합성가스의 일회전환율이 높고 저온에서 가동되는 메틸포메이트 중간체 메탄올합성 공정의 상용화 가능성을 검토하기 위해 촉매의 개발 및 공정 변수의 변화를 조사하였다. 기존의 cooper chromite 촉매를 대체하는 노력으로 염기성 담체를 응용한 Cu/MgO는 성능 및 지속성에서 copper chromite에 비해 열등하였다. 균질촉매로 같이 사용되는 KOCH3를 비균질화하기 위해 polyaniline계열의 음이온교환수지를 제조하여 적용한 결과, 가능성은 확인하였으나 촉매가 안정적이지 않았다. Copper chromite + KOCH3 촉매계를 사용하여 최적의 반응조건을 조사한 결과, 250 cc의 메탄올 액체용매에 20-40 g의 cooper chromite 및 5 g의 KOCH3를 투입하고 180℃ 및 61기압에서 1,000 L/kg·hr의 유속의 합성가스를 주입하는 것으로 판명되었다. 이 조건에서 메틸포메이트 중간체 공정의 문제점으로 알려진 극소량의 CO2에 의한 촉매 비활성화가 극복되어 1%의 CO2가 포함된 합성가스를 사용하여도 촉매계의 활성이 유지되었다. 특히 석탄의 가스화에 의해 제조되는 합성가스의 조성인 H2/CO의 비가 1 이하인 가스의 수소전환율이 70%에 이르며 반응속도는 6 gmole/kg·hr 이상이었다. 메탄올 대신 triglyme을 용매로 사용한 결과 약간의 반응속도 감소에도 불구하고, 반응생성물의 회수가 용이한 장점이 있어 액상 메탄올 합성 공정에 적용 가능성을 보여주었다.

New catalysts development and process variable study have been carried out to seek the possibility of developing methyl formate intermediate methanol synthesis process into commercial scale. Cu/MgO was prepared in an effort to replace the copper chromite catalyst. Cu/MgO was inferior to copper chromite in terms of the weight-based activity and the stability. An attempt to substitute the homogeneous(methanol-soluble) KOCH3 catalyst with an anion-exchanged polyaniline resin was partially successful since anion-exchanged resin showed some activity but it seems to dissolve in the methanol solvent. The best combination of the catalysts is Ba-promoted copper chromite with KOCH3 . The optimum reaction condition is at 180, 61 atm with syngas flowing at 1,000 L/kg·hr to the reaction mixture of 40 g of copper chromite and 5 g of KOCH3 dispersed in 250 cc of methanol. At this condition, the problem of severe deactivation of the catalytic system by a few ppm of CO2 has been overcome and the system was stable up to 1% of CO2 in the feed gas. The catalytic system was stable when feed gas was syngas generated from coal gasification (H2 /CO=1) with 70% of H2 conversion at the rate of 6 gmole/kg·hr. When triglyme was used as a solvent instead of methanol, slight reduction in the rate of reaction was observed. However, the use of triglyme can make the recovery of the product methanol much easier than the methanol solvent system.

Methyl Formate Methanol Synthesis Coal-Derived Syngas Cu/MgO

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