Study On Removal Of Naphthenic Acid From Oil By Ionic Liquids

With the exploitation and utilization of crude oil, heavy crude oil output rises with its density, viscosity and acid value increase. Acid crude oil has great corrosion on equipment during processing, the corrosion of processing equipment is mainly caused by naphthenic acid, which content is highest in the oil, accounting for about 90%. In this thesis, we will discuss the deacidification technology of acid oil by using ionic liquid. Ionic liquids are low melting point salts that represent an exciting new class of reaction solvents for catalysis.The removal of acid naphthenate from acid oil with ionic liquids was systematically investigated. Ionic liquids such as [EMIm]Br, [BMIm]Br, [HMIm]Br and [OMIm]Br were used to investigate the effects of deacidification. As the alkyl chain of ionic liquid cations got longer, the higher deacidification rate was got. It seems that long alkyl chain of ionic liquids had something to do with deacidification performance. When the mass ratio of [OMIm]Br-to-oil was 14%, the white oil was reacted for 30 min under the temperature 323K, and then rested for 2 h, the deacidification rate can reach 96.6%. [BMIM]Br-AICI3 was used to investigate the effects of deacidification. Experimental results show that at the temperature of 323K under the condition of the AICI3 molar ratio is 0.2, and the mass ratio of 4%, the deacidification rate was near to 80%. And the reaction time of 4h is enough. The repetitive reaction experiments of [BMIM]Br-AICI3 showed the possibility of continuous reaction, the IL can be reused to some extent.The study shows that the deacidification using ionic liquids is feasible, and the reaction is rapid under the normal temperature and pressure, it's also easy to separate the ionic liquids from the mixture. The preliminary results reveal that the process saves time, consumes less energy, product separates easier and produces less pollution to environment.