Meeting future NOX emission regulations by adding an electrically heated mixer

New regulations by the California Air Resources Board (CARB) demand a stringent 0.02 g/hp-hr tailpipe NO x limit year 2027, requiring Selective Catalytic Reduction (SCR) catalysts to provide high conversions even at low (below 200°C) exhaust temperatures. This work describes utilizing an Electrically Heated Mixer System (EHM system) upstream of Light-Off (LO-SCR) catalyst followed conventional aftertreatment (AT) system containing DOC, DPF, and SCR, enabling meeting CARB’s emission target. The AT were hydrothermally aged Full Useful Life. Conventional unheated Diesel Exhaust Fluid (DEF) was injected both LO-SCR primary downstream SCR. EHM allowed for DEF be as 130°C LO-SCR, whereas, in previous studies, 180°C or dosed with heated DEF. combination DEF, system, SCR enabled needed increase efficiency temperatures, which observed drive cycles such cold-FTP, LLC, World Harmonized Transient Cycle (WHTC). There several-fold reductions using this configuration compared its baseline: 3.3-fold reduction FTP, 22-fold Low Load (LLC), 38-fold Beverage Cycle, 8-fold “Stay Hot” 10-fold WHTC. Finally, it is shown that can heat gas, during cold start, without needing additional heating hardware integrated into system. These results performing changes engine base calibration.