Physical and Chemical Properties of Ethanol-Biodiesel Blends for Diesel Engines

This paper discusses the physical-chemical properties of ethanol-biodiesel blends considered as fuel for diesel engines. Attention is focused on the properties that significantly influence the injection, the engine characteristics, and subsequently, the exhaust emissions. In this context, the following properties have been investigated experimentally: fuel stability, density, viscosity, cold filter plugging point (CFPP), cloud point (CP), pour point (PP), flash point, filter plugging tendency (FPT), corrosiveness, lubricity, Fourier transformation infrared analysis, carbon-hydrogen-nitrogen (CHN) composition, and water content. Physical and chemical properties of biodiesel and ethanol-biodiesel blends have been measured according to the requirements and test methods for biodiesel (EN14214). The tested fuels were pure biodiesel (B100), 5% (v/v) ethanol biodiesel blend (E05B95), 10% (v/v) ethanol-biodiesel blend (E10B90), and 15% (v/v) ethanol-biodiesel blend (E15B85). It has been proven that, for ethanol-biodiesel blends, additives are not necessary to ensure stability under low-temperature conditions. Furthermore, cold weather properties, such as CP and PP, are improved by adding ethanol to biodiesel. In general, the results show that ethanol in biodiesel influences beneficially the most important fuel properties of the blended fuel. Potentially, this may offer a possibility to improve engine characteristics. However, to confirm this assumption, further engine tests have to be performed.