W. Jozewicz et Bk. Gullett, REACTION-MECHANISMS OF DRY CA-BASED SORBENTS WITH GASEOUS HCL, Industrial & engineering chemistry research, 34(2), 1995, pp. 607-612
The mechanisms of HCl reaction with dry Ca(OH)(2) or CaO sorbents in f
lue gas cleaning applications were investigated by differential scanni
ng calorimetry (DSC), thermogravimetry, and X-ray diffraction, A short
-time differential reactor (STDR) was used to contact 1000 ppm HCl wit
h dry sorbents at temperatures ranging from 100 to 600 degrees C. The
product of HCl reaction with Ca(OH)(2) over the 100-600 degrees C rang
e in the STDR was identified as a solid solution of CaCl2.2H(2)O and C
aClOH. Subsequently, the Cl/Ca molar ratio in the product was determin
ed to be less than 2. The product of the HCl reaction with CaO in the
STDR over the 100-600 degrees C range was identified as CaClOH. When s
canned by DSC, samples of both CaO and Ca(OH)(2) that were previously
exposed to HCl in the STDR revealed an endotherm between 530 and 590 d
egrees C. The amount of enthalpy correlated well with the chemically d
etermined sample conversion.