Course: BFM 202 Biodiesel Production

Lecture

Esterification
Credits
BFM 202 Biodiesel Production Unit 5 Lecture has been adapted from "ENGY 131 Unit 5 Commentary Catalysis" 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

Karl  Fischer experimented with catalysis and discovered that by
reacting carboxylic acid with methanol, the equilibrium shifts toward
greater biodiesel yields. This process is known as the Fischer
Esterification Reaction.

Although sulfuric acid has been the traditional catalyst used with
low-cost, high-FFA feedstock, it has many negatives including the
production of sulfur compounds that cause the biodiesel to fail ASTM
specifications. A significant downside of using sulfuric acid is
associated with the cost of removing that acid's derivatives in
order to comply with EPA standards and to protect the quality of the
downstream transesterification process.

Solid acid catalysts have cost advantages over liquid acid catalysts
since they are easier to recycle, separate from the final products, and
easier to meet environmental requirements. Ongoing research for
high quality, solid catalysts continues. Some examples include:

- polymerics
- zeolites
- superacids (sulfated zirconia and niobic acid)

These may eliminate corrosion, replace liquid acids and separation,
and reduce environmental concerns.