Effects of SDBS and BS-12 on functional groups/wettability of multicomponent acidified lignite

Abstract

In order to explore the influence mechanism of different surfactants on the wettability of coal samples acidified with multi-component acid solutions, the effects of multi-component acid solutions and surfactant composite acid solutions on the functional groups and microcrystalline structures of coal samples were studied. In this paper, a multicomponent acid solution consisting of sodium dodecyl benzene sulfonate (SDBS), dodecyl dimethyl betaine (BS-12), hydrofluoric acid (HF), and citric acid (C6H8O7) was used to acidification and contact angle experiments on coal samples. Fourier transform infrared spectroscopy (FTIR) results show that acidification can promote the formation of CO and CO, and the synergistic effect of surfactant BS-12 on multi-component acid solution is more prominent. X-ray diffraction (XRD) results show that the variation trend of aromatic lamellar diameter La of coal samples is consistent with the aromatic layer spacing d002. Surfactants can slow down the damage of multi-component acid solution to the microcrystalline structure of coal samples. The change of contact angle shows that the instantaneous synergistic wetting effect of BS-12 is better than that of SDBS. At the same time, molecular dynamics simulation technology was used to verify the effect of surfactants on the wettability of multi-component acid solutions. Therefore, this study provides a feasible method and theoretical guidance for improving the efficiency of coal production and utilization through chemical means.