催化学报 ›› 2025, Vol. 71: 25-53.DOI: 10.1016/S1872-2067(24)60248-2

• 综述 • 上一篇    下一篇

胡敏素形成机理、抑制策略和增值应用方面的研究进展

王毅同a,1, 张超锋b,1, 蔡诚a,*(), 黄曹兴b, 沈晓骏c, 楼宏铭d, 胡常伟e, 潘学军f, 王峰g,*(), 谢君a,*()   

  1. a华南农业大学生物质工程研究院, 广东省农林生物质能源工程技术研究中心能源植物资源与利用重点实验室, 广东广州 510642, 中国
    b南京林业大学轻工与食品工程学院, 江苏省森林资源高效加工利用协同创新中心, 江苏南京 210037, 中国
    c北京林业大学森林资源高效生产国家重点实验室, 北京 100083, 中国
    d华南理工大学化学与化学工程学院, 广东省绿色化工产品技术重点实验室, 广东广州 510641, 中国
    e四川大学化学学院绿色化学与技术教育部重点实验室, 四川成都 610065, 中国
    f威斯康星大学麦迪逊分校生物系统工程系, 威斯康星, 美国
    g中国科学院大连化学物理研究所催化国家重点实验室, 大连清洁能源国家实验室, 辽宁大连 116023, 中国
  • 收稿日期:2024-12-18 接受日期:2025-02-08 出版日期:2025-04-18 发布日期:2025-04-13
  • 通讯作者: * 电子信箱: wangfeng@dicp.ac.cn (王峰), chengcai@scau.edu.cn (蔡诚), xiejun@scau.edu.cn (谢君).
  • 作者简介:

    1共同第一作者.

  • 基金资助:
    国家重点研发计划(2021YFC2101602);国家自然科学基金(22378150);国家自然科学基金(32471809);广州市科学技术协会青年人才支持项目(QT2024-009);南京林业大学高层次人才引进研究基金(163105164);江苏省自然科学基金(BK20220106)

Advances in humins formation mechanism, inhibition strategies, and value-added applications

Yitong Wanga,1, Chaofeng Zhangb,1, Cheng Caia,*(), Caoxing Huangb, Xiaojun Shenc, Hongming Loud, Changwei Hue, Xuejun Panf, Feng Wangg,*(), Jun Xiea,*()   

  1. aKey Laboratory of Energy Plants Resource and Utilization, Guangdong Engineering Technology Research Center for Agricultural and Forestry Biomass, Institute of Biomass Engineering, South China Agricultural University, Guangzhou 510642, Guangdong, China
    bJiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing 210037, Jiangsu, China
    cState Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing 100083, China
    dSchool of Chemistry and Chemical Engineering, Guangdong Provincial Key Lab of Green Chemical Product Technology, South China University of Technology, Guangzhou 510641, Guangdong, China
    eKey Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610065, Sichuan, China
    fDepartment of Biological Systems Engineering, University of Wisconsin-Madison, 460 Henry Mall, Madison, WI, 53706, USA
    gState Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China
  • Received:2024-12-18 Accepted:2025-02-08 Online:2025-04-18 Published:2025-04-13
  • Contact: * E-mail: wangfeng@dicp.ac.cn (F. Wang), chengcai@scau.edu.cn (C. Cai),xiejun@scau.edu.cn (J. Xie).
  • About author:Cheng Cai graduated from the School of Chemistry and Chemical Engineering, South China University of Technology in 2020, and carried out postdoctoral work at the Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China in 2021. Now he is working in the Institute of Biomass Engineering, South China Agricultural University. His main interests include chemical catalytic conversion of lignocellulose, immobilization of enzyme, preparation and application of lignin and cellulosic materials.
    Feng Wang received his PhD degree from the Dalian Institute of Chemical Physics, Chinese Academy of Sciences in 2005, and went to the University of California, Berkeley, USA for postdoctoral work in the same year. He is currently the Deputy Director of Dalian Institute of Chemical Physics, Chinese Academy of Sciences. His research interests include multiphase catalytic reactions, catalytic conversion of biomass, photocatalytic conversion, life cycle assessment and economic and technology assessment.
    Jun Xie graduated from the College of Life Sciences of Sichuan University in 2001 with a Doctor of Science degree, and joined South China Agricultural University (SCAU) in August 2003 as a professor and supervisor of doctoral students. He is currently the Director of the Institute of Biomass Engineering, South China Agricultural University. His main research areas are catalytic conversion of biomass energy, efficient energy and medicinal plant resources and utilization, and preparation and application of small molecule collagen peptides.

    1Contributed to this work equally.

