The purification of raw glycerin in biodiesel production can provide economic benefits and help to avoid residue
accumulation, thus reducing environmental impacts. In this work, the glycerin obtained from biodiesel
production by catalytic transesterification o fwaste cooking oil was purified by sequential extraction with organic
solvents, followed by discoloration with activated coal and monitoring by 1H NMR spectroscopy. Through
sequential extraction with petroleum ether and toluene, in that order, followed by discoloration with activated
carbon, 99.2% pure glycerin was obtained. This technique is shown to allow for glycerin purification using less
drastic or hazardous conditions than those commonly applied in vacuum distillation.