| Acidic ionic liquids are composed of organic cations and inorganic or organic anions. They are all liquid at or nearly room temperature and are salts which can give protons(or contain lively acidic protons). As a kind of new catalytic materials, acidic ionic liquids had win more and more people's good graces.According to the reaction mechanism of the dehydration of tert-butyl alcohol, the kinetics and thermodynamics factors which affect the reaction were analyzed. The influence of the process conditions including temperature, pressure and the concentration of TBA on the reaction chemical equilibrium of the dehydration of tert-butyl alcohol was investigated by using software Aspen plus.Four kinds of acidic ionic liquid catalysts were prepared, which contain group of SO3H, according to two-steps synthesis methods. The structures of the target compounds were confirmed by 1H-NMR,13C-NMR and IR spectrometry. The decomposition temperature of the compounds prepared were tested by TGA. And by applying the Hammett index method and the PH meter, the change of the ionic liquids acidity were observed.In this paper, the high pressure reactor vessel was built. Based on the dehydration of tert-butyl alcohol, the reaction activity of the acidic ionic liquids prepared in the paper was evaluated.By applying ionic liquid [Mim(CH2)3SO3H]+[CF3SO3]- as the catalyst, the effects of the process conditions, which include reaction temperature, reaction time, catalyst dosage and the concentration of TBA, on the dehydration of tert-butyl alcohol were systematically studied. With using the producing rate of isobutylene as the technical index, the process parameters were optimized according to the orthogonal experimental methods.It is found that the acidic ionic liquids prepared have high catalytic activity and trong acidity, and that they have good thermol stable performance and can be used repeatedly. The results indicate that the optimum process conditions are as follows:temperature-120℃, catalyst-8%, time-50min. |
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