Upgrading the Properties of the Crude Oil-Water System for EOR with Simultaneous Effects of a Homologous Series of NanoGemini Surface-Active Ionic Liquids, Electrolytes, and pH

Effective Synergistic Action of Benzimidazolium Nano Gemini Ionic Liquid and Conventional Surfactant for Chemical Enhanced Oil Recovery

Blends of newly developed Gemini surface-active ionic liquids (GSAILs) and conventional surfactants offer significant enhancements to the interfacial properties between crude oil and water, providing economic benefits in chemically enhanced oil recovery. In this study, the mixtures of a benzimidazolium cationic GSAIL, [C4benzim-C6-benzimC4][Br2], and sodium dodecyl benzenesulfonate (SDBS) were successfully utilized for improving crude oil-water interfacial properties. The research revealed synergistic effects of up to 99.6% in reducing interfacial tension (IFT), achieving a low IFT value of 0.04 mN m-1 corresponding to an optimal GSAIL mole fraction of 0.2 for the mixture of surfactants. Additionally, significant synergies of 53.4 and 74% were observed in oil-water emulsification and in surface wettability when using a GSAIL mole fraction of 0.2. These results showcase the importance of the dominant interaction between the opposite-charged surfactants. The Frumkin isotherm and the Rosen model were employed for the theoretical study of adsorption behavior of individual surfactants and their mixture at the interface, demonstrating reasonable parameter variations. The overall findings emphasize the potential of utilizing these unique blends to enhance oil recovery processes through tailored interfacial properties.

A comparative study on the design and application of new nano benzimidazolium gemini ionic liquids for curing interfacial properties of the crude oil-water system

Gemini surface active ionic liquids (GSAILs) are considered a new prosperous class of ionic liquids and recognized as high performance materials. The present study explores the capabilities of the newly synthesized GSAILs, constructed from two benzimidazole rings attached via a four or a six carbon spacer, namely [C₄benzim-C_n-benzimC₄][Br₂], n = 4 and 6. The products were characterized with FT-IR, NMR, XRD, TGA, DTG and SEM methods and were used in curing interfacial properties of the crude oil-water system. The interfacial tension (IFT) was reduced to about 64 and 71% under critical micelle concentrations (CMCs) of 0.028 and 0.025 mol dm^-3 at 298.2 K for n = 4 and 6 GSAILs, respectively. Temperature significantly assisted this effect. Both the GSAILs could transfer the wettability of the solid surface from oil-wet to water-wet. Further, stable oil/water emulsions were produced, having emulsion indices of 74.2 and 77.3% for n = 4 and 6 GSAILs, respectively. Compared to homologous imidazolium GSAILs, the benzimidazolium products revealed better performance in the sense of exhibiting desired effects on the investigated interfacial properties. These can be attributed to the stronger hydrophobicity of the benzimidazolium rings as well as better spreading of the molecular charges. The Frumkin isotherm could exactly reproduce the IFT data, leading to precise determination of the important adsorption and thermodynamic parameters.