Study On The Preparation Of Cyclopentanol By Catalysis Hydration Of Cyclopentene

Cyclopentanol is a kind of valuable fine chemical raw materials which widely used inpharmaceutical, dye, spices, and other industries and also is an important intermediate fororganic synthesis. Cyclopentanol can be prepared by adipic acid、borohydride-oxidation andhydration of cyclopentene. With the rapid development of the petroleum chemical industry inrecent years, cyclopenten resource is rich. Scholars both at home and abroad pay attention tostudy on the preparation of cyclopentanol by catalysis hydration of cyclopenten.The present hydration method is the indirect hydration and the direct hydration ofcyclopenten. Compared with indirect hydration of H2SO4, Direct hydration has disadvantages oflow conversion, but it has advantages of less waste pollution, recycling of cyclopentene whichhas low boiling point and so on. Therefor, Direct hydration belongs to the environmental friendlyprocess and has very good development prospect. This paper prepared cyclopentanol usedcyclopenten as raw material by one-step catalyze hydration using self-regulating solid superacidas catalyst.Firstly, the modification on solid superacid catalyst of hydration reaction is studied. Thethree kinds of catalysts were prepared via impregnation-deposition method. The acid strengthand structure of the solid superacid were characterized by BET、IR、XRD、NH3-TPD and TG.The results showed that the introduction of SiO₂can increase specific surface area of catalyst,concequently increasing the activty centre of solid super acid surface. It was found that catalyst,SO42/SnO₂-SiO₂, had optimum activity. Furthermore, the suitable conditions of preparation ofthe catalyst were obtained: acid precipitant is （NH₄）NO₃, m（SnO₂）:m（SiO₂）=1:1, the concentration of impregnant is3mol/L, the calcination temperature is500℃.Secondly, The cyclopentanol was synthesized by hydration reaction of cyclopentene,catalyzed by solid superacid of SO₄²/SnO₂-SiO₂.The influencing factors of the hydration havebeen discussed. The optimal reaction conditions were as followings: the quality of phenol equalsto the quality of cyclopentene, that molar ratio of H2O to cyclopentene was6:1, the quality ofcatalyst equals to15%water’s quality mass, the reactive temperature was130℃, reaction timewas4h, the initial pressure was1.5MPa, stirring speed was600r/min. Under these conditions, theconversion of cyclopentene was9.65%, and the selectivity to cyclopentanol was97.73%.