KIT | KIT-Bibliothek | Impressum | Datenschutz

Advances and challenges of ammonia delivery by urea-water sprays in SCR systems

Börnhorst, M. 1,2; Deutschmann, O. ORCID iD icon 1,2
1 Institut für Katalyseforschung und -technologie (IKFT), Karlsruher Institut für Technologie (KIT)
2 Institut für Technische Chemie und Polymerchemie (ITCP), Karlsruher Institut für Technologie (KIT)


Over the past decades, selective catalytic reduction (SCR) using aqueous urea sprays as ammonia precursor has become the prevalent technique for NO$_{X}$ emission control in mobile applications. Preparation of ammonia from urea water sprays still represents a challenge in aftertreatment engineering as complex interactions of multi-phase physics and chemical reactions have to be handled. Increasingly stringent emission legislations and the ongoing development of fuel-efficient engines and close-coupled aftertreatment systems raise high demands to SCR systems. Due to highly transient conditions and short mixing lengths, incomplete spray evaporation can result in liquid/wall contact and formation of solid urea deposits lowering ammonia selectivity and homogeneity. This article reviews the ongoing development of SCR systems with focus on the efficient evaporation and decomposition of the injected spray for a homogeneous ammonia distribution in front of the SCR catalyst. Critical aspects of spray evaporation and impingement, liquid film and deposit formation are pointed out and potentials for system optimization are discussed.

Verlagsausgabe §
DOI: 10.5445/IR/1000136971
Veröffentlicht am 08.09.2021
DOI: 10.1016/j.pecs.2021.100949
Zitationen: 25
Web of Science
Zitationen: 21
Zitationen: 27
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Technische Chemie und Polymerchemie (ITCP)
Publikationstyp Zeitschriftenaufsatz
Publikationsmonat/-jahr 11.2021
Sprache Englisch
Identifikator ISSN: 0360-1285, 1873-216X
KITopen-ID: 1000136971
Erschienen in Progress in Energy and Combustion Science
Verlag Elsevier
Band 87
Seiten Art.-Nr.: 100949
Nachgewiesen in Dimensions
Web of Science
KIT – Die Forschungsuniversität in der Helmholtz-Gemeinschaft
KITopen Landing Page