Alkali-enhanced hydrothermal purification of plastic pyrolysis oils

A method for preparing fuel components from waste pyrolysis oil (WPO), the method comprising:

• a) providing a waste pyrolysis oil, containing as a major part, plastic pyrolysis oil (PPO), tyre pyrolysis oil (TPO), or mixtures thereof, the waste pyrolysis oil including as the major part hydrocarbons, and including impurities formed as:
• chlorine compounds, containing from 20 mg/kg chlorine of the WPO to 3500 mg/kg chlorine of the WPO;
• nitrogen compounds, containing from 50 mg/kg nitrogen of the WPO to 10,000 mg/kg nitrogen of the WPO;
• sulphur compounds, containing from 10 mg/kg sulphur of the WPO to 15,000 mg/kg sulphur of the WPO;
• silicon compounds, containing from 20 mg/kg silicon of the WPO to 2000 mg/kg silicon of the WPO;
• b) purifying the waste pyrolysis oil by subjecting it to a hydrothermal treatment with water or with water having a pH above 7 at 150-450° C., where an oil to water ratio is from 9:1 to 1:9 (weight/weight);
• c) separating the hydrothermally treated waste pyrolysis oil from an aqueous phase;
• d) preparing a hydroprocessing feed
• consisting essentially of the hydrothermally treated waste pyrolysis oil;
• or
• consisting essentially of a mixture of the hydrothermally treated waste pyrolysis oil and one or more feed(s) selected from a list consisting of oxygen-containing biological oils having less than 50 mg/kg chlorine and less than 1 mg/kg silicon and hydrocarbons having less than 50 mg/kg chlorine and less than 1 mg/kg silicon;
• e) hydroprocessing the hydroprocessing feed catalytically with hydrogen to cause hydrogenation, and/or one or more of:
• hydrodeoxygenation (HDO), hydrodesulfurisation (HDS), hydrodenitrification (HDN), hydrodechlorination (HDCl), hydrodearomatization (HDAr), and hydroisomerisation (HI), at a temperature between 270° C. and 390° C., at a pressure between 2 MPa and 8 MPa, at a WHSV in a range from 0.1 h−1 to 10 h−1, and a H2 flow of 50-2000 nl H2/l feed in a presence of a hydrodeoxygenation catalyst;
• and
• f) recovering from a hydroprocessed product at least one hydrocarbon fraction boiling in a liquid fuel range;
• wherein in step b) the hydrothermal treatment is conducted so as to cause at least a 50% reduction of silicon compounds of the WPO.