2.3.3.1 Cetane Rating (CR)

The two most beneficial properties of biodiesel are its higher cetane rat­ings (CR) and better lubricating properties than the ultra-low sulfur diesel (ULSD). The CR of biodiesel ranges between 50 and 60, whereas that of ULSD ranges between 45 and 50. On the other hand, the CR of vegetable oil ranges

FIGURE 2.7

A schematic of biodiesel manufacturing process via transesterification.

between 35 and 45. Addition (or blending) of biodiesel in petrodiesel in a low concentration is reported to reduce fuel system wear, resulting in a beneficial effect to diesel engines.