FCC过程中稀土改性含铜分子筛的DeNO_x性能研究

Rare Earth-Promoted Copper-Containing Zeolite for DeNO_x

以 ZSM- 5和锐钛矿为原料 ,利用离子交换和等量浸渍法制备了 3种催化剂 ,模拟 FCC再生器条件 ,以CO为还原剂 ,分别考察了反应温度及反应体系中氧气的浓度、水蒸汽和二氧化硫的存在对催化剂 De NOx 性能的影响 .结果表明 ,低温 (≤ 5 5 0℃ )时催化剂的活性很低 ;氧气的存在使催化剂的 De NOx 活性降低 ;H2 O的存在有利于催化剂低温 (≤ 5 5 0℃ )活性的提高 ,但对不同催化剂在 72 0℃时的活性却有不同的影响 ;反应体系中引入SO2 后 ,含铈催化剂催化活性急剧增加 ,而不含铈催化剂的活性却迅速降低 ;SO2 对催化剂 De NOx

Three catalysts were prepared by ion\|exchanged and incipient wetness methods using ZSM\|5 and anatase as raw materials. Simulating the FCC regenerator conditions and using CO as the reductant, effects of reaction temperature, the presence of O\-2, H\-2O or SO\-2 in the reaction system on DeNO x activity of catalysts were examined. The results show that the activity of catalysts was very low at temperature ≤550 ℃; the presence of O\-2 decreases the activity of catalysts; the presence of H\-2O gives rise to the increase of the activity of catalysts in ≤550 ℃ temperature regime, whereas complex effects occur at 720 ℃; the introduction of SO\-2 is responsible for the rapid increase of DeNO x activity of cerium\|containing catalysts and sharp decrease of that of cerium\|free catalyst; the effect of SO\-2 on DeNO x activity of the catalysts is reversible.