Full fractionation of cellulose, hemicellulose, and lignin in pith-leaf containing corn stover by one-step treatment using aqueous formic acid

•Pith and leaf containing corn stover was fractionated in aqueous formic acid system.•Paper made from fractionation residue showed comparable strength to conventional paper.•Xylose yield reached 11.2 % on the weight basis of untreated rind and pith.•Lignin showed less aliphatic hydroxy groups by 37.9 %–46.6 than conventional technical lignins. Corn stover is collectable byproduct of grain production in agriculture. In this work, pith and leaf containing corn stover was fractionated into cellulose fibers, sugars, and lignin with remarkable yields of 38.9 %, 5.2 % and 25.4 %, respectively by one-step treatment using 85.0 % aqueous formic acid (FA) at conditions of 130 °C for 30 min. Paper sheet was prepared using the obtained cellulose fibers and showed excellent physical strength in terms of tensile index of 50.1 N·m/g, burst index of 3.0 kPa·m2/g and tear index of 6.1 mN·m2/g, comparable to the paper sheet made of conventional alkaline pulp. The obtained sugars contain 61 % of xylose, 17 % of glucose, 15 % of arabinose, 6 % of galactose and 1 % of mannose. The obtained water-insoluble lignin showed less aliphatic hydroxy groups by 37.9 %–46.6% than conventional technical lignins. This property is helpful to the lignin valorization in biodegradable polymer industry as interface-compatible fillers.