Auto-induced temperature-rise effects of ultrasonic irradiation (UI) on the esterification performance of jatropha oil (JO) were studied. Comparisons with other methods of mechanical mixing (MM) and hand shaking mixing were made. Major system parameters examined include: esterification time (tE), settling time (tS) after esterification and temperature. Properties of acid value (AV), iodine value (IV), kinematic viscosity (KV) and density of JO and ester product were measured. The esterification conversion efficiencies (η) were determined and assessed. Sulfuric acid was used to catalyze the esterification using methyl alcohol. For esterification without temperature control, η at tE=10 and 30min for UI of 56.73 and 83.23% are much higher than those for MM of 36.76 and 42.48%, respectively. At tE=10min, the jatropha oil esters produced via UI and MM respectively possess AV of 15.82 and 23.12mg KOH/g, IV of 111.49 and 113.22g I2/100g, KV of 22.41 and 22.51mm2/s and density of 913.8 and 913.58kg/m3, showing that UI is much better than MM in enhancing the reduction of AV. The tE exhibits more vigorous effect on AV for UI than MM. The UI offers auto-induced temperature-rise, improving the mixing and esterification extents.
Bibliographical noteFunding Information:
The authors gratefully acknowledge the Ministry of Science and Technology of Taiwan (MOST) (formerly National Science Council of Taiwan) for supporting this study. Mr. Cesar Augusto Andrade-Tacca also greatly thanks the Ministry of Education of Taiwan (MOE) and the National Taiwan University (NTU) for the grants supporting his study at the Graduate Institute of Environmental Engineering of NTU.
- Acid value
- Jatropha oil
- Methyl ester
- Ultrasonic irradiation