Novel designs of fluidized bed combustors for low pollutant emissions
- Delft Univ. of Technology (Netherlands). Dept. of Chemical Engineering
- Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Chemical Engineering
It is known that NH{sub 3}, released during the devolatilization of fuel, is an important precursor for NO formation in fluidized bed combustors. On the other hand, NH{sub 3} may be used as a reducing agent in the thermal DeNO{sub x} process to reduce NO{sub x} emission levels. In this paper, a new concept of fluidized bed combustors is proposed based on the idea of in situ reduction of NO{sub x} by self-produced NH{sub 3} from fuel without lowering the sulfur capture level. This design is intended to separate the NH{sub 3} release process under reducing conditions from the char combustion process under oxidizing conditions; this self-released NH{sub 3}, together with some combustibles, is mixed with gaseous combustion products in the upper part of the combustor for a further reduction of the NO{sub x} formed during combustion. Furthermore, the combustion of the combustibles may cause the temperature to rise in this upper zone and thereby reduce the emission of N{sub 2}O. The applications of this design to bubbling and circulating fluidized bed combustors are described and the mechanisms of the main reactions involved discussed.
- OSTI ID:
- 287996
- Report Number(s):
- CONF-950522--; ISBN 0-7918-1305-3
- Country of Publication:
- United States
- Language:
- English
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