The present invention provides a process of catalytic depolymerization of polystyrene involving a spherical catalyst, an apparatus for carrying out the depolymerization, recovering the aromatic rich liquid product and recycling the catalyst without any decrease in the catalytic performance. Further, the present invention provides that the aromatic rich liquid product includes styrene, xylene, benzene, ethyl benzene, with styrene content greater than 65%. Additionally, the catalyst involved in the depolymerization process is a spherical catalyst that is easily recovered from coke/char formed during the process and is recycled and reused without any decrease in the catalytic performance.