A New Technical Research On Synthesis Of Cyclohexene Oxide

Cyclohexene Oxide, also known as1,2-epoxy cyclohexane, can be used as intermediates to synthetize many chemical products like adhesive, crown ether, unsaturated polyester, the adipic acid, cyclohexanediol, propargite and so on. Furthermore it is also a kind of organic solvent which is applicated in a wide range. Based on the previous studies, we chose the molecular oxygen as the oxidant, the transition metal ions Co2+instead Keggin type molybdophosphoric acid as the catalyzer to investigate the synthesis of cyclohexene oxide from cyclohexene in differential reactor. The main research contents and results about epoxidation of cyclohexene are as follows:(1) In allusion to the system of oxidating cyclohexene by molecule oxygen, the supported heteropoly acid catalysts were prepared. Some important reaction conditions during the catalyst preparation were examined such as the amount of raw material, reaction time, reaction temperature and the pH. The experimental results show that the yield of phosphomolybdic acid reached92%under the optimal conditions:n (Na2MoO4):n (Na2HPO3)=1:12, the reaction temperature of102℃, the reaction time of0.5h and the pH of0.7. Then we prepared the the transition metal ions Co2+instead Keggin type molybdophosphoric acid and carried it on prepared activated carbon. The structures of the synthesized catalysts were characterized by FTIR.(2) Analysis method was established. The primary product is cyclohexene oxide by gas chromatograph analysis. Internal reference standard method was used to establishing standard curves of cyclohexene/n-heptane and cyclohexene oxide/n-heptane. The Precision and accuracy of this method is verified by experiments.(3) Optimization of reaction process conditions about epoxidation of cyclohexene were found. Some important reaction conditions such as reaction temperature, reaction pressure, the flux of cyclohexene, the flux of molecular oxygen, the amount of catalyst and reaction time were examined. The experimental results show that the catalyst reveals high catalytic performance with the yield of cyclohexene oxide reached8.5%under the optimal conditions:the reaction temperature is260℃, the reaction pressure is1.7MPa, the flux of cyclohexene is0.05mL/min, the flux of molecular oxygen is9mL/min, the amount of catalyst is1.5g and reaction time is24h.