Method for producing renewable fuel and base oil

A method for combined production of aviation fuel and base oil both of biological origin, the method comprising:

• providing feedstock of biological origin containing fatty acids and/or esters of fatty acids;
• subjecting the feedstock to hydrotreatment and isomerization to obtain a paraffinic hydrocarbon intermediate;
• fractionating said paraffinic hydrocarbon intermediate into at least two fractions,
• a lighter fraction fulfilling a specification ASTM D7566-20 Annex A2 for aviation fuel, and
• a heavier fraction fulfilling the following specifications for a base oil component, containing:
• saturates (ASTM D2007) more than 90 wt-%;
• sulfur content (ASTM D 1552/D2622/D3120/D4294/D4927) 0.03 wt-% or less;
• kinematic viscosity 100° C. (EN ISO 3104/ASTMD445) between 1.3-3.5 mm2/s;
• kinematic viscosity 40° C. (EN ISO 3104/ASTMD445) between 3.4-13 mm2/s;
• pour point (ASTM D 97) less than −24° C.;
• flash point (ENISO2719/ASTMD93) more than 120° C.;
• and
• adjusting a production capacity of the lighter fraction and a production capacity of the heavier fraction by selection of process conditions, and/or isomerization process conditions, to produce a yield of the lighter fraction of 60-90 wt-% of a total weight of the formed fractions, and to produce yield of the heavier fraction of 10-40 wt-% of the total weight of the formed fractions;
• wherein a combined yield of the two fractions is at least 98 wt-% of the paraffinic hydrocarbon intermediate of biological origin.