Effect of Cu Addition onto CaO/Al<sub>2</sub>O<sub>3</sub> Catalyst for Naphthenic Acid Removal from Crude Oil

Abstract

Oil is one of the most important energy sources for the world and will likely remain so for many decades, even in the most optimistic projection about the growth of alternative energy sources. Petroleum industry nowadays faced a problem when the naphthenic acid (NA) compound naturally present in the acidic crude oil tends to induce corrosion in oil refining process. Total Acid Number (TAN) represent the amount of naphthenic acid in the oil with the permissible limit of TAN in crude oil is less than 1. Various methods had been used to remove NA in crude oil such as dilution and caustic washing. But all methods have their own weakness. Hence, in order to overcome the acidic crude oil problem, a new catalytic deacidification technique will be introduced in this study. Three types of crude: Petronas Penapisan Melaka Heavy Crude (Crude A) and Light Crude (Crude B) and Korean Crude (Crude C) were studied. Parameters studied were dosing amount of basic chemical used, catalyst calcination temperature, and percentage of the basic chemical in the co-solvent. The basic chemical used in this study was ammonia solution in ethylene glycol (NH3-EG). By using Ca/Al2O3 catalyst with calcination temperature of 10000C, the results showed 66.7% (1000 mg/L of NH3-EG) reduction in TAN for crude A, 53.9% reduction for crude B while for crude C the percentage of TAN reduction was 41% only. Addition of Cu as a dopant in this study had increased the TAN reduction for all three types of crude oil. TAN in crude A (80% of TAN reduction) and crude B (77% of TAN reduction) were successfully reduced to less than 1 with only using 1000 mg/L of NH3-EG with the aids of Cu/Ca (10:90)/Al2O3 catalyst at calcination temperature of 10000C while for crude C the TAN was still higher than 1 but the percentage of TAN reduction increased to 46%.