US EPA

1446521 

Journal Article 

Esterification and Deacidification of a Waste Cooking Oil (TAN 68.81 mg KOH/g) for Biodiesel Production 

Ding, J; Xia, Z; Lu, Jie 

2012 

Yes 

Energies
ISSN: 1996-1073 

5 

8 

2683-2691 

10.3390/en5082683 

WOS:000308241500004 

Oils with high content of free fatty acid (FFA) can be
treated by acid esterification where an alcohol reacts with the given oil in the presence of acid
catalyst. The investigated parameters include methanol to oil ratio, temperature and amount of
catalyst. The optimum conditions for acid esterification which could reduce FFA content in the
feedstock to less than 1.88% (acid value 3.76 mg KOH/g waste cooking oil) were 50 degrees C, 20%
methanol to oil ratio (by volume) and 0.4 vol.% H2SO4 after 5 h. However, oil with an acid value
of more than 1 mg KOH/g oil cannot meet the alkaline catalyzed transesterification conditions.
Under the conditions of NaOH concentration 0.5 N, excess alkali 15%, 60 degrees C, 40 min, the
FFA removal rate for deacidification reached 77.11% (acid value 0.86 mg KOH/g esterified oil).
The acid value of deacidification product was reduced below 0.86 mg KOH/g esterified oil, thus
meeting the base-catalyzed trans-esterification conditions. 

biodiesel; deacidification; esterification; free fatty acids; waste cooking oil