Course: BFM 202 Biodiesel Production

Lecture

Animal and Plant Lipids
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.

Animal and Plant Lipids

Any animal or plant lipid could be a feedstock for the production of
biodiesel. These choices are regionally dependent and determine the
final cost of biodiesel based upon their availability and how much
material handling is involved. The decision factors include:
- uninterruptable supply
- cost
- ease of collection
- feedstock and fuel storage stability
- fuel quality
- engine
- performance

Europe converts rapeseed and sunflower oils, tropical climates use palm
oil, and the U.S. depends primarily upon animal and soybeans.

Animal fats, referred to as tallow, can be the least expensive feedstock
because they are animal industry by-products. They contain high levels
of saturated fatty acids which means they also have higher melting
points. This translates to higher certain value but, in colder climates,
can precipitate and cause poor engine performance. Only tallow with low
FFA levels can be successfully converted using alkali-catalyzed
transesterication.

In the U.S., yellow grease (FFA to 15%) and brown grease (FFA > 15%)
are “recovered vegetable oils” from deep fat frying. Click on this article for a
description of this process:
Rotisserie Chicken, Biofuel and Sam's Club: Creative Sustainability.

It is normal to use only refined oils since they do not contain lecithin
and gum. Both can precipitate from oil and complicate the washing phase
of the biodiesel production cycle in addition to storage and handling
challenges. Degumming is performed through bleaching and other degumming
processes that also reduce the phosphorus in biodiesel.

Refined vegetable oils can cost 10-15% more to process than unrefined.