Study On Denitration Performance Of FCC Flue Gas By Copper-based Oxide Catalyst

Nitrogen oxides(NOx)are one of the major air pollutants,which can cause acid rain and damage the ozone layer.Traditional FCC flue gas DeNOx catalysts had problems such as narrow active temperature window and poor stability at high temperature.Therefore,it has become a new hot spot to study FCC flue gas DeNOx catalysts with wide active temperature window and good high temperature stability.In this paper,CuO/Al2O3 series catalysts were prepared by impregnation method.The effects of CuO loading,baking time,baking temperature and different additives(Fe?Co?Ni)on DeNOx activity of catalysts were investigated.The main conclusions were as follows:(1)The Cu-15 catalyst with 15 wt%loading had the best DeNOx activity.The best calcination temperature was 700 ?,and the best baking time was 4 h;(2)The influence of different additives on DeNOx activity for this catalyst was Cu-Fe>Cu-Co>Cu-15>Cu-Ni.A series of ZrO2-Al2O3 composite supports with different Zr/Al ratio(mass ratio)were prepared by co-precipitation method.The CuO-15/ZrO2-Al2O3 catalysts were prepared by impregnation method.The effects of Zr/Al ratio.additives(Mg?Ce?Fe)?CO concentration and O2 concentration on the DeNOx activity of catalysts were investigated.The catalysts were analyzed by XRD?SEM?H2-TPR?BET?and XPS.The main conclusions were as follows:(1)Compared with Cu-15 catalyst,Zat-60(Zr/Al mass ratio of 6:4)catalyst was beneficial to improve low-temperature DeNOx activity,which may be related to Al0.1Zr0.9O0.95 solid solution on the surface of the catalyst carrier?CuO active phase and higher content of Cu+ species;(2)The addition of different additives(Mg?Fe?Ce)could further increase the reactivity of the catalyst,among which the effect of Mg is the most obvious.Because the addition of Mg was beneficial to increase the content of Cu+ species and the adsorbed oxygen species on the catalyst surface;(3)The CO/NO value had a great influence on the DeNOx activity of Zat-60-Mg catalyst.When the CO concentration was increased from 0.1%to 0.6%,the corresponding temperature decreased by about 150 ?;(4)The difference on the DeNOx activity of Zat-60-Mg catalyst with O2 concentration(0?0.3%)was below the low temperature range(450 ?).When the temperature was higher than 450 ?,the DeNOx activity of the catalyst was over 99%.The catalyst was almost inactive when O2 concentration was 1%.The CeO2-Al2O3 composite carrier with different Ce/Al ratio(mass ratio)was prepared by impregnation method.The CeO2-Al2O3 catalyst was prepared by impregnation method.The influence of Ce/Al ratio?additives(Mg?Zr?La)?CO concentration and O2 concentration on the DeNOx activity of catalysts were investigated.The main conclusions were as follows:(1)The Cat-50(Ce/Al mass ratio is 5:5)catalyst achieved at 99%when the reaction temperature was 380 ?,which decreased 170 ? compared with the Cu-15 catalyst;(2)The influence of different additives on catalyst activity was Mg>Zr>La;(3)When O2 concentration was lower than 0.3%,the DeNOx activity of the catalyst showd a difference in the low temperature zone(350 ?).When O2 concentration was 0.5%,the activity of the catalyst in the low temperature range decreased significantly,but the DeNOx rate could still maintain about 99% after 550 ?.