Issue
HWAHAK KONGHAK,
Vol.37, No.4, 504-509, 1999
LaM상에서 암모니아와 메탄올로부터 메틸아민의 합성시 반응조건이 활성과 선택성에 미치는 영향
Influence of Reaction Conditions on Activity and Selectivity in the Synthesis of Methylamine from Ammonia and Methanol over LaM
수소형 모더나이트(HM)와 이를 lanthanum 이온으로 이온교환한 LaM를 만들고 그의 구조적인 특성변화를 XRD, 산성을 IR에 의하여 측정하고 암모니아와 메탄올로부터 메틸아민 반응에서 반응온도, 반응압력, 접촉시간 및 암모니아/메탄올의 비를 변화시키며 활성과 DMA의 선택성을 연구하였다. 두 시료의 경우 모두 활성과 선택성의 변화는 80h 내에서는 일어나지 않았으며 온도상승에 따라 활성이 증가하며 온도에 다라 전화율의 변화가 큰 영역에서 DMA의 선택성이 가장 크다. LaM이 HM보다 활성은 좀 떨어지나 DMA의 선택성이 커서 HM의 30%에 비해 약 최대 50%를 나타내었다. 암모니아/메탄올의 비의 증가에 따라 알코올의 전화율이 증가하고 space velocity의 증가에 따라서는 전화율이 감소하나 space velocity가 2-4 h-1이상에서는 거의 변화가 없었다. 반응압력의 증가는 MMA의 생성을 급격히 감소시키며 DMA의 선택성을 증가시켰으나 약 4atm 이상에서는 전화율에 크게 영향을 주지 못했다.
Hydrogen mordenite(HM) was ion-exchanged with lanthanum to give LaM and these catalysts were characterized by using XRD for crystallinity and IR for acidities/structures of the catalysts. The effects of reaction conditions such as reaction temperature, pressure, contact time and ratio of ammonia/methanol on the catalytic activity of methylamine synthesis and the selectivity to dimethylamine(DMA) were investigated from ammonia and methanol. The catalytic activity and DMA-selectivity of these catalysts remained for 80 h, and maximum selectivities of DMA were obtained at temperature range of methanol was rapidly converted. The DMA selectivity on LaM was 50% which was larger than that of 30% obtained on HM. The conversion of methanol increased with the ratio of ammonia/methanol and decreased with space velocity, but for the space velocity, 2-4h-1 it was constant. The elevation of reaction pressure rapidly reduced the amount of produced monomethlamine, but increased selectivity of DMA up to 4 atm.
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