| 摘要 |
<P>PROBLEM TO BE SOLVED: To effectively cleaning nitrogen oxides, even in gas to be treated with the amount of nitrogen oxides in the gas fluctuated. <P>SOLUTION: The cleaning method of nitrogen oxide includes the following steps of: (1) introducing ammonia or urea at 100-650°C into the gas which contains nitrogen oxides, oxygen, and hydrogen with oxygen concentration in the gas is 0-5 vol.%; (2) making the gas pass through a catalyst at a space velocity of 1,000-1,000,000 hr<SP>-1</SP>; (3) measuring the nitrogen oxides and/or ammonia or urea contained in the gas after passing through the catalyst; (4) increasing an ammonia amount or a urea amount in the step (1), when the nitrogen oxides are detected in the step (3); and (5) reducing the amount of ammonia or urea in the step (1), when the ammonia or urea is detected in the step (3). <P>COPYRIGHT: (C)2010,JPO&INPIT |
