Synergistic effects of surfactant-assisted ionic liquid pretreatment rice straw

[Display omitted] •Surfactants-assisted ionic liquid pretreatment rice straw in a single system.•Surfactant increased lignin removal by 32.53% compared with IL-only pretreatment.•High total reducing sugar yield was obtained with IL+1% SDS-pretreated rice straw.•IL+1% SDS-pretreated rice straw exhibited lower cellulose crystallinity. The aim of this work was to study an environmentally friendly method for pretreating rice straw by using 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) as an ionic liquid (IL) assisted by surfactants. Different temperatures, reaction times, and surfactant concentrations were studied. Compared with [BMIM]Cl only pretreatment, the addition of 1% sodium dodecyl sulfate (SDS) and 1% cetyl trimethyl ammonium bromide (CTAB) increased lignin removal to 49.48% and 34.76%, respectively. Untreated and pretreated rice straw was thoroughly characterized through FTIR, XRD, and FE-SEM. Cellulose crystallinity and surface morphology of the rice straw were substantially altered after surfactant-assisted IL pretreatment. In conclusion, surfactant-assisted IL pretreatment is an effective method for producing fermentable sugars from lignocellulosic substrates.