Optimizing the Polyethylene Oxide and Polypropylene Oxide Contents in Diethylenetriamine-Based Surfactants for Destabilization of a Water-in-Oil Emulsion

Abstract

In this work, we used polyoxyalkylenated diethylenetriamine (DETA) demulsifier with various polyethylene oxide (PEO) and polypropylene oxide (PPO) contents to destabilize a stable waterin-oil emulsion. The demulsifiers were characterized by the relative solubility number (RSN). The efficiency of emulsion destabilization was measured by the degree of separation of the oil and water phases. It was found that the destabilization of an emulsion is closely correlated with the PO and EO numbers. When the PO number in a molecule is much greater than the EO number, the surfactant gives a very low oil resolution rate, requires high dosages, and produces a stable middle phase. When a surfactant contains more EO than PO, it gives a high oil resolution rate at a low dosage, but it is easily overdosed, and some surfactants of this type (high molecular weight) also produce a stable middle emulsion phase. When the PO and EO numbers in the surfactant are close to equal, the surfactant breaks the emulsion rapidly at a very low dosage, does not show overdosing at very high dosage, and does not produce a stable middle phase. Therefore, surfactants with balanced PO and EO numbers give optimal performance.

Effect of the structure of commercial poly(ethylene oxide-b-propylene oxide) demulsifier bases on the demulsification of water-in-crude oil emulsions: elucidation of the demulsification mechanism

“…The poly(propylene oxide) (PPO) segment is more lipophilic and mainly interacts with the organic phase. [26][27][28] The common bases used in the formulation of the commercial demulsifiers are polyoxyalkylated alkyl-phenolformaldehyde resins and polyoxyalkylated glycols. Other components, such as polyoxyalkylated epoxy resins, polyoxyalkylated amines, polyestereamines and sulfonic acid salts, can be used at lower concentrations.…”

Polyoxyalkylated diethylenetriamine polymeric surfactants: molecular structure effect on thin wetting films

“…The role of electrostatic disjoining pressure has been evidenced when comparing the curve for surfactant solutions without electrolyte added with two other h(C A ) curves which refer to surfactant aqueous solutions containing 5×10 −4 mol/ dm 3 NaCl or 10 −2 mol/dm 3 NaCl [7]. With NaCl concentration increase, h values decrease and at 10 −2 mol/dm 3 NaCl the maximum in the h(C A ) dependence completely disappears.…”

“…Various polymeric surfactants are used as demulsifiers, particularly the branch-type ones, e.g., star-like polymers, grafted polymers, dendritic polymers, etc. [3][4][5][6][7]. These demulsifiers have the ability to adhere to natural substances that stabilize the emulsions, e.g., organic materials such as asphaltenes, oil resins, and paraffins.…”

“…Emulsions stabilized by inorganic particles can be broken down by modifying particle wettability via adding oil-or water-soluble demulsifiers. The destabilization of emulsion/ dispersion by special surfactants is of theoretical and practical interest [1][2][3][4][5][6][7].…”

Demulsification efficiency of some novel styrene/maleic anhydride ester copolymers

“…It increases as this ratio increases up to unity, at which the oil resolution is the highest. 29 A decrease in the PPO/PEO ratio leads to an increase in the hydrophilic part in the demulsifier molecule, which increases the affinity of the molecule to the coil. This coiling may hinder the adsorption of the demulsifier molecules on the oil/water interface, and so the demulsification efficiency decreases.…”