EXHAUST GAS RECIRCULATION (EGR)

EGR is a technique employed to reduce the emission of nitrogen oxide (NOx) in engines. It works by re-circulating some of the engine’s exhaust gas back to the cylinder. This helps dilute the oxygen in the incoming air stream and provide gases inert to combustion that act as absorbents of combustion heat to reduce peak in-cylinder temperatures. NOx is thus produced in a very narrow band of high cylinder temperatures and pressures.