微波场下粉煤灰/电石渣负载Na2O协同脱硫脱硝

以粉煤灰与电石渣的混合物(FC)作为载体,Na₂O为活性组分,采用超声波浸渍法制备了吸附剂Na₂O/FC。通过XRD、BET、SEM分析对吸附剂进行表征,探讨在微波辐射下吸附剂协同脱硫脱硝机制。结果表明:微波下Na₂O负载可显著提高吸附剂的性能;6%Na₂O/FC(其中6%代表活性组分Na₂O在吸附剂中质量分数)的协同脱硫脱硝性能最佳,其脱硫t_90%和t_50%(t_x%为吸附剂的脱硫率或脱硝率达到x%时的反应时间)分别为12,73 min,脱硝t_90%和t_50%分别为4,16 min。机理分析表明:协同脱硫脱硝过程起初以物理吸附为主,反应进行一段时间后以化学吸附为主。微波下吸附剂Na₂O/FC的化学吸附过程为活性氧将SO₂和NO氧化为SO₃和N₂O₅后,SO₃和N₂O₅与金属氧化物反应生成Ca₅(SiO₄)₂SO₄、(Mg_xCa_1-x)(NO₃)₂、CaSO₄等硫酸盐和硝酸盐,同时活性组分Na₂O可直接与吸附态的SO₂与NO结合生成Na₂SO₃和NaNO₃。

EXPERIMENTAL STUDY ON SIMULTANEOUS DENITRATION AND DESULFURIZATION BY FLY ASH AND CARBIDE SLAG SUPPORTED Na2O UNDER MICROWAVE FIELD

In this paper, the mixture of fly ash and carbide slag(FC) was used as the carrier, Na₂O as the active component, and the adsorbent x% Na₂O/FC(x% represents the mass ratio of active component Na₂O in the adsorbent) was prepared by ultrasonic impregnation method. The adsorbents were characterized by XRD, BET and SEM, and the mechanism of simultaneous desulfurization and denitration of adsorbents under microwave radiation was discussed. The results showed that Na₂O loading under microwave significantly improved the performance of the adsorbent. Simultaneous desulfurization and denitrification performance of 6%Na₂O/FC was the best. The desulfurization t_90% and t_50%(t_x% was the reaction time when the desulfurization rate of adsorbents or the denitrification rate reached x%) were 12 min and 73 min, and the denitrification t_90% and t_50% were 4 min and 16 min. The mechanism analysis showed that the simultaneous desulfurization and denitration process was dominated by physical adsorption at first, and chemical adsorption after a period of reaction. The chemisorption process of Na₂O/FC adsorbent under microwave was found as follows: SO₂ and NO were oxidized into SO₃ and N₂O₅ by active oxygen species, and SO₃ and N₂O₅ reacted with metal oxides to generate sulfates and nitrates such as Ca₅(SiO₄)₂SO₄,(Mg_xCa_1-x)(NO₃)₂ and CaSO₄. At the same time, the active component Na₂O directly reacted with the adsorbed SO₂ and NO to form Na₂SO₃ and NaNO₃.