Destruction of perfluoro and hydrofluorocarbon compounds in effluent gas, e.g. from semiconductor production, involves preconcentration, plasma treatment and removal of acid products

摘要

In a method for the destruction of perfluoro compounds (PFC) and hydrofluorocarbon compounds (HFC) in effluent gas by plasma treatment, the effluent is preconcentrated to a PFC/HFC content of 5000 ppmv to 5 vol% before plasma treatment, which may be followed if necessary by treatment to remove certain conversion products, especially acids. A method for the destruction of gaseous perfluoro compounds (PFC) and/or hydrofluorocarbon compounds (HFC) in gaseous effluents by injecting the effluent into a plasma so as to break the bonds between fluorine and other elements with the formation of different fluorine compounds such as COF2, SO2F2, SOF4, F2, HF etc. The method involves preconcentration of the effluent to a PFC/HFC content of 5000 ppmv to 5 vol% before plasma treatment, after which the plasma-treated gas may if necessary be injected into a medium for eliminating certain species in the gas, especially acids. An independent claim is also included for apparatus for use in the above method (preferably using plasma with a high flux density) which also includes a preconcentration unit to produce the above mixture for injection.