Abstract—Hydrogen chloride (HCl) is an acidic pollutant that is present in the flue gases of most municipal and hazardous waste incinerators. It is important to treat gaseous HCl in incineration streams efficiently to avoid adverse environmental consequences. The removal of hydrogen chloride gas using hydroxysodalite (Na
8Al
6Si
6O
24(OH)
2) at high temperatures (600–900 °C) using a fixed-bed flow-type reactor was investigated in this study. HCl was efficiently removed from N2 containing 1000-ppmv HCl with a reaction time of 2 h at high temperatures. The hydroxysodalite reacted efficiently with the HCl gas at temperatures between 600 and 800 °C, and was transformed into sodalite (Na
8Al
6Si
6O
24Cl
2). The amount of HCl fixed increased as the temperature increased to 800 °C but decreased when the temperature was increased to 900 °C because some of the hydroxysodalite and sodalite was transformed into nepheline (NaAlSiO
4). The most chlorine was fixed at 800 °C (the amount fixed was 56 mg/g). The reaction kinetics were assessed, and the pseudo-first-order and pseudo-second-order rate constants were calculated. Removal experiments showed that the removal process followed pseudo-second-order kinetics rather than pseudo-first-order kinetics. Increasing the temperature of the fixed-bed reactor to 800 °C increased the amount of HCl that was removed while keeping the removal kinetics almost the same.
Index Terms—Gaseous HCl, HCl removal, high temperature, hydroxysodalite, reaction kinetics.
Takaaki Wajima is with the Department of Urban Environment Systems, Graduate School of Engineering, Chiba University, Japan (e-mail: wajima@ tu.chiba-u.ac.jp).
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Cite: Takaaki Wajima, "Kinetics of the Removal of Hydrogen Chloride Gas Using Hydroxysodalite at High Temperatures," International Journal of Chemical Engineering and Applications vol. 7, no. 4, pp. 235-238, 2016.