PURPOSE: To provide a denitration method of high reliability denitrating NOx in exhaust gas of an internal combustion engine of a lean air/fuel ratio in a highly efficient manner.
CONSTITUTION: In a denitration catalyst wherein activated alumina is used as a support and indium, silver and/or silver oxide are supported on the support, in the relation between the pore radius measured by a nitrogen gas adsorbing method and pore radius of activated alumina, the total pore vol. value of pores with a pore radius of 300 or less is set to A, the total pore vol. value of pores with a pore radius of 50 or less is set to B and the total pore vol. value of pores with a pore radius of 100-300 is set to C. The denitration catalyst wherein B is 30% or more of A and C is 15% or less of C and the exhaust gas passing through a denitration catalyst bed are set to a temp. range of 450-600°C at a catalyst inlet.
SUGANO TAIJI
WAKABAYASHI MASAO
