生物质能作为目前使用量最大的可再生能源形式,具有储量巨大、零碳排放、可再生及供应稳定等优点。生物质焦作为生物质能利用的重要形式,其反应活性因原料种类不同表现出巨大差异,严重阻碍了生物质能的进一步研究和利用。生物质焦的反应活性主要受无机元素、织构特性及碳结构的影响。拉曼光谱作为近年来发展迅猛的碳结构表征技术,已广泛应用于生物质焦的物理、化学结构特性研究。从生物质焦拉曼光谱的特征峰位置、特征峰宽、特征峰强度比和特征峰面积等光谱参数出发,综述国内外生物质焦的碳结构,并解析了生物质焦在热化学转化中碳结构的演化规律。拉曼光谱能有效表征生物质焦的碳骨架结构,高度有序的芳香或石墨化结构会降低生物质焦的反应性。目前对生物质焦反应活性与拉曼光谱参数表征的碳骨架结构之间的相关性研究仍较少,且多聚焦在单一种类生物质,其结论普适性仍需验证。也有少量关于多种生物质原料的焦反应活性和拉曼光谱表征研究,但未给出定量的结论。介绍笔者在多种生物质原料的焦反应活性与焦的拉曼光谱指标的关联性方面的研究进展,以期为生物质燃料的反应活性后续研究提供参考。展望未来,生物质焦的拉曼光谱研究发展潜力很大,目前主要研究仍基于一阶拉曼光谱区域分析,二阶拉曼光谱未受到重视;一些前沿的拉曼光谱技术,如表面增强拉曼光谱、针尖增强拉曼光谱、相干反斯托克斯拉曼散射等,也尚未引入生物质焦的碳结构表征和反应活性研究中,未来应重点考虑。

Biomass energy, as the most extensively utilized source of renewable energy, has advantages such as substantial reserves, theabsence of carbon emissions, renewability, and consistent supply. The usage of biomass char is a significant aspect of biomass energy utilization, and its reactivity varies greatly due to different types of raw materials, which seriously hinders the advancement of research and theutilization of biomass energy. The reactivity of biomass char is primarily influenced by inorganic components, texture properties, and carbon structure. Raman spectroscopy, as a fast-advancing technique for characterizing carbon structures, has has been widely used in thestudy of the physical and chemical properties of biomass char. In this paper, starting from the spectral parameters such as band position,band width, band intensity ratio, and band area of biomass coke Raman spectroscopy, the carbon structure of biomass char at home andabroad was summarized. The changes in carbon structure during the thermochemical transformation of biomass char were thoroughly analyzed. Raman spectroscopy is a reliable method for analyzing the carbon skeleton structure of biomass char. The presence of a well-organized aromatic or graphitized structure in the char will decrease its reactivity. Currently, there is a limited amount of research on the relationships between the reactivity of biomass char and the carbon skeleton structure characterized by Raman spectroscopy. These studies mostly concentrate on a specific type of biomass, and the generalizability of its findings still needs to be verified. There are also a fewstudies on the char reactivity and Raman spectrum of various biomass raw materials. However, no quantitative conclusions have been given. The research findings on the relationships between the char reactivity of different biomass feedstock and the Raman parameters of charwere introduced, in order to offer a reference for future studies on the reactivity of biomass fuel. The future holds enormous potential for thedevelopment of Raman spectroscopy in analyzing biomass char. Currently, the primary focus of study is on analyzing the spectral region ofthe first-order Raman spectrum. The second-order Raman spectrum has not received much attention. In addition, advanced Raman spectroscopy techniques, including surface-enhanced Raman spectroscopy, tip-enhanced Raman spectroscopy, and coherent anti-Stokes Raman scattering, have not yet been utilized in the analysis of carbon structure and reactivity in biomass char, and should be given priority consideration in the future.

0 引言

1 影响生物质焦反应活性的因素

   1.1 无机元素

   1.2 焦颗粒织构特性

   1.3 微观碳结构特性

2 拉曼光谱在碳结构上的研究

   2.1 生物质原料

   2.2 生物质焦结构

3 拉曼光谱与生物质焦反应活性关联研究

4 结语与展望