Rotary Continuous Flow Reactor And Its Application In Transesterification

Mixing is a common and very important unit operation of chemical engineering.Traditional mixing equipment has many disadvantages,such as large volume,high cost,low efficiency and difficulty in continuous operation.To solve the above issues,a new rotary continuous flow reactor was developed in this study,which has advantages of good mixing effect,high mass transfer efficiency and ease in continuous operation.In this study,the power consumption and performance of the reactor and the application of the reactor in transesterification reaction were investigated.The effect of various factors on the power consumption was examined.The correlation between power consumption and rotational speed,density and viscosity was obtained.As regards to the performance of reactor,the residence time distribution?RTD?and particle size distribution of dispersed phase in the reactor were determined.The flow model of the fluid in the reactor was developed.The effects of rotational speed,temperature and flow rate on the particle size of dispersed phase were obtained.Based on the above research,the application of the reactor was explored using the reaction system of triglyceride and methanol.The research results showed that:?1?The power consumption of the reactor was studied using soybean oil-water system as the research object.The effects of rotational speed,temperature and flow rate on power consumption were examined.The results showed that the power consumption increased with increase in rotational speed.No obvious change in power consumption was observed with flow rate.The power consumption decreased with the increasing temperature.In addition,the empirical correlation of power consumption with rotational speed,density and viscosity was obtained,with the results agreeing well with the experimental results.?2?The sauter average diameter(D₃₂)of the dispersed phase in the reactor was measured.It was found that D₃₂ of the dispersed phase decreased with the increase in rotational speed.When the rotational speed was higher than 500 r/min,no obvious change in D₃₂ was observed.The increase in D₃₂ was found with the increasing temperature.At a low speed?200 r/min?,D₃₂ decreased with the increase in mixing time,while at a high speed?500²000 r/min?,D₃₂ did not change with the increasing mixing time.The specific surface area of the dispersed phase was about 150000 m²/m³,which was much larger than that under stirring condition.?3?By measuring the residence time distribution of the reactor,it was found that the flow form of the fluid existed between the plug flow and the complete mixing flow.According to the multi-stage mixing model and the axial diffusion model,the fluid in the reactor had large axial diffusion,yet it did not reach the state of complete mixing flow.?4?The application of the reactor in transesterification reaction was studied using soybean oil and methanol as the raw material.The results showed that the transesterification effect first increased and then decreased with the increase in rotational speed and methanol to soybean oil mass ratio.No obvious effect of flow rate on transesterification reaction was found.The optimum conditions were as follows:reaction temperature 60?,methanol to soybean oil mass ratio 40:100,rotational speed1500 r/min,KOH amount 1 wt%,flow rate 160 mL/min and reaction time 5 min.The mass fraction of fatty acid methyl ester in the final product reached 85%.