Course: BFM 202 Biodiesel Production

Lecture

Esterfication
Credits
BFM 202 Biodiesel Production Unit 4 Lecture has been adapted from "ENGY 131 Lesson 4 Alternate Biodiesel Feedstocks” 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.

Esterification

In order to use high FFA feedstock, a preliminary reaction known as
esterification is applied. Esterification reacts an alcohol and an acid to
form an ester that is then converted to biodiesel via transesterification.
The issue with esterification is the expense of this additional reaction.
Esterification is the common name for the chemical reaction where two
reactants (normally, an alcohol and an acid) form an ester. Esters are common
in organic chemistry and biological materials, and often have a characteristic
pleasant, fruity odor. This leads to their extensive use in the fragrance and
flavor industries.

Ever wonder why expensive perfumes and spices can be duplicated and
sold for a fraction of the cost? The expensive version is produced using
nature's plants. The inexpensive version is a by-product of petroleum
and biofuel production.

Feedstocks that are high in FFA and moisture cause unwanted side
reactions to occur during processing and prevent direct
transesterification. FFAs are converted to soap which consumes
significant amounts of catalyst and results in additional costs.

These soaps cause separation difficulties by creating an emulsion layer
between the biodiesel and the glycerin. Therefore, this emulsion must be
stored until it separates which adds cost, time, and yield loss.
Additional purification is also required.

In a last few years, dramatic and significant changes have been made in
the field of biodiesel. Aggressive research efforts continue to search
for the most viable feedstocks. It is quite a challenge to keep up with
the ever-changing feedstock choices, enzymatic treatment solutions, and
plant process technologies to uncover the least expensive and least
labor intensive methods to convert biomass to liquid fuel.

Additional Resource

Introducing Esters © Jim Clark, chemguide.co.uk