Quantification of urea-spray non-uniformity effects on the H2-assisted NO reduction and NH3 slip over an Ag/Al2O3 catalyst
Journal article, 2015

Selective catalytic reduction of nitrogen oxides (NOx) with ammonia (NH3-SCR) is an efficient technology for lean NOx removal in automotive applications. In the current work, a kinetic model for hydrogen-assisted NH3-SCR over a silver-alumina (Ag/Al2O3) monolith catalyst is adapted to the corresponding experimental results. The degree of non-uniformity in the NH3 dose to individual catalyst channels during operation of a urea-SCR system is also investigated and the NH3 dose probability distribution functions are derived. The effects of NH3 non-uniformity on the NO conversion and NH3 slip are studied over an otherwise optimal Ag/Al2O3 system. Above the stoichiometric point, the NH3 slip is shown to increase almost linearly with increasing NH3 dosage. Channels that receive significantly lower NH3 dose than the stoichiometric one exhibit low NO conversion, whereas there is no discernable increase in the NO conversion above an NH3 dose four times the average. These results highlight the importance of the interaction between the design of the NH3 dosing system and the performance of the catalytic system.

NOx reduction

NH3-SCR

NH3 slip

Ag/Al2O3

Author

Linda Ström

Competence Centre for Catalysis (KCK)

Henrik Ström

Chalmers, Applied Mechanics, Fluid Dynamics

Andreas Darnell

Nilcon Engineering AB

Per-Anders Carlsson

Competence Centre for Catalysis (KCK)

Magnus Skoglundh

Competence Centre for Catalysis (KCK)

Hanna Härelind

Competence Centre for Catalysis (KCK)

Energy Procedia

18766102 (ISSN)

Vol. 75 2317-2322

Fundamental studies of active sites and reaction mechanisms for lean NOx reduction over Ag-alumina

Swedish Research Council (VR), 2012-08-15 -- 2018-08-31.

Driving Forces

Sustainable development

Subject Categories

Materials Engineering

Chemical Process Engineering

Chemical Engineering

Fluid Mechanics and Acoustics

Roots

Basic sciences

Areas of Advance

Materials Science

DOI

10.1016/j.egypro.2015.07.431

More information

Latest update

10/28/2018