Course: BFM 202 Biodiesel Production

Lecture

Reducing High Viscosity Oils to Biodiesel Fuel
Credits
BFM 202 Biodiesel Production Unit 3 Lecture has been adapted from "ENGY 131 Unit 3 Transestrification Made Simple" 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.

Unit 3 Transesterification and Other Biodiesel Conversion Technologies

The Biodiesel Magazine is an excellent online source of quality information about the biodiesel industry, technological advances, and regulatory matters. For this unit, please read the article

“Jon Van Gerpen: looking at the biodiesel process in a new way,“
by Ron Kotrba, Biodiesel Magazine © BBB International

Reducing High Viscosity Oils to Biodiesel Fuel

There are four basic methods used to reduce high viscosity oils to a
fuel that can be used in diesel engines without experiencing engine
deposits.

- Transesterification
- Direct Use and Blending
- Pyrolysis
- Microemulsion

What is transesterification?

Biodiesel is the result of mixing methanol, a catalyst, and a refined
oil. This mixture is heated and the resulting reaction, known as
transesterification, creates two primary products: methyl esters and
glycerin. Methyl ester is the chemical compound referred to as
biodiesel. The glycerin by-product is heavier than biodiesel, and gravity
separates the glycerin by settling it to the bottom of the tank where it
can be drawn off.

The biodiesel is then water-washed to remove contaminants. During the
wash, water absorbs the excess methanol, catalyst, and soap. The wash
water is heavier than the biodiesel and settles to the bottom of the
tank where it can also be drawn off. Depending upon the feedstock and
catalyst used, it may take several wash cycles to complete this
purification step. The recovered methanol is separated and recycled back
into the mixing stage of the process. Prior to commercial use, the
biodiesel is analyzed in accordance to ASTM D 6751 specifications. The
high-quality biodiesel is then shipped by rail or truck for distribution.

Fuel quality is determined by the choices in feedstock, the fatty acid content
of the vegetable oil or animal fat, and the processes used in production.
In the U.S., highly refined soybean and cooking oils are typically reacted
with methanol to create biodiesel. Canola is also used.