Optimization of basic catalyst with ammoniated polyethylene glycol for the removal of naphthenic acid from petroleum crude oil by Box–Behnken design

Abstract

Naphthenic acid (NA) removal from petroleum crude oil was investigated and optimized through the utilization of a formulated basic chemical and a basic catalyst. The response surface method (RSM) by Box–Behnken design (BBD) was employed for this purpose. Ammoniated polyethylene glycol (NH3-PEG) and cerium oxide supported on alumina were selected as the basic chemical and basic catalyst, respectively. Synthesizing of the catalyst was conducted through the wet impregnation method, and calcination was performed at temperatures of 400, 700, and 1000 °C. Brunauer–Emmett–Teller analysis (BET), field emission scanning electron microscopy-energy dispersive X-ray (FESEM-EDX), and X-ray diffraction analysis (XRD) were employed for characterizing the catalyst. A preliminary study revealed that the finest catalytic activity was achieved with the calcination of the Ce/Al2O3 catalyst at 1000 °C with a NH3-PEG concentration of 1000 mg/L and a percentage of NH3-PEG/oil mass ratio of 0.40. The optimization of the parameters, which comprise catalyst calcination temperature, concentration of NH3-PEG, and the percentage of NH3-PEG/oil mass ratio on the deacidification of NA, was achieved through the utilization of the response surface method (RSM) by BBD. The optimal conditions were realized at a catalyst calcination temperature of 1,050.54 °C, a NH3-PEG concentration of 853.10 mg/L, and a percentage of NH3-PEG/oil mass ratio of 0.47. With a 0.41 % margin of error, the results from RSM were deemed in good agreement with the experimental values.