Spatially Resolved Measurements of HNCO Hydrolysis over SCR Catalysts

Abstract

In order to understand deposit formation during urea selective catalytic reduction (SCR) resulting from isocyanic acid (HNCO) formation, the present study investigates the potential of HNCO hydrolysis by spatially resolved gas phase concentration profiles along a single catalyst channel of commercial Cu-zeolite and V-based SCR catalysts. The spatially resolved profiles, obtained in a special hot gas test rig via capillary technique, provide information on reaction rates of HNCO hydrolysis, NH 3 adsorption and NO conversion, hereby revealing a better performance of the standard V-based catalyst regarding the HNCO hydrolysis, which is attributed to the TiO 2 support.

Coupling of Liquid and Surface Chemistry in Urea SCR Systems

“…Furthermore, a mechanism for HNCO hydrolysis from Hauck et al [46] is added. The combined model is compared to spatially resolved experiments from Eck et al [36] and own measurements. Finally the validated channel model is combined with a model for the urea decomposition to simulate the case of an impacting droplet onto the catalyst.…”

“…Experimental data was taken from Eck et al [36] and additional experiments were performed on the same hot gas test rig equipped with a VWT monolith.…”

Tap Reactor for Temporally and Spatially Resolved Analysis of the CO2 Methanation Reaction

“…To obtain a deeper insight into the dynamically operated reaction and its kinetics, spatially resolved reactors gather valuable data about the reaction progress. In the past years, several spatially resolved reactor types, e.g., monolith [13][14][15][16][17], catalytic foam [18][19][20], and catalytic plate [21][22][23][24][25] reactors, have been developed and applied in research. All reactors work according to the same principle: a sampling capillary is moved lengthwise through the reactor gathering gas samples on various positions.…”