Patent ID: 6015285
Filing Date: 2000-01-18
Classification: B01J,F23C,F23R

Abstract:
A process for combustion of a fuel comprising the steps of:mixing an oxygen-containing gas with a fuel to form a combustible mixture;contacting the combustible mixture in a first zone with a first zone combustion catalyst comprising PdO disposed on a support selected from the group consisting of La.sub.2 O.sub.3 -stabilized .gamma.-Al.sub.2 O.sub.3, La-stabilized .gamma.-Al.sub.2 O.sub.3, Ce-stabilized .gamma.-Al.sub.2 O.sub.3, Ba-stabilized .gamma.-Al.sub.2 O.sub.3, and La.sub.2 O.sub.3 hexa-aluminate at reaction conditions sufficient to combust a portion of said fuel and produce a first zone combustion catalyst temperature no greater than about 800.degree. C., said first zone combustion catalyst being coated by a diffusion barrier layer selected from the group consisting of .alpha.-Al.sub.2 O.sub.3 and La.sub.2 O.sub.3 -11Al.sub.2 O.sub.3 hexa-aluminate; andcontacting the partially combusted fuel from the first zone in a second zone with a second zone combustion catalyst selected from the group consisting of La.sub.0.5 Sr.sub.0.5 MnAl.sub.11 O.sub.19, PdO on La.sub.2 O.sub.3.11Al.sub.2 O.sub.3 hexa-aluminate, and La.sub.0.2 Sr.sub.0.8 MnAl.sub.11 O.sub.19.