Optimization of furfural production from d-xylose with formic acid as catalyst in a reactive extraction system

► The reactive extraction has been accepted as a prospective method for furfural production. ► The high boiling solvent, o-nitrotoluene, was recommended as extraction solvent. ► Formic acid, compared to mineral acids, has lower-corrosive and cleaner production properties. ► The statistical models established by RSM can predict the yield and selectivity of furfural. ► The use of halides in aqueous solutions enhances the furfural yield and selectivity.