the domestic market, The fundamental reason is that its core technology is not mature enough, leading to high production costs. Reducing industry energy consumption and realizing recycling of by-products have become the key to the healthy and sustainable development of domestic polysilicon industry. The modified Siemens method is the mainstream process for the production of polysilicon. How to deal with the large quantity of silicon tetrachloride for every 1 ton polysilicon by-product about 15 tons of silicon tetrachloride has become a huge bottleneck restricting the development of polycrystalline silicon industry. The production of trichlorosilicon by hydrogenation of hydrochlorinated tetrachloride can realize the closed-circuit circulation of the material and reduce the production cost greatly. It has been paid more and more attention to by the industry. The problems of high energy consumption and low reaction conversion in the existing high temperature hydrogenation process and cold hydrogenation process need to be solved. How to improve the conversion rate of silicon tetrachloride and save energy and reduce consumption has become the research hotspot of hydrogenation technology. In order to solve this problem, the plasma hydrogenation process of silicon tetrachloride (DBD) was investigated, and the nickel-based catalyst was used in the hydrogenation at high temperature. The main contents and results are as follows: (1) DBD plasma discharge is proposed for hydrogenation of silicon tetrachloride, and plasma generator and quartz casing reactor are designed to build a professional experimental platform. The discharge conditions of DBD plasma and the hydrogenation of silicon tetrachloride were investigated. In DBD low temperature plasma, silicon tetrachloride is hydrogenated to produce trichlorosilicon. In the range of test power, the yield of trichlorosilicon increases with the increase of plasma power. Under the experimental conditions, the maximum yield of trichlorosilicon is 12.1. (2) the reaction progress is not easy to control during the hydrogenation of DBD plasma. The plasma reduction of silicon tetrachloride does not stop at the step of producing trichlorosilicon, but continues to reduce to form elemental silicon. High temperature silicon tetrachloride gas entrainment of amorphous silica fume to form conductive smoke, changed the original discharge structure, discharge spacing greatly smaller, discharge uniformity is not easy to control. (3) different nickel catalysts were prepared by impregnation method. The catalytic effects of four kinds of catalysts for hydrogenation of silicon tetrachloride were compared. The results showed that Ni / HZSM-5 had the best catalytic performance. The optimum reaction conditions are as follows: nickel loading 10, reaction temperature 850 鈩，
本文编号：2234599
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