Enhanced dechlorination of chlorobenzene and in situ dry sorption of resultant Cl-compounds by CaO and Na2CO3 sorbent beds incorporated with Fe2O3

The dechlorination of C6H5Cl and the in situ dry sorption of Cl-compounds produced by C6H5Cl decomposition in an alkaline sorbent of CaO or Na2CO3 incorporated with Fe2O3 were studied. A sample gas containing C6H5Cl at an initial concentration of 500 ppm balanced by either N2, O2 (5%)-N2 or H2O (10%)-N2 carrier gas was introduced into a lab-scale quartz tube reactor where CaO or Na2CO3 sorbent was packed with Fe2O3. Subsequently, the effect of Fe2O3 addition to CaO or Na2CO3 on the removal of C6H5Cl, achieved by the decomposition of C6H5Cl as well as the dry sorption of Cl-compounds produced by C6H5Cl decomposition, was investigated.It was found that the decomposition of C6H5Cl in CaO or Na2CO3 sorbent bed incorporated with Fe2O3 occurred in the lower temperatures, compared to the case when only CaO or Na2CO3 sorbent bed was used. Thus, Fe2O3 was found to play a catalytic role in the oxidative decomposition of C6H5Cl. Further, the decomposition of C6H5Cl in a bed containing only Fe2O3 was promoted by the presence of O2 and H2O in the reaction atmosphere. Moreover, a higher amount of Cl was absorbed in the combined CaO/Fe2O3 and Na2CO3/Fe2O3 beds, compared to the absorption of Cl-compounds in only CaO or Na2CO3 sorbent bed. Finally, the comparison of CaO and Na2CO3 sorbents showed that the decomposition of C6H5Cl and the in situ dry sorption of the resultant Cl-compounds in the combined Na2CO3 and Fe2O3 beds were higher than those in the combined CaO and Fe2O3 beds.