Performance of Adsorbents for NO2 in Furnace Flue Gas

To meet the emission standard of nitrogen oxides(NOx)in the flue gas of batch furnaces through dry adsorption,a calcium-silica inorganic adsorbent was prepared with limestone and quartz as raw materials.Sample Cu-BTC 1# was obtained by solvothermal synthesis,drying and purification in vacuum at 120 ℃ using trimesic acid(H3BTC)and copper nitrate trihydrate(Cu(NO3)2·3H20)as raw materials;likewise,sample Cu-BTC 3# was obtained at 200 ℃.Sample Cu-BTC 2# was obtained by hydrothermal synthesis,drying and purification in air(metal-organic frameworks,1,3,5-benzene tricarboxylic acid copper).The two types of materials were tested in terms of the NO2 adsorption,and then the specific surface area,pore volume,NO2 adsorption performance,phase composition,microstructure and thermal stability of the adsorbent materials were explored via N2 physical adsorption-desorption,SEM,XRD and TG characterization.The results show that:(1)the Cu-BTC samples have higher adsorption capacity than the calcium-silica adsorbent,in which sample Cu-BTC 34 has the largest specific surface area and pore volume,thus adsorption capacity for NO2;(2)the calcium-silica adsorbent has better thermal stability and lower total mass loss during the entire process than the Cu-BTC samples;sample Cu-BTC 2# has the best thermal stability among the three Cu-BTC samples,and the metal Cu active sites of the Cu-BTC samples can be exposed at least above 150 ℃.