LaVallie Audrey L, Bilek Honza, Andrianova Anastasia, Furey Kathryn, Voeller Keith, Yao Bin, Kozliak Evguenii, Kubátová Alena
Department of Chemistry, University of North Dakota, 151 Cornell St. Grand Forks, ND 58202, USA.
Department of Chemistry, University of North Dakota, 151 Cornell St. Grand Forks, ND 58202, USA; PREOL, a.s. Terezínská 1214, 410 02 Lovosice, Czech Republic.
Bioresour Technol. 2021 Dec;342:125974. doi: 10.1016/j.biortech.2021.125974. Epub 2021 Sep 20.
The objective of the study was to investigate alkali lignin polymerization/depolymerization pathways in subcritical water (SW) without additives. Following a SW treatment at 200, 250, 275 and 300 °C, the products were subjected to a comprehensive suite of analyses addressing the product speciation and molecular weight (MW) distribution. The MW reduction (1.4 times) in the solid products following the SW treatment indicated a surprisingly reduced impact of cross-linking/repolymerization at 300 °C and lower temperatures. This was further confirmed by thermal carbon analysis (TCA) showing a reduction in pyrolytic charring after the SW treatment. The TD-Py gas chromatography analysis of the SW treated lignin indicated that the solid residue is less oxygenated than the initial lignin (23 vs. 29% as confirmed by elemental analysis). Thus, deoxygenation rather than re-polymerization appears to be the main process route in the absence of catalysts within the temperature range considered.
该研究的目的是调查在无添加剂的亚临界水（SW）中碱木质素的聚合/解聚途径。在200、250、275和300°C下进行SW处理后，对产物进行了一系列全面分析，以确定产物形态和分子量（MW）分布。SW处理后固体产物的分子量降低（1.4倍）表明，在300°C及更低温度下，交联/再聚合的影响出人意料地降低。热碳分析（TCA）进一步证实了这一点，该分析表明SW处理后热解炭化减少。对经SW处理的木质素进行的热脱附-热解气相色谱分析表明，固体残留物的氧化程度低于初始木质素（元素分析证实分别为23%和29%）。因此，在所考虑的温度范围内，在无催化剂的情况下，脱氧而非再聚合似乎是主要的工艺路线。
