Decomposition of Trichlorobenzene Isomers by Co-Grinding with CaO

Two types of trichlorobenzene (TCB) isomers, 1,2,3- and 1,3,5-, were subjected to grinding in air with CaO in a planetary ball mill to investigate their decomposition phenomena. Results showed that TCB samples were decomposed by the co-grinding to form calcium chloride hydrate and amorphous carbon as the main products, with other minor compositions such as carbon dioxide and water. There was no significant difference in the decomposition phenomena between the two isomers. Radicals were generated during the decomposition process, predominantly due to the rupture of C-Cl bonds in the molecule. Supported by the simulation data, we concluded that dehydrochlorination during TCB decomposition process to form hydrochloride (HCl, further to CaOHCl) exhibited the lower possibility, suggesting dechlorination rather than dehydrochlorination as the plausible decomposition pathway.