불균일상 촉매를 이용한 대두유의 에스테르화 반응

Abstract

불균일상 촉매를 이용한 대두유와 메탄올간의 에스테르화 반응에 대하여 조사하였다. 온도 40∼<TEX>$65^{\circ}C$</TEX>에서 대두유와 메탄올 혼합물 내 성분 분배를 측정하였다. NaOH, CaO, Ca(OH)<TEX>$_2$</TEX>, MgO, Mg(OH)<TEX>$_2$</TEX>, and Ba(OH)<TEX>$_2$</TEX>과 같은 촉매에 대하여 반응 혼합물의 글리세린 함량을 측정하였다. 측정된 글리세린 농도로부터 반응 혼합물의 전화율을 계산하였다. 촉매 투여량, 보조용매 그리고 반응온도의 최종전화율에 대한 영향을 조사하였다. 대두유에 대한 메탄올의 용해도는 메탄올에 대한 대두유의 용해도보다 월등히 컸다. 대두유의 에스테르화 반응에 불균일상 촉매를 사용한 경우 최종전화율은 불균일상 촉매의 염기도에 크게 의존하였고, 촉매 금속의 염기도 증가에 따라 증가하였다. 알칼리 금속의 수산화물이 산화물 보다 효과적이었으며, 산화물은 촉매효과를 보이지 않았다. Ca(OH)<TEX>$_2$</TEX>를 에스테르화 반응의 촉매로 사용한 경우, 최종전화율의 최대값이 촉매 투여량 4%일 때 측정되었다. 최종전화율과 반응속도는 온도증가에 따라 증가하였으며 5<TEX>$0^{\circ}C$</TEX>에서 급격한 증가를 보였다. Ba(OH)<TEX>$_2$</TEX>를 촉매로 사용한 경우 보조용매로 HCl<TEX>$_2$</TEX>를 투여하면, 투여량 3%일 때 최종전화율의 최대값이 측정되었다. Using heterogeneous catalyst, esterification reaction of soybean oil (SBO) with methanol was investigated. Distributions of components in mixtures of soybean oil and methanol were measured at temperatures ranging from 40 to <TEX>$65^{\circ}C$</TEX>. Glycerine contents of reaction mixtures were measured for the different kinds of catalysts, such as NaOH, CaO, Ca(OH)<TEX>$_2$</TEX>, MgO, Mg(OH)<TEX>$_2$</TEX>, and Ba(OH)<TEX>$_2$</TEX>. Based on the measured glycerine concentrations, conversions of the reaction mixtures were calculated. The effects of dose of catalyst, cosolvent and reaction temperature on final conversion were examined. Solubility of methanol in soybean oil was substantially greater than that of soybean oil in methanol. When the esterification reaction of soybean oil was catalyzed by heterogeneous catalyst, final conversion was strongly dependent on the alkalinity of the heterogeneous catalyst, and increased with the alkalinity of the catalyst material. Hydroxides from the alkali metals were more effective than oxides, which actually had no catalytic effects. When Ca(OH)<TEX>$_2$</TEX> was used for the esterification catalyst, maximum value of final conversion was measured at dose of 4%. The final conversion and reaction rate increased with reaction temperature, and showed substantial increment at reaction temperature of 5<TEX>$0^{\circ}C$</TEX>. When cosolvent, CHCl<TEX>$_3$</TEX>, was added into the reaction mixture of soybean oil which catalyzed by Ba(OH)<TEX>$_2$</TEX>, maximum value of final conversion was appeared at dose of 3%.