Numerical Simulation of Axial Species Distribution of SCR Reaction over Fe-Zeolite Catalyst

被引：0

作者：

Lyu Z. ^{[1
]}

Su Q. ^{[1
,2
,3
]}

Tong D. ^{[1
]}

Zhang X. ^{[1
]}

Li N. ^{[2
]}

Li L. ^{[2
]}

机构：

[1] State Key Laboratory of Engine and Powertrain System, Weichai Power Company Limited, Weifang

[2] Institute of Internal Combustion Engine, Dalian University of Technology, Dalian

[3] Weichai Power Emission Solutions Incorporated, Weifang

来源：

Neiranji Xuebao/Transactions of CSICE (Chinese Society for Internal Combustion Engines) | 2024年 / 42卷 / 03期

关键词：

axial distribution; diesel engine; numerical simulation; selective catalytic reduction; zeolite catalyst;

D O I：

10.16236/j.cnki.nrjxb.202403029

中图分类号：

学科分类号：

摘要：

A kinetic model of NH3-SCR catalytic reaction over Fe-zeolite catalyst was established to predict the NOx reduction performance of the catalyst and to investigate the axial species distribution during SCR reaction. The model is composed of NH3 adsorption and desorption，NH3 oxidation，NO oxidation，NOx reduction and N2O formation reactions. The results show that the model can predict the variation of species concentration in axial space. It was found that the Fe-zeolite catalyst is sensitive to molar ratio of n(NO2)/n(NOx) ， and the optimal n(NO2)/n(NOx) is 0.5. Because of the NH3 inhibition effect，the SCR activity is low at the temperature lower than 300 ℃，while high at the temperature above 400 ℃. In addition，the SCR reaction of Fe-zeolite occurs mainly in the inlet and middle segments of the catalyst. At the temperature of 300 ℃ and the space velocity of 60 000 h-1，up to 90% NOx conversion could be achieved in the front half of the catalyst. The utilization rate of the catalyst is low at the outlet segment of the catalyst. Furthermore，the transient performance of the model was investigated，and it is found that the transient response of Fe-zeolite catalyst was improved with the temperature increasing. © 2024 Chinese Society for Internal Combustion Engines. All rights reserved.

引用

页码：245 / 252

页数：7

共 20 条

[1] 3, 3, pp. 200-217, (2012)
[2] Chapman D M., Behavior of titania-supported vanadia and tungsta SCR catalysts at high temperatures in reactant streams：Tungsten and vanadium oxide and hydroxide vapor pressure reduction by surficial stabilization[J], Applied Catalysis A：General, 392, 1, pp. 143-150, (2011)
[3] 35, 1, pp. 53-59, (2017)
[4] 38, 2, pp. 161-168, (2020)
[5] Hamoud H I，, Valtchev V，, Daturi M., Selective catalytic reduction of NOx over Cu- and Fe-exchanged zeolites and their mechanical mixture[J], Applied Catalysis B ：Environmental, 250, pp. 419-428, (2019)
[6] Wang A, Wang Y，, Walter E D，, Et al., NH3-SCR on Cu ， Fe and Cu ＋ Fe exchanged beta and SSZ-13 catalysts：Hydrothermal aging and propylene poisoning effects[J], Catalysis Today, 320, pp. 91-99, (2019)
[7] Joshi S Y，, Kumar A, Et al., New insights into the mechanism of NH3-SCR over Cu- and Fe-zeolite catalyst：Apparent negative activation energy at high temperature and catalyst unit design consequences[J], Applied Catalysis B：Environmental, 226, pp. 565-574, (2018)
[8] Kovarik L，, Washton N M，, Kukkadapu R，, Et al., Transformation of active sites in Fe/SSZ-13 SCR catalysts during hydrothermal aging：A spectroscopic，microscopic，and kinetics study[J], ACS Catalysis, 7, pp. 2458-2470, (2017)
[9] Tsukamoto Y，, Fukuma T，, Kusaka J., Analysis and modeling of NOx reduction based on the reactivity of Cu active sites and Brønsted acid sites in a Cu-chabazite SCR catalyst[C], (2019)
[10] Zhang D, Yang R T., N2O Formation pathways over zeolite-supported Cu and Fe catalysts in NH3-SCR[J], Energy & Fuels, 32, 2, pp. 2170-2182, (2018)

← 1 2 →