Structured catalyst for the selective reduction of nitrogen oxides by ammonia using a hydrolisable compound

• Main Authors: KREUZER, THOMAS, LOX, EGBERT, LEYRER, JUERGEN, DEMEL, YVONNE, HARRIS, MICHAEL
• Format: Patent
• Language: English; French; German
• Published: 04.01.2006
• Subjects: BLASTING; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; STEAM ENGINES; THEIR RELEVANT APPARATUS; TRANSPORTING; WEAPONS

A structurized catalyst selectively reduces nitrogen oxides (NOx) in the lean exhaust gas stream from an internal combustion engine with ammonia (NH3). A hydrolyzable ammonium compound is injected into the structurized catalyst and contains a selective reduction catalyst and a catalyst for hydrolysis of the ammonium compound to NH3 as coating on the selective reduction catalyst. A structurized catalyst selectively reduces nitrogen oxides (NOx) in the lean exhaust gas stream from an internal combustion engine with ammonia (NH3). A hydrolyzable ammonium compound is injected in aerosol form into the structurized catalyst. The structurized catalyst is monolithic and has several flow paths for the lean exhaust gas stream between its inlet and outlet ends. The structurized catalyst contains a selective reduction catalyst and a catalyst for hydrolysis of the ammonium compound to NH3 as coating on the selective reduction catalyst.