An experimental study on hydrotreatment of ligno-cellulosic hydrothermal liquefaction (HTL) bio-crude to achieve a bio-feed compatible for co-processing at a refinery was made to investigate the effect of operating temperature, pressure and hydrogen to oil ratio. Using a conventional NiMo/Al2O3 hydrotreating catalyst at 350 degrees C and 337 NL H-2/L bio-crude, a promising bio-feed with 0.3 wt.%O, a HHV of 43.9 MJ/kg, a density of 894 kg/m(3) and an FT-IR spectra very similar to Northern Sea fossil crude oil was obtained. This work suggests that a gradual and sustainable phase-in of bio-feed through co-processing at existing refineries can be facilitated by intermediate hydrotreating of the bio-crude from hydrothermal liquefaction. (C) 2015 Elsevier Ltd. All rights reserved.