Study on synthesis and properties of novel bisphenyl sulphonate Gemini surfactant based on lignin for enhanced oil recovery

In this study, we successfully synthesized a new bisphenyl sulphonate Gemini surfactant (BPSG) from lignin using a simple method. And a comprehensive evaluation of the physicochemical properties of this BPSG surfactant was conducted, including surface activity, emulsification stability, salinity tolerance, static adsorption, and oil/water interfacial activity. Comparing the BPSG surfactant with commonly used single-chain surfactants like dodecylbenzene sulfonate (SDBS) and lignin sulphobetaine zwitterionic surfactant (LSBA), our results demonstrated that the BPSG surfactant exhibited higher surface activity and superior emulsification stability. Even at a NaCl concentration of 5.0 wt%, the oil-water emulsion prepared by BPSG surfactant remained stable. Furthermore, the BPSG surfactant displayed remarkable interfacial activities and resistance to salt. It effectively reduced the interfacial tension (IFT) between Huabei crude oil and brine to an ultra-low level of 10−3 mN/m without any additional additives. And the BPSG surfactant showed enhanced alkali synergy compared to common surfactants and maintained the ultra-low oil/water IFT across a wide range of salinity levels. The static adsorption experiments revealed that BPSG had significantly lower adsorption amount on the quartz sand compared to ordinary surfactants, allowing for the sustained achievement of ultra-low IFT during the adsorption process for up to four consecutive days.