An increasing demand for conventional crude oil makes it becomes an important source of energy nowadays, but the raw crude oil contains Naphthenic Acids (NAs), which will cause severe operational problems for the oil refineries in the petroleum industry. The presence of this compound will also affect the price and quality of the oil processed. Therefore, the removal of NAs becomes a great concern and challenge for the oil refineries. The goal of this study is to develop a catalytic extraction with ethanolic 2-methylimidazole with the aid of heterogenous K/Al2O3 and Ca/Al2O3 catalysts to remove the NAs in high Total Acid Number (TAN) crude oil. The catalysts were prepared by aqueous Incipient Wet Impregnation (IWI) method. Various parameters were studied including reaction temperature (27-45oC), catalyst loading (5-20wt%), and catalyst calcination temperature (700-1000oC) were investigated in detail to optimize the TAN reduction. The supported catalysts were characterized by using X-Ray Diffraction Spectroscopy (XRD), Scanning Electron Microscopy- Energy Dispersive X-Ray (SEM-EDX), Fourier Transform Infrared Spectroscopy (FTIR) and Thermal Gravimetry Analysis (TGA). Approximately, 89% TAN removal in mg KOH/g was successfully reduced when using Ca/Al2O3 catalyst while for K/Al2O3 catalyst, 83% reduction was achieved by using catalyst loading at 20 wt%, reaction temperature of 35oC and reaction time of 15 minutes. Thus, the treated acidic crude oil has met the PETRONAS requirement as the TAN must be below 1.0 mg KOH/g.
Keyword: crude oil, extraction, heterogenous catalyst, naphthenic acid