Fractionation of triticale, wheat, barley, oats, canola, and mustard straws for the production of carbohydrates and lignins

Five cereal (triticale, durum wheat, CPS wheat, feed barley, oats) and two oilseed (canola, mustard) straws were fractionated with pressurized low polarity water in a flow-through reactor at 165 °C with a flow rate of 115 mL/min and a solvent-to-solid ratio of 60 mL/g. The conversion and extraction of the major carbohydrates and lignin from the reactor system during hydrothermal treatment was largely completed within the first 20–30 min. Glucan content of all straws were enriched by the process. More than 90% of the xylan and nearly 50% of the lignin were extracted and there was no effect on yield due to crop species. However, there were differences in solid residue and liquid extract composition. Cereal crops yielded a residue richer in glucan and lower in lignin. Oilseed crop residues contained very low levels of ash. Xylo-oligosaccharides from oilseed crops contain more acetyl and uronic acid substituents.

► Seven straw species were fractionated with PLPW in a flow-through reactor.
► The hydrothermal reaction was completed after the first 20–30 min.
► Glucan content of all straw residues were enriched by the process.
► There was no effect on carbohydrate or lignin yield due to crop species.
► Xylo-oligosaccharides from oilseed crops contain more acetyl and uronic substituents.