Biodiesel Effects on U.S. Light-Duty Tier 2 Engine and Emission Control Systems - Part 2

Raising interest in Diesel powered passenger cars in the United States in combination with the government mandated policy to reduce dependency of foreign oil, leads to the desire of operating Diesel vehicles with Biodiesel fuel blends.

There is only limited information related to the impact of Biodiesel fuels on the performance of advanced emission control systems. In this project the implementation of a NOx storage and a SCR emission control system and the development for optimal performance are evaluated. The main focus remains on the discussion of the differences between the fuels which is done for the development as well as useful life aged components.

From emission control standpoint only marginal effects could be observed as a result of the Biodiesel operation. The NOx storage catalyst results showed lower tailpipe emissions which were attributed to the lower exhaust temperature profile during the test cycle. The SCR catalyst tailpipe results were fuel neutral. The engine-out emissions formation showed increased NOx and decreased HC emissions with the Biodiesel blend. The observed effect specifically on NOx was up to 10% increase with the B20 blend. There was some impact on fuel economy which was attributed to higher combustion efficiency resulting in approximately 2% improved fuel economy with Biodiesel. There was no measurable impact of Biodiesel operation on the engine mechanics including fuel injection system.