Design And Numerical Simulation Of Methanol To Aromatics(MTA) Fluidized Bed Reactor

The development of methanol-to-aromatic(MTA)technology promotes the demand for the research and development of circulating turbulent fluidized bed(CTFB).In view of the issue of uneven radial distribution of particles in circulating turbulent fluidized bed,a novel gas distributor was designed by fractal theory and then the designed fractal gas distributor was fabricated by 3D printing technique,which solves the bottleneck in the fabrication of fractal structure.The effect of fractal distributor on circulating turbulence fluidized bed was studied through cold model test and numerical simulation.The developed electrical capacitance tomography(ECT)system was applied in the cold model test for measuring the radial distribution of particles under different gas velocities,bed heights and axial positions which is in fluidized section equipped with different gas distributors.The test result shows that the fractal gas distributor could achieve a more uniform particle distribution in radial direction;among two types of fractal gas distributor,which included two-layer and one-layer gas distributor,the particle concentration with two-layer gas distributor was higher while the method doesn't obtain radial distribution as good as the one-layer gas distributor.Additionally,based on Euler-Euler two-fluid model used CFD software,a modified drag force model was applied to simulate the fluidized bed.Compared with the traditional drag force model,the simulated result shows that the modified model gives more reasonable prediction for the distribution between gas and solid phases,which is conducive to the optimum design of fractal gas distributor in large-scale industrial plant.At last,a CFD-DEM computation model was tested to simulate the flow dynamics of turbulent fluidized bed.Because of the model considered interaction between the gas-particle and particle-particle,results show that this multi-phase coupling model can predict the flow field more accurately.