New method for oil recovery from distillation waters, Alexander Fleisher, Essential OiIs & Spices, Israel
During water-steam distillation, a considerable part of essential oil often remains in distillation waters. This part, enriched in oxygenated compounds, should be extracted for the achievement of a true replica of plant smell and for oil yield increase. For rose and similar oils, such extraction is of the utmost importance, since the distillation water contains the main part of the oil. Known extraction processes are, as a rule, complicated and expensive. Widely used cohobation offen yields oils of inferior smell caused by partial chemical alterations.
The described new oil recovery method is based on modified frontal liquid chromatography. Distillation water flows continuously through the column packed with blocks of porous polytetrafluorethylene (PTFE), which holds on its surface about 20%V/V of low boiling water immiscible organic solvent. The saturated solvent is periodically replaced by a fresh one without stopping the process. The time of column saturation is calculated from efficiency datum (HETP) and the distribution coefficient of the most polar oil constituent in the water-solvent system. Preparation of the liquid phase support in blocks provides stability and efficiency for large diameter columns (200-400 mm HETP is about 20-50 mm). Use of PTFE excludes any changes in oil composition.