Paraffin wax is usually obtained through waxing operation from petroleum paraffin by solvent. This wax contains oil and its purification is performed by extracting oil from it.
For the first time, purification, oil extracting and separation of petroleum waxes were performed through distillation in Scotland . This method is based on the melting temperature of kinds of paraffin and paraffin waxes obtained from petroleum which are obtained from oil wells. Nowadays there are several methods for refining and recrystallizing petroleum waxes.
In distillation operation, some waxes are heated slowly in such a way that the temperature of the existent oils in it, is equal to the lowest melting temperature of the wax, so that it starts to drip (distil) from under the mass of paraffin wax. So the extracted oil and the wax remain at a higher melting temperature. Basically, the distillation method is used when the base paraffin wax has large crystals (high molecular weight) and the space among the crystals is large. Because in such situation, we can say that these crystals are soaked in the existing oil, which are extracted through distillation of this oil from the crystal network. Therefore, we can concluded that this method has practical limits.