NOVELTY - Purifying (P1) a vapor product stream obtained from cracking of biomass catalyzed by a fluidized solid catalyst, involves: a)separating catalyst from the vapor product stream to provide a de-catalyzed vapor product stream; and b) cyclonically separating solid biomass residue from the de-catalyzed vapor product stream to provide a purified vapor product stream, where cyclonically separating solid biomass residue involves bringing the de-catalyzed vapor product stream to a gas velocity of 35-80 m/second.    USE - For purifying a vapor product stream obtained from cracking of biomass catalyzed by a fluidized solid catalyst (claimed) to form liquid fuels or other useful chemicals.    ADVANTAGE - The methods and apparatus enhances purity of product streams obtained from fluid catalytic cracking of biomass. The methods and separator arrangements for purifying fluid catalytic cracking (FCC) streams can greatly improve the purity of vapor product streams obtained from fluid catalytic cracking of biomass e.g. in a riser reactor, whilst also enhancing process reliability and component durability. By cyclonically separating solid biomass residue after separating catalyst from the vapor product stream, product stream purity is enhanced in an efficient and durable manner. Once catalyst has been removed from the vapor product stream, it is possible to separate cyclonically solid but typically fine, light, soft and non-combustible residues that result from catalytic cracking of biomass, using high gas velocities that can otherwise lead to increased or unacceptable cyclonic abrasion or erosion. With the process, an increased separation of solid biomass residue can be achieved whilst essentially maintaining hardware integrity.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) converting (M2) a biomass material into a purified vapor product stream, involving: contacting the biomass material with a fluidized solid catalytic cracking catalyst to obtain a vapor product stream comprising at least one cracked products and solid biomass residue; and purifying the vapor product stream according to the method (M1) to provide a purified product stream;    (2) a separator arrangement (A1) (126/226) for separating solids from a vapor product stream obtained from cracking of biomass catalyzed by a fluidized solid catalyst, comprising: a catalyst separating unit (2) for separating solid catalyst (128) from the vapor product stream (10) to provide a de-catalyzed vapor product stream (12); and a cyclonic residue separator (8) for separating solid biomass residue (14) from the de-catalyzed vapor product stream that is operatively connected to the catalyst separation unit; and    (3) a fluid catalytic cracking reactor or unit for converting a biomass material into a purified vapor product stream, comprising: a reactor vessel containing biomass material and a fluidized solid catalytic cracking catalyst; and a separator arrangement (A1) that is operatively connected to the reactor vessel.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic diagram of the separator arrangement.    Cyclonic residue separator (8)    Vapor product stream (10)    De-catalyzed vapor product stream (12)    Solid biomass residue (14)    Separator arrangement (126/226)    Spent cracking solid catalyst (128)