Method for the preparation of a catalysed monolithic body or a catalysed particulate filter by capillary suction of sol-solution containing catalytically active material and metal oxide catalyst carriers or precursors thereof into pores of monolithic substrate.

According to the present invention, a wall-flow type particulate filter in which pressure loss is suppressed despite a large formation region of a catalyst layer is provided. The particulate filter disclosed herein includes a wall-flow type base material and a catalyst layer formed on the base material. The base material includes an inlet side cell whose only end part on an exhaust gas entry side is open, an outlet side cell whose only end part on an exhaust gas exit side is open, and a partition wall that sections between the inlet side cell and the outlet side cell and includes a plurality of pores communicating between the inlet side cell and the outlet side cell. A first catalyst layer is formed on a surface of the partition wall that is in contact with the inlet side cell. The first catalyst layer is provided in a region over 80% of a total length of the base material from an end part of the base material on the exhaust gas entry side toward an end part thereof on the exhaust gas exit side. In at least a region from a position corresponding to 20% of the total length of the base material to a position corresponding to 80% thereof, from the end part of the base material on the exhaust gas entry side, the first catalyst layer is inclined so that a thickness of the first catalyst layer decreases from the end part on the exhaust gas entry side toward the end part on the exhaust gas exit side.

A catalyst subassembly for a device for purifying exhaust gases from an internal combustion engine, in particular a diesel engine, includes an SCRF catalyst and an SCR catalyst upstream of the SCRF catalyst. The two catalysts are arranged in a common catalyst housing. The catalyst housing, the SCRF catalyst and the SCR catalyst can be selected from a modular system for different variants of the internal combustion engine.

A catalyst for exhaust gas purification, which is capable of effectively purifying an exhaust gas. A catalyst for exhaust gas purification, which includes first catalyst particles, second catalyst particles and carrier particles that support the first catalyst particles and the second catalyst particles. The first catalyst particles are Pd particles or PdRh alloy particles; and the second catalyst particles are PdRh alloy particles. The molar ratio of Rh to the total of Pd and Rh in the first catalyst particles is 0.50 times or less the molar ratio of Rh to the total of Pd and Rh in the second catalyst particles.

A combustion system operated at low cost is provided. A combustion system 1 includes a combustion device 10 that burns fuel, an exhaust line L1 through which exhaust gas flows, the exhaust gas being generated through combustion of the fuel in the combustion device 10, an air preheater 30 that is disposed in the exhaust line L1 and that recovers heat from the exhaust gas, and a denitration device 40 that is disposed in the exhaust line L1 and that removes nitrogen oxide from the exhaust gas using a denitration catalyst. The denitration device 40 is disposed downstream from the air preheater 30 in the exhaust line L1, and the denitration catalyst contains 43 wt % or more of vanadium pentoxide and has a BET specific surface area of 30 m.sup.2/g or more.

There is provided a catalyst that exhibits a high denitration efficiency at a relatively low temperature and does not cause oxidation of SO.sub.2 in a selective catalytic reduction reaction that uses ammonia as a reducing agent. A denitration catalyst molded in a block shape contains 43 wt % or more of vanadium pentoxide. The denitration catalyst has a BET specific surface area of 30 m.sup.2/g or more and is used for denitration at 200? C. or lower.

There is provided a method for recycling a catalyst that exhibits a high denitration efficiency at a relatively low temperature and does not cause oxidation of SO.sub.2 in a selective catalytic reduction reaction that uses ammonia as a reducing agent. A method for recycling a denitration catalyst includes a step of removing a used denitration catalyst from a denitration device and then coating the used denitration catalyst with a catalyst component. The catalyst component contains 43 wt % or more of vanadium pentoxide and has a BET specific surface area of 30 m.sup.2/g or more, and the denitration catalyst after recycling is used for denitration at 200? C. or lower.

There is provided a method for recycling a catalyst that exhibits a high denitration efficiency at a relatively low temperature and does not cause oxidation of SO.sub.2 in a selective catalytic reduction reaction that uses ammonia as a reducing agent. A method for recycling a denitration catalyst includes a step of spraying an aqueous solution with a pH of 7 or more onto a used denitration catalyst while the denitration catalyst is set in a denitration device to remove a surface of the denitration catalyst. The denitration catalyst contains 43 wt % or more of vanadium pentoxide and has a BET specific surface area of 30 m.sup.2/g or more. The denitration catalyst after recycling is used for denitration at 200? C. or lower.

There is provided a catalyst that exhibits a high denitration efficiency at a relatively low temperature and does not cause oxidation of SO.sub.2 in a selective catalytic reduction reaction that uses ammonia as a reducing agent. A denitration catalyst contains 3.3 wt % or more of vanadium oxide in terms of vanadium pentoxide and has a BET specific surface area of 10 m.sup.2/g or more.

A combustion system for ships operated at low cost is provided. A combustion system 1 for ships includes an internal combustion engine 20 that burns fuel, an exhaust line L2 through which exhaust gas flows, the exhaust gas being generated through combustion of the fuel in the internal combustion engine 20, an exhaust heat recovery device 40 that is disposed in the exhaust line L2 and that recovers exhaust heat from the exhaust gas discharged from the internal combustion engine 20, and a denitration device 50 that is disposed in the exhaust line L2 and that removes nitrogen oxide from the exhaust gas using a denitration catalyst. The denitration device 50 is disposed downstream from the exhaust heat recovery device 40 in the exhaust line L2. The denitration catalyst contains 43 wt % or more of vanadium pentoxide and has a BET specific surface area of 30 m.sup.2/g or more.