The Application of K/Al2O3 with Ethanolic 2-Metylimidazole for the Extraction of Naphthenic Acid from Crude Oil

  • Noraini Safar Che Harun Universiti Teknologi MARA
  • Norshahidatul Akmar Mohd Shohaimi Universiti Teknologi MARA Pahang
  • Ahmad Zamani Ab Halim Universiti Malaysia Pahang, Kuantan, Pahang
  • Nor Hakimin Abdullah Universiti Malaysia Kelantan
  • Nurasmat Mohd Shukri Universiti Sains Malaysia
Keywords: Catalysts; crude oil; naphthenic acid; total acid number


The world's economy is largely dependent on fossil fuels such as petroleum crude oil. Crude oil processing in the oil refinery can cause serious corrosion problems associated with the presence of naphthenic acids (NAs) which reduce the quality of the oil. The presence of these acidic compounds leads to an increase in the Total Acid Number (TAN) value and a decrease in the oil price which can affect the oil industry. The aim of this study was to overcome corrosion problems by reducing the TAN to less than 1.0 mg KOH/g using ethanolic 2-methylimidazole with the aid of a K/Al2O3 catalyst. Petronas Penapisan Melaka crude oil with an original TAN value of 4.38 mg KOH/g was used as feedstock in this study. The parameters investigated were reaction time, reaction temperature, catalyst loading and catalyst calcination temperature. The alumina supported catalyst was synthesized through Incipient Wetness Impregnation (IWI) methods and characterized using X-ray Diffraction Spectroscopy (XRD) and Scanning Electron Microscopy (SEM). The TAN of crude oil was successfully lowered to 0.74 mg KOH/g using a K/Al2O3 catalyst at a calcination temperature of 1000oC. Increasing the calcination temperature from 700 to 1000oC further reduced the TAN value of crude oil.