The transesterification of palm oil and methanol catalyzed by Brønsted acidic ionic liquids was investigated. Four eco-friendly Brønsted acidic ionic liquids were prepared and their structures were characterized by NMR

FT-IR and TG-DTG. The results demonstrated that[CyN

1

1

PrSO

3

H

]

[

p

-TSA

]

was more efficient than the other ionic liquids and chosen as catalyst for further research. The influences of various reaction parameters on the conversion of palm oil to biodiesel were performed

and the orthogonal test was investigated to seek the optimum reaction conditions

which were illustrated as follows:methanol to oil mole ratio of 24:1

catalyst dosage of 3.0 wt% of oil

reaction temperature of 120℃

reaction time of 150 min

and the biodiesel yield achieved 98.4%. In addition

kinetic study was established for the conversion process

with activation energy and preexponential factor of 122.93 kJ·mol

-1

and 1.83×10

15

respectively. Meanwhile

seven-time recycling runs of ionic liquid were completed with ignorable loss of its catalyst activity. The refined biodiesel met the biodiesel standard EN

14214.