Temperature-Programmed Alkaline Thermal Treatment of Lignocellulosic Biomass to Produce Fractionated Hydrogen with High Production Capacity
Guojie Liu, Houfang Lu, Xingyu Gong, Kejing Wu, Guoqing Guan, Bin Liang
Abstract
H 2 production is severely limited by inefficient conversion of feedstock, inevitable char formation, and methanation reactions aggravated by the slow heating rate during conventional alkaline thermal treatment (ATT) of biomass. Herein, a temperature-programmed alkaline thermal treatment (TP-ATT) incorporating dehydrogenation below 250 °C and rapid alkalinization at 600 °C is developed to produce fractionated H 2 with a high production capacity of 46.06 mmol·g –1 of cellulose. The H 2 produced via NaOH-promoted dehydrogenation exhibits a high purity of 98%. Optimized TP-ATT achieves complete conversions of cellulose and hemicellulose, and the H 2 productions are 46, 24, and 89% higher than those of conventional ATT from cellulose, hemicellulose, and lignin, respectively. Fast heating and steam-promoted alkalinization reactions are essential for the efficient conversion of char with high H 2 production. TP-ATT of cellulose realizes a 98.14% energy recovery of both H 2 and CH 4 . The TP-ATT technology is applicable to different real biomass with approximately 43% higher H 2 production than conventional ATT.