Research On Fluid Flowing Characteristics And Lumped Reaction Kinetics Model In Hydrogenation Reactor

Recent years,the hydrogenation process are developed rapidly with the degradation of global crude oil and the upgrade of the standard of fuels.As the key equipment of the hydrogenation process,the hydrogenation reactor has a harsh working condition and complex flowing field.The conventional experimental method is not enough to study the equipment economically and efficiently.In this paper,the flow and reaction in the reactor are studied by the numerical simulation method.Firstly,the industrial-scaled three dimensional model is established,and the velocity and pressure distribution in the reactor are obtained.The simulation result indicates there are obvious pressure drop in the catalyst beds,and the drop changes approximately linearly.There are serious materials gathering near the region of entrance distributor,pore plate and tray,which is adverse to the reaction in the catalyst beds;The fluid in the bed will redistribute along the radial direction and the uniform distribution needs a distance of 3~4 times the diameter of the reactor;When different kind of entrance distributor is adopted,the initial distribution state on the catalyst beds is similar.Therefore the structure optimization aimed at the distributing performance should be focused on the structure and the arrangement of the vapor-liquid distributor.And then,the widely-used UOC vapor-liquid distributor is studied,the simulation results shows that the reactant is converging in the center of distributor;A venture distributor is designed,which size and structure is optimized by the numerical simulation method;According to the assessment result of the relative inhomogeneity values,the venture distributor behaves better than the UOC distributor under different capacity and material.At last,a lumped reaction kinetics model is established.The flow and reaction in the catalyst bed are simulated under different condition of porosity,capacity and ratio of hydrogen to oil.The optimized operation parameter is obtained.