Fluidized-bed-combustion fundamentals: How they favor fines-coarse beds

Book · Sun Dec 31 04:00:00 EST 1995

OSTI ID:287940

Garcia-Mallol, J A; Shaffer, E J ^[1]

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1. Foster Wheeler Energy Corp., Clinton, NJ (United States)

Environmental regulations of the energy generation sector threaten to phase out some important fuel resources, because of their high sulfur content. It is becoming unfeasible to burn these fuels by the classical Pulverized Coal firing methods, because of the ever increasing requirement of Flue Gas Desulfurization equipment, which has very high capital and operating cost. An alternate response to the regulations is Coal Washing, thereby creating rejects which cannot be burned by the classic methods. All of this has resulted in a greater use of, and dependence on, natural gas. At the same time, the globalization of the energy market has made available a vast array of less expensive of waste fuels (i.e., imported coals, cokes and other solid fuels and byproducts) which, when utilized with the proper combustion system, provide a cost-advantageous alternative to natural gas. Consequently, Fluidized Bed Combustion (FBC) of crushed solid fuels is frequently considered. Fundamental formulations on Fluidization, Char Combustion and Sulfur Capture are reviewed in the paper. Emphasis is placed on the validity of historical fluidization diagrams in view of the latest FBC technologies. The transition zone between the bed proper and the pneumatic transport zone is addressed, as well as their Heat Transfer. Singled out as fluidization`s determining factor, depending on which fuel and process, are ash composition or the effect on sulfur sorbent behavior of the fuel type and sulfur content. Implications of these fundamentals are identified for the various FBC applications, including Atmospheric or Pressurized, Conventional or Circulating, and for different fuels. Sample economics for commercial available FBC types are included, contrasted with those of hydrocarbon-fuel-fired boilers.

• OSTI ID: 287940
• Report Number(s): CONF-950522--; ISBN 0-7918-1305-3
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
AIR POLLUTION ABATEMENT
ATMOSPHERIC PRESSURE
CHARS
COMBUSTION KINETICS
CULM
ECONOMICS
ENTRAINMENT
FLUIDIZED-BED COMBUSTION
FLUIDIZED-BED COMBUSTORS
HEAT TRANSFER
LIMESTONE
NUMERICAL DATA
PARTICLE SIZE
PARTICULATES
PRESSURIZATION
SORBENT INJECTION PROCESSES
STEAM GENERATORS
SULFUR DIOXIDE
TAILINGS
TECHNOLOGY ASSESSMENT