Naphthenic acid removal from crude oil by liquid-liquid extraction using ionic liquids.

• Main Author: KHAIDZIR, SAKINAH
• Format: Thesis
• Language: English
• Published: 2021
• Subjects: TP Chemical technology
• Online Access: http://utpedia.utp.edu.my/22792/1/SakinahBintiKhaidzir_17010601.pdf; http://utpedia.utp.edu.my/22792/
• Institution: Universiti Teknologi Petronas

The global low acidic crude oil is gradually depleting as it is one of the main sources in fulfilling global energy demand. High acidic crude oil is still in abundance which allows it to have a significant potential to replace low acidic crude oil. However, high acidic crude oil poses significant problems whereby it causes complications in oil refineries such as corrosion problems which will lead to various equipment failure. This is due to the high amount of naphthenic acid present in the crude oil. In order to use the crude oil safely, naphthenic acid removal is necessary. However, the current available techniques pose serious problems such as the conventional method producing a large amount of waste and the treated crude oil still contains high acid content. Ionic liquids as designer solvents act as a positive prospect in naphthenic acid extraction. In this study, eight (8) ionic liquids have been successfully synthesized namely piperidinium and pyrrolidinium based ionic liquids with different anions which are trifluoromethanesulfonate, phenolate and dicyanamide. Naphthenic acid extraction from model oil using the synthesized ionic liquids were studied by using two different techniques which are the mechanical stirring and ultrasonic assistance. Extraction study at various ionic liquid/model oil ratio was performed where the initial and final amount of naphthenic acid in model oil were determined. The piperidinium based ionic liquid with phenolate anion showed the best potential to extract the naphthenic acid from model oil. It is able to completely remove all the acid at a small amount of ionic liquid/model oil ratio of 0.010 and 0.0025 for the mechanical stirring method and ultrasonic assistance method, respectively. Ultrasonic assistance shows a remarkable potential in enhancing the extraction efficiency of naphthenic acid. Study on effect of ultrasonic parameters namely ionic liquid/oil ratio, amplitude and time were also conducted using response surface methodology (RSM).