Cellulose, hemicellulose, and lignin constitute the basic components of biomass. Knowledge of the interactions between cellulose and lignin during pyrolysis is crucial for unraveling the pyrolysis characteristics of biomass. In this study, for the co-pyrolysis of cellulose and lignin to produce biochar, three influencing factors were selected: pyrolysis temperature (400–800 °C), residence time (5–30 min), and lignin percentage (0–100 %). Pyrolysis experiments were conducted in a vertical tube furnace and the impact of these three factors on the characteristics of biochar was comprehensively explored employing response surface methodology. The results revealed obvious differences between actual values and theoretical values. Specifically, the results showed that the interaction between cellulose and lignin increased the biochar yield, oxygen content, volatile content, and ash content by 6.14 %, 22.85 %, 30.95 %, and 46.75 %, respectively. In contrast, the carbon content, fixed carbon content, and HHV of biochar were relatively reduced by 9.38 %, 11.80 %, and 3.3 %, respectively. Furthermore, Raman spectra of biochar showed that the actual value of graphitization degree of biochar was higher than the theoretical value. This was further corroborated by XPS analysis, wherein owing to the interactions between cellulose and lignin, the actual C-C bond content decreased in contrast to the theoretical value. However, the contents of C-O, CO, COOH functional groups, and aromatic rings increased. Finally, the summary of the co-pyrolysis rules of cellulose and lignin provided a reference for optimal pyrolysis conditions and understanding the mechanism of co-pyrolysis.

中文翻译：

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纤维素和木质素的共热解：使用响应面法研究热解温度、停留时间和木质素百分比对生物炭性能的影响


纤维素、半纤维素和木质素构成生物质的基本成分。了解热解过程中纤维素和木质素之间的相互作用对于揭示生物质的热解特性至关重要。在本研究中，对于纤维素和木质素共热解生产生物炭，选择了三个影响因素：热解温度（400-800℃）、停留时间（5-30min）和木质素百分比（0-100％） ）。在立式管式炉中进行热解实验，采用响应面法综合探讨这三个因素对生物炭特性的影响。结果显示实际值与理论值存在明显差异。具体来说，结果表明，纤维素和木质素之间的相互作用使生物炭产量、氧含量、挥发分含量和灰分含量分别增加了6.14%、22.85%、30.95%和46.75%。相比之下，生物炭的碳含量、固定碳含量和HHV分别相对降低了9.38%、11.80%和3.3%。此外，生物炭的拉曼光谱表明，生物炭石墨化度的实际值高于理论值。 XPS分析进一步证实了这一点，其中由于纤维素和木质素之间的相互作用，实际C-C键含量与理论值相比有所下降。然而，C-O、CO、COOH官能团和芳香环的含量增加。最后总结了纤维素和木质素的共热解规律，为优化热解条件和理解共热解机理提供了参考。