Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
ChemSusChem. 2012 Aug;5(8):1449-54. doi: 10.1002/cssc.201100770. Epub 2012 Apr 5.
The use of cellulose is hampered by difficulties with breaking up the biopolymer into soluble products. Herein, we show that the impregnation of cellulosic substrates with catalytic amounts of a strong acid (e.g., H(2)SO(4), HCl) is a highly effective strategy for minimizing the contact problem commonly experienced in mechanically assisted, solid-state reactions. Milling the acid-impregnated cellulose fully converts the substrate into water-soluble oligosaccharides within 2 h. In aqueous solution, soluble products are easily hydrolyzed at 130 °C in 1 h, leading to 91 % conversion of the glucan fraction of α-cellulose into glucose, and 96 % of the xylans into xylose. Minor products are glucose dimers (8 %), 5-hydroxymethylfurfural (1 %) and furfural (4 %). Milling practical feedstocks (e.g., wood, sugarcane bagasse, and switchgrass) also results to water-soluble products (oligosaccharides and lignin fragments). The integrated approach (solid-state depolymerization in combination with liquid-phase hydrolysis) could well hold the key to a highly efficient "entry process" in biorefinery schemes.
纤维素的使用受到将生物聚合物分解成可溶性产物的困难的阻碍。在此，我们表明，用催化量的强酸（例如 H(2)SO(4)、HCl）浸渍纤维素底物是一种非常有效的策略，可以最小化机械辅助固态反应中常见的接触问题。将酸浸渍的纤维素完全研磨在 2 小时内将底物完全转化为水溶性低聚糖。在水溶液中，可溶性产物在 130°C 下在 1 小时内很容易水解，导致α-纤维素的葡聚糖部分转化为葡萄糖的转化率为 91%，木聚糖转化为木糖的转化率为 96%。少量产物为葡萄糖二聚体（8%）、5-羟甲基糠醛（1%）和糠醛（4%）。研磨实际的原料（例如木材、甘蔗渣和柳枝稷）也会得到水溶性产物（低聚糖和木质素片段）。这种综合方法（固态解聚与液相水解相结合）可能是生物精炼厂方案中高效“进入过程”的关键。
