| 摘要 |
The present invention relates to a reducing method of a nitrous oxide in exhaust gas discharged from a manufacturing process of a semiconductor, especially a semiconductor or a display device such as a plasma reactor which uses a large amount of fluorinated gas, by using a catalytic reactor including a zeolite catalyst in which an iron ion is impregnated, and to a method for effectively removing a nitrous oxide by selectively injecting a reducing agent or controlling a supply condition of the catalyst reactor, depending on the amount of nitrous oxide included in the discharged exhaust gas. More specifically, the present invention comprises: a first step of measuring the concentration of the nitrous oxide in the exhaust gas of the semiconductor process; and a 2-1 step of performing a decomposition of the nitrous oxide in the catalyst reactor, when the concentration range of the nitrous oxide measured in the first step is less than 200 ppm; or a 2-2 step of providing the exhaust gas to the catalyst reactor and simultaneously providing an ammonia gas as a reducing agent, in order to perform the decomposition and the reduction simultaneously in the catalyst reactor, when the concentration range of the nitrous oxide measured in the second step is equal or more than 200 ppm. By previously or continuously monitoring the concentration of the nitrous oxide in the exhaust gas, the decomposition condition of the exhaust gas is appropriately changed according to the concentration of the nitrous oxide, thereby having an optimal removal efficiency of the nitrous oxide, and economically operating a removal unit simultaneously. |
