ACID CATALYZED DEHYDRATION USING SUPERCRITICAL WATER WITH CARBON DIOXIDE AS A MILD CATALYST

摘要

In this study, we examined the dehydration of cyclohexanol to cyclohexene in the much presence of carbon dioxide in supercritical water. At 653 K and 0.5 g cm~(-3) of water density the yield of cyclohexene reached 60% in the presence of 7.5 mol% carbon dioxide, but in the absence of carbon dioxide the yield of cyclohexene was only 10%. The yield of cyclohexene tended to increase with increasing the carbon dioxide concentration and water density. Hydration of cyclohexene to cyclohexanol was also studied as a reverse reaction of dehydration of cyclohexanol, it was confirmed that the addition of carbon dioxide accelerated the hydration as well as the dehydration.