A novel treatment denoted as the “Thermal-dissolution based carbon enrichment (TDCE)” was proposed in our previous work to effectively deoxygenate and de-ash biomass under mild conditions. The main reactions during this process occurred in a highly-dispersed and inert medium, thus its mechanism was unclear. In this study, cellulose was chosen as the model compound to investigate the underlying reaction mechanisms of TDCE process. It was confirmed that three distinct stages were involved in this process, which were physical dissolution stage, intramolecular deoxygenation and rearrangement stage, and stabilization stage. The deoxygenation attributed to the intramolecular dehydration at around 300 °C and the formations of CO₂ and CO through subsequent aromatization in liquid phase at around 350 °C. Around 67% and 19% of oxygen were removed by these two pathways, respectively. About 80% of carbon remained in the solid products in all conditions. A two-step process was verified for the aromatic substance formation: furan structure formation at the beginning and the subsequent conversion to benzene ring. Especially, unlike large molecular bio-char formation in conventional pyrolysis, small molecular aromatics were formed in TDCE process. Undoubtedly, the highly-dispersed and inert medium contributed to these intramolecular reactions and suppressed the intermolecular reactions, although it wasn’t involved in the chemical reactions. Hence, the unique reaction mechanism of biomass in a highly-dispersed medium was specified, providing theoretical guidance to the practical application of TDCE method.

在我们以前的工作中，提出了一种称为“基于热溶解的碳富集（TDCE）”的新颖处理方法，可以在温和条件下有效地对生物质进行脱氧和除灰。在此过程中，主要反应发生在高度分散的惰性介质中，因此其机理尚不清楚。在这项研究中，选择纤维素作为模型化合物来研究TDCE过程的潜在反应机理。证实了该过程涉及三个不同的阶段，即物理溶解阶段，分子内脱氧和重排阶段以及稳定阶段。脱氧归因于大约300°C的分子内脱水和CO ₂的形成然后在约350°C的液相中进行芳构化后生成一氧化碳和一氧化碳。通过这两个途径分别除去了大约67％和19％的氧气。在所有条件下，约80％的碳保留在固体产品中。验证了芳香族物质形成的两步过程：开始时形成呋喃结构，随后转化为苯环。特别是，与常规热解过程中形成大分子生物炭不同，在TDCE工艺中会形成小分子芳族化合物。毫无疑问，高度分散和惰性的介质虽然不参与化学反应，但却有助于这些分子内反应并抑制了分子​​间反应。因此，确定了生物质在高分散介质中独特的反应机理，