NOVELTY - Supplying hydrogen to a hydrocatalytic biomass conversion reaction, comprises e.g.: (a) providing a biomass feedstock (11) containing cellulose and water; (b) contacting biomass feedstock with hydrogen in the presence of a catalyst of activating molecular hydrogen to form a hydrocatalytically treated mixture (13); (c) separating hydrocatalytically treated mixture into at least a first bottom fraction and a first overhead fraction; and (d) partially oxidizing first bottom fraction to produce a gas mixture comprising carbon monoxide and hydrogen.    USE - The method is useful for supplying hydrogen to a hydrocatalytic biomass conversion reaction (claimed) which is useful for producing gasoline hydrocarbons, diesel fuels and jet fuels.    ADVANTAGE - The method is cost-effective and reduces the carbon footprint of the fuels formed from the thermocatalytic reaction as at least a portion of the hydrogen used in the thermocatalytic reaction has low carbon footprint.    DETAILED DESCRIPTION - Supplying hydrogen to a hydrocatalytic biomass conversion reaction, comprises: (a) providing a biomass feedstock (11) containing cellulose and water; (b) contacting the biomass feedstock with hydrogen in the presence of a catalyst capable of activating molecular hydrogen to form a hydrocatalytically treated mixture (13); (c) separating the hydrocatalytically treated mixture into at least a first bottom fraction and a first overhead fraction, where the first bottom fraction comprises at least one compound having a separation point having a temperature of 100-600 degrees C and a pressure of atmospheric pressure; (d) partially oxidizing the first bottom fraction to produce a gas mixture comprising carbon monoxide and hydrogen; (e) providing the gas mixture to a water gas shift reaction zone external to where the biomass feedstock is contacted with hydrogen to generate hydrogen and carbon dioxide; and (f) providing the hydrogen from step (e) for use in step (b). An INDEPENDENT CLAIM is also included for a biomass conversion system comprising: a hydrocatalytic treatment system (12) configured to allow contact of a biomass feedstock with hydrogen in the presence of a catalyst capable of activating molecular hydrogen to form a hydrocatalytically treated mixture; a first separation zone coupled to an output of the hydrocatalytic treatment system, the separation zone (14) configured to separate the hydrocatalytically treated mixture into a first overhead fraction and a first bottom fraction; a gasification system coupled to an output of the first separation zone to receive the bottom fraction, where the gasification system is configured to partially oxidize the first bottom fraction to produce a gas mixture comprising carbon monoxide and hydrogen; and a water-gas shift reaction zone (20) coupled to an outlet of the gasification system, where the water-gas shift reaction zone is configured to convert the gas mixture into hydrogen and carbon dioxide, and an outlet of the water-gas shift reaction zone is coupled to the hydrocatalytic treatment system.    DESCRIPTION OF DRAWING(S) - The figure shows a method to supply hydrogen to a hydrocatalytic reaction.    Biomass feedstock (11)    Hydrocatalytic treatment system (12)    Hydrocatalytically treated mixture (13)    Separation zone (14)    Water gas shift reaction zone (20)