Dehydrochlorination and recovery of hydrochloric acid by thermal treatment of a chloride ion-intercalated hydrotalcite-like compound

We examined the dehydrochlorination of a chloride ion-intercalated hydrotalcite-like compound (Cl^--HT) on thermal treatment under water vapor, and the subsequent recovery of hydrochloric acid. The degree of dehydrochlorination increased with increasing temperature, partial pressure of water vapor, and time, whereas the hydrochloric acid concentration decreased with increasing partial pressure of water vapor and time. Greater than 90% dehydrochlorination and greater than 20 wt.% recovery of hydrochloric acid could be obtained by thermal treatment of Cl^--HT in the conditions as follows; temperature: 550 °C, time: 0.5 h, water vapor: 7%.