Production of ethylene and propylene from pyrolysis plastic oil

A process for the purification of a liquified waste polymer comprising the following steps:

• a) providing a feedstream (1) containing liquified waste polymer, wherein said feedstream (1) contains at least 0.1 wt. % to at most 80 wt. % of dienes based on the total weight of said feedstream (1);
• c) performing a polymerization reaction on said feedstream (1) under polymerization conditions to obtain a first product stream (3) comprising an oligomeric product (33) wherein the polymerization is a cationic polymerization and the cationic polymerization is performed in the presence of an acidic catalyst, wherein the acidic catalyst is a Brönsted acid or a Lewis acid;
• d) optionally, performing a neutralization reaction by contacting said first product stream (3) with a basic compound (25) to obtain a neutralized product stream (4) and removing said basic compound from neutralized product stream (4) to obtain a second product stream (5);
• g) performing a separation to separate the oligomeric product (33) from the purified liquified waste polymer (34);
• and
• j) performing a steam cracking reaction of said purified liquified waste polymer (34) to produce olefins such as ethylene and propylene and aromatics.