The reduction of recycled-NO x in coal combustion with O 2/recycled flue gas under low recycling ratio
Abstract
The emission and reduction of NO x in coal combustion with O 2/recycled flue gas were investigated in an electric heated up-flow-tube combustor with a high volatile bituminous coal. The recycling ratio of flue gas ranged from 0 to 0.4, and the concentrations of recycled-NO in inlet gas were 0, 500 and 1000 ppm. Reduction efficiency of the recycled-NO x changed both with equivalence ratio and recycling ratio. More than 60% recycled-NO was reduced when equivalence ratio ϕ>1.4. Less recycled-NO was reduced under lower recycling ratio than that under higher recycling ratio. HCN and NH 3 were also detected with GC-FTD. The results indicated that HCN emissions decreased with the increase of recycled-NO concentration in inlet gas. No obvious influence of temperature on the reduction of recycled-NO was found. The experiments on recycled-NO 2 demonstrated a consistent trend similar to the NO recycle tests.
- Publication:
-
Fuel
- Pub Date:
- January 2001
- DOI:
- 10.1016/S0016-2361(01)00048-5
- Bibcode:
- 2001Fuel...80.1851H
- Keywords:
-
- Combustion;
- Flue gas;
- Equivalence ratio