Fig. 2From: Characterization of lignin derived from water-only and dilute acid flowthrough pretreatment of poplar wood at elevated temperaturesLignin removal and recovery as RSL and RISL. a Water-only and b 0.05 % (w/w) H2SO4 flowthrough pretreatment (temperature: 160–270 °C, time: 0–12 min, flowrate: 25 ml/min)Back to article page