| 摘要 |
PURPOSE:To improve low-temperature igniting property and permit stabilized combustion at a high temperature by a method wherein the combustible gas is burnt by arranging specified catalysts at a fore stage and an after stage respectively. CONSTITUTION:A catalyst, constituted of a bearer containing a composite oxide consisting of a single compound, or two or more of oxides selected from alumina, silica, titania or zirconia, and an activating constituent of palladium oxide borne by said bearer, is arranged at a fore stage (inlet side of gas) while another catalyst, consisting of a bearer containing the oxide of rare earth elements and palladium oxide as well as the oxide of rare earth elements, which are borne by said bearer, is arranged at an after stage. When most hardly combustible methane, for example, is burnt, the oxidation of methane is started in the fore stage catalyst at 400 deg.C or lower while the temperature of the fore stage catalyst layer is controlled so as to be lower than 700 deg.C and the temperature of the after stage catalyst is controlled so as to be within the range of 700-1000 deg.C. According to this method, low-temperature igniting property can be improved. |
