31 January 2005
The US EPA has announced an agreement with the Ford Motor Company, where Ford will test the in-cylinder emission control technology developed and patented by the EPA, called “Clean Diesel Combustion” (CDC).
“Diesel engines are an extremely attractive technology to help achieve EPA’s future emissions standards,” said Jeff Holmstead, EPA assistant administrator for air and radiation. “The challenge has been to maintain diesel’s efficiency, while making the diesel ultra-clean in a cost effective manner. Moving these types of innovative technologies from the laboratory to the marketplace is essential, if we are to continue to improve air quality for all Americans.”
Ford and EPA announced the agreement at EPA’s National Vehicle and Fuel Emissions Laboratory in Ann Arbor, MI, where they showcased a Ford Galaxy minivan to demonstrate the clean diesel technology. The diesel minivan gets 30-40% better mileage than a gasoline minivan, while meeting EPA’s Tier 2 bin 5 NOx emission standard of 0.07 grams per mile without NOx aftertreatment.
The CDC technology appears to be a “massive EGR” combustion concept, where the engine is operated at very high EGR rates to lower the intake oxygen content to some 11-14% and to maintain the peak combustion temperature below 2100 K. According to the EPA, the key CDC features are:
- Fuel System: Uses a hydraulically intensified fuel system to lower PM and smoke emissions, and improve engine efficiency.
- Boost System: Increases the engine power and the efficiency of the combustion process, thus reducing emissions and increasing fuel economy.
- Low Pressure Exhaust Gas Recirculation (EGR): Lowers the peak combustion temperature to reduce the formation of NOx.
- Patriculate Filter: Reduces the remaining smoke, unburned hydrocarbons (HC) and carbon monoxide in the exhaust.
The EPA first discussed the concept of CDC in 2000, and then partnered with FEV who helped with the development. In 2004, the EPA announced a partnership with International to test the new technology in heavy-duty truck applications.