Breakthough diesel

Ricardo claims to have achieved a significant milestone in its push to develop a cleaner diesel engine.

The company has now demonstrated that a diesel engine it has under development can meet the US Federal Tier II Bin 5 standard for emissions without the use of NOx aftertreatment.

The research is continuing with the aim of demonstrating clean diesel technology capable of achieving US Super Ultra-Low Emission (SULEV) and Tier II Bin 2 requirements.

Started in late 2005, the early stages of the research project focused on developing technologies to deliver engine-out exhaust emissions without NOx aftertreatment that achieve the Tier II Bin 5 US emission requirements, delivering NOx levels approximately one-sixth those of Euro 5.

These technologies include advanced air handling systems, two-stage series-sequential turbocharging, advanced exhaust gas recirculation, and application of closed-loop cylinder pressure-based engine controls.

In parallel, an exhaust aftertreatment system has been developed which combines a diesel oxidation catalyst (DOC) and diesel particulate filter (DPF).  When combined with engine optimisation, this has delivered Tier II Bin 5 emission levels without NOX aftertreatment.