Synthesis and characterization of new demulsifiers based on Octylphenol-formaldehyde resins for treating water in crude oil emulsions
The demulsification of water in heavy crude oil emulsion with water droplet size in the microscale has drawn great attention because of their high stability and difficulty of separation. In the present work, three types of ethylene amine based demulsifiers were prepared in one step through the interaction of melamine, triethylenetetramine, and hexamethylenetetramine with Octylphenol formaldehyde resins. The hydrphile-lipophile balances (HLB) of amphiphilic polyethylenamine (APEA) abbreviated as DVTA, DVM, and DVHT have been adjusted for meeting the demulsification requirements.
To confirm their chemical structures, 1HNMR as well as FTIR spectra were used. At a temperature of 25°C, the surface properties as well as the thermodynamic parameters such as surface tension (c) and effectiveness, minimum surface area (Amin) and maximum surface excess (Cmax) have been studied. The acquired data revealed that the increase of the concentration of the demulsifier and water content, causes an increase in the efficiency of demulsification. The efficiency of the demulsification that is related to synthesized APEA was assessed using separation time, demulsifier dose, and HLB values.
The efficiency of these demulsifiers was tested on water in oil emulsions (w/o) at different concentrations (250, 500 and 1000 ppm) and 90/10%, 70/30% and 50/50% water content. The results suggested that the prepared demulsifiers had high ability to reduce the surface and interfacial tensions and also broke successfully water in Basra crude oil emulsions. The demulsification efficiency of DVM reached 92 % after 120 min. and 500 ppm for crude oil/water emulsion (70/30 vol %).