Electrically Heated Catalyst: A Powerful Tool for Aftertreatment Optimization 2023-01-0351

New electrical exhaust aftertreatment heating systems are in development to address the expected Euro7 regulation in Europe. These systems considerably shorten the light =-off time of the catalyst, even under extreme boundary conditions, for example start and drive away at -7°C. The pollutant limits foreseen for Europe are less severe than for example a US Tier3/Bin30 level, but the boundary conditions considered (temperature, altitude, driving patterns) are much broader than on the chassis dyno cycle. CARB has proposed within the ACCII draft further development of the LEVIII regulation to eliminate loopholes and ensure that internal combustion engines emissions remain low while transitioning the fleet to Zero emission vehicles. A proposal with similar scope from the EPA on federal level is expected.

This paper shows how the Electrical Heated Catalyst (EHC) technology is developed and optimized and points out the differences between US and European requirements. The use of EHC allows a single system to address several aspects of the future US regulations. Simulation and test results have been completed on different levels: heater, full catalyst system, engine, vehicle. These different aspects are displayed and discussed, along with the key parameters of the EHC system, especially voltage, power, thermal inertia and control technologies. Finally, further perspectives are given on the potential of the system to reach a near Zero emissions level on vehicle.