Construction and demolition lignocellulosic wastes to bioethanol

This work deals with conversion of four construction and demolition (C&D) lignocellulosic wastes including OSB, chipboard, plywood, and wallpaper to ethanol by separate enzymatic hydrolysis and fermentation (SHF). Similar to other lignocelluloses, the wastes were resistant to the enzymatic hydrolysis, in which only up to 7% of their cellulose was hydrolyzed. Therefore, the lignocellulosic wastes were treated with phosphoric acid, sodium hydroxide, or N-methylmorpholine-N-oxide (NMMO), which resulted in improving the subsequent enzymatic hydrolysis to 38.2–94.6% of the theoretical yield. The best performance was obtained after pretreatment by concentrated phosphoric acid, followed by NMMO. The pretreated and hydrolyzed C&D wastes were then successfully fermented by baker’s yeast to ethanol with 70.5–84.2% of the theoretical yields. The results indicate the possibility of producing 160 ml ethanol from each kg of the C&D wastes at the best conditions.

► Construction and demolition (C&D) lignocellulosic wastes can be converted to bioethanol. ► The wastes are resistant to the enzymatic hydrolysis. ► The pretreatment by concentrated phosphoric acid can efficiently improve ethanol yields. ► The hydrolyzates were successfully fermented by baker’s yeast to ethanol. ► Each kg of the C&D wastes produced 160 ml ethanol.