NOVELTY - Two-stage process (M1) for the conversion of solid particulate biomass material (11) involves: first stage in which at least part of the solid particulate biomass material is subjected to thermal pyrolysis in a first zone of a reactor (10) to produce primary reaction products; and second stage in which at least part of the primary reaction products is catalytically converted to secondary reaction products in a second zone of the reactor (20) optionally in presence of a catalyst (13), where the first and second zone of the reactor are in fluid communication.    USE - For the conversion of a solid particulate biomass material (claimed); e.g. cellulose-containing materials including algae, paper waste, and cotton linters; lignocellulosic materials including forestry waste, such as wood chips, saw dust, pulping waste, and tree branches; agricultural waste such as corn stover, wheat straw, bagasse, and energy crops such as eucalyptus, switch grass, and coppice; for converting solid particulate biomass material to gaseous and liquid product; for producing fuels and specialty chemicals.    ADVANTAGE - The method converts solid biomass materials to liquid fuels as a way to reduce mankind's dependence on fossil fuel, to increase the use of renewable energy sources, and to reduce the build-up of carbon dioxide in the earth's atmosphere. The method converts solid biomass into gaseous and liquid products that do not require extensive particle size reduction of the solid biomass material feed and do not require extensive upgrading of the reaction products. The method is cost effective; provides complete conversion of the solid particulate biomass material, while avoiding excessive cracking of the primary reaction products.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a two-stage reactor (10) comprises: first stage reactor in which at least part of particulate solid biomass material is thermally pyrolyzed to form primary reaction products and second stage reactor in which at least part of the primary reaction products are catalytically converted to secondary reaction products, where the second stage reactor being in fluid communication with the first stage reactor.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a two-stage reactor.    Two-stage reactor (1)    First stage reactor (10)    Second stage reactor (20)    Biomass material (11)    Lift gas (12)    Deactivated catalyst particles (13)    Area of first stage reactor (14)    Injection point (22)    Gas/vapor stream (30)    Solid stream (32)    Fractionator (40)    Fractions (41,42,43,44)    Gas stream (45)    Stripper 50 (50)    Stream (51)    Regenerator (60)    Flue gas (61)    Regenerated catalyst particles (62)    Stream of an oxygen-containing gas (64)