UREA FRACTIONATION OF USED PALM OIL METHYL ESTERS

Urea has shown a remarkable ability in forming well-defined and easy-to-handle crystalline complexes. In general, the use of urea as a ligand provides efficient separation in fat with a wide variety of straight chain compounds but is not applicable to fat containing branched or cyclic compounds. This study was conducted to investigate the fractionation of used frying oil (palm-based) methyl esters (UFOME) with urea and the separation profile according to their degree of unsaturation. A comparison on the effectiveness of fractionation was made with the increment of the treatment level of urea. The urea was added at different ratios (UFOME: urea, w/w) i.e. 1:0.5, 1:0.75 and 1:1. It was found that the most effective fractionation of the unsaturated methyl esters (ME) was achieved when the treatment level of UFOME: urea was 1:0.75. The unsaturated ME was enriched from 58.81% to 88.03% after the urea fractionation. The enriched unsaturated ME will be a useful feedstock for oleochemicals and other processes requiring high level of unsaturation in their fatty acyl chain.