Glossary of Biodiesel Terms

Diesel fuel made from crude oil (regular diesel). Also simply called diesel, dino-diesel. It is a light fuel oil similar to kerosene that is used as a motor fuel for large trucks, and to a lesser degree, passenger vehicles. This is the diesel you see for sale at the gas station.

Any fuel oil that is made from vegetable or animal fats using the process of transesterification. It is considered a fully renewable fuel, and usually a “green” fuel because the carbon dioxide it creates is absorbed back by the plants that make the biodiesel, so the net carbon dioxide that is left in the environment (theoretically) is zero. It is considered non-toxic (less toxic than table salt) and non-flammable, as the flash point is typically around 300 degrees F, making is much safer to store and handle than regular diesel or kerosene. Many gas stations are now offering blends of biodiesel and petrodiesel, or even pure biodiesel in warmer latitudes.

Kerosene (paraffin oil)
Another fuel oil that is used primarily as a heating fuel, for portable stoves, lanterns and other sources where ventilation is adequate. It produces an unacceptable amount of carbon monoxide to use indoors for most applications. It is very similar to diesel fuel and can be used in place of diesel in a limited fashion. It is also used as jet fuel, rocket fuel (when mixed with liquid oxygen) . It has a very low flash point, which makes storing large quantities potentially dangerous. Kerosene is sometimes blended into regular diesel to lower the gel point, primarily in northern states that experience colder winters.

Straight Vegetable Oil. Some vehicles can be modified to run this as primary fuel, although most still use petro or biodiesel to start the vehicle, then switch over to the SVO tank for normal operation.

Waste Vegetable Oil. Basically the same as SVO except it has been used, typically in restaurants to cool foods such as french fries, fish, chicken or other frozen or fresh foods. Typically it must be filtered and/or washed before using. It is readily converted into biodiesel through transesterification via methanol and lye, or can be used (after filtering) in a SVO vehicle.

According to Wikipedia: In organic chemistry, transesterification is the process of exchanging the alkoxy group of an ester compound by another alcohol. These reactions are often catalyzed by the addition of an acid or base.

In English: Certain chemicals, when mixed, will create two different chemicals. With the right chemicals, the process is called transesterification, such as mixing oil, lye and methanol to make biodiesel and glycerol. An example is when your grandmother used to make lye soap by boiling down lard (cow fat) with lye (from certain wood and ash) and alcohol from the still (ethyl alcohol, which works but not as well as methyl). The result was lye soap (glycerol with some lye left over) and lamp oil (biodiesel). She was simply doing the low tech version of what is still done today to make biodiesel. Of course, many people now make biodiesel in their own homes using better technology, but it is still a simple process.

B5, B10, B20, etc.
This is the universally accepted method for indicating a blend of biodiesel and petrodiesel. The number in front of the B is the ratio of biodiesel, thus B5 is 5% biodiesel, 95% petrodiesel. B20 is 20% biodiesiel and 80% petrodiesel, etc.

Methyl Alcohol (aka: wood alcohol or methanol)
This is the simplest alcohol and is used for a antifreeze (particularly in windshield wiper fluids), solvent, fuel and the catalyst to create biodiesel. It is commonly used in pure form as a race car fuel, and is sometimes blended with gasoline to oxygenate the fuel and reduce pollution (although ethyl alcohol is more commonly used for this purpose due to the lower toxicity).

It is extremely poisonous and can not be made safe by dilution. If ingested in relatively small quantities, it causes blindness, liver failure and other issues, including death. When burned it produces carbon dioxide and water. The flames from a methanol fire are invisible, which causes problems for race car drivers involved in wrecks, however, it can be extinguished with simple water.

Ethyl Alcohol (aka: corn liquor or grain alcohol)
Ethyl alcohol is the alcohol in “adult beverages”. It is mildly toxic. It is sometimes mixed with methyl alcohol for the purpose of making in poisonous (thus undrinkable) for certain applications, in a denaturant. It can be used to create biodiesel, although it requires more alcohol and is more expensive. The advantages of using ethyl alcohol include the ability to make your own (assuming owning a small still is legal in your area…) and the much lower toxicity of the stored material.

Gel Point
This is the temperature that a given fuel oil (petrodiesel, biodiesel, kerosene) will begin to gel, thus making it harder for the fuel to flow and be useful. One of the problems with biodiesel is the higher gel point, but this varies according to the oil used to create the fuel. This is one reason it is blended in colder environments, to insure it will flow at reasonable temperatures.

Lye (credit to Wikipedia )
Available commercially as “Red Devil Lye” and others, it is a caustic solution. There are two basic kinds, sodium hydroxide (soda lye) and potassium hydroxide (less common potash lye). They have a tremendous number of commercial uses, from farming to food preparation. Hominy is simply corn that is soaked in lye, for instance.

Lye is used as one of the catalysts (along with alcohol) for turning oil into biodiesel, although you must use the dry, undiluted mixes for this purpose.

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