REDUCTION REMOVING PROCESS FOR NITROGEN OXIDE

摘要

PURPOSE:To remove efficiently NOx without lowering the activity of a catalyst to be used and also remove an incomplete combustion product which may be possibly emitted from said NOx removal. CONSTITUTION:Exhaust gas is brought into contact with a metal alminate catalyst of fourth period transition metal under the presence of hydrocarbons or an oxygen-containing compound (hereinafter referred to as hydrocarbons) in exhaust gas or introduced from outside in the oxidation atmosphere in which excessive oxygen exists. Said catalyst accelerates the reaction of NOx and hydrocarbons prior to the reaction of oxygen and hydrocarbons in the oxidation atmosphere to remove NOx in the exhaust gas with high efficiency. Also, exhaust gas after being in contact with the catalyst is brought into contact with the oxidation catalyst to remove an incomplete combustion composition.