Effects of Dual Injection Operations on Combustion Performances and Particulate Matter Emissions in a Spark Ignition Engine Fueled with Second-Generation Biogasoline

In order to combat global warming, climate change mitigation is the automotive industry’s primary challenge. Sustainable biofuels have been introduced as one of the leading solutions to reduce the life cycle CO2 emissions. One of the main challenges of biofuel as a drop-in sustainable fuel is the performance and tailpipe emissions. The second-generation biogasoline mixed with ethanol has proven that it could be introduced as a drop-in fuel with the same performance and tailpipe emission at the same level compared to fossil fuel.

This study aims to experimentally investigate the effect of port and direct fuel injections on the particulate matter (PM) emissions in a boosted spark ignition (SI) engine fuelled by Euro 6 standard biofuel with a 99 octane number blended with 20% ethanol in comparison to a fossil fuel baseline. The single-cylinder SI engine was equipped with two fuel injectors: a centrally mounted high-pressure injector and a port fuel injector in the intake port. It was operated with externally boosted air. The split injection ratio was adjusted from 100% Direct injections (DI) to 100% port fuel injection (PFI) to investigate the combustion characteristics and particulate emissions (PM) at different engine loads and speeds.

The results indicate that by changing 100% DI to 80% PFI, PM emissions were dropped by 96.56% at a low load operation of 4.6 bar IMEP at 2000rpm for the biogasoline and by 84% for the fossil fuel while maintaining the same indicated thermal efficiency and a similar level of other emissions. However, at a higher load above 10 bar IMEP, it was found that DI operation reduced particulate numbers (PN) by 64% and 38% for biogasoline and fossil fuel, respectively, and enabled more stable operation at 3000rpm with higher load operation regions.