이산화탄소를 2단계 접촉수소화 반응시켜 메탄올의 수율을 높이려는 연구를 하였다. 1st- stage에서는 Cu/ZnO/Al₂O₃,Fe₂O₃ /Cr₂O₃,혹은 MoS₂/TiO₂ 촉매를 이용하여 역수성가스 반응을수행하여 CO₂를 CO로 전환하였으며 ,2nd-stage에서는 상업화된 메탄올 합성 촉매인 Cu/ZnO/Al₂O₃를 이용하여 메탄올 합성을 시도하였다. 2단계 이산화탄소의수소화 반응시 역수성가스 반응에서 생성된 CO가 메탄올 합성 반응에 크게 기여했으며,이로 인해 메탄올 수율이 향상되었다. 특히, 1단계 수소화 반응의 경우와 비교해 보았을 때 2단계 메탄올 합성 반응의 경우 2-3배의 수율 향상을 얻을 수 있었다. 또한 이산화탄소의 2단계 수소화 반응에서 메탄올 수율은 반응가스 조성비(H₂/CO₂)가 4일때 제일 높게 나타났다. 이산화탄소의 2단계 수소화 반응에서 메탄올의 수율을 높이기 위해서는 lst-stage의 역수성가스 반응촉매에서 CO₂를CO로 많이 전환시켜야하며, 반응기에 유입되는 반응물의 조성(H₂/CO₂)은 lst-stage를 거친가스의 조성이 상업적인 반응물의 조성에 근접하도록 만들어야 한다는 결론을 얻었다.

A two-stage CO₂ hydrogenation reaction was conducted to increase methanol yield. At 1st-stage, CO₂ was converted to CO by reverse water-gas shift reaction with Cu/ZnO/Al₂O₃, Fe₂O₃/Cr₂O₃, or MoS₂ /TiO ₂ catalysts, then at 2nd- stage, methanol was synthesized by a commercial methanol synthesis catalyst, Cu/ZnO/Al₂ O₃. In the case of two-stage CO₂ hydrogenation reaction, CO which was produced by 1st-stage reverse water-gas shift reaction contributed to the methanol synthesis and increased the methanol yield. In particular, for the two-stage CO ₂ hydrogenation reaction, methanol yield was two or three times higher than single-stage's one. In the two-stage CO₂ hydrogenation reaction, the highest methanol yield was obtained when H₂/CO₂ ratio was 4. Finally, to increase the methanol yield the more CO₂ should be converted to CO in the 1st-stage, and the feed gas ratio of the 1st-stage should be adjusted, so the effluent gas composition of the 1st-stage becomes to be close to the composition of commercial processes.

CO₂ Hydrogenation Methanol Synthesis Two-Stage Strategy to Synthesize Methanol

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