An Exhaust Gas Aftertreatment System to Reduce Particulates for Full-Size Passenger Cars

An exhaust gas aftertreatment system employing thermal regeneration has been developed to lower the particulate emissions from the intercooled Volvo 760 turbo-diesei engine. This system consists, primarily, of a honeycomb trap, a modified exhaust manifold and controlled compressor and intercooler bypasses.

With this aftertreatment system, the particulate emissions can be lowered below the 0.2 g/mi standard (FTP-75 cycle) without unacceptable deterioration of the other pollutant emissions and the vehicle driveability. After operating the vehicle for more than 220 miles over consecutive FTP test cycles, the backpressure was found to remain constant up to approximately 70 miles. A brief description of the vehicle test procedure, accomplished during low ambient temperatures, is also provided. Problem areas which still remain are temperature control and thermal resistance as they relate to trap durability.