Purity of solvent used in de-oiling units

1. The content of oil components in solvent depends on the fractional composition of the raw material and on the vapor velocity in the columns. The higher the vapor velocity, the more petroleum products get into the solvent. 2. Solvent regenerated in columns operating with steam introduction has the greatest content of oil components. 3. To obtain a solvent with an oil content not over 0.02–0.05%, the regeneration block columns (except the steaming columns must be subjected to fractionation in a separate column. 4. All possibility of contaminating the solvent with oil through leakage in the equipment should be eliminated.