Margellou Antigoni G, Psochia Eleni A, Torofias Stylianos A, Pappa Christina P, Triantafyllidis Konstantinos S
Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
ACS Sustain Resour Manag. 2024 Jun 18;1(7):1432-1443. doi: 10.1021/acssusresmgt.4c00093. eCollection 2024 Jul 25.
Sustainable production of bio-based materials and chemicals requires integrated approaches which utilize all fractions of lignocellulosic biomass. In this work, highly crystalline cellulose was isolated via combined pretreatment/fractionation and extraction processes from beechwood sawdust. The proposed approach was based on the selective recovery of hemicellulose components in the first step, followed by enhanced delignification in the second step, permitting the efficient recovery of the remaining cellulose via bleaching in the final step. Hydrothermal pretreatment under tailored conditions in neat water or dilute acid resulted in almost complete hemicellulose removal (80-96 wt %) in the liquid fraction. In the second step, the formed surface lignin was isolated via mild extraction while enhanced removal of both native/structural and surface lignin (71 wt %) was achieved by applying the organosolv treatment using dilute sulfuric acid as catalyst. Dilute sulfuric acid pretreatment followed by acid catalyzed organosolv pretreatment proved to be the most efficient combined approach, leading to 80 wt % hemicellulose removal as xylose monomer, and 71 wt % delignification. High crystallinity cellulose (<88%), with an overall cellulose recovery of 68-91 wt % based on native cellulose in parent biomass was isolated in the last step via bleaching of all pretreated biomass solids. The proposed integrated biorefinery procedures that aim to whole "waste" biomass valorization, replacing fossil resources, with the use of green solvents (water, ethanol) at relatively mild temperature/pressure conditions, are in line with the scope of several United Nations Sustainable Development Goals, such as UN SDG 8, 11, 12, and 13.
生物基材料和化学品的可持续生产需要采用综合方法，以利用木质纤维素生物质的所有组分。在这项工作中，通过联合预处理/分级分离和提取工艺从山毛榉木屑中分离出了高结晶度纤维素。所提出的方法基于第一步中半纤维素组分的选择性回收，随后在第二步中强化脱木质素，从而在最后一步通过漂白实现剩余纤维素的高效回收。在纯水或稀酸中在定制条件下进行水热预处理，可使液体馏分中的半纤维素几乎完全去除（80 - 96 wt%）。在第二步中，通过温和提取分离出形成的表面木质素，同时使用稀硫酸作为催化剂进行有机溶剂处理，可实现天然/结构木质素和表面木质素的强化去除（71 wt%）。事实证明，稀硫酸预处理后进行酸催化有机溶剂预处理是最有效的联合方法，可导致80 wt%的半纤维素以木糖单体形式去除，以及71 wt%的脱木质素。在最后一步，通过对所有预处理后的生物质固体进行漂白，分离出了高结晶度纤维素（<88%），基于原始生物质中的天然纤维素，纤维素的总回收率为68 - 91 wt%。所提出的旨在实现整个“废弃”生物质增值、替代化石资源，并在相对温和的温度/压力条件下使用绿色溶剂（水、乙醇）的综合生物炼制程序，符合联合国若干可持续发展目标的范畴，如联合国可持续发展目标8、11、12和13。
