Abstract

In the pursuit of sustainable biomass utilization, this study investigates the hydrothermal treatment of birchwood and its subsequent impact on enzymatic hydrolysis lignin (EHL). Additionally, birchwood undergoes processing with NaOH (4% w/w) within a Parr reactor to precipitate lignin from the black liquor, resulting in lignin-rich substrates (LRSs) which are then subject to thorough characterization. Notably, EHL produced after hydrothermal pretreatment at 190 °C exhibits the highest lignin content at 67%, while kraft lignin (KL) obtained at 140 °C (pH 1.5) produces 65% lignin content. Among these LRSs, the KL sample produced at 190 °C (pH 4) stands out, displaying a robust aromatic skeletal structure and an abundance of methoxyl groups, primarily owing to its high purity. Furthermore, for these LRSs' it is shown that chemical configuration influences their thermal behaviour, allowing the lignin to be tailored for diverse applications, from low melting point materials to carbonaceous materials capable of withstanding temperatures exceeding 700 °C. This comprehensive understanding of the chemical, thermal, and physical attributes of LRSs not only enriches our knowledge of lignin-rich substrates but also paves the way for the development of sustainable bio-based materials, marking a step towards sustainable materials development.

中文翻译：

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来自桦木的酶解木质素和硫酸盐木质素：功能性生物基材料的来源

摘要

为了追求可持续的生物质利用，本研究调查了桦木的水热处理及其对酶解木质素（EHL）的后续影响。此外，桦木在帕尔反应器中用 NaOH (4% w/w) 进行处理，以从黑液中沉淀出木质素，从而产生富含木质素的底物 (LRS)，然后对其进行彻底的表征。值得注意的是，在 190 °C 水热预处理后产生的 EHL 的木质素含量最高，为 67%，而在 140 °C (pH 1.5) 下获得的牛皮纸木质素 (KL) 产生的木质素含量为 65%。在这些 LRS 中，在 190 °C (pH 4) 下生产的 KL 样品脱颖而出，显示出强大的芳香​​族骨架结构和丰富的甲氧基，这主要是由于其高纯度。此外，对于这些 LRS，研究表明化学构型会影响其热行为，从而使木质素能够适应不同的应用，从低熔点材料到能够承受超过 700 °C 温度的碳质材料。对LRS化学、热和物理属性的全面了解不仅丰富了我们对富含木质素基质的认识，而且为可持续生物基材料的开发铺平了道路，标志着向可持续材料开发迈出了一步。