Polyethylene glycol (PEG) of different molecular weights, namely, 200, 400,
600 and 1,000 g/mol was reacted with dodecyl phenol to form compounds havi
ng different hydrophile-lipophile balances and hence different surface acti
vities. The demulsification efficiency of the prepared surfactants in break
ing up water-in-crude oil emulsions was evaluated. The data revealed that d
emulsification efficiency increases with increasing demulsifier concentrati
on, contact time and hydrophilicity. The effect of temperature, NaCl concen
tration (salinity) and solvents on demulsification efficiency was investiga
ted. The demulsification efficiency of the studied surfactants was found to
increase with increasing temperature and decreasing salinity of the aqueou
s phase. A mixture of xylene and isopropanol was found to be the best solve
nt for the prepared demulsifier with respect to demulsification properties.