IMO sulfur regulations are expected to increase the blending ratio of catalytic cracking fuels, such as LCO (Light Cycle Oil) and CLO (Clarified Oil), with marine fuels. The aim of this paper is to investigate whether blending those fuels can cause any specific problems.
The authors prepared test fuels blended with LCO and ones without it based on the cetane index. The effects of these fuels on the ignition, combustion and exhaust characteristics of diesel spray were investigated by combusting it. We found that delayed ignition of the test fuels showed close association with the cetane index even when pilot injection was performed following ambient temperature changes. It was also learned that the emission characteristics of diesel spray were correlated with delayed ignition, and that an increase in NOx emissions was prevented at high temperature because of a reduction in the burnt volume caused by restricted air entrainment. In our experiments using a series of test fuels, the blending of LCO has not presented any specific problems that affect the ignitability and emission characteristics of diesel spray.
