Influences of fractional separation on the structure and reactivity of wheat straw cellulose for producing 5-hydroxymethylfurfural

• Optimal solvothermal separation (GVL/H2O, 60% GVL, 205°C, 1.7 h) yields wheat straw cellulose with 89.4% purity and 86.7% recovery. • High fractional separation efficiency (purity × recovery) and low crystallinity of cellulose synergistically enhance HMF yield. • Drying of separated cellulose (heat or freeze) re-crystallizes it, reducing HMF yield; wet cellulose gives 58.6% HMF molar yield, 1.5× higher than microcrystalline cellulose. • The study underscores avoiding drying steps in cellulose biorefinery to maintain reactivity for HMF production.