Study On The Compound Modified Adsorption Of SO₂ And NO_x With The Silicate Based Porous Material

The silicate-based porous material prepared from coal-based solid waste has the advantage of low cost and safety,however,its saturated adsorption capacity and specific surface area are lower than that of other porous materials.In this paper,we proposed the idea that silicate based porous material could be modified by various modifiers to increase the adsorption property,which would meet the industrial requirements and has various application fields.The porous material was modified by G-1,G-2,G-3,G-4 and G-5 modifiers,respectively.The influence of atmosphere condition and material properties inSO₂adsorption on silicate based porous materials was studied through fixed bed adsorption.The optimum adsorption temperature was located at 50?and optimum silicate based was200 mesh.The water content and oxygen content in gas could enhance the adsorption effect of silicate based porous material on SO₂.The effect of compound modification on the adsorption properties of the materials was also studied.The results showed that the silicate-based porous material modified by G-1 has the best adsorption capacity on SO₂,and its maximum equilibrium adsorption capacity was 76.66mg/g.When the temperature was increased to 300°C,the G-1 modified silicate-based porous material remained stable and did not desorb,after the adsorption was saturated.Similarly,the effects of G-1,G-2,G-3,G-4 and G-5 modifiers on NOx adsorption performance were studied.At NO and NO₂ concentration of 250ppm,reaction temperature of 50?,oxygen content of 6%,300 mesh particle size,superficial gas velocity of 500mL/min,the water content of 15%²0%,NO₂ removal rate can reach 81.23%and the NO removal rate was 58.32%.The removal efficiency of NO and NO₂ from the modified silicate based porous materials was further investigated by flue gas in the same condition above.The results showed that G-1 and G-5 modifiers have good effect on removing NO₂.The removal rate of G-2 to NO increased by 20%,and the removal rate of NO₂ hardly increased,but there was a certain removal effect on mixed NO and NO₂.The G-2 modified the silicate based porous material given out NO₂ desorption rate of 58.73%,and NO desorption rate of 86.04%,when the temperature was 200?.Based on the samples in the first two chapters,the synergistic removal effect of SO₂and NO_X by modified silicate-based porous materials was studied.The SO₂ concentration was 1200mg/m³ in the entrance,together with NO_X entrance concentration of 250 ppm,superficial gas velocity of 500mL/min,temperature of 55?,the adsorption material of 300mesh,water content of 20%,oxygen content of 6%.The silicate-based material of SO₂removal rate was 100%under the above conditions,and the NO_X removal rate was 59.64%.When the additive amount of G-1 was 70%,the adsorption amount of SO₂ was 64.25mg/g,the adsorption amount of NO₂ was 37.86mg/g,and the removal rate of NO_X was90%.When the temperature was 300?,SO₂ remained not desorbed,NO₂ desorption rate was 13.14%,NO desorption rate was 63.29%.According to microstructure characterization,the glass fibrous and laminar structures on the surface of silicate-based porous materials disappeared gradually after modified by G-1-2 modifier,and the surface was became more sleeker.The surface of the material after adsorption saturation became more rough,and there were more particles on it.The flue gas removal products were mainly composed by sulfate,nitrate,and a small amount of sulfite,nitrite composition.