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.

A catalyzed particulate filter includes at least one inflow channel including one end where a fluid inflows and another end that is blocked and extends in a length direction, at least one outflow channel including one end that is blocked and another end where the fluid outflows, and the other end extends in the length direction, at least one porous wall defining a boundary between the inflow channel and the outflow channel neighboring each other and extending in the length direction, and a catalyzed supporting member disposed on an inside of the outflow channel, wherein the supporting member includes a plurality of balls.

A catalyzed particulate filter includes at least one inflow channel including one end where a fluid inflows and another end that is blocked and extends in a length direction, at least one outflow channel including one end that is blocked and another end where the fluid outflows, and the other end extends in the length direction, at least one porous wall defining a boundary between the inflow channel and the outflow channel neighboring each other and extending in the length direction, and a catalyzed supporting member disposed on an inside of the outflow channel, wherein the supporting member includes a plurality of balls.

Provided is an engine device of a working vehicle structured such that a first case and a second case can be firmly fixed with a high rigidly by sharing supporting loads of the first case and the second case by an engine room and a working portion. In the engine device of the working vehicle having the first case which removes particulate matter in exhaust gas of an engine, and the second case which removes nitrogen oxide in the exhaust gas of the engine, the first case is provided in an outer side of the engine room which is inward provided with the engine via a first case support body, and the second case is provided in the working portion which is adjacent to the engine room via a second case support body.