Exhaust Emissions and Performance of a Spark Ignition Engine Using Oxygen Enriched Intake Air

Abstract

Oxygen was added to the intake air of a spark ignition engine to determine its effects on exhaust emissions and engine performance. Increasing the content of O₂ in the intake air of the engine from 21 to 32 percent by volume, increased exhaust nitric oxide emissions, decreased exhaust hydrocarbon emissions, decreased thermal efficiency and permitted leaner engine operation. These effects can be largely attributed to high flame temperatures and/or flame speeds with Os enriched air.