Method and apparatus for treating a waste gas containing fluorine-containing compounds

Abstract

An apparatus for treatment of a waste gas, containing fluorine-containing compounds, comprises: a solids treating device for separating solids from the waste gas; an addition device for adding H 2 and/or H 2 O, or H 2 and/or H 2 O and O 2 , as a decomposition assist gas to the waste gas leaving the solids treating device; a thermal decomposition device that is packed with γ-alumina heated at 600 - 900 ° C., and which thermally decomposes the waste gas to which the decomposition assist gas has been added; an acidic gas treating device for removing acidic gases from the thermally decomposed waste gas; and channels or lines for connecting these devices in sequence. The apparatus preferably includes an air ejector which is capable of adjusting an internal pressure of the apparatus.

1 - 7 . (canceled)  
   
   
       8 . A method for treating waste gas, comprising: 
 separating solids from a waste gas containing fluorine-containing compounds;    adding to said waste gas H 2  and/or H 2 O or H 2  and/or H 2 O and O 2  as a decomposition assist gas;    thermally decomposing said waste gas by contacting said waste gas with γ-alumina at a temperature of from 500° C. to 1000° C., thereby providing a decomposed waste gas; and    removing acidic gases from said decomposed waste gas.    
   
   
       9 . The method according to  claim 8 , wherein 
 thermally decomposing said waste gas by contacting said waste gas with γ-alumina at a temperature of from 500° C. to 1000° C. comprises thermally decomposing said waste gas by contacting said waste gas with γ-alumina at a temperature of from 600° C. to 900° C.    
   
   
       10 . The method according to  claim 8 , wherein 
 separating solids from a waste gas containing fluorine-containing compounds comprises separating solids from a waste gas containing perfluoro-carbons and fluorinated hydrocarbons as well as oxidizing gases, acidic gases and CO.    
   
   
       11 . The method according to  claim 10 , wherein 
 separating solids from a waste gas containing perfluoro-carbons and fluorinated hydrocarbons as well as oxidizing gases, acidic gases and CO comprises separating solids from a waste gas supplied from a semiconductor fabrication process.