Characterization and deacidification of acidic petroleum crude oil utilizing metal oxide catalyst supported on alumina and ammoniated polyethylene glycol solution

Abstract

The presence of naphthenic acid (NA) in petroleum crude oil may cause serious corrosion problem for refinery processing equipment. In this work, an alternative method to remove NA is investigated based on the catalytic deacidification reaction to achieve the target of lowering the total acid number (TAN) as required by PETRONAS to be less than 1. Ammoniated polyethylene glycol (NH3-PEG) was formulated as a deacidifying agent with various concentrations ranging from 100 – 1000 mg/L for crude oil. Cerium oxide based catalyst supported on alumina was synthesized via wet impregnation method and characterized using X-ray diffraction spectroscopy (XRD), Brunauer–Emmett–Teller (BET) and thermogravimetry analysis-differential thermal analysis (TGA-DTA). Parameters such as amount of basic chemical dosing, type of metal oxides, catalyst calcination temperature and reusability of catalyst on the removal of NA was studied. The results showed the TAN value for crude oil was reduced by 70.6% to a TAN of 0.74 mg KOH/g by using 1000 mg/L of NH3-PEG dosing aids by Ce/Al2O3 catalyst calcined at 1000 °C.