  • Supported by:
    National Key Research and Development Program of China(2021YFC2101602);National Natural Science Foundation of China(22378150);National Natural Science Foundation of China(32471809);Young Talent Support Project of Guangzhou Association for Science and Technology(QT2024-009);Research Fund for High-level Talents Introduction of Nanjing Forestry University(163105164);Natural Science Foundation of Jiangsu Province(BK20220106)

摘要:

木质纤维素生物质精炼是实现可再生资源高效利用的重要途径. 然而, 胡敏素在木质纤维素预处理和催化转化过程中的形成不仅导致了碳资源浪费, 还会引起反应器管道堵塞、化剂失活以及产品分离困难等问题, 严重影响生物质精炼的效率和经济性. 因此, 深入探究胡敏素的生成机制, 开发高效的抑制策略, 并探索其高值化利用途径, 对于提高生物质精炼过程的原子经济性和生产安全性具有重要意义. 本文围绕胡敏素的结构与生成机制, 系统总结了纤维素与半纤维素在精炼过程中经中间体随机缩合形成胡敏素的详细路径, 分析多因素对其形成的影响, 提出抑制策略, 并探讨其高值化应用途径, 旨在为胡敏素化学研究提供理论指导.
基于胡敏素的结构特征和形成机制差异, 本文从木质纤维素三组分转化角度将胡敏素的形成机制分为纤维素衍生路径、纤维素衍生路径和木质素参与的反应路径. 在纤维素衍生路径中, 纤维素水解生成葡萄糖, 进一步异构化为果糖并脱水形成5-羟甲基糠醛(HMF), 其分子间通过缩醛化、醚化反应以及衍生物之间的酯化和醛醇缩合反应, 逐步缩合形成胡敏素骨架. 在半纤维素衍生路径中, 木糖脱水生成糠醛(FF)及其后续转化是形成胡敏素的主要途径, 具体表现为FF分子间的亲电取代反应、FF衍生物之间的醇醛缩合反应以及FF与其氧化产物之间的酯化反应. 此外, 当原料含木质素时, 其降解产生的小分子片段可通过接枝作用嵌入胡敏素结构, 形成杂化组分. 胡敏素的形成受多重因素影响: 生物质原料的等级与类型作为本质因素, 直接影响胡敏素的结构与形成路径差异; pH值、温度和反应时间等工艺参数通过改变中间体稳定性影响缩合反应进程; 催化剂与添加剂的种类及性质可选择性抑制副反应路径. 针对上述机制, 本文提出了侧重于溶剂体系和催化剂系统的胡敏素有效抑制策略. 在溶剂体系方面, 采用多相溶剂系统可构建高效催化微环境, 通过稳定中间体、促进产物及时分离及保护反应基团减少缩合; 在催化剂设计方面, 通过调控孔径结构、活性位点分布及功能化修饰, 可提升目标反应选择性. 此外, 开发胡敏素定向转化技术是实现其高值化利用, 降低碳资源损失的关键. 例如, 将胡敏素液化/热解转化为小分子芳烃可作为燃料替代品, 解聚生成呋喃化合物可用于医药中间体合成; 同时, 以其为碳源制备合成树脂、自交联泡沫、多孔催化剂或功能碳材料, 可拓展其在材料领域的应用价值.
综上所述, 本文系统解析了胡敏素的多路径形成机制, 提出了针对性的抑制策略及增值利用的最新见解, 为生物质精炼领域催化剂的定向设计开发、艺优化和副产物增值提供了理论参考, 有望推动生物质基化学品的绿色、济和高效生产.

关键词: 胡敏素, 木质纤维素, 生物质精炼, 生物质转化, 伪木质素

Abstract:

Humins, as a group of by-products formed through the condensation and coupling of fragment intermediates during lignocellulosic biomass refining, can cause numerous negative effects such as the wastage of carbon resources, clogging of reactor piping, deactivation of catalyst, and barriers to product separation. Elucidating the generation mechanism of humins, developing efficient inhibitors, and even utilizing them as a resource, both from the perspective of atom economy and safe production, constitutes a research endeavor replete with challenges and opportunities. Orbiting the critical issue of humins structure and its generation mechanism from cellulose and hemicellulose resources, the random condensation between intermediates such as 5-hydroxymethylfurfural, furfural, 2,5-dioxo-6-hydroxyhexanal, and 1,2,4-benzenetriol etc. were systematically summarized. Additionally, the presence of lignin in real biorefining processes further promotes the formation of a special type of humins known as "pseudo-lignin". The influences of various factors, including raw materials, reaction temperature and time, acid-base environment, as well as solvent systems and catalysts, on the formation of humins were comprehensively analyzed. To minimize the formation of humins, the design of efficient solvent systems and catalysts is crucial. Furthermore, this review investigates the approaches to value-added applications of humins. The corresponding summary could provide guidance for the development of the humins chemistry.

Key words: Humins, Lignocellulosic, Biomass refining, Biomass conversion, Pseudo-lignin