Electrically Heated Extruded Metal Converters for Low Emission Vehicles

The primary objective of this work is to demonstrate that an extruded metal electrically heated catalyst (EHC) in combination with a traditional converter can achieve the Low and Ultra-Low California standards. With various aged EHC/converter systems and various heating strategies, typical FTP non-methane hydrocarbon (NMHC) emissions range from .015 to .030 g/mi. However, NMHC emissions as low as .008 g/mi are achieved.

In addition to reducing emissions, experiments were conducted to investigate the impact various heating strategies and system design parameters have on electrical energy usage. The conclusions are that electrical energy requirements can be significantly reduced by:

• Locating the EHC close to the main converter.
• Locating the EHC and main converter close to the engine.
• Reducing the mass of the EHC.
• Heating the EHC prior to engine start-up.