Synthesis Cyclohexylbenzene With Benzene And Cyclohexene Catalyzed By Triethylamine Hydrochloride Ionic Liquid

Cyclohexylbenzene is also known as phenyl-cyclohexene, is an important chemical intermediate and a high-boiling solvent. CHB is mainly used to make lithium additives, produce phenol and cyclohexanone, it can also be used as raw material for the synthesis of liquid crystal, etc., so it has a very wide range of applications. Currently, CHB has a price of about 120,000 yuan per ton, so the research of the synthetic technology of CHB to obtain product with high yield and purity is with very considerable economic value.Triethylamine hydrochloride-aluminum chloride ionic liquid is one of the commonly used catalysts for the alkylation reaction. Under the protection of nitrogen,the orthogonal test and single factor test method was adopted, the product is analyzed by gas chromatography using internal standard method. Using the average yield of CHB after ionic liquid were used for the first and second time as an indicator, the effect of mole ratio of aluminium chloride and triethylamine hydrochloride, reaction temperature, reaction time on the catalytic properties of ionic liquid was investigated.By one step method, after the ice water bath and warm water bath, the optimum synthetic conditions of triethylamine hydrochloride-aluminium chloride ionic liquid was got.With benzene and cyclohexene as raw material, on the basis of the ionic liquid synthetic conditions, the synthetic conditions of CHB was optimized. The effect of dosage of ionic liquid, reaction time, reaction temperature, the molar ratio of benzene and cyclohexene on the yield of CHB was investigated, the purity of CHB is more than 99.5% and the average yield of CHB is 88.09% under the optimum conditions.On the basis of synthetic conditions of CHB, ionic liquid was used for recycle and the influence of standing time on the recycle properties of ionic liquid wasinvestigated, the preferred standing time of ionic liquid is determined to be 2.5~3 h,the ionic liquid can be recycled four times and maintain high activity. The effect of the amount of aluminum chloride on the properties of recycled ionic liquid was investigated, the results show that ionic liquid can be used for three times and maintain a high activity when the amount of aluminum chloride is 50% of its original mass. By three methods of infrared spectroscopy, thermal analysis, metal ions and EDTA complex, the ionic liquid was taken away by the organic phase was determined to be one reason of ionic liquid deactivation.