Method of upgrading highly olefinic oils derived from waste plastic pyrolysis

A method of waste plastics pyrolysis oil upgrading via hydroprocessing comprising the steps of:

• a) combining a highly-olefinic pyrolysis oil liquid feed with hydrogen gas and a saturated near zero-olefins stream to form an attenuated feed stream to a first hydroprocessing reactor,
• b) contacting the attenuated feed stream with a series of hydroprocessing catalysts in a two-stage process with at least two hydroprocessing reactors, wherein a first reactor series of at least one reactor operates in the first stage at a lower temperature and/or pressure than the second stage in order to mainly saturate double-bonds and at least one second reactor, which operate(s) in the second stage, at higher temperature and/or pressure than the first stage, in order to mainly remove heteroatomic compounds;
• c) splitting the product of the first stage reactor, which is a saturated near-zero olefins stream, into at least two portions by flashing it on a separator vessel;
• wherein a first portion serves as the attenuation stream in step a), and a second portion serves as feed to the second stage.