The disposal of waste plastic poses serious problem to the environment. Among the various recycling techniques, the liquefaction of waste plastics is a suitable option for the recovery of feedstock for refinery. The presence of chlorinated plastics in the municipal waste plastics poses various problems during the liquefaction process as they produce corrosive HCI and chlorinated hydrocarbons. Dehalogenation process is a key technology in feedstock recycling of mixed halogenated waste plastics. Two different approaches have been made to solve the mixed halogenated waste plastics recycling. The first approach (two step process) is the degradation of waste plastics  (first step) and dehalogenation process (second step) for the plastic-derived oil in a fixed bed flow type reactor, The second approach (single step process) is the simultaneous degradation and dehalogenation of waste plastics with chlorinated (PVC) and brominated  plastics.