Heat-treated active carbons for use in denitration, processes for producing same denitration method using same, and denitration systems using same

摘要

PCT No. PCT/JP96/02737 Sec. 371 Date Apr. 22, 1997 Sec. 102(e) Date Apr. 22, 1997 PCT Filed Sep. 24, 1996 PCT Pub. No. WO97/12671 PCT Pub. Date Apr. 10, 1997This invention relates to a technique for removing nitrogen oxides (NOx) present in exhaust gases discharged from boilers and the like. When the temperature of the exhaust gas is 100 DEG C. or below, a heat-treated active carbon produced by heat-treating a raw active carbon at 600 to 1,200 DEG C. in a non-oxidizing atmosphere so as to remove oxygen-containing functional groups present at the surfaces thereof and thereby reduce the atomic surface oxygen/surface carbon ratio to 0.05 or less is preferably used. When the temperature of the exhaust gas exceeds 100 DEG C., a heat-treated active carbon produced by heat-treating a raw active carbon at 600 to 1,200 DEG C. in a non-oxidizing atmosphere and activating the surfaces thereof with sulfuric acid or nitric acid to impart oxidizing oxygen-containing functional groups thereto is preferably used.