NOVELTY - Two-stage reactor (1) comprises: a first stage reactor operated at a temperature T1 in which at least part of the solid particulate biomass material is subjected to a pyrolysis reaction, and forming primary reaction products; and a second stage reactor operated at a temperature T2, which is higher than T1, in which at least part of the primary reaction products are subjected to a catalytic conversion reaction, and forming secondary reaction products, where the second stage reactor is in fluid communication with the first stage reactor.    USE - The two-stage reactor is useful for converting a solid particulate biomass material (claimed) to gaseous product comprising carbon dioxide, carbon monoxide, and relatively minor amounts of hydrogen, methane and ethylene, liquid product such as liquid fuels and specialty chemicals.    ADVANTAGE - The two-stage reactor do not require extensive particle size reduction of the solid biomass material feed and do not require extensive upgrading of the reaction products. The process is optimized resulting in an overall increase of the performance such as higher yield of bio-oil, lower oxygen content of bio-oil, lower yields of coke formation and overall higher quality of the final conversion product.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a two-stage process for converting solid particulate biomass material (14), comprising either: a first stage (10) comprising subjecting at least part of the solid particulate biomass material to a pyrolysis reaction in a first zone operated at a temperature T1 to produce primary reaction products, and a second stage (12) comprising subjecting at least part of the primary reaction products to a catalytic conversion reaction in a second zone operated at a temperature T2, which is higher than T1, and in the presence of a catalyst, to produce secondary reaction products, where the first and second zones are in fluid communication; or charging the solid particulate biomass material to a circulating fluidized reactor, pyrolyzing at least a portion of the solid particulate biomass material to form primary reaction products within a lower zone of the circulating fluidized reactor operated at a temperature T1, and catalytically converting at least a portion of the primary reaction products into secondary reaction products in the presence of a catalyst within an upper zone of the circulating fluidized reactor operated at a temperature T2, which is higher than T1.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a two-stage reactor.    Two-stage reactor (1)    First stage (10)    Second stage (12)    Biomass material (14)    Lift gas. (16)