Engineering Study And Optimization Of Reactor For Continuous Solution Copolymerization Of Butadiene And Styrene

A pilot plant was set up to study the operation and configuration parameters' influences on transport phenomena and polymer property in SSBR continuous stirred tank reactor, which was composed of a cold model CSTR system, a Phase Doppler Particle Analyzer (PDPA) and a process simulation work station. The assignment is to optimize the continuous polymerization reactor for SSBR.Tri-dimension PDPA is applied to test flow fields induced by impellers (CBY-II, A310, A310 transformed), which are the same configuration as those in CSTR but smaller in size. For CBY-II, the larger the Re, the stronger the axial down stream; with the baffles, the macromixing becomes more notable; in small Re region, for H=1/3T, mixing is strong in bottom and up stream is found near the tank wall, for H=1/2T, there are two mixing transition zones in top and bottom, for H=2/3T, secondary flow is found in bottom and the mixing there are weak. For double CBY-II impellers, there is no mixing transition zone in the tank, and the circle stream is full of the entire tank. For A310 and A310 transformed, the axial down stream resembles that of CBY-II, but power consumption (Np) of A310 is smaller than that of CBY-II, It is feasible to replace CBY-II with A310.In a cylindrical tank with elliptical bottom and 0.476m in diameter, it is divided into three zones by annulus shutters, and the center one is subdivided into two zones. The influences of impeller configurations on each zone's mixing time are studied and an optimized impellers type and fixing configuration is gained, also the rotate speed (N). The influences of feed flux and impeller configuration on each zone's residence time distribution (RTD) are discussed. The results confirm the above conclusions.The whole CSTR RTD with different feed flux and bypass reflux is studied in detail to reveal the backmixing phenomena in the multistage reactor. The feed flux is the main factor in determining the system RTD, while the bypass influence becomes obvious with the larger feed flux. The larger the bypass flux, the longer the residence time. It is recommended that the bypass flux be small enough for heat balance.inBased on n-BuLi initiating anionic polymerization mechanism, a multi CSTR polymerization process model with bypass reflux is set up on Aspen Polymer Plus, reflux ratio and feed flux influences on polymer output are studied with sensitivity analyse. The reflux ratio should be small enough to remove the heat flux from the reactor. The feed flux can be improve to 0.3~0.4kg/sec to enhance the production efficiency. The simulation conclusions should be verified in practice.The conclusions of this research project can be applied as references and basis of further research, engineering design and scale-up of SSBR continuous polymerization reactor.