接触水素化反応による二酸化炭素のメタノール変換技術の評価

抄録

The recent status of catalytic hydrogenation of carbon dioxide to methanol was investigated. Although catalytic hydrogenation of CO₂ requires H₂ and energy, it shows much higher reaction rate than other CO₂ conversion technologies. Especially, conversion to methanol is a promising technology because of its excellent characteristics as a fuel. Thermodynamically, lower temperatures and lower pressures are favorable for methanol synthesis from CO₂ and higher temperatures are favorable for the reverse water gas shift reaction. Thus, a catalyst which is highly active below 473 K promises low-energy conversion to methanol. CO₂ hydrogenation technology is classi-fied into a gas-phase synthesis and a liquid-phase synthesis from its reaction method. In the gas-phase synthesis, Cu/ZnO-based catalysts show space time yields comparable to those in the conventional methanol production process from syngas. The liquid-phase synthesis employing a homogeneous catalyst is expected to operate at lower temperatures than the gas-phase synthesis. In order to achieve efficient CO₂ conversion to methanol, it is necessary to develop an active catalyst system at lower temperatures.