Patent ID: 7507329

Claim:
A process for reducing the naphthenic acidity of petroleum oils or their fractions, wherein said process comprises: a) providing a feed of petroleum oil or its fractions with between 0.1 and 99 wt % of emulsified/dispersed water in oil, said feed containing salts and a content of naphthenic acids measured as TAN between 0.1 and 10 mg KOH/g of oil; b) directing said feed of petroleum oil or its fractions with emulsified/dispersed water and salts towards a radiation emitting device in the microwave range and submitting said feed in the liquid phase under pressure between 0.7 and 4.5 MPa at temperatures between 50° C. and 350° C. to said microwave energy, applying said energy in the range of 1 mm to 30 cm on said petroleum feed, so that the presence of salts, the applied temperature and the high dielectric constant of water droplets make that the heat is absorbed on the spot by the water and heat it preferentially to oil, while the naphthenic compounds in the interface between the droplets and the oil receive said heat; c) effecting the decomposition of the carboxylic acids responsible for the naphthenic acidity in said feed of petroleum oil or its fractions at temperatures around 320° C., generating CO 2 ; d) with the aid of any known separating device, separating any generated gas phase, water and oil; e) recovering petroleum oil or its fractions of reduced content in naphthenic acids, and where: i) the feed of petroleum oil or its fractions is free from any added solid; ii) the migration trend of the naphthenic acids towards the emulsified phase, by concentrating said acids in a fraction of the overall feed, allows the application of the microwave radiation to a fraction that is smaller than the total feed.