NOVELTY - Method of integrated biomass fast pyrolysis and fractionation comprises: (a) providing a feedstock comprising biomass; (b) introducing the prepared biomass to a reactor and converting the biomass, in the presence of a heat carrier, to a reaction mixture comprising e.g. biochar; (c) removing at least some of the solid biochar from the reaction mixture to produce an intermediate mixture; (d) introducing the intermediate mixture to a multi-stage separator; (e) recovering and recycling at least some of the non-condensable gas from the mixture back into the reactor; and (f) recovering.    USE - The method is useful for producing biochar product and bio-oil fractions. The bio-oil fraction is directly useful in or for upgrading fuels, chemicals and materials.    ADVANTAGE - The integrated, low-capital cost, low-pressure fast pyrolysis method produces distinct, value-added, stable bio-oil fractions having unique properties making them superior to conventional bio-oil. The method produces and stores stable biochar.    DETAILED DESCRIPTION - Method of integrated biomass fast pyrolysis and fractionation comprises: (a) providing a feedstock comprising biomass; (b) introducing the prepared biomass to a reactor, which is operated under fast pyrolysis conditions and converting the biomass, in the presence of a heat carrier and/or a heated gas, to a reaction mixture comprising condensable vapors, aerosol droplets, non-condensable gases, and solid biochar; (c) removing at least some of the solid biochar from the reaction mixture to produce an intermediate mixture comprising condensable vapors, aerosol droplets and non-condensable gases; (d) introducing the intermediate mixture to a multi-stage separator comprising at least one heated electrochemical separator followed by at least one heat exchanger, where the electrochemical separator and the heat exchanger are operated under effective conditions to collect individual liquid bio-oil fractions including a final liquid bio-oil fraction, each derived from the condensable vapors and the aerosol droplets, where the heat exchanger and the electrochemical separator are operated with a heat exchanger wall temperature and an electrochemical separator wall temperature maintained above the water saturation temperature at the water vapor pressure determined within the heat exchanger and the electrochemical separator, respectively, such that water content is maximized in the final liquid bio-oil fraction; (e) recovering and recycling at least some of the non-condensable gas from the intermediate mixture back into the reactor; and (f) recovering at least some of the solid biochar as a cooled, stable biochar product.    DESCRIPTION OF DRAWING(S) - The diagram shows a low-cost, integrated fast pyrolysis process including biomass storage, preparation, pretreatment, and conversion using a bubbling fluidized bed reactor.