Removal of naphthenic acids from high acidity Korean crude oil utilizing catalytic deacidification method

Abstract

Catalytic deacidification is a fascinating method to decrease the naphthenic acids (NAs) concentration of highly acidic petroleum crude because these acids caused serious corrosion in refinery equipment. Korean crude oil with a total acid number (TAN) of 8.32mgKOH/g was used to test the performance of catalytic deacidification technology. A basic chemical with a dosing of 4% ammonia solution in polyethylene glycol (NH3-PEG) was used as the acid removal agent with concentrations of 100, 500, and 1000mg/L. Cerium oxide, zinc oxide and tin oxide based catalysts supported onto alumina prepared with different calcination temperatures and types of dopants were used to aid in the deacidification reaction. The potential catalyst was characterized by BET, EPR and CO2-TPD for its physicochemical properties. The results showed 93.3% reduction for Korean crude oil using Cu/Ce (10:90)/Al2O3 calcined at 1000°C. This catalyst has the highest BET surface area of 87.12m2/g with higher dispersion of Cu2+ species on the CeO surface detected using EPR spectra and higher total basic site measured using CO2-TPD. These properties contributed to the excellent catalytic performance which remove the NAs in the Korean crude oil and concurrently reduced the TAN value below than one.