A process for upgrading a bio-oil stream is disclosed. The process comprises reacting a bio-oil stream with hydrogen in the presence of a catalyst in a reactor to produce an upgraded bio-oil stream. A recycle oil stream is taken from the upgraded bio-oil stream. The recycle oil stream is recycled to the reactor to provide the upgraded bio-oil stream. Concentration of functional groups such as an oxygenate group in the recycle oil stream is measured. Based on the measurement of the concentration of the oxygenate in the recycle oil stream, the recycle rate of the recycle oil stream can be adjusted.

A process and process plant for partial hydroprocessing of a feedstock including oxygenates, including the steps of directing the feedstock, an amount of make-up hydrogen and a recycle gas to a catalytic hydrotreatment process under conditions converting 30-95% of oxygenates to hydrocarbons, to provide a partially hydroprocessed product stream, adding an amount of recycled wash water including at least 0.1 wt % oxygenates, to an amount of the hydroprocessed product stream, optionally in combination with a further amount of wash water, to provide a combined hydroprocessed product stream, cooling the combined hydroprocessed product stream and separating it in a vapor product fraction, a liquid aqueous fraction and a liquid product fraction, withdrawing as a waste stream a first amount of the liquid aqueous fraction either as a purge or by a purification process, directing as the amount of recycled wash water, at least a second amount of said liquid aqueous fraction.

A process and process plant for partial hydroprocessing of a feedstock including oxygenates, including the steps of directing the feedstock, an amount of make-up hydrogen and a recycle gas to a catalytic hydrotreatment process under conditions converting 30-95% of oxygenates to hydrocarbons, to provide a partially hydroprocessed product stream, adding an amount of recycled wash water including at least 0.1 wt % oxygenates, to an amount of the hydroprocessed product stream, optionally in combination with a further amount of wash water, to provide a combined hydroprocessed product stream, cooling the combined hydroprocessed product stream and separating it in a vapor product fraction, a liquid aqueous fraction and a liquid product fraction, withdrawing as a waste stream a first amount of the liquid aqueous fraction either as a purge or by a purification process, directing as the amount of recycled wash water, at least a second amount of said liquid aqueous fraction.