The Study On Preparation Of Mercury Adsorbent Material For Flue Gas And Absorption Of Mercury Performance

In this paper,we compared the adsorption performance of the carrier before and after modification,and studied the adsorption performance of the adsorbent under different active materials,loadings and activation calcination temperature.The adsorption mechanism of gaseous zero-valent mercury on the surface of metal adsorbents was studied by means of XRD,SEM and EDS,combined with the mercury removal performance evaluation results of adsorbents,optimization of adsorbent preparation process parameters,trying to get stable and efficient adsorption performance,with renewable capacity,industrial production and application of metal adsorbent.Through the carrier mercury removal performance evaluation found that,the maximum adsorption rate of porous Al2O3 and ZrO2 materials is 40%?50%,the mercury removal performance of aluminum foam is the second,reaching 35%.The mercury removal performance of porous ZnAl the worst,only 8%.The mercury removal efficiency of AgNO3 modified porous Al2O3 material increased to 98%,and the time to reach 70%penetration rate was 50h,while that of Na2S and FeCl3 modified porous Al2O3 was only 50%,reaching 70%Penetration rate of less than 10h.The analysis showed that the surface of modified adsorbent showed more uniform dispersion of particles,porosity and specific surface area more,the adsorbent can provide more reactive interface,will increase the contact probability of adsorbent and mercury,and the modified adsorbent surface active sites increase,thereby promoting the adsorbent mercury removal performance.Among the modified Al2O3-based adsorbents,AgNO3 has better mercury removal activity than FeC13 and Na2S,and AgNO3 as a modifier is the main factor to promote the adsorption efficiency.Two kinds of metal oxide adsorbents Ag/Fe and Mn/Fe were also prepared.The mercury removal efficiency of Mn/Fe adsorbent was almost zero.And 7wt%Ag/Fe adsorption rate was 95%;5wt%Ag/Fe mercury removal performance followed by the adsorption rate of 90%;3wt%Ag/Fe mercury removal efficiency of 85%;lwt%Ag/Fe off mercury worst performance,the maximum adsorption rate of 10%.In-depth study found that 7wt%Ag/Fe mercury removal efficiency within 30h can be maintained at 90%or more,In 60h can be maintained at 80%or more.The results show that with the AgNO3 loading increasing to 7%,the newly formed Ag2O in the adsorbent reacts with Hg to form HgO and Ag,which promotes the increase of the mercury adsorbent capacity.Comprehensive comparison of the mercury removal performance of several adsorbents,under the conditions of the study,iron-based adsorption modified by 7wt%AgNO3 has stable and efficient adsorption performance and regeneration ability,suitable for the removal of gaseous zero-valent mercury in low-temperature flue gas.