MS Simulation And Experimental Study Of Modified Zeolite Mercury Removal Sorbent

In the Chinese energy structure,the coal occupies an important position,consumption accounts for the world nearly about 30%.And in the next period of time this change will be seldom.Moreover,coal combustion bring serious harms to environment,the mercury pollution in these harms caused global attention.Meanwhile,Chinese mercury pollution is the one of the most serious countries.So our government departments have issued relevant policy,required to take effective measures to control mercury emissions.In these measures,The sorbent injection technology is the most application prospect and the most mature technology.But the current research results exists a lot of problems,such as lowly adsorption efficiency,complicated application conditions,high cost and secondary pollution.Consequently,in this paper the natural clinoptilolite was as the research object which is cheaper and richer reserves,a series of mercury adsorbents were synthesis and preparation.And these mercury adsorbents' adsorption property and adsorption mechanism were studed.This paper used the method of combine material analysis software “Materials studio” analog computation with laboratory test carrying out research.Utilied MS analyze the skeleton structure of the natural clinoptilolite and analog calculate the adsorption isotherm,adsorption energy and adsorption density while the natural clinoptilolite adsorption Hg⁰.Forecast the possiblity of the natural clinoptilolite serve as the mercury adsorbents,and the mercury adsorption experiments verify its adsorption performance of Hg⁰.Then screen out one metal loading in the natural clinoptilolite,preparate a series of mercury adsorbents,systematic study adsorptive property.Finally adopt the material characterization,experimental analysis and simulation calculation method for the study of modified to take off the mercury adsorbent adsorption way and mechanism.The specific research results are as follows.?1?The natural clinoptilolite have good performance of mercury adsorption.Materials studio simulation,perdiction and analysis indicate the skeleton structure is stratified structure and uniform distribution a large number of channel,The adsorption of mercury will decrease with temperature increase,adsorption energy in the scope of physical adsorption.After the mercury adorsportion experiment,results The best adsporption tenperature is 110 ?,the adsorption efficiency is 44.63%,the duration is 30 min.So,the natural clinoptilolite can adsorption Hg⁰,effection is good.?2?Ag have good modification effect for natural clinoptilolite.Utilize MS simulate screening of modified active metal from Pd,“Pt,Au,Ir,Ag,Rh” as the principle od high load index,materials easy,economical applicable.The result indicate the single crystal cell average load order is “Pt>Ir>Ag>Pd>Au>Rh”,load energy and density sequence is “Pt>Ir>Ag>Rh>Pd>Au”,full loading number sequence is “Pt>Pd>Rh>Ag>Ir>Au”.Full energy density analysis testified Ag is only one matel which load in clinoptilolite by high energy.Consequently,Ag was screen out as the modified active metal.?3?The adsorption efficiency of modified zeolite reach up to 90.32%.A series of mercury adsorbents were prepared by Sol-Gel,ion exchange,ultrasonic concussion,high temperature reduction.Respectively in the different concentration of modification,adsorption temperature,adsorption time under the condition of experimental study on the effect of adsorption.The result showed that The modified zeolite adsorbent named 3^# is the best adsorbent,which adsorbent temperature between 110¹40 ?,similar to Co al-fired flue gas temperature.And 3^# adsorbent's maximum adsorption aging can reach90 min.The adsorption efficiency of 3^# modified zeolite reach up to 90.32%,which can be used as Coal-fired flue gas mercury adsorbent.?4?The modified zeolite adsorbent is superparamagnetic mesoporous materials which loading silver.XRD results clinoptilolite is Na type clinoptilolite,after be modified,Ag and Fe₃O₄ have been successfully loaded.BET showed that the adsorbents are me-soporous materials and magnetometer prove after modified have a super paramagnetic properties.?5?The modified zeolite adsorbent have physical adsorption and the stability of the chemical adsorption when using it adsorb Hg⁰.Through the analysis of the experimental system of mercury discover the modified adsorbent have three kinds effects for adsorb Hg⁰,include physical adsorption,catalytic oxidation and metal alloy.In addition,CASPET was used to simulated calculated adsorption bond energy and density of states.The consequence show that adsorption bond energy equal to 5136.46 ev,bonding is stable.Adsorptive behavior is solid chemical adsorption.Not easy to take off the attached.?6?The research is a pioneer of utilizing the magnetic microspheres and the Ag modified the natural clinoptilolite,prepared a adsorbent which have a good performan-ce for absorbed mercury.Preparation of modified zeolite to take off the mercury adsorbent not only have physical and chemical adsorption characteristics of adsorption of Hg⁰ effect is very good,but also with super paramagnetic properties,adsorbent recycling.Emploing Materials studio analog filter modified active substances,utilize quantum chemistry and density functional theory such as detection of theoretical calculation and analysis of modified zeolite adsorbent adsorption mechanism,has the certain innovation in research methods.