Spent sorbent reactivation using steam

Book · Sun Dec 31 04:00:00 EST 1995

OSTI ID:287943

Julien, S; Brereton, C M.H.; Lim, C J; Grace, J R ^[1]; Chiu, J H; Skowyra, R S ^[2]

---

1. Univ. of British Columbia, Vancouver, British Columbia (Canada)
2. Combustion Engineering Inc., Windsor, CT (United States)

Experiments were carried out in a bench scale fluidized bed reactor using spent sorbent and fly ash captured in the baghouse of a circulating fluidized bed combustor. When the spent sorbent was reactivated with steam at temperatures from 250 to 600 C and then exposed to a simulated flue gas mixture containing SO{sub 2} at typical combustion temperatures, there was considerable additional capture of sulfur by the reactivated sorbent. The optimum reactivation temperature for the tested ash appears to be about 450 C for the tested ash. The observations are explained in terms of thermodynamic equilibrium and bulk diffusion mechanism in which steam diffuses through a CaSO{sub 4} shell and reacts with unreacted CaO to generate Ca(OH){sub 2} leading to cracking so that SO{sub 2} can penetrate into the core when the reactivated particles are re-exposed to combustion conditions.

• OSTI ID: 287943
• Report Number(s): CONF-950522--; ISBN 0-7918-1305-3
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
20 FOSSIL-FUELED POWER PLANTS
ADSORBENTS
AIR POLLUTION CONTROL
CALCIUM HYDROXIDES
CALCIUM OXIDES
CALCIUM SULFATES
CHEMICAL PROPERTIES
COAL
EXPERIMENTAL DATA
FLUIDIZED-BED COMBUSTION
FLUIDIZED-BED COMBUSTORS
FLY ASH
FOSSIL-FUEL POWER PLANTS
HYDRATION
LIMESTONE
PHYSICAL PROPERTIES
REGENERATION
SORBENT INJECTION PROCESSES
SULFUR DIOXIDE
TEST FACILITIES