Molecular Simulation Of The Adsorption Of Toxic Pollutant In The Atmosphere In Zeolites

Environmental governance is an important subject in today's society.Sulfide,nitride and carbides are common air pollutions which cause severe harms to human health and environment.It is found that zeolite is a good adsorbent and can be used for adsorption and separation of toxic gases.In this work,first of all,molecular simulation was used to study the adsorption of 95kinds of all-silica zeolite to six kinds of toxic gases under different pressure at ambient temperature.Then the adsorption and separation of 95 kinds of all-silica zeolite to SO₂/N₂/O₂ and H₂S/N₂/O₂ ternary mixtures are also studied by molecular simulation,and finally,this way was used to study the adsorption and separation of the six kinds of X-type zeolite containing metal ions to H₂S/N₂/O₂ ternary mixtures.The influence of zeolite structure on the adsorption and separation to remove 6 toxic gases was studied at molecular scale.Grand Canonical Monte Carlo?GCMC?simulations was performed to examine the capability of 95 kinds of all-silica zeolites in the removal of the six toxic gases,predict the adsorption isotherms of the six gases on all the zeolites,and screen some good candidates to remove toxic gases.Simulation results suggested that zeolite structures with accessible surface area of1600-1800 m²/g and pore diameter of 6.0-7.0?,such as AFY and PAU,have exceptional ability in capturing H₂S,NO,NO₂,CO and NH₃ at room temperature and an atmospheric pressure.The gas SO₂ has strong molecular interactions themselves,making it easily adsorbed on the zeolites containing larger accessible surface area?1700-2700 m²/g?and pore diameter?7.0-14.0??.However,at saturated adsorption,zeolites RWY,IRR,JSR,TSC,and ITT are found to exhibit better abilities to capture these gases.In the H₂S/N₂/O₂ ternary mixture system,RHO is the best candidate to remove H₂S,and the selectivity parameter is 9.7.The following candidates are MER,AFY,PAU,MOR.In the SO2/N2/O2 ternary mixture system,MOR is the best material for removing SO2,the selectivity parameter is 1264.5,and the following candidates are EON,RHO,UFI,MER.In addition,the selectivity coefficient of zeolite is linear with the loading of gases,and the selectivity coefficient of the gas has a function of two times with the working capacity.The results showed that RHO,MOR and MER had good selectivity for H2S and SO2,and these two gases were most easily adsorbed in the secondary structure containing eight yuan ring in the zeolite.As the six kinds of X-type zeolites,the results showed that the adsorption performance of monovalent alkali metal particles on the hydrogen sulfide in air is better than that of divalent alkali metal particles,especially for the zeolites containing sodium ion at room temperature.This study provides useful computational insights in choosing and designing zeolite structures with good performance to remove toxic gases for air purification,thereby facilitating the development and application of exhaust gas-processing technology in industry.