Development of Emission Control Systems to Enable High NOx Conversion on Heavy Duty Diesel Engines
Selective Catalytic Reduction (SCR) systems have been demonstrated as effective solutions for controlling NOx emissions from Heavy Duty diesel engines. Future HD diesel engines are being designed for higher engine out NOx to improve fuel economy, while discussions are in progress for tightening NOx emissions from HD engines post 2020. This will require increasingly higher NOx conversions across the emission control system and will challenge the current aftertreatment designs. Typical 2010/2013 Heavy Duty systems include a diesel oxidation catalyst (DOC) along with a catalyzed diesel particulate filter (CDPF) in addition to the SCR sub-assembly. For future aftertreatment designs, advanced technologies such as cold start concept (dCSC™) catalyst, SCR coated on filter (SCRF® hereafter referred to as SCR-DPF) and SCR coated on high porous flow through substrates can be utilized to achieve high NOx conversions, in combination with improved control strategies.