Neutralization of highly acidic crude oil utilizing 2-methylimidazole in polyethylene glycol solution / Nur Syafiqah Afiqah Ishak

The naphthenic acids (NA) compound occurs naturally in the acidic crude oil and
caused corrosion problem in refinery processing. Variuos method can be used to
reduce the NAs concentration of acidic petroleum crude either by using catalytic
decarboxylation, dilution or caustic washing but all these methods has its own
drawbacks. The objective of this study is to reduce TAN value of crude oil by
neutralization process using catalyst and reagents. The TAN value can be
determined when testing on crude oil sample with various parameters such as
catalysts calcination temperature, catalyst loading and reagent concentration. The
acid removal agent used is a mixture of 10% 2-methylimidazole in PEG with
reagent concentration of 100, 500, 1000 and 1500 ppm. Calcium was chosen as a
base for the catalyst while Cu and Ni were used as a dopant. The potential catalyst
was characterized by FTIR and TGA-DTG for its physical and chemical
characteristic. The alumina supported catalysts were prepared at different
calcination temperature of 800°C, 900°C and 1000°C. The FTIR results showed
that the CH-stretching of both catalysts after reaction might come from the PEG
reagent for impurities occurred around 1437.96-2921.9 cm-I
. TGA-DTG
thermogram showed a complete formation of metal oxide occurred at 670°C. Total
weight loss for Cu/Ca and Ni/Ca (l0:90)/AI203 are 24.76% and 25.70%
respectively. By using a catalyst with calcination temperature 1000°C, 7 beads of
catalyst loading, 500 ppm of 2-methylimidazole in PEG, reaction temperature
(35°C) and 5 minutes reaction times, the result shows 97% deduction of TAN
value from 3.93 to 0.13 mg KOH/g respectively. In conclusion, the TAN value of
PPM crude oils was successfully reduced to below than I mg KOH/g by catalytic
neutralization method which offered simple technique and environmentally
friendly.