Synthesis of Cyclohexene by the Chlorocyclohexane Method
|School||East China University of Science and Technology|
|Keywords||chlorocyclohexane chlorination cyclohexene dichlorocyclohexane comprehensive utilization|
As an important organic raw material, cyclohexene is widely used in pharmaceuticals industry, pesticide intermediates, petroleum industry and polymer synthesis industry. This thesis is focused on solving the problems encountered in China regarding the industrialization of existing synthetic methods for cyclohexene. The main contents of this thesis are summarized as following:1. Preparation of chlorocyclohexane by the chlorination of cyclohexaneThrough the study of affecting factors in the chlorination of cyclohexane by chlorine, we conclude that the conversion of cyclohexane is about 25.0%, the selectivity of chlorocyclohexane is about 95.0%, and the yield is more than 94.0%, when initiating agent is blue light, reaction temperature is 40℃, reaction time is 1.0h, and the flow rate of chlorine is 10.0L/hr,.2. Preparation of cyclohexene by the dehydrochlorination of chlorocyclohexaneThrough the study of affecting factors in using gaseous phase catalystic dehydrochlorination of chlorocyclohexane to prepare cyclohexene, we conclude that:reaction temperature is 140℃, reation pressure is 0.08MPa, reation airspeed is 0.8hr-1,catalyst is stable using for 300.Ohr, the single conversion of chlorocyclohexane is more than 40.0%, the selectivity of cyclohexene is more than 98.0%, and the yield is more than 96.0%.3. Research on the comprehensive utilization of dichlorocyclohexaneThe comprehensive utilization of dichlorocyclohexane can meet the demand of by-product recyclization and environmental protection. The method of comprehensive utilization of dichlorocyclohexane is studied. By optimizing the dichlorocyclohexane alkaline hydrolysis process condition, we conclude that:reaction temperature is 180℃, alkaline: dichlorocyclohexane is 2.5:1, reaction time is 2.Ohr, the concentration of alkali is 15.0%, the conversion of dichlorocyclohexane is more than 99.0%. The modified condition of cycloolefin hydrogenation is listed as following:hydrogenation catalyst is Raney Ni, using amount is 5.0g, reaction pressure is 1.0MPa, reation time is 2.Ohr, reaction temperature is 120℃,the conversion of raw material is more than 99.8%. Finally, dichlorocyclohexane is converted to cyclohexane and 2-cyclohexenol.The yield of cyclohexane is 56.6%. The yield of cyclohexenol is 34.9%. The total yield is 91.5%.