(173g) Application of Ferric Sulfate as Catalyst for Conversion of Free Fatty Content of Acid Oil to Biodiesel

Biodiesel is an alternative fuel for diesel engines consisting of the

alkyl monoesters of fatty acids from vegetable oils. Currently most of

the biodiesel is produced from transesterification reaction. This

reaction requires vegetable oil, methanol, and an alkaline catalyst.

But, the high cost of vegetable oil, its importance as a food product

and presence of high content of FFA makes cost-effective production of

biodiesel very challenging.

In our research, we are investigating the conversion of the free fatty

acids (FFA) content of waste acid-oils from refineries to biodiesel

and related kinetics. The problem with processing these acid-oils

containing large amounts of FFAs that cannot be converted to biodiesel

using an alkaline catalyst. In this paper, we propose application of

ferric sulphate as acid catalyst to esterify the free fatty acids

before transesterifying the triglycerides with an alkaline catalyst to

complete the reaction. Therefore, the synthesis of biodiesel now

consists of two-step acid-base catalysis.

The paper discusses the reaction kinetic analysis of the

above-mentioned acid catalyzed step to finalize the catalyst loadings,

methanol proportions and the reaction time for obtaining optimum

conversion.