Cr改性VPO/TiO_(2)低温SCR催化剂脱硝及抗硫、抗水性能

Performance of Cr-modified VPO/TiO_(2) low-temperature SCR catalyst on denitration and resistance of sulfur and water

为了促进钢铁工业烟气脱硝技术发展,本文采用浸渍法制备VPO-PEG-Cr/Ti催化剂,并对其低温脱硝活性、抗硫抗水性能进行测试。活性测试结果表明:当n(V)/n(P)(摩尔比)为5,Cr质量分数为2%,活性组分负载量为10%时,催化剂在150~350℃温度范围内的脱硝率达98%以上;当反应温度为200℃,烟气中含2600 mg/m^(3) SO_(2)、8%的H_(2)O时,催化剂的脱硝效率几乎没有下降。结合NH_(3)-IR分析可知,磷酸和Cr的添加增加了催化剂的表面酸性,抑制了SO_(2)的吸附及催化转化,PEG和TiO_(2)增大了VPO催化剂的比表面积,增加了活性位点的暴露量。FT-IR、TG结果表明,通硫通水测试后,在催化剂表面几乎没有硫酸盐沉积,催化剂呈现出良好的抗硫抗水性能。

In order to promote the development of flue gas denitrification technology in the steel industry,an impregnation method is used to prepare VPO-PEG-Cr/Ti catalysts,while their low-temperature denitrification activity and resistance of sulfur and water are tested.The activity test results show that when n(V)/n(P)(molar ratio)is 5,Cr mass fraction is 2%,the amount of active component load is 10%,the denitrification rate of the catalyst reaches more than 98%in the temperature range of 150~350℃.When the reaction temperature is 200℃and the flue gas contains 2600 mg/m^(3) SO_(2) and 8%H_(2)O,the denitrification efficiency of the catalyst is hardly decreased.Combined with the NH_(3)-IR analysis,the addition of phosphoric acid and Cr increases the surface acidity of the catalyst and inhibits the adsorption and catalytic conversion of SO_(2),PEG and TiO_(2) increase the specific surface area of the VPO catalyst and the exposure of active sites.The FT-IR and TG results show that there is almost no sulfate deposition on the catalyst surface after the through-sulfur and through-water tests,and the catalyst shows good sulfur and water resistance.