Numerical Simulation Of Wear Characteristics Of Hydrogen Separation Membranein The Fluidized Bed Reactor

In order to solve the limitation of thermodynamic balance in the catalytic reforming hydrogen production technology,the actual hydrogen production process is far from the theoretical maximum hydrogen output and the problem of hindering the heat and mass transfer performance of the reactor due to the formation of carbon deposits.The researchers used the permeable membrane in the fluidized bed reactor to separate hydrogen from the reaction system to directly obtain high-purity hydrogen and increase hydrogen production,thus proposing the concept of a fluidized bed membrane reactor.Due to the high flow rate in the fluidized bed and the continuous circulation of catalyst particles,the wall surface of the palladium membrane in the fluidized bed membrane reactor will cause problems even if the corresponding countermeasures are taken,that is,the catalyst particles will interact with the surface of the palladium membrane under fluidization conditions Vigorous collision and friction make the palladium membrane wear,making it impossible to separate hydrogen normally.In this paper,the finite element analysis method is used to simulate the impact of the particles on the wall of the palladium film.A mathematical model of the impact of the alumina particles on the wall of the palladium film is constructed,and the process of the impact of the alumina particles on the wall of the palladium film is simulated by finite element software.Analyze the simulation results of the software,summarize the wear laws of single particles impacting the palladium film wall,and use data analysis software to perform multiple nonlinear regression analysis to study the relationship between impact speed,impact angle and impact wear amount to establish the prediction of particle impact palladium film wear model.Then,the three-dimensional fluidized bed membrane reactor model was established using discrete element software.The catalyst particles were added to the fluidized bed membrane reactor for simulation to obtain the corresponding flow characteristics.The coupled model of the catalyst particles impacting the palladium membrane wall wear prediction model was used to calculate the wear..The results show that due to the effect of permeability,the concentration of particles near the wall surface is higher,and the concentration near the center is lower.The total wear in the dense phase zone at the bottom is the largest,which is higher than that in other parts.As the height continues to increase,the amount of wear shows a decreasing trend.At the same time,the hydrogen separation process of the fluidized bed membrane reactor at different eccentric distances is studied.The results show that the change of the eccentric distance can reduce the resistance of the concentration polarization layer and increase the degree of hydrogen separation,but the eccentric distance is too large.Membrane arrangement is notconducive to the reduction of concentration polarization resistance.Finally,the gas heating process of the fluidized bed membrane reactor was simulated to study and analyze the influence of the hydrogen permeability of the palladium membrane on the diffusion characteristics of the particles in the flow field and the amount of wall wear.The results show that the bed temperature of the membrane reactor keeps rising with time,which leads to the continuous increase of the permeability of the palladium membrane to hydrogen,which in turn leads to the unevenness of the separation degree of hydrogen.The uniformity is becoming more and more remarkable.Comparing the cumulative wear of various heights of fluidized bed membrane reactors with and without permeability under heating conditions,it can be found that the maximum wear and cumulative wear under non-permeability conditions are larger.