TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: In the process of treating pyrolysis oil, the partially deoxygenated pyrolysis oil in step (c) has an oxygen content (on dry basis) of 15-17 wt.%. The hydrocarbon feed has an initial boiling point of at least 220 degrees C, as measured according to ASTM D-2887. The hydrogenation step is performed at a temperature of 300-450 degrees C, and at a pressure of 50-100 bars in the presence of nickel, cobalt and/or molybdenum based catalyst. The process of treating pyrolysis oil further comprises blending the product fraction obtained in step (e) with at least one fuel component other than the product fraction and/or an additive. Preferred Components: The mineral crude oil is gas oil. EXAMPLE - Pyrolysis oil obtained from forest residue (2.5 kg) was loaded into the reactor followed by 5 wt.% of fresh ruthenium/carbon catalyst. The maximum operating temperature and pressure were 350 degrees C and 340 bars, respectively. Hydrogen was added to the reactor until the desired reaction pressure was reached (290 bars). A product containing one aqueous phase and one or two phases of partially deoxygenated pyrolysis oil was obtained, after the reactor was left to cool down overnight. The partially deoxygenated pyrolysis oil fractions which were a part of the product were filtered to remove the ruthenium/carbon catalyst, where the oxygen content of the partially deoxygenated pyrolysis oils obtained after hydrodeoxygenation was 17 wt.%. The partially deoxygenated pyrolysis oil was blended with hydrotreated gas oil in a weight ratio of 1:4 and some amount of isopropanol to prepare a feed composition. The feed composition contained partially deoxygenated pyrolysis oil (20 wt.%), isopropanol (1.5 wt.%), and hydrotreated gas oil (78.5 wt.%), which was subjected to the hydrogenation step in a continuous hydrotreatment unit in the presence of a presulfided nickel-molybdenum hydrotreatment catalyst at 300-320 degrees C and the pressure was maintained at 60 bar with 1% hydrogen sulfide in the off-gas, where the gas flow rate was 20 Nl/hour, the ratio of gas to oil was 2000 Nl/kg and the weight hourly space velocity maintained in the reactor was 1 kg/l/hour. The product stream obtained was separated in a gas/liquid separator.