Abstract: Environmental friendly rubber processing oil was prepared from naphthenic base crude feed using extraction or adsorption methods to remove polynuclear aromatic hydrocarbons (PAHs). The comparable experiments between preparation methods were carried out and the results showed that the removal of PAHs by extraction was much better than that by adsorption, thus extraction method was adopted. The effect of various solvents including complex solvent and extracting conditions on the removal of PAHs was investigated, as well as the properties of solvent raffinate. Results indicated that the complex solvent exhibited improved separation effect, its maximum separation coefficient reached up to 220.0 under the following process conditions: a solvent/oil ratio of 2, extracting at 60℃ for 15 min and using stirring speed of 150 r/min. After secondary extraction, the PAHs content in solvent raffinate was reduced to 1.7% from 14.0%. The yield of solvent raffinate was more than 82%, and its hydrocarbon group compositions were improved. By adding certain viscosity improver the quality of the final product could meet the product standard for VIVATEC500 rubber processing oil, which is an environmental friendly product.

Key words: naphthenic base oil, development, environmental protection, rubber processing oil