Fig. 3From: A comparison of various lignin-extraction methods to enhance the accessibility and ease of enzymatic hydrolysis of the cellulosic component of steam-pretreated poplarLignin removal and cellulose recovery resulting from deep eutectic solvent (DES) extraction of steam-pretreated poplar (SP2). Poplar wood was steam pretreated at 190 °C for 9.9 (SP2) and then subjected to DES extraction at varying temperatures of a 130 °C, b 160 °C, c 190 °C and residence times of 1.5–6 hBack to article page