Single Bank NOx Adsorber for Heavy Duty Diesel Engines

In a NO_x adsorber programme the feasibility for applying this technology to heavy duty diesel engines was investigated.

After modelling and simulations for realising best λ < 1 engine conditions a platform was build which was used to obtain good NO_x adsorber regeneration settings in a number of steady state key points without violating pre-defined limits. With these results the NO_x adsorber was evaluated and tested. Besides establishing NO_x conversions and BSFC penalties the programme also looked at the adsorber capabilities of dealing with sulphur poisoning and how well the adsorber could be de-sulphurised.

This programme showed clearly the stronger and weaker points in the NO_x adsorber technology for heavy duty application. From NO_x conversion - BSFC penalty trade off curves it became clear that at lower loads high conversions (> 90%) with small fuel penalties (< 2.5%) were possible. However at high load the conversions were reduced (< 70%) and the fuel penalties increased (> 6%). Another conclusion is that more catalyst durability development is required. Provided this durability plus the robustness towards (de-) sulphurisation improves then the single bank NO_x adsorber technology could have potential for heavy duty applications.