Effect of Organic Alkalis on Interfacial Tensions of Surfactant/Polymer Solutions against Hydrocarbons

Abstract

The dynamic interfacial tensions (IFTs) of enhanced oil recovery (EOR) surfactant/polymer/organic alkali systems against a homologous series of alkanes have been investigated by a spinning drop interfacial tensiometer. Two organic alkalis with different molecular sizes, ethanolamine (EA) and diethanolamine (DEA), two surfactants with high interfacial activity, heavy alkyl benzenesulfonate (HABS) and petroleum sulfonate (SLPS), and two kinds of polymers, partly hydrolyzed polyacrylamide (HPAM) and hydrophobically modified polyacrylamide (HMPAM), were employed to study the real mechanisms controlling the IFT behavior. The experimental results show that the addition of organic alkali may affect the dynamic IFTs of surfactant solutions through different mechanisms. First, the possible reaction of organic alkali with the oil-soluble components in industrial surfactants will influence the surface active spices at the interface and enhance the dynamic behavior. Second, the hydrophilic–lipophilic balance (HLB) of the surfactant may vary, and the surfactant may become more water-soluble because of the ionization of oil-soluble components, especially for HABS. Finally, the organic counterion with larger molecular sizes may affect the arrangement of interfacial surfactant molecules. For both HABS and SLPS surfactants, interfacial interactions between the hydrophobic part of surfactants and the hydrophobic blocks of HMPAM will reduce the interfacial concentration of surfactant monomers by forming aggregates and result in an obvious increment of the IFT value. On the other hand, HPAM will obviously enhance the water solubility of the surfactant/organic alkali solutions and reduce the IFT values for the hydrocarbons with lower alkyl carbon number (ACN).

Synergistic Effect of Brine System Containing Mixed Monovalent (NaCl, KCl) and Divalent (MgCl2, MgSO4) Salts on the Interfacial Tension of Pure Hydrocarbon–Brine System Relevant for Low Salinity Water Flooding

“…The IFT trend obtained in the present study for hydrocarbon−brine system is also analogous to the hydrocarbon−brine system that contains petroleum sulfonate. 47 It was observed that the relative decrease in IFT with respect to 0 ppm salt concentration for n-heptane−brine system is more than that of toluene−brine system for mixed monovalent and divalent brine system. The impact of composition of salt on the IFT of n-heptane−brine system and toluene−brine system was the same and of the order B9 > B8 > B7.…”

Performance and Biomass Characteristics of SBRs Treating High-Salinity Wastewater at Presence of Anionic Surfactants

“…The comparison of Figure 1a,d showed that that the concentration of NO 3 − -N is the highest, while the removal rate of NH 4 + -N is the lowest, in the presence of SDS. It was found that the activated sludge in SBRs was affected not only by surfactants [23,33], but also by high salinity [20,26,34]. High salinity has a strong inhibition effect on sludge activity [18], but the interaction between surfactant and salt weakens the inhibition of salt on the activated sludge.…”

“…When the dosage of SDBS is 0.02 g/g dry sludge, the activity of amylase and proteinase is the best [25]. Moreover, the interaction between salt and surfactant can affect the interfacial tension of the surfactant [26], thus affecting the sludge activity. However, the role of surfactant on the activated sludge system is still unclear, especially under the high salt conditions.…”

The effect of NaOH on lowering interfacial tension of oil/alkylbenzene sulfonates solution

“…For example, the concentration of ABS itself, temperature, concentration of electrolytes in solution, [8][9][10][11] organic bases, 12,13 and so on can affect the reduction of IFT. Specically, the ABS structure is the most complex factor.…”