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Model for flue‐gas desulfurization in a circulating dry scrubber
Author(s) -
Neathery James K.
Publication year - 1996
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690420123
Subject(s) - flue gas desulfurization , slurry , sorbent , mass transfer , wet scrubber , scrubber , chemistry , mass transfer coefficient , flue gas , evaporation , absorption (acoustics) , data scrubbing , diffusion , particle (ecology) , waste management , chemical engineering , chromatography , materials science , adsorption , thermodynamics , composite material , organic chemistry , physics , oceanography , engineering , geology
Abstract A simple model was developed to describe the absorption of SO 2 in a circulating dry scrubbing (CDS) process, which is a semidry, lime‐based, flue‐gas desulfurization (FGD) process that utilizes a circulating fluidized bed arrangement for contacting a sorbent with SO 2 ‐laden flue gas under “coolside” conditions. The reaction chemistry is thought to be similar to that of spray‐drying absorption. The liquid‐phase mass‐transfer coefficient was successfully modeled as a function of the sorbent particle spacing on the wetted surfaces. Gas‐phase mass‐transfer resistances were assumed to be insignificant. Due to the high surface area available in a CDS reactor, the evaporation rate of water from the slurry was modeled as “constant‐rate” drying according to classic spray‐dryer theory. However, the “falling‐rate” and “diffusion” evaporation stages were negligible in CDS since sorbent particle bunching at the surface of the slurry is nonexistent.