410 FLUIDIZED BED COMBUSTION
material a good candidate for use in cement kilns and con-
crete. The maximum sulfur content per ASTM standards is
1.2% by weight or 3.1% by weight as sulfi tes. The material
has been found useful for building roads, manufacturing
gravel and formed bricks or tiles, and for roofi ng and fl ooring
material.^3
Other advantages of PFBC’s include compactness
because of smaller bed requirements, plant cycle effi cien-
cies of 40–42% and subsequent reduced fuel costs, and unit
modularity for ease in increasing future capacity.^8
Disadvantages include in-bed tube erosion and potential
damage to the gas turbine if the hot gas clean-up is ineffec-
tive. It should be noted that the technology is too new to
accurately assess its advantages versus its disadvantages.CHARACTERIZATION OF SOLID WASTES FROM
FLUIDIZED BEDSThe characterization and use of fl uidized-bed-combus-
tion coal/limestone ash is discussed in the articles of Behr-
Andres and Hutzler^23 and Anthony et al.^24 The former dealt
with the use of the mixture in concrete and asphalt. The latter
presented chemical and physical properties for the waste
(see Tables 1 and 2 above).
Hot-gas cleanup (HGCU) technologies have emerged as
key components of advanced power generation technologies
such as pressurized fl uidized-bed combustion (PFBC), and
integrated gasifi cation combined cycle (IGCC). The main
difference between HGCUs and conventional particulate
removal technologies (ESP and baghouses) is that HGCUs
operate at higher temperatures (500 to 1,000C) and pres-
sures (1 to 2 MPa), which eliminates the need for cooling
of the gas. See Website (2005): http://www.worldbank.org/
html/fpd/em/power/EA/mitigatn/aqpchgas.stmREFERENCES- Robert H. Melvin and Reid E. Bicknell, “Startup and Preliminary
Operation of the Largest Circulating Fluid-Bed Combustion Boiler in
a Utility Environment—NUCLA CFB Demonstration Project,” Paper
Presented at the 50th American Power Conference, Chicago, Illinois,
April 18–20, 1988 p. 2. - Jason Makansi and Robert Schweiger, “Fluidized-bed boilers,” Power,
May 1987, p. 9.
3. Efficiency and Emissions Improvements by Means of PFBC Retrofits
(Finspong, Sweden: Asea PFBC Component Test Facility, S-61220,
1988), p. 2.
4. Taylor Moore, “Fluidized bed at TVA,” EPRI Journal, March 1989,
p. 27.
5. Asea Babcock PFBC Update, 1, No. 3 (Fall 1988), n. pag.
6. Code of Federal Regulations, Vol. 40, Part 60, Revised as of July 1988.
7. Charles Sedman and William Ellison, “German FGD/DeNO x Expe-
rience,” Presented at the Third Annual Pittsburgh Coal Conference,
Pittrsburgh, Pennsylvania, September 1986.
8. Asea Babcock PFBC Update, 1, No. 2 (Summer 1988), n. pag.
9. Jason Makansi, “Users pause, designers wrestle with fluid-bed boiler
scaleup,” Power, July 1988, p. 2.
10. David Osthus, John Larva, and Don Rens, “Update of the Black Dog
Atmospheric Fluidized-Bed Combustion Project,” Paper Presented at
the 50th American Power Conference, Chicago, Illinois, April 18–20,
1988, p. 1.
11. Bob Schweiger, ed., “Fluidized-bed boilers achieve commercial status
worldwide,” Power, Feb. 1985, p. 9.
12. R.A. Cochran and D.L. Martin, “Comparison and Assessment of Cur-
rent Major Power Generation Alternatives,” Presented at the Power-Gen
Exhibition and Conference for Fossil and Solid Fuel Power Generation
in Orlando, Florida, Boston, Massachusetts, Dec. 1988, p. 2.
13. Sheldon D. Strauss, “Fluidized bed keys direct alkali recovery,” Power,
Feb. 1985, p. 1.
14. Melvin and Bicknell, p. 6 (see 1).
15. Bob Schweiger, ed., “U.S.’s largest commercial CFB burns coal cleanly
in California,” Power, Oct. 1986, p. 2.
16. Efficiency and Emissions Improvement by Means of PFBC Retrofits,
p. 10.
17. A.A. Jonke et al. , “Reduction of Atmospheric Pollution by the Appli-
cation of Fluidized-Bed Combustion,” Argonne National Laboratory,
Publication No. ANL/ES-CEN-1002, 1970, n. pag.
18. A. Skopp and G. Hammons, “NO x Formation and Control in
Fluidized-Bed Coal Combustion Processes,” ASME Winter Annual
Meeting, Nov./Dec., 1971.
19. Jason Makansi, “Meeting future NO x caps goes beyond furnace modi-
fications,” Power, September 1985, p. 1.
20. Reduction of Nitric Oxide with Metal Sulfides, Research Triangle Park:
U.S. E.P.A., EPA-600/7078–213, Nov. 1978, pp. 1–5.
21. Ibid, p. 3.
22. Ed Cichanowicz, “Selective catalytic reduction controls NO x in
Europe,” Power, August 1988, p. 2.
23. Christina B. Behr-Andres and Neil J. Hutzler, “Characterization and
use of fluidized-bed-combustion coal ash,” Journal of Environmental
Engineering, November/December 1994, p. 1488–506.
24. E.J. Anthony, G.G. Ross, E.E. Berry, R.T. Hemings. and R.K. Kissel,
“Characterization of Solid Wastes from Circulating Fluidized Bed
Combustion”, Trans. of the ASME Vol. 117, March 1995, 18–23.
JAMES SANDERSON
Environmental Protection Agency
Washington, D.C.FISH ECOLOGY: see POLLUTION EFFECTS ON FISH; THERMAL EFFECTS ON
FISH ECOLOGYC006_001_r03.indd 410C006_001_r03.indd 410 11/18/2005 2:28:16 PM11/18/2005 2:28:16 PM