Structural features and changes of lignocellulosic biomass during thermochemical pretreatments: A synchrotron X-ray scattering study on photoperiod-sensitive sorghum

► WAXD and SAXS were used to study biomass structural changes during various pretreatments. ► The outside rind had oriented crystal peaks. ► The crystalline structures of the inner pith and leaf were less ordered. ► A smooth pore-boundary surface structure of cellulose was noted by SAXS results after acid pretreatment. ► Alkali pretreatment transformed part of cellulose to a more stable form and increased the crystal size.