The role of thermally induced fractures in the calcination and sulfation behavior of sorbents in fluidized bed combustion
- Pennsylvania State Univ., University Park, PA (United States). Energy and Fuel Research Center
In atmospheric pressure, circulating fluidized bed combustors, sorbents are used to minimize SO{sub 2} emissions. It is generally accepted that CaO, formed by decomposition of CaCO{sub 3}, reacts with SO{sub 2} and O{sub 2}: CaCO{sub 3} {yields} CaO + CO{sub 2} and CaO + SO{sub 2} + 1/2 O{sub 2} {yields} CaSO{sub 4} rather than direct sulfation of CaCO{sub 3}: CaCO{sub 3} + SO{sub 2} + 1/2 O{sub 2} {yields} CaSO{sub 4} + CO{sub 2}. Therefore, the physical structure of a calcine, e.g. pore size distribution, accessible surface area, plays an important role in subsequent sulfation behavior. While the use of sorbents to capture SO{sub 2} from combustion gases has been in practice for decades, experimental evaluation is still necessary for selecting a sorbent for a specific application. Naturally occurring sorbents, composed of individual grains of carbonate crystallites, vary greatly in their chemical composition and physical structure. The variation in sorbent properties is often reflected in calcination and sulfation behavior. The present work involved studying the effect of particle size and grain size on the sulfation behavior of six sorbents. The samples covered a wide range of chemical compositions (limestone to dolostone), physical strengths (low to high) and grain structures (fine to coarse-grained).
- OSTI ID:
- 257034
- Report Number(s):
- CONF-950952--
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ADSORBENTS
AIR POLLUTION ABATEMENT
CALCINATION
CALCIUM CARBONATES
CALCIUM OXIDES
COMPARATIVE EVALUATIONS
EXPERIMENTAL DATA
FLUIDIZED-BED COMBUSTORS
FRACTURE PROPERTIES
MINERALOGY
PHYSICAL PROPERTIES
SAMPLE PREPARATION
SORBENT INJECTION PROCESSES
SORPTIVE PROPERTIES
SULFATION
SULFUR DIOXIDE