The present invention discloses a process of refining crude oil while retaining essential ingredients like tocopherol, sterol, phospholipids, oil soluble vitamins, etc. The free fatty acids are removed by treating the oil with the macro-porous or macro-reticular weak base anion exchange resin at oil / resin ratio of 10 for 5 hour. The acid oil/ waste or spent oil can also be refined by the process of the invention and the refined oil thereafter used in biodiesel production.
