NOVELTY - Producing (P1) bio-oil involves: (a) thermochemically converting biomass in conversion reactor to form conversion effluent of vapor conversion products; (b) partially condensing the vapor conversion products in partial condenser to form first water-rich overhead stream and first water-depleted stream; (c) separating at least portion of the first water-rich overhead stream to form second water-rich stream and second water-depleted stream; and (d) introducing reflux stream into partial condenser.    USE - For separating water from bio-oil by using a partial condenser; in transportation fuels, hydrocarbon chemicals, and/or specialty chemicals.    ADVANTAGE - The process provides an effective and flexible process for producing bio-oil; and efficient removal of water from bio-oil.    DETAILED DESCRIPTION - Producing (P1) bio-oil involves: (a) thermochemically converting biomass in a conversion reactor to produce a conversion effluent comprising vapor conversion products; (b) partially condensing at least a portion of the vapor conversion products in a partial condenser to produce a first water-rich overhead stream comprising non-condensable gases, water, and light organic compounds and a first water-depleted stream comprising condensed bio-oil; (c) separating at least a portion of the first water-rich overhead stream in a separator to produce a second water-rich stream comprising water and water-soluble light organic compounds and a second water-depleted stream comprising water-insoluble light organic compounds; and (d) introducing a reflux stream into the partial condenser, optionally (d) fractionating at least a portion of the second water-rich stream in a fractionator to produce a third water-rich stream comprising water and a third water-depleted stream comprising water-soluble light organic compounds, where the reflux stream comprises at least a portion of first water-depleted stream and/or at least a portion of the second water-depleted stream. An INDEPENDENT CLAIM is included for a system for producing bio-oil, comprising: a biomass feedstock source for providing solid particulate biomass; a conversion reactor for thermally converting at least a portion of the solid particulate biomass feedstock into condensable vapor conversion products; a partial condenser for partially condensing at least a portion of the condensable vapor conversion products into a first water-rich overhead stream and a first water-depleted stream comprising condensed bio-oil, where the partial condenser comprises a reflux inlet; a condenser for condensing at least a portion of the first water-rich overhead stream to produce a second water-depleted stream and second water-rich stream; a reflux system for routing at least a portion of the second water-depleted stream to the reflux inlet of the partial condenser; and a fractionator for separating at least a portion of second water-rich stream to produce a third water-rich stream and a third water-depleted stream.