| abstract |
PURPOSE: To efficiently reduce nitrogen oxides by bringing the waste gas contg. nitrogen oxides and mixed with gaseous ammonia into contact with an acid- resistant zeolite catalyst contg. copper and/or iron at high temps. and at a specified space velocity. n CONSTITUTION: The waste gas contg. nitrogen oxides and mixed with gaseous ammonia is brought into contact with an acid-resistant zeolite catalyst contg. copper and/or iron at high temps. to remove the nitrogen oxides. In this case, the process is carried out at 200-600°C and at 2,000-60,000 h - space velocity corresponding to 0.5-100 m 3 i.N./h.m 2 catalyst area load. Mordenite-structure zeolite is used as the zeolite and the SiO 2 -to-Al 2 O 3 molar ratio is preferably controlled to ≥8. The zeolite further contg. cerium and molybdenum is more appropriately used. n COPYRIGHT: (C)1990,JPO |