Oblon, Spivak, McClelland, Maier & Neustadt, P.C.
Method for removing nitrogen oxides in exhaust gas
A process for removing nitrogen oxides in exhaust gases is provided. The process comprises mixing an exhaust gas generated during the chemical vapor deposition process for producing semiconductors and containing dinitrogen monoxide (N2O), nitrogen monoxide (NO) and nitrogen dioxide (NO2) with ammonia (NH3) in an amount 0.5-3 times the sum of the stoichiometric amount corresponding to nitrogen monoxide and the stoichiometric amount corresponding to nitrogen dioxide; and then contacting said mixed gas with a noble metal catalyst at a sufficiently high temperature to decompose dinitrogen monoxide, nitrogen monoxide and nitrogen dioxide. Dinitrogen monoxide (N2O), nitrogen monoxide (NO) and nitrogen dioxide (NO2) in exhaust gases can be treated in one step. No N2O is produced as a by-product.
Ebara Corporation
Y B B B
Y02C B01D B01D B01D
additional inventional inventional inventional
Kiyomi Yoichi
Arakawa Mori