What is the difference between Biodiesel and Straight Vegetable Oil (SVO)?
Both biodiesel and vegetable oil can be used in a compression-ignition (diesel) engine. Biodiesel is produced from vegetable oils or animal fats through a chemical process called transesterification whereby the glycerin is separated out. Biodiesel does not contain petroleum, though it can be blended in any proportion with petroleum diesel. No modification is required to run your diesel vehicle on biodiesel. It is registered with the EPA, and is a legally recognized motor fuel. In order to run on straight vegetable oil, a fuel heating system must be added to your diesel vehicle. Burning vegetable oil may not be good for the environment or for the engine, as vegetable oil contains glycerin while biodiesel does not. Unlike biodiesel, vegetable oil is not registered with the Environmental Protection Agency (EPA), and is not a legally recognized motor fuel. Burning biodiesel produces a faint odor often difficult to detect.
A. Straight vegetable oil is pure vegetable oil. The term “biodiesel” usually refers to alkyl ester (usually methyl ester). These esters are derived from vegetable oil. The sticky glycerine (glycerol) component of the original triglyceride (vegetable oil) is replaced with another alcohol component via the process known as transesterification. Methanol is most often used for this, since it is widely available, the least expensive, and gives a reliable chemical reaction.
