Abstract The entrained-flow pressurized pyrolysis of lignin, cellulose, and xylan was investigated to determine the composition of pyrolysis products and the reaction mechanisms. The influence of biomass components (lignin, cellulose, and xylan) and pyrolysis conditions was investigated. The results showed that under atmospheric pressure, the decomposition of lignin formed saturated aliphatic hydrocarbons (SAHCs), phenolics, and PAHs, while cellulose and xylan mainly generated phenolics, sugars, carbonyls, alcohols, and PAHs. Increasing the pyrolysis pressure and temperature was found to drastically promote the generation of PAHs, accompanied by a decrease in phenolics, SAHCs, sugars, carbonyls, and SRAHCs. The ring growth via Diels-Alder cycloaddition reaction pathways in combination with hydrogen abstraction/C2H2 addition (HACA) was postulated to be the mechanism of the formation of PAHs. The 4-ring PAHs (pyrene, fluoranthene) and 3-ring PAHs (phenanthrene, fluorene) were found to dominate the lignin bio-oil, while the bio-oil from cellulose and xylan mainly contained 2-ring PAHs (naphthalene). Elevated pressures and temperatures were also found to significantly increase the selectivity of H2 in the bio-gas.

中文翻译：

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了解在加压夹带流条件下木质纤维素生物质组分热解过程中多芳烃的产量增加

摘要 对木质素、纤维素和木聚糖的夹带流加压热解进行了研究，以确定热解产物的组成和反应机理。研究了生物质成分（木质素、纤维素和木聚糖）和热解条件的影响。结果表明，在常压下，木质素分解生成饱和脂肪烃（SAHCs）、酚类和PAHs，而纤维素和木聚糖主要生成酚类、糖类、羰基类、醇类和PAHs。发现增加热解压力和温度会显着促进 PAH 的产生，同时酚类、SAHC、糖、羰基和 SRAHC 的减少。通过 Diels-Alder 环加成反应途径与夺氢/C2H2 加成 (HACA) 相结合的环生长被认为是 PAH 形成的机制。4-环多环芳烃（芘、荧蒽）和 3-环多环芳烃（菲、芴）被发现在木质素生物油中占主导地位，而来自纤维素和木聚糖的生物油主要包含 2-环多环芳烃（萘）。还发现升高的压力和温度会显着提高沼气中 H2 的选择性。