Commercial ILs and metal salts were used to produce Jatropha biodiesel directly.
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91% Esterification yield was achieved by using [BMIm][TS]-AlCl3 at 80 °C.
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Transesterification was promoted by [BMIm][TS]-MCln greatly.
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Adding ZnCl2 in IL increased Jatropha biodiesel yield from 63.7% to 92.5%.
Abstract
Catalytic conversion of un-pretreated Jatropha oil with high-acid value (13.8 mg KOH/g) to biodiesel was studied in ionic liquids (ILs) with metal chlorides. Several commercial ILs were used to catalyze the esterification of oleic acid. It was found that 1-butyl-3-methylimidazolium tosylate {[BMIm][TS]} had high catalytic activity with 93% esterification rate for oleic acid at 140 °C but only 63.7% Jatropha biodiesel yield at 200 °C. When ZnCl2 was added to [BMIm][TS], a maximum Jatropha biodiesel yield of 92.5% was achieved at 180 °C. Addition of metal ions supplied Lewis acidic sites in ILs promoted both esterification and transestrification reactions. It was also found that the transition metal ions performed higher catalytic activity in transestrification than the ions of Group A. Mixture of [BMIm][TS] and ZnCl2 was easily separated from products for reuse to avoid producing pollutants.
Graphical abstract
Jatropha biodiesel yield in ionic liquid and metal chlorides.
The authors regret that there were some errors in our above paper because of inadvertent mistakes in calculations of biodiesel yield. The authors apologize for any inconvenience that this may have caused. The entire article is reprinted with the errors corrected.