Title: Emission Control Advances on Diesel Engines
Specific Purpose Statement: To inform my audience about diesel emission technologies. Central Idea Statement: There has been three major technologies added to diesel exhaust systems since 2003 including an EGR, DPF, and SCR that have dramatically reduced NOx emissions (smog gases).
I. Who knows the fundamental difference between a gas and diesel engine? A. A gas engine uses spark to ignite gasoline while a diesel engine uses compressed air to ignite the diesel fuel. II. Diesel engines in turn run more efficiently or simply get better miles per gallon than a similar sized gasoline engine. A. A diesel engine are more efficient up to 20% (Popular Mechanics) B. Although diesel engines run more efficiently they produce 30% higher emissions or smog producing gases than gas engines. (Popular Mechanics) C. In the last decade new technology has lowered the amount smog produced by diesel engines. D. In 2003 an EGR was developed followed by a DPF in 2007 and most recently a SCR in 2010. (Phil Romba of Light and Medium Fleet Magazine) E. What does this mean to you, well you all breathe air right? Transition/ Internal Preview: So 2003 started the wave of new technologies in diesel engines starting with the development of the EGR. Body
I. An EGR or exhaust gas recirculation systems is part of the exhaust system which is also known as the tailpipe. A. Since it takes air to make an engine run and not all air is used when the engine is running some is recirculated back into the engine to be reused. B. This simple design of reusing unused air lowers the temperature of the oxygen being burned which reduces the amount of smog gases produced. (Master Technicians Service Conference) Transition: Although the EGR worked well emission standards again changed in 2007. II. Diesel Particulate Filter or DPF is also part of the exhaust system and works...