NOVELTY - A catalyst reaction device (20) has a hydrogenation catalyst (22) having an active component with respect to hydrogenated reaction of unsaturated hydrocarbon in gasified gas.    USE - For gasification system, fuel cell electric power generation system and chemical alteration system (all claimed).    ADVANTAGE - The catalytic reaction device has simple structure and is economical. The deposition of carbon in modification catalyst and fuel cell electrode, and disintegration of electrode are prevented. The reduction of performance of modification catalyst or fuel cell is efficiently prevented. The fuel cell electric power generation system has high electric power generation efficiency. Hydrogenation reaction is efficiently promoted and side reaction is suppressed.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) gasification system, which has gasifier (10) for producing gasified gas from biomass or waste material, and the catalytic reaction device provided at flow path of gasified gas produced by the gasifier;    (2) fuel cell electric power generation system, which has catalytic reaction device provided at flow path of gasified gas, modification catalyst apparatus for modifying gasified gas, provided at flow path of gasified gas and positioned at downstream from catalytic reaction device, and fuel cell (40) for generating electric power using modified gasified gas;    (3) chemical alteration system, which has catalytic reaction device provided at flow path of gasified gas, modification catalyst apparatus for modifying gasified gas, provided at flow path of gasified gas and positioned at downstream from catalytic reaction device, and chemical alteration device for converting modified gasified gas into liquid fuel; and    (4) post-processing of gasified gas, which involves removing unsaturated hydrocarbon in gasified gas.    DESCRIPTION OF DRAWING(S) - The figure shows the schematic view of fuel cell electric power generation system. (Drawing includes non-English language text)    Gasifier (10)    Catalytic reaction device (20)    hydrogenation catalyst (22)    Modifier (30)    Modification catalyst (32)    Fuel cell (40)