A system and method for converting biomass into fluid hydrocarbon products to minimize the use of fossil fuels, provide energy and chemical feedstock security, and sustainable and/or carbon neutral electric power, are disclosed. For example, fast pyrolysis can be performed on biomass to produce pygas and char using a maximum processing temperature of about 650° C. The pygas is provided to an independent reactor without the addition of an oxidizing agent for catalytically converting the pygas to hydrocarbons using a maximum processing temperature of about 650° C. A system comprising fast pyrolysis means producing a pygas and char, independent catalytic conversion means downstream of the fast pyrolysis for converting the pygas to hydrocarbons, and a hydrogen source, external to the system and/or produced by a steam reformer by steam reformation of at least a portion of the hydrocarbons, coupled to catalytic conversion means, also are described.