Surface wear of cement kiln SCR denitrification catalyst based on CFD-DEM
WU Yue
QIAN Fuping
YU Lingtao
LI Mingyue
HUANG Naijin
WU Hao
ZHENG Zhimin
Abstract：Objective This study investigates the surface wear on selective catalytic reduction(SCR)catalysts in cement kilns under various conditions to determine optimized solutions for reducing wear.It aims to identify key factors affecting catalyst surface wear and proposes optimized measures to reduce wear and extend the catalyst's service life.
Methods A coupled approach using computational fluid dynamics(CFD)and the discrete element method(DEM)was applied to simulate wear on the cement kiln SCR catalyst surface.The accuracy of the numerical simulation model was validated using experimental data to ensure that the model could accurately reflect actual operating conditions.After validation,simulations were conducted to investigate the effects of different inlet velocities,incidence angles,and particle sizes on catalyst surface wear.The study analyzed the flow characteristics and impact mechanisms of particles at various inlet velocities and explored how changes in incidence angles affected wear distribution patterns.Additionally,the study investigated the movement trajectories of particles with different sizes and their impact on the amount and uniformity of wear distribution.
Results and Discussion As inlet velocity increased,both the average initial wear and the mean steady-state wear on the catalyst surface increased due to the higher kinetic energy generated from the impacting particles.Larger incidence angles reduced the contact area between particles and the surface,leading to decreased wear.Smaller particles resulted in lower average wear and standard deviation with a more uniform wear distribution,extending the catalyst's service life.The experimental data showed that at inlet velocities of 2,3,4,and 5 m/s,the mean wear on the catalyst surface stabilized at 1.12×10-7,1.32×10-7,2.52× 10-7,and 3.78×10-7 mm,respectively.Appro×imately 10 seconds later,the standard deviation of wear peaked,suggesting that the wear pattern stabilized at this point.At inlet velocities of 2,3,4,and 5 m/s,the ma×imum standard deviation values were 1.82×10-8,2.41×10-8,2.46×10-8,and 2.52×10-8 mm,respectively.This findings indicated that higher velocities caused greater wear and variability in wear distribution,likely due to the complex dynamic processes of high-velocity particle impacting on catalyst surface.
Conclusion The standard deviation of wear on the catalyst surface initially increases and then decreases over time,indicating high variability in the early stages of wear,possibly due to random particle impacts.However,as the system gradually stabi-lizes,wear variability decreases.Similarly,the maximum wear amount initially increases and then declines,likely due to the chaotic movement of particles generating significant impact energy in the early stages.Then as the system stabilizes,the move-ment also subsides.Furthermore,the study reveals that smaller particles tend to cause more variability in surface wear,while larger particles have a more pronounced impact on the maximum wear.These findings are crucial for understanding catalyst sur-face wear mechanisms and provide valuable insights for catalyst material selection and operational strategies to mitigate wear in practical applications.
Keywords：CFD-DEMSCR denitrificationwear prediction modelcatalyst
Publication Date：2025-09-01
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：14( 168-181 )