Patent ID: 7704473
Filing Date: 2010-04-27
Classification: B01D,B01J,F01N

Abstract:
1. A purification method for exhaust gas from an internal combustion engine, wherein said purification method uses an exhaust gas purification apparatus comprising an oxidation zone installed with an oxidation catalyst supporting both platinum and palladium, and a filtering zone installed with a particulate filter, along exhaust gas flow at the exhaust gas passage of an internal combustion engine, characterized in that hydrocarbon-based liquid is supplied to the inflow side of the exhaust gas of said oxidation zone at the time when 2 to 10 g of particulates per 1 liter of said particulate filter are caught, to raise temperature of said exhaust gas up to equal to or higher than 550° C. by said oxidation catalyst so as to make the residue of said particulate filter combusted, wherein said oxidation catalyst comprises refractory inorganic oxide powders containing platinum and palladium, coated on a 3-dimensional monolithic refractory structure, a mass ratio of platinum/palladium being 20/1 to 1/1, a total amount of palladium and platinum being 0.3 to 20 g per 100 g of the refractory inorganic oxide, and said refractory inorganic oxide being at least one selected from the group consisting of alumina, silica-containing alumina, zirconia and titania.