PRODUCTION OF SULPHUR HEXAFLUORIDE

Over the last two decades sulphur hexafluoride (SF₆) gas has been used in high voltage circuit breakers, transformers, gas insulated transmission lines, X-ray machines and particle accelerators. It is also being used for non-electrical applications like protective atmosphere in magnesium casting and as tracer gas for leak detection. With the rapid growth of switch- gear industry and various other fields in India it is expected that the demand for SF₆ gas will increase enormously. Since SF₆ is not manufactured in India, the entire demand is therefore met by import. BARC has developed a process know-how for the manufacture of SF₆ gas at a semi-pilot plant level. This also includes the manufacture of fluorine, the vital raw material. 

 The production of SF6 gas broadly consists of four major process steps, namely, 

• Production of fluorine gas by electrolytic process

• Fluorination of sulfur to produce SF₆ gas

• Purification of SF₆ where all the by-products and other impurities are scrubbed off through various unit operations

• Condensation and recovery of the product

The product conforms to International Electro-chemical Commission Specification-376 including its non-toxicity. The product recovery is well over 80%.