Comparative analysis of natural and synthetic surfactant adsorption by quartz minerals: an experimental study

The efficacy of surfactant flooding for enhanced oil recovery (EOR) can be considerably diminished by the adsorption of surfactant on reservoir rocks. The primary purpose of this study is to assess the equilibrium adsorption behavior of natural (Ziziphus Spina-Christi, ZSC) and to compare with that of synthetic (Sodium Dodecyl Sulfate, SDS) surfactants onto sandstone (quartz) minerals, which has been rarely reported in the available literature. Such a systematic investigation is beneficial for selecting a proper surfactant in EOR applications. For this purpose, electrical conductivity (EC), ultraviolet-visible spectrophotometry (UV-Vis), and Fourier transform infrared (FTIR) techniques were employed to measure the adsorption of surfactant on quartz minerals. From the results of this study, it can be pointed out that the maximum adsorption of SDS and ZCS on quartz minerals is approximately 3 mg/g and 25 mg/g, respectively. The adsorption rate of both surfactants increased with increasing surfactant concentration up to the critical micelle concentration (CMC). The Langmuir, Freundlich, and Temkin isotherm models were used to predict the experimental data. Based on the experimental findings, the Langmuir isotherm provides a good fit to the experimental data, with coefficients of determination (R²) of 0.9917 for ZSC and 0.9858 for SDS.