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Thermodynamics and reaction mechanism of urea decomposition

Tischer, Steffen; Börnhorst, Marion; Amsler, Jonas; Schoch, Günter; Deutschmann, Olaf

Abstract (englisch):
The selective catalytic reduction technique for automotive applications depends on ammonia production from a urea-water solution by thermolysis and hydrolysis. In this process, undesired liquid and solid by-products are formed in the exhaust pipe. The formation and decomposition of these by-products have been studied by thermogravimetric analysis and differential scanning calorimetry. A new reaction scheme is proposed that emphasizes the role of thermodynamic equilibrium of the reactants in liquid and solid phases. Thermodynamic data for triuret have been refined. The observed phenomenon of liquefaction and re-solidification of biuret in the temperature range 193–230 °C is explained by formation of a eutectic mixture with urea.

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Postprint §
DOI: 10.5445/IR/1000096321
Frei zugänglich ab 09.07.2020
Zugehörige Institution(en) am KIT Institut für Technische Chemie und Polymerchemie (ITCP)
Institut für Katalyseforschung und -Technologie (IKFT)
Publikationstyp Zeitschriftenaufsatz
Jahr 2019
Sprache Englisch
Identifikator ISSN: 1463-9076, 1463-9084
KITopen-ID: 1000096321
HGF-Programm 37.03.01 (POF III, LK 01)
Erschienen in Physical chemistry, chemical physics
Band 21
Heft 30
Seiten 16785-16797
Vorab online veröffentlicht am 08.07.2019
Nachgewiesen in Web of Science
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