In this study, the depolymerization of naked oat stem cell wall and the dissolution of its chemical compositions during autohydrolysis in subcritical water (150−210 °C, 0.38–1.85 MPa) were investigated, to explore the potential of naked oat stems as raw materials for green biorefinery. Our results showed that the sequence of lignin removal was from parenchyma cells to sclerenchyma fibers in the tissues, and from the middle lamella to the inner side of the cell wall, and finally to the middle layer of the cell wall. The total lignin removal rate reached the highest value (47.7 %) at 190 °C, and by this time, the cell wall was depolymerized and the autohydrolysis residue was in the form of pulp. At 190 °C, the hemicellulose side chain was degraded by 100 %, and the ash was almost completely removed. When the reaction temperature was further increased to 210 °C, the removal rate of xylose was close to 100 %, and degradation of the cellulose crystal zone began. We found that in moderately subcritical water, all the chemical compositions of naked oat stem were expected to be dissolved in a controllable and orderly manner. Our findings will play a substantial role in solving the problem of lignocellulosic biomass composite cell wall resistance to depolymerization in a single green solvent.

在这项研究中，研究了在亚临界水（150-210°C，0.38-1.85 MPa）中自水解过程中裸燕麦干细胞壁的解聚及其化学成分的溶解，以探索裸燕麦茎作为原料的潜力用于绿色生物精炼。我们的结果表明，木质素去除的顺序是从组织中的薄壁组织细胞到厚壁组织纤维，从中间层到细胞壁的内侧，最后到细胞壁的中层。总木质素去除率在190℃时达到最高值（47.7%），此时细胞壁解聚，自水解残渣呈纸浆状。在190°C时，半纤维素侧链100%降解，灰分几乎完全去除。当反应温度进一步升高到210℃时，木糖去除率接近100%，纤维素晶区开始降解。我们发现，在中等亚临界水中，裸燕麦茎的所有化学成分都有望以可控和有序的方式溶解。我们的发现将在解决木质纤维素生物质复合细胞壁在单一绿色溶剂中抗解聚的问题方面发挥重要作用。