| abstract |
[PROBLEMS] To prevent urea from melting and solidifying when supplying an aqueous urea solution into a system, and to efficiently decompose the aqueous urea solution to ammonia with low heat consumption. Furthermore, the urea aqueous solution is decomposed into ammonia at a lower reaction temperature to improve operability and reduce costs. An apparatus including a nozzle housed in a coating member is disposed at a position close to room temperature, and an urea aqueous solution is supplied into the system to prevent the urea aqueous solution from melting and solidifying. Further, the exhaust gas is heated to a reaction temperature at which the exhaust gas can be decomposed into ammonia. Since this is used as a heating source, the amount of heat consumption is small, and the aqueous urea solution is efficiently decomposed into ammonia. Further, a urea aqueous solution decomposition catalyst is disposed on the upper surface of the evaporating section, and the urea aqueous solution is decomposed into ammonia at a lower reaction temperature. |