Automated semi-commercial plant for obtaining grained silicon with the use of silicomethane-hydrogen mixture thermal decomposition in boiling bed reactor

Summary
Belarussian academic Institute has developed the plant for continuous-mode production of grained solar-grade polycrystalline silicon (up to 1mm grain size) from silicomethane. Main advantages: high efficiency, relatively easy to operate and a possibility to arrange continuous automated process, low specific energy consumption as compared to core-type reactors available. Institute offers one-off plants and high-tech fine-grained silicon carbide production lines under contracts with the customer.

Description
Technical characteristics of fluidized bed reactor:[br][/br]- capacity - up to 3 kg/h;[br][/br]- flow silane - 2500 l/h;[br][/br]- hydrogen flow - 18 000 l/h;[br][/br]- flow of inert gas - 18000 l/h;[br][/br]- the internal diameter of the working zone of the reactor – [br][/br] 150 mm;[br][/br]- temperature in the zone of the fluidized bed - 850 °C;[br][/br]- the power of the external electric resistance heater – [br][/br] up to 25 kW;[br][/br]- feed size of silicon - from 0.25 to 0.30 mm;[br][/br]- paged silicon particles - up to 1 mm.[br][/br]Plant operation is based on making a boiling (fluidised) bed of fine silicon inoculation particles followed by silicon deposition on their surface. To achieve this, a quartz reactor is loaded with an original amount of fine silicon inoculation particles with specified size-proportional particle distribution. Then degassing and nitrogen blowdown procedures are carried out for the reactor and gas mains in order to remove moisture and air traces from process fluid. To make a boiling inoculation particle bed, fluidizing nitrogen gas is fed via a gas distributing grating to the reactor bottom during the warm-up procedure. As the boiling bed temperature rises nitrogen is gradually replaced by hydrogen. When the boiling bed reaches its working temperature the reactor is loaded with silicomethane-hydrogen mixture. The following silicomethane thermal decomposition results in silicon depositing on the surface of silicon inoculation particles. As this takes place the particles grow bigger and form polycrystalline silicon grains. On reaching some particular size they are moved down into the reactor bottom and output. To ensure continuous operation the reactor is then fed with a specified amount of silicon inoculation particles anew. 

---

Technology Type
 Process
 Design
Other: semi-commercial plant

---

Technology Benefits
• high efficiency; [br][/br]• relatively easy to operate and a possibility to arrange continuous automated process; [br][/br]• low specific energy consumption as compared to core-type reactors available

Technology Differentiation and Uniqueness
Developed an original process technology and equipment for the production of solar energy components.

Technological Keywords
PLANT DESIGN AND MAINTENANCE, MATERIALS TECHNOLOGY, Optical Materials, RENEWABLE SOURCES OF ENERGY, Photovoltaics

---

Development Stage
 Prototype (demonstration available for testing)
 Results of demonstration test available
 Currently in use/production

---

Intellectual Property Rights
 Secret Know-How

---

Range of Applications
solar energy industry, development of technology for photovoltaic detectors

---

Classifier Used at the Enterprise Europe Network
 Environment
 Intelligent Energy

---

Classifier Used at the EU Innovation Relay Centres
 Energy
 Environment & Safety
 Industrial Manufacturing, Material and Transport Technologies
 Other Industrial Manufacturing Technologies

---

Classifier Used at the Technology Transfer Network of yet2.com Inc.
 Energy
 Environmental
 Manufacturing

---

Classifier Used at the UNIDO
 Electricity, Gas And Steam
 Water Works And Supply

---

Preferable Regions
 North America
 South America
 Europe
 Asia
 Africa
 Australia

---

Practical Experience
There are and developed: plant breadboard model equipped with boiling bed reactor; mathematical models ensuring boiling reactor process and scale-up optimization; basic calculation data on semi-commercial plants for obtaining grained silicon with the use of silicomethane-hydrogen mixture thermal decomposition in boiling bed reactor.

---

Environmental Impact
No

---

Type of Collaboration Sought
 Joint Venture
 License
 For Sale

---

Available Technical Assistance
 Documentation
 Personnel

---

Link to this profile: http://ictt.by/ShowRequests/ShowTitlesOffCat.aspx?loc=1&ru=0&id=2231