Understanding the NH3 adsorption mechanism on a vanadium-based SCR catalyst: A data-driven modeling approach
Journal article, 2022

Ammonia adsorption is a precondition for the selective catalytic reduction (SCR) of nitrogen oxides (NOx) to take place and it influences catalyst performance under transient conditions. For a vanadium-based SCR catalyst NH3 adsorption takes place on multiple adsorption sites over the catalyst surface with different behaviours depending on temperature, gas concentration and catalyst oxidation state. In this study, a mechanistic NH3 adsorption model within the framework of Langmuir adsorption models was developed for describing the NH3 adsorption isotherms obtained with a gas flow reactor for a vanadium-based SCR. The model was created by a data-driven modeling process, which involves different steps. First, a large set of candidate models was created systematically by combining multiple feasible adsorption mechanisms. Then, a parameter estimation workflow was performed using three different objective functions with increased complexity. Finally, a model reconciliation step was executed and a quality assessment was done for creating a unified robust model with a high degree of validity. As a result of this method, an NH3 adsorption model with five adsorption sites with different mechanisms was obtained that captures the main features from the experimental data. Furthermore, the model parameters have physical significance and relate to the adsorption strength and spatial arrangement for NH3 and water molecules. The proposed model can be used in the development of transient models with increased validity over a wide experimental region.

Vanadium-SCR

Kinetic studies

Ammonia adsorption

Parameter estimation

Author

Andres Felipe Suarez Corredor

Chalmers, Chemistry and Chemical Engineering, Chemical Technology

Scania CV AB

Matthäus U. Bäbler

Royal Institute of Technology (KTH)

Louise Olsson

Chalmers, Chemistry and Chemical Engineering, Chemical Technology

Magnus Skoglundh

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Björn Westerberg

Scania CV AB

Chemical Engineering Science

0009-2509 (ISSN)

Vol. 262 117975

Subject Categories

Chemical Engineering

DOI

10.1016/j.ces.2022.117975

More information

Latest update

9/2/2022 7