Chemical Analysis of Exhaust Emissions from a Gasoline Direct Injection SI Engine 2004-01-1445
The exhaust emissions from a gasoline direct injection (GDI) engine were sampled using the bottle in bag method and analysed using gas chromatography/mass spectrometry (GC/MS). The GDI engine was run two times using two specially mixed fuels: a typical European base fuel containing additive and a fuel representing worst-case of European gasolines, which is a standardized European fuel, CEC RF 86-A-96, prone to form deposits. The engine was run 60 h for each fuel simulating city driving. Emissions were taken at times 0 h (at the start of the engine), 30 h and 60 h.
As a complement, particulate emissions derived from the additized base fuel were sampled on a glass filter during the first 30 h engine run. The extractable organics contained in the filter were analysed using GC/MS analysis.
Generally, the emissions were dominated by gasoline components with similar relations as in the gasoline. However, for additized base fuel at 30 and 60 h the emissions were less similar to the gasoline used. The worst-case fuel produced significantly higher levels of the measured major components compared to the additized base fuel. These higher levels may be due to a less efficient combustion producing significant amounts of unburned gasoline.
In the filter we found higher alkanes and similar oxygenated compounds originating from more and less degraded engine oil components.