NOVELTY - A jet-biofuel manufacturing system consists of a pulverizer (10), a thermal decomposition apparatus (20), a refiner (40), a hydrocarbon synthesis apparatus (70), a hydrogen supply system (60), and an adjusting device (50). The hydrogen supply system adds measured amount of hydrogen gas between the purifier and hydrocarbon synthesis apparatus. The adjusting device adjusts the molar ratio of carbon and hydrogen in the mixed gas of purified dry distillation gas and added hydrogen to 1:2-1:6.    USE - System is used for manufacturing jet biofuel (claimed).    ADVANTAGE - The system enables stable manufacture of jet biofuel with high yield. The circulation of unreacted off gas provides hydrocarbon oil within target molecular-weight range. The refiner efficiently removes all impurities.    DETAILED DESCRIPTION - A jet-biofuel manufacturing system consists of a pulverizer, a thermal decomposition apparatus, a refiner, a hydrocarbon synthesis apparatus, a hydrogen supply system, and an adjusting device. The pulverizer pulverizes a raw material derived from timber into wood chips of preset size having preset water-content ratio, carbon content per unit mass, and hydrogen content rate. The decomposition apparatus thermally decomposes the pulverized wood chips into dry distillation gas. The refiner refines the dry distillation gas. The hydrocarbon synthesis apparatus converts the refined gas into jet biofuel in the presence of a hydrocarbon synthesis catalyst. The hydrogen supply system adds measured amount of hydrogen gas between the refiner and hydrocarbon synthesis apparatus. The adjusting device adjusts the molar ratio of carbon and hydrogen in the mixed gas of purified dry distillation gas and added hydrogen to 1:2-1:6 based on the content of carbon component in the wood chips, and hydrogen component. An INDEPENDENT CLAIM is included for manufacture of jet biofuel, which involves converting the mixed gas prepared using the system into a hydrocarbon, and separating into hydrocarbon oil (80) and unreacted portion.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the jet-biofuel manufacturing system. (Drawing includes non-English language text)    Pulverizer (10)    Thermal decomposition apparatus (20)    Refiner (40)    Adjusting device (50)    Hydrogen supply system (60)    Hydrocarbon synthesis apparatus (70)    Hydrocarbon oil (80)