The synergistic mechanism of nitrogen-containing chemicals (NCCs) production was explored from the co-pyrolysis of corn cob and the three major biomass components (cellulose, xylan, and lignin) with urea. Compared to individual pyrolysis, the stability of co-pyrolysis oil was significantly enhanced. The three components showed a synergistic effect during co-pyrolysis. The phenolic compounds generated from lignin interacted with the pyran compounds produced from cellulose or xylan. Especially in the presence of urea, this cross-reaction enhanced the formation of nitrogen-containing heterocycles (NHCs). At 500 ℃, the highest yield of NCCs was observed in the co-pyrolysis oil of corn cob and urea, reaching 47.6 wt%. The NHCs exhibited a selectivity of up to 96.9 wt%. The high concentration of urea promoted the pyrolysis of hemicellulose and cellulose, inhibiting the reaction between cellulose-derived products and free amines to form amines. FT-IR analysis of the char revealed that the addition of urea promoted the decomposition of corn cob, enhancing C–H bond breakdown and dehydrogenation reactions. Finally, a potential formation mechanism for the primary NHCs during the co-pyrolysis of corn cob and urea was proposed. The findings of this paper provide theoretical support for the production of NCCs from biomass through the synergistic interaction of its three components.

中文翻译：

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3组分富氮热解的协同效应及氮转化机理


从玉米芯和三种主要生物质成分（纤维素、木聚糖和木质素）与尿素的共热解中探索了含氮化学品 （NCC） 生产的协同机制。与单独的热解相比，共热解油的稳定性显着增强。这三种组分在共热解过程中表现出协同作用。木质素生成的酚类化合物与纤维素或木聚糖生成的吡喃化合物相互作用。特别是在尿素存在下，这种交叉反应促进了含氮杂环 （NHC） 的形成。在 500 °C 时，玉米芯和尿素的共热解油中观察到 NCCs 的产率最高，达到 47.6 wt%。NHC 表现出高达 96.9 wt% 的选择性。高浓度的尿素促进了半纤维素和纤维素的热解，抑制了纤维素衍生产物与游离胺的反应生成胺。焦炭的 FT-IR 分析表明，尿素的添加促进了玉米芯的分解，增强了 C-H 键的分解和脱氢反应。最后，提出了玉米芯和尿素共热解过程中原生NHCs的潜在形成机制。本文的研究结果为通过其 3 种组分的协同相互作用从生物质生产 NCCs 提供了理论支持。