NOVELTY - A BTL fuel manufacturing system consists of a preprocessor (10), a thermal decomposition apparatus (20) which thermally decomposes biomass feedstock (AA) to form dry distillation gas, a purifier (40) which purifies the dry distillation gas, and a hydrocarbon synthesis apparatus (70) which converts purified gas into hydrocarbon oil (80). A hydrogen supply system (50) and an adjusting device (60) for mixing purified dry distillation gas and hydrogen, are provided between the purifier and hydrocarbon synthesis apparatus.    USE - System is used for manufacturing BTL fuel for use as jet biofuel (both claimed).    ADVANTAGE - The system enables efficient manufacture of BTL fuel having stable property, with high yield.    DETAILED DESCRIPTION - A BTL fuel manufacturing system consists of a preprocessor for preprocessing biomass feedstock to preset size, preset water-content ratio, carbon content, and hydrogen content of a unit mass, a thermal decomposition apparatus which thermally decomposes biomass feedstock to form dry distillation gas, a purifier which purifies the dry distillation gas, and a hydrocarbon synthesis apparatus which converts purified gas into hydrocarbon oil in the presence of a hydrocarbon synthesis catalyst. A hydrogen supply system which carries out measured-addition of hydrogen gas, and an adjusting device which adjusts the purified dry distillation gas and supplied hydrogen to a mixed gas such that the molar ratio of dry distillation gas, carbon, and hydrogen is 1:2-1:6 based on content of carbon component and hydrogen component in the feedstock, are provided between the purifier and hydrocarbon synthesis apparatus. An INDEPENDENT CLAIM is included for manufacture of BTL, which involves preprocessing biomass feedstock, supplying preprocessed biomass feedstock into the thermal decomposition apparatus, purifying emitted dry distillation gas, preparing mixed gas, converting the prepared mixed gas into a hydrocarbon, and separating the mixed gas into hydrocarbon oil and unreacted portion.    DESCRIPTION OF DRAWING(S) - The drawing shows a flowchart of the BTL manufacturing system. (Drawing includes non-English language text)    Preprocessor (10)    Thermal decomposition apparatus (20)    Superheated steam (30)    Purifier (40)    Adjusting device (50)    Hydrogen supply system (60)    Hydrocarbon synthesis apparatus (70)    Hydrocarbon oil (80)    Biomass feedstock (AA)