| Abstract | Renewable fuels usually consist of paraffinic hydrocarbons and are free of sulfur and aromatics. Although most renewable fuels meet the conventional fuel requirements for internal combustion engine applications, differences in fuel properties between renewable fuels and petroleum-based fuels still exist. The effect of renewable fuels on conventional diesel engines has been investigated by many researchers. However, few studies have been conducted on the effect of renewable fuels on combustion and emission performance of homogeneous charge compression ignition(HCCI)engines. In this paper, the combustion and emission characteristics of an HCCI engine are experimentally investigated when four neat renewable fuel components and their blends with a petroleum-based diesel were used. The ratios of renewable fuel components in the blends were changed from zero to 100%. The experiments were conducted over a wide range of operational conditions. Energy efficiency and regulated emissions data were collected and analyzed. The results suggest that compared to the petroleum-based diesel fuel, all four investigated renewable fuel components increase the fraction of heat release during low temperature stage and reduce the ignition temperature when applied to an HCCI engine. As a result, the investigated renewable fuel components advance combustion phasing of an HCCI engine. While three of the four investigated renewable fuel components improve the energy efficiency when blended with the petroleum-based diesel, one renewable fuel component deteriorates energy efficiency. The effects of renewable fuel components on emissions vary, with some reducing emissions while others not having a clear trend affecting emissions. |
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