H2-DeNOx II

Brief description

Ultra-low-NO_x concept for the latest generation of diesel engines. Integration of H₂-DeNO_x and AdBlue electrolysis in a modern large-scale diesel exhaust aftertreatment system.

Question

In order to meet current and future emission limits, the focus for diesel engines is on low-temperature NO_X reduction. The SCR and NSC processes used to date, in combination with very efficient engines and urban driving, show insufficient NO_X conversion rates due to low exhaust gas temperatures (100 - 200 °C).

In order to extend NO_X conversion towards lower temperatures, catalyzed reduction using hydrogen as an additional DeNO_X technology is an option. The hydrogen is produced electrolytically from AdBlue in the vehicle and supplements the SCR systems used as standard.

Procedure and project objective

• Selection of promising H₂ DeNO_x catalysts based on literature
• Evaluation of the catalysts in the laboratory and optimization of the best catalyst in terms of conversion and selectivity
• Evaluation and validation of the best catalyst under real conditions on the engine test bench
• Development of electrocatalytic H₂ generation through electrolysis of AdBlue
• Integration of the overall system into the vehicle environment
• Overall evaluation with regard to NO_x conversion, secondary emissions, H₂ and energy consumption

Publications

Esser, E., Kureti, S., Heckemüller, L., Todt, A. et al., "Low-Temperature NO_x Reduction by H₂ in Diesel Engine Exhaust," SAE Technical Paper 2022-01-0538, 2022.