New amphiphilic pyridinium ionic liquids for demulsification of water Arabic heavy crude oil emulsions

Abstract

Recently ionic liquids (ILs) have been approved recognition as environmentally safe chemicals in a wide variety of applications including petroleum industry. In the present work, new amphiphilic pyridinium ILs were synthesized via the reaction of 4-amino pyridine with 1-bromotetradecane to form quaternized amino pyridinium bromide followed by ethoxylation of the amino group to form ethoxylate amino pyridinium bromide IL (QEP). Finally, QEP was quaternized using triflouroacetic acid to produce diquaternized pyridinium bromide IL (DQEP). The surface activities of the prepared pyridinium ILs were determined in their aqueous solutions to confirm the amphiphilicity of QEP and DQEP ILs. Zeta potential measurements were also carried out to verify the positive charges on the IL colloids in their aqueous solutions. Relative solubility number values of QEP and DQEP ILs were measured to show the higher hydrophobicity of DQEP than QEP. The prepared ILs were applied as demulsifiers for water in petroleum crude oil (W/O) emulsions having different compositions. The demulsification mechanism of QEP and DQEP ILs were investigated using optical microscope, interfacial tension (IFT), RSN measurements and ILs/asphaltene interactions. The presence of QEP and DQEP was reduced the IFT to confirm their abilities on interaction with the asphaltene layer at interface to successfully dehydrate W/O emulsions. The demulsification efficiencies of QEP and DQEP reached 100% for W/O emulsion (50/50 vol%) and (30/70 and 10/90 vol%), respectively to confirm the ability of these pyridinium ILs to be applied as demulsifiers for crude oil emulsions.