Circulating fluidized-bed boilers: Enhancing reagent utilization while maintaining proper SO{sub 2} removal

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:617732

Dubose, R E; Ray, D M ^[1]; Wofford, J; Buecker, B

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1. Univ. of North Carolina, Chapel Hill, NC (United States)

Unit performance, and related operation and maintenance costs, for circulating fluidized bed (CFB) combustors are very dependent on the sorbent selected for SO{sub 2} removal. Limestone is the typical reagent of choice, but variations in quality can have a dramatic impact on the reaction efficiency. This paper discusses the results of full-scale tests and subsequent use of a high-quality sorbent in the two CFBs serving the University of North Carolina at Chapel Hill. The tests were necessary because of the desire to optimize performance based on the economics of limestone utilization and ash disposal. It was considered, also, that the reagent in use prior to the tests was not very reactive and caused ash handling problems. Project organizers used the full-scale tests to examine the effects of sorbent quality and grind size on the efficiency of the process. The tests indicated that reagent consumption would be reduced by 50% or more with the new sorbent. Plant personnel verified this conclusion when they began feeding the new reagent on a permanent basis. Reagent usage and ash production significantly decreased and have remained low in the three years since the change was made. The results outlined in this paper clearly indicate the large impact that reagent quality has on CFB operation. For present and prospective CFB managers, these results can justify the search for, and use of, limestone sorbents that might otherwise be considered too expensive or too distant from the plant. 39 figs.

• OSTI ID: 617732
• Report Number(s): CONF-9711121--
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
ADSORBENTS
CIRCULATING SYSTEMS
EFFICIENCY
FLUIDIZED BED BOILERS
PERFORMANCE TESTING
REAGENTS
SULFUR DIOXIDE