Course: BFM 202 Biodiesel Production

Lecture

Viscosity
Credits
BFM 202 Biodiesel Production Unit 1 Reading has been adapted from "ENGY 131 Unit 1 Commentary: What is biodiesel?" by Southeastern Illinois College.

ENGY 131 Biodiesel Production course content by Southeastern Illinois College is licensed under a Creative Commons Attribution 3.0 Unported License. Except where indicated otherwise.

Viscosity

Viscosity describes a fuel's ability to atomize as it is injected into the combustion chamber. The smaller the fuel droplets, the more complete the combustion and the longer the life of the fuel injection system which contributes to biodiesel's reputation as a clean burning fuel.

Viscosity is the measure of resistance-to-flow of a liquid due to internal friction. This property effects the atomization of biodiesel fuel as it is injected into the combustion chamber and ultimately helps predict engine deposits. The higher the viscosity the more susceptible a fuel is to problems. Neat oils have a high viscosity and are usually not used as an alternative fuel. Petrodiesel fuel has a lower viscosity than that of biodiesel.

The kinematic viscosity of biodiesel from frying or cooking oils is higher than that produced from pure vegetable oils. This is due to higher levels of fatty esters and trns fatty compounds. ASTM D445 and ISO 3104 specify the viscosity standards.