The Mesoscale Simulation Of The Catalytic Removal Of Nitrogenous Exhaust Based On Various Topology Molecular Sieve

The molecular sieves are widely used as catalytic materials due to its unique pore structure, high specific surface area and the ability of ion exchange, which attract attention from the academic and industry. Because of the advantages of good low temperature activity, high thermal stability and harmless to the environment, The molecular sieves has great advantages on the shape-selective and acid catalytic performance. Therefore, present work investigated the adsorption and diffusion characteristics for nitrogenous exhaust in eight different channel with different topology zeolites(MFI?BEA?MOR etc.) via computer simulation, especially the grand canonical monte carlo and molecular dynamics method, from the perspective of simulation method. The main contents and conclusion of present work were detailedly described as follows.In terms of adsorption, thethesis studies the influence on the adsorption properties of nitrogenous exhaust at different temperature? different topology molecular sieve structure and the existence of the silica alumina ratio. Compare the adsorption characteristics with the molecular sieves of all silicon structure and the one transition metal ions (Cu) modified.Through the study of adsorption and diffusion properties for nitrogenous exhaust in different topology structure of zeolite molecular sieves, it can provide the theoretical support which is not easily get from laboratory in the process of catalytic removal of nitrogenous exhaust.It is shown that the adsorption quantity decrease with the increase of temperature. The reactions are exothermic reaction.It can be seen that the adsorption position related to the topology of the molecular sieve, and the number of adsorption sites are also different.By studying the adsorbate gases and the relationship between molecular sieve topology, we can see that due to the different topology structure of molecular sieve itself naturally unique channel structure, it determines its own channel of free different volume size, and the free volume size of different decision the amount of adsorption in molecular sieve again, which determines the adsorbate into the saturated adsorption amount of molecular sieve. It was shown that the exist of Al makes the adsorption amount increases obviously, but with the increase of silicon alumina ratio the adsorption quantity decreased.By considering the influence of adsorption capacity and adsorption interaction energy, two molecular sieve structures are chosen for nitrogenous exhaust as the most advantageous zeolites used in the catalytic removal process.In the aspect of diffusion, itstudies the influence of different configurations on the diffusion process of nitrogenous exhaust at different temperature?different topology molecular sieve structures and different adsorption quantity.by studying temperature, different adsorption quantity and the influence of different topology structure on diffusion coefficientresearches show that the diffusion coefficients increased with the rising of temperature, andit has more obvious effects than NH3 on the diffusion coefficient for NO over the NH3-SCR system. Also by exploring the diffusion path of adsorption mass gas spread in the molecular sieve, it can provide the effective basis theory for nitrogenous exhaust catalytic removal process...