After 2010, the application of EGR into spark ignited engines was expanded-not for NOx control but for fuel economy purposes. It was this heavy-duty application that attracted the most attention to EGR, due to the more difficult technical challenges compared to the earlier light-duty applications. While there were applications to heavy-duty diesel dating back to the 1970s, it was not until the early 2000s that cooled EGR became very common in heavy-duty diesel engines in North America. Following the early gasoline application, EGR was also introduced to diesel passenger cars and light-duty trucks and then heavy-duty diesel engines. After the early 1990s, some gasoline fueled applications were able to dispense with EGR. ДЇrom 1972/73 to the late 1980s EGR was commonly used for NOx control in spark-ignited gasoline fueled passenger car and light-duty truck engines in North America. By the 1970s, EGR was being seriously considered as a NOx control measure for diesel engines. While NOx reductions had been reported with EGR as early as 1940, the first engine experiments to investigate the NOx reduction potential of EGR appeared to be carried out in the late 1950s in SI engines. Some of these include: imparting knock resistance and reducing the need for high load fuel enrichment in SI engines, aiding vaporization of liquid fuels in SI engines, as an enabler for closed cycle diesel engines, for improving the ignition quality of difficult-to-ignite fuels in diesel engines or for improving the performance of SCR catalysts. While the application of EGR for NOx reduction is the most common reason for applying EGR to modern commercial diesel engines, its potential application extents to other purposes as well.

EGR is also used in gasoline engines, primarily in order to reduce pumping work and increase engine efficiency.Д®xhaust gas recirculation (EGR) is an emission control technology allowing significant NOx emission reductions from most types of diesel engines: from light-duty engines through medium- and heavy-duty engine applications right up to low-speed, two-stroke marine engines. Several configurations have been proposed, including high- and low-pressure loop EGR, as well as hybrid systems. The EGR reduces NOx through lowering the oxygen concentration in the combustion chamber, as well as through heat absorption. Abstract: Exhaust gas recirculation (EGR) is an effective strategy to control NOx emissions from diesel engines.

Why is nox stuck at 99 percent