Cold Conversion Equipment

In the trichlorosilane (TCS) production and deposition processes, significant quantities of co-product silicon tetrachloride (STC) are generated. The STC must be recovered, converted to TCS, and recycled to make the polysilicon production process cost-effective. There are two production technologies for conversion of STC-to-TCS: the thermal process operating at ~1200 Co and the hydrogenation (cold conversion) process operating at ~550 Co. PPP-E supplies process technology and equipment for both processes. The Cold Conversion Process was developed by PPP Equipment Corporation (PPP-E) in response to the abundance of STC in China and the difficulties of obtaining anhydrous HCl at some plant sites. This advanced process has higher STC-to-TCS conversion than the thermal process.

In addition to the process technology, PPP Equipment Corporation has developed the key equipment for the Cold Conversion process; the advanced Fluidized Bed Reactor (FBR) for the hydrogenation of STC-to-TCS. This technology was developed by our experts to meet performance, operability, and maintainability requirements, using high pressure and lower temperature operating parameters, with higher conversion of STC.

Benefits of PPP-E’s Cold Conversion Technology

• PPP-E provides advanced FBR technology for STC-to-TCS conversion based on the proven hydrogenation process.
• PPP-E developed the Cold Converter design incorporating enhancements to the following key issues:
  • Fluidization characteristics/bed behavior
  • Metal chlorides plugging
  • Erosion/safety
  • Heating requirements
  • Catalysis
  • FBR vessel geometry
  • Gas flow, distribution, density
  • Pressure drop and residence time
  • Operational modes
  • MGSi solid feed system
  • Gas/solid separation
• PPP-E provides operator training utilizing our numerous experts in this hydrogenation FBR technology who have operated these plants in the United States and other countries around the world.

PPP-E incorporates other enhancements to a proven cold converter design to provide a robust and safely designed system with decreased downtime due to outages from high problematic or maintenance areas known from existing operating plants.

PPP-E has developed this FBR based on many years of technology development in specialized Fluidized Bed Reactors to meet performance requirements and reduce safety risks. Combined with our separation/purification system, the TCS produced from cold conversion is very cost competitive with respect to both CAPEX and OPEX compared to hydrochlorination TCS production. PPP-E provides the Cold Conversion FBR and settler equipment.

PPP-E offers complete solutions of the cold conversion system including:

• Complete polysilicon plant utilizing Cold Conversion for TCS Synthesis
• Cold Conversion package to replace Thermal Converter including recycled chlorosilanes
• Stand-alone purified TCS Synthesis Cold Conversion package with distillation to meet both solar grade or electronic grade polysilicon from TCS CVD deposition
• Stand-alone crude Cold Conversion package