生物质焦利用过程中碳的转化水平决定后续利用的总体效率，而生物质焦的转化率一定程度上取决于生物质的理化结构。为探究稻壳高温快速热解过程中焦结构的演变，设计并搭建了稻壳高温快速热解系统。通过对稻壳热解停留时间和温度进行精确的控制，精确控制反应进程。以扫描电子显微镜、拉曼光谱、比表面积分析、傅里叶红外光谱等测量手段对所得稻壳焦的物理化学结构进行了表征。研究不同热解温度和停留时间下稻壳焦的产率、孔隙的种类与发展、化学官能团和碳结构的变化。结果表明，热解温度越高，停留时间越长，生物质焦产率越低，焦表面碎裂越明显，孔隙结构越发达。在热解温度为1300 ℃、停留13 s时，稻壳焦比表面积最大为141.17 m²/g，孔径主要分布在2～10 nm，表面出现明显碎裂痕迹。热解温度升高和停留时间延长，使得稻壳焦的化学结构变得越来越脱氧，碳结构高度有序化，稻壳焦中具有6个及以上稠合苯环的芳环浓度增加。高温对稻壳焦中C—O键、—OH破坏明显，导致支链和桥键断裂，含氧官能团释放和碳骨架石墨化。表面碳元素主要是以C—C/C—H为主，停留时间5 s时含量从900 ℃的63.86%增加到1 300 ℃的68.27%。而C—H、C—O、C=O和COO—含量均有不同程度的降低。表面氧元素主要以COO和COOH为主。随着热解温度升高，稻壳焦中苯环数量逐渐减少，芳香环平均数增加，表面亚甲基数量减少，碳活性降低。总结稻壳焦结构演化规律将为优化热解条件、提高热解效率及后续稻壳焦燃烧和气化利用提供参考。

The conversion level of carbon in the process of biomass char utilization determines the overall efficiency of subsequent utilization, while the conversion rate of biomass char depends to a certain extent on the physical and chemical structure of biomass. In order to explore the evolution of char structure during high-temperature rapid pyrolysis of rice husk, a high-temperature rapid pyrolysis system of rice husk was designed and built. Through the accurate control of the residence time and temperature of rice husk pyrolysis, the reaction process can be accurately controlled. The physical and chemical structure of rice husk char was characterized by scanning electron microscope, Raman spectroscopy, specific surface area analysis and Fourier transform infrared spectroscopy. The yield of rice husk char, the type and development of pores, the changes of chemical functional groups and carbon structure under different pyrolysis temperatures and residence times were studied. The results were analyzed to obtain the trends of yield, pore types and development, chemical functional groups, and carbon structure of rice husk char at different pyrolysis temperatures and residence times. When the pyrolysis temperature is 1 300 ℃ and residence time is 13 s, the maximum specific surface area of rice husk char is 141.17 m²/g, the pore size is mainly distributed between 2−10 nm, and the surface structure is obviously broken. With the increase of pyrolysis temperature and residence time, the chemical structure of rice husk char becomes more and more deoxidized. The long residence time drives the highly ordered char structure of rice husk char and the concentration of aromatic rings with six or more dense benzene rings in rice husk char increases. High temperature significantly damaged the C—O bond and —OH bond in rice husk char, resulting in the breaking of the branch chain and bridge bond, release of oxygen-containing functional groups and graphitization of the carbon skeleton. The surface carbon elements were mainly dominated by C—C/C—H, and the content of carbon increases from 63.86% at 900 ℃ to 68.27% at 1300 ℃ when the residence time is 5 s. However, the contents of C—H, C—O, C=O and COO— decreased to different degrees. The surface oxygen elements were mainly dominated by COO and COOH. As the pyrolysis temperature increased, the number of benzene rings in rice husk char gradually decreased, the average number of aromatic rings increased, the number of surface methylene groups decreased, and the carbon activity decreased. Summarizing the structural evolution law of rice husk char will provide a reference for optimizing pyrolysis conditions, improving pyrolysis efficiency and subsequent combustion and gasification utilization of rice husk char.