US EPA

1040210 

Journal Article 

Ferric sulphate catalysed esterification of free fatty acids in waste cooking oil 

Gan, S; Ng, HK; Ooi, CW; Motala, NO; Ismail, MA 

2010 

Yes 

Bioresource Technology
ISSN: 0960-8524
EISSN: 1873-2976 

101 

19 

7338-7343 

English 

20435468 

10.1016/j.biortech.2010.04.028 

WOS:000279894400021 

In this work, the esterification of free fatty acids (FFA) in waste cooking oil catalysed by ferric sulphate was studied as a pre-treatment step for biodiesel production. The effects of reaction time, methanol to oil ratio, catalyst concentration and temperature on the conversion of FFA were investigated on a laboratory scale. The results showed that the conversion of FFA reached equilibrium after an hour, and was positively dependent on the methanol to oil molar ratio and temperature. An optimum catalyst concentration of 2 wt.% gave maximum FFA conversion of 59.2%. For catalyst loadings of 2 wt.% and below, this catalysed esterification was proposed to follow a pseudo-homogeneous pathway akin to mineral acid-catalysed esterification, driven by the H(+) ions produced through the hydrolysis of metal complex [Fe(H(2)O)(6)](3+) (aq). 

Esterification; Free fatty acids; Waste cooking oil; Ferric sulphate; Biodiesel