NOVELTY - A method (m1) for deoxygenating biomass-derived pyrolysis oil, involves dividing a feedstock stream comprising the biomass-derived pyrolysis oil into portions including first feedstock portion and a second feedstock portion; combining the first feedstock portion with heated organic liquid stream; contacting with first deoxygenating catalyst in the presence of hydrogen; combining second feedstock portion with formed effluent to form a second heated diluted pyoil feed stream; and contacting with second deoxygenating catalyst.    USE - For deoxygenating biomass-derived pyrolysis oil (claimed).    ADVANTAGE - By partially cooling the low-oxygen pyoil effluent between reaction zones, reaction conditions such as temperature and pressure can be more effectively controlled throughout the process for deoxygenating the biomass-derived pyrolysis oil. Also, by contacting the deoxygenating catalyst(s) with the diluted biomass-derived pyrolysis oil including hydrogen at the hydroprocessing conditions, the amount of glassy brown polymer or powdery brown char formed on the deoxygenating catalyst is reduced or minimized relative to conventional methods. By diluting portions of the biomass-derived pyrolysis oil in the feedstock stream with the heated organic liquid stream or the intermediate low-oxygen pyoil effluent, simple reactions of the biomass-derived pyrolysis oil with hydrogen to form a lower-oxygen biomass-derived pyrolysis oil are effectively increased and dominate while secondary polymerization reactions of biomass-derived pyrolysis oil components with themselves are reduced or minimized, thus reducing or minimizing the formation of glassy brown polymers or powdery brown char on the deoxygenating catalyst. Therefore, a low-oxygen biomass-derived pyrolysis oil can be produced without plugging the deoxygenating catalyst/reaction zones, thus increasing run duration and improving processibility of the biomass-derived pyrolysis oil.    DETAILED DESCRIPTION - A method (m1) for deoxygenating biomass-derived pyrolysis oil, involves dividing a feedstock stream comprising the biomass-derived pyrolysis oil and having a first temperature of less than or equal to 60 degrees C into portions including a first feedstock portion and a second feedstock portion; combining the first feedstock portion with a heated organic liquid stream to form a first heated diluted pyoil feed stream; contacting the first heated diluted pyoil feed stream with a first deoxygenating catalyst in the presence of hydrogen in a first reaction zone at first hydroprocessing conditions effective to form a first intermediate low-oxygen pyoil effluent; combining the second feedstock portion with the first intermediate low-oxygen pyoil effluent to form a second heated diluted pyoil feed stream; and contacting the second heated diluted pyoil feed stream with a second deoxygenating catalyst in the presence of hydrogen in a second reaction zone at second hydroprocessing conditions effective to form additional low-oxygen pyoil effluent, and where the first and second deoxygenating catalysts are the optionally same types of catalyst. An INDEPENDENT CLAIM is included for apparatus for deoxygenating a biomass-derived pyrolysis oil, the apparatus comprising: the apparatus configured to receive a feedstock stream comprising the biomass-derived pyrolysis oil; first reaction zone configured to contain a first deoxygenating catalyst; and second reaction zone configured to contain a second deoxygenating catalyst.