The dechlorination of chloroorganic compounds from PVC-containing mixed plastic-derived oil was studied over iron oxide and iron oxide-carbon composite catalysts. The catalysts are characterised by nitrogen adsorption and X-ray diffraction. The catalysts are deactivated initially due to the adsorption of HCl gas that is produced during the reaction. Continuous adsorption of HCl on iron oxide leads to the conversion of iron oxide to iron chloride. The catalysts' deactivation was overcome by removing the reversible adsorbed HCl gas continuously, using He as a carrier gas.