Total Acid Number Reduction of Naphthenic Acid Using Subcritical Methanol: A Kinetic Study

Document Type : Research Article


1 Centre of Research in Ionic Liquids, Universiti Teknologi Petronas, 32610 Bandar Seri Iskandar, Perak, MALAYSIA

2 Department of Petroleum Engineering, Universiti Teknologi Petronas, 32610 Bandar Seri Iskandar, Perak, MALAYSIA


The aim of this study is to explore the capability of subcritical methanol to reduce the acidity of naphthenic acids and to determine reaction kinetics for large-scale reactor design.The experiments were carried out in a 25 mL autoclave reactor (China) at temperatures of 70-120oC, Methanol Partial Pressures (MPPs) of 0.1-1.5 MPa, and reaction times of 0-60 min. The total acid number content of the samples was analyzed using ASTM D 974 techniques. Experimental results reveal that total acid number reduction of naphthenic acids increased with increasing reaction temperature, MPP, and reaction time. Approximately 74.20% total acid number was reduced at a temperature of 120oC, a MPP of 1 MPa, and a reaction time of 60 min. Experimental data revealed that total acid number removal reaction kinetics followed second-order kinetics with an activation energy of 11.27 kcal/mol. Therefore, subcritical methanol is able to reduce the total acid number of naphthenic acids without the addition of any catalyst.


Main Subjects

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