NOVELTY - A composite waste disposal system comprises low-calorie content waste-treatment line equipped with methane-fermentation tank (11), high calorie waste-treatment line equipped with gasifier (21), gas-purification apparatus (24), and liquid-fuel synthesizing apparatus. Apparatus (24) purifies gasified gas (22) generated in the gasifier. The liquid-fuel synthesizing apparatus synthesizes liquid fuel from purified gas. Biogas generated in the methane-fermentation tank is supplied as combustion improver to the gasifier.    USE - The system is used for disposal of composite waste such as municipal solid waste and industrial waste.    ADVANTAGE - The system efficiently enables disposal of composite waste, and has favorable durability and transport property of gas produced by gasification process or methane-fermentation processing.    DETAILED DESCRIPTION - A composite waste disposal system comprises a low-calorie content waste-treatment line equipped with a methane-fermentation tank which carries out methane-fermentation processing of low-calorie content waste material, a high calorie waste-treatment line equipped with a gasifier which gasifies high calorie waste material, a gas-purification apparatus, and a liquid-fuel synthesizing apparatus. The gas-purification apparatus purifies gas generated in the gasifier. The liquid-fuel synthesizing apparatus synthesizes liquid fuel from purified gas containing hydrogen and carbon monoxide as main component. Biogas generated in the methane-fermentation tank is supplied as combustion improver to the gasifier.    DESCRIPTION OF DRAWING(S) - The figure shows the flowchart of the composite waste disposal system. (Drawing includes non-English language text).    Low-calorie content garbage (low-calorie content waste material) (10)    Methane-fermentation tank (11)    High calorie garbage (high calorie waste material) (20)    Gasifier (21)    Gasified gas (22)    Gas-purification apparatus (24)    Methanol-synthesis apparatus (25)