If you were to design a process package for the recovery of polysilicon off-gases, how would you approach it?
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Currently, the processes used for exhaust gas recovery mainly rely on CDI; no other processes have been seen. If one wants to develop a new set of processes for exhaust gas recovery, here’s how I think one should approach it. There are three key points: first is the purification of hydrogen, which should still be achieved through pressure swing adsorption, as this method is relatively mature, and there are many companies in China that specialize in this technology； The second is the separation of chlorosilanes and hydrogen chloride; the difference between the two lies mainly in their boiling points. Thus, deep cryogenic distillation is used according to the CDI process. I have been considering whether other separation methods could be employed apart from distillation, such as membrane separation ； Third is the integration of processes to reduce energy consumption – just a starting point……
I can say a few things about the existing processes; as for improvements and innovations, I can only offer some assistance
Reply to 1# wuzibo1984: There are various forms of exhaust gas recapture nowadays: 1. CDI； 2. The “CDI-like” process used by Beijing Nonferrous Research Institute in Zhongsi’s so-called independent intellectual property rights ； 3. Recovery process based on pressure swing adsorption (has certain drawbacks for large-scale projects) ； 4. The “CDI+PSA” process developed through the collaboration between Chengda Company and Saipuixing Company ； 5. Integrated processes for certain projects that use PSA instead of CDI as the adsorption column. Using membrane separation to separate chlorosilanes from hydrogen chloride is not feasible; this can be seen from the properties of the membrane material
For exhaust gas recovery, the key issue is what to do with the recovered gas~~~ The pressure swing adsorption process doesn’t seem to be operating properly either
Reply to 4# zhangweicheng: Could you explain it in more detail?
Reply to 1# wuzibo1984: We are a company specialized in the manufacturing of high-temperature and high-pressure filtration equipment. Our patented high-temperature and high-pressure ceramic filters can operate at temperatures above 600 degrees Celsius and under pressures of up to 4.0 MPa. They possess properties such as corrosion resistance and wear resistance. These filters are currently being used in the cold hydrogenation process at Luoyang Zhongsi for the filtration of high-temperature silicon powder. If you have any related needs, feel free to contact me: phone number 13053363308, email address: zoomber88@126.com