V2O_5/TiO_2催化剂选择性催化还原脱除NO_x的研究

Investigation of selective catalytic reduction of NO_x with V_2O_5/TiO_2 as catalysts

通过浸渍法制备 V2 O5/ Ti O2 催化剂 ,在固定床反应器中进行NH3选择性催化还原脱除 NOx的研究。结果表明 ,对于 1 0 0 / 1 4 0目催化剂 ,NOx转化率随反应时间线性增加 ,NH3选择性催化还原 NOx反应为一级反应 ,反应活化能为 98.2 3 k J· mol- 1。对于片状催化剂 ,气体流量和催化剂的厚度对脱氮反应有较大的影响 ,气体流量增加 ,NOx转化率提高 ,当流量增至 1 2 0 L· h- 1后 ,NOx转化率趋于稳定 ;催化剂厚度由0 .1 cm增至 0 .2 cm,NOx转化率从 83%降至 40 % ,催化剂有效因子从0 .2 54降至 0 .1 2 7。对于 0 .1 cm厚的片状催化剂 ,在 573 K和空速 1 .4s- 1 条件下 ,NOx 转化率可达 92 %。

The present paper aims to introduce the author's method of preparing V_2O_5/TiO_2 catalysts for selective catalytic reduction of NO_x with NH_3 in a fixed bed reactor by means of impregnation. As for the first order reaction of NH_3 reduced to NO_x, the rate increases lineally with reaction time with the active energy being 95.1 kJ·mol^(-1) in the particle form of 100/140 meshs. For the pallet catalysts, the enhanced gas flow and the catalyst's thinner thickness may have strong influence on the reaction of denitrification, which would remain steady when the flux reached 120 L·h^(-1). On the other hand, the pallet catalyst may get thickened from 0.1cm to 0.2 cm, causing NO_x conversion to reduce from 83% to 40%, and the inter-diffusion efficiency factor to lower from 0.254 to 0.127. And finally, under the condition of 573 K and 1.4 s^(-1), NO_x conversion would be able to reach 92% over the pallet catalysts with the thickness of 0.1 cm.