水性ガスシフト反応に及ぼす還元鉄ペレットの触媒効果

抄録

In order to investigate the catalytic activity of Reduced Iron Pellets (RIP) to the water gas shift reaction, hematite pellets were reduced at different conditions of temperature (873K-1 273 K) and reducing gas (H₂ and CO) to make catalysts. Rate of water gas shift reaction was measured by detecting the concentration change of gas during shallow packed beds which consisted of the RIP as catalyst. Reaction rate of the water gas shift reaction catalyzed with the RIP was apparently represented within the experimental conditions by the equation on the basis of mass action law. Apparent activation energy of the rate constant measured was 8.2-24 kJ/mol for H₂ reduction and 23-45 kJ/mol for CO reduction respectively.
The RIP reduced at lower temperature or by H₂ gas was found to have higher catalytic activity than that reduced at higher temperature or by CO gas. Another phenomenon obseved was the decrease in the catalytic activity of the RIP when the experimental temperature for the water gas shift reaction exceeded the temperature of reduction. According to the measurements of the physical properties of the RIP such as pore size distribution, specific area and porosity, decay of the catalytic activity was caused by the change of the physical properties of the catalysts, mainly decrease of specific area.