Selective Removal Of Polycyclic Aromatic Hydrocarbons (PCA's) From Mineral Oils

A consideration of the term ‘Aromaticity! and its significance in mineral oils is presented. Current methods for reducing the aromaticity of mineral oils is reviewed and possible methods of improved refining suggested, A specific analytical method for estimating the extent of PCA reduction in mineral oils was developed and used in the assessment of batch and continuous Solvent extraction techniques. Five different extraction solvents were assessed namely; f'-methyl-2-pyrrolidone (NMP), Dimethyl formamide (OMF), Dimethyl sulphoxide (OSC), Sulpholane and Furfural, using a "model! hydrocarton composition mixture and commercial dewaxed base luboil. The assessment Was continued: with the same solvents but improved by a modification which incorporated maleic anhydride as a complexing agent, Subsequent investigation show that the solvent feed .Make-up,. can be recovered in a usable form with the minimum of - The experimental results obtained from this work @howed that the order of .solvent effectiveness to PCA removal generally depended on the aromaticity of the oil but that -and NiP and OMS0 were most effective, while furfural volume sulpholane were least effective, considerably less oil of NMp was required to produce a specific raffinate as compared with other solvents but its overall other performance was found to be reduced when combined with found solvents, The addition of water to solvents was Was considerably to increase the raffinate yield but the PCA removal reduced, Taffinate Significant improvements in both PCA removal and with yield were effected by modifying the solvent can a complexing agent (M4). Modified solvent approach technically, therefore be seen to be of considerable interest extraction further work with continuous multistage same improvements.