As an important intermediate for the synthesis of vitamin E,oxoisophorone(KIP)can be produced by oxidation of isophorone.There are two main methods for the synthesis of KIP.The first one is isomerizing?-isophorone(?-IP)into ?-isophorone(?-IP),and then to oxidize ?-IP into KIP.The second synthesis method is direct-oxidation of ?-IP to KIP.However,in the first method,due to the stable chemical properties of ?-IP,the isomerization of ?-IP into ?-IP requires a high reaction temperature and high energy consumption.The conversion rate is also low.In the second method,the reaction time required to produce KIP by oxidation of ?-IP is long and the conversion of oxidation of ?-IP is lower than that of ?-IP.A rotating packed bed(RPB)is an efficient gas-liquid and liquid-liquid mass transfer and mixing device,which has been widely used in separation and reaction process intensification in chemical industry.On the basis of the research,oxidizing ?-IP to KIP in the RPB will realize the progress and development of preparation KIP by ?-IP.The main results are shown as follows:(1)Using NHPI as catalyst to oxidize ?-IP without solvent in the condition of STR,the effects of reaction time,reaction temperature,oxygen flow rate,and catalyst amount on the conversion rate and yield were studied.The optimal operating conditions were determined as:STR rotation speed of 600 r·min-1,oxygen flow rate of 40 L·h-1,reaction temperature of 60?,reaction time of 4 h,and NHPI of 5 mol%.(2)Using RPB to oxidize ?-IP without solvent.The effects of RPB rotation speed,reaction time,reaction temperature,oxygen flow rate,liquid flow rate,and catalyst amount on the reaction conversion and yield were investigated.The optimal operating conditions were determined as:RPB rotation speed of 800 r·min-1,STR rotation speed of 600 r·min-1,reaction temperature of 60?,oxygen flow rate of 20 L·h-1,liquid flow rate of 20 L·h-1,NHPI of 5 mol%.After 1 h of reaction under this condition,the conversion can reach 24.28%and the selectivity is 73.81%.(3)Using RPB+STR to oxidize ?-IP without solvent.The optimal operating conditions were determined as:RPB rotation speed of 800 r·min-1,STR rotation speed of 600 r·min-1,reaction temperature of 60?,oxygen flow rate of 20 L·h-1,liquid flow rate of 20 L·h-1,NHPI of 5 mol%.After 1h of reaction under this condition,the conversion can reach 26.69%and the selectivity is 72.68%.Compared RPB+STR to RPB under the optimal operating conditions,the conversion and yield has a significant improvement,but the selectivity has a decrease,which shows that the catalytic oxidation of?-IP to KIP mainly happened in the RPB. |