Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China; Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China; Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China.
Waste Manag. 2021 Feb 15;121:255-264. doi: 10.1016/j.wasman.2020.12.023. Epub 2021 Jan 1.
Potassium is an inorganic mineral element in biomass and has a significant catalytic effect on biomass pyrolysis. In this work, the effect of potassium on the pyrolysis of biomass components (cellulose, xylan and lignin) was investigated with the help of thermogravimetric analyzer coupled to fourier transform infrared spectrometer (TG-FTIR) and pyrolysis-gas chromatography coupled to mass spectrometry (Py-GC/MS). The results showed that potassium accelerated the start of the main pyrolysis stage of the biomass components, reduced the weight loss rate for cellulose and lignin, and increased the weight loss rate for xylan. On the other hand, potassium presented a promotion effect on the formation of char for cellulose but a suppression effect for lignin. In addition, an increasing potassium content promoted the release of volatile products for xylan. Product distribution analysis found that potassium promoted the scission of glycosidic bonds and the decomposition of glucose units, resulting in a sharp yield decrease of carbohydrates and a yield increase of furans, aldehydes and ketones. In addition, an increased production of CO was obtained, indicating that potassium favors the cleavage and reforming of carboxyl (COOH) and carbonyl (CO) groups. Furthermore, the effect of potassium on the pyrolysis of cellulose and xylan was stronger than that on lignin pyrolysis. The effect on the pyrolysis reaction also resulted in a higher activation energy for the decomposition of biomass components, especially at high temperature intervals. Moreover, the higher the content of potassium added, the greater the increase was in the activation energy.
钾是生物质中的一种无机矿物质元素，对生物质热解具有显著的催化作用。在这项工作中，借助热重分析仪与傅里叶变换红外光谱仪联用（TG-FTIR）和热解-气相色谱与质谱联用（Py-GC/MS），研究了钾对生物质组分（纤维素、木聚糖和木质素）热解的影响。结果表明，钾加速了生物质组分主要热解阶段的开始，降低了纤维素和木质素的失重率，增加了木聚糖的失重率。另一方面，钾对纤维素的炭形成呈现促进作用，但对木质素呈现抑制作用。此外，钾含量的增加促进了木聚糖挥发产物的释放。产物分布分析发现，钾促进了糖苷键的断裂和葡萄糖单元的分解，导致碳水化合物产量急剧下降，呋喃、醛和酮的产量增加。此外，还获得了 CO 的产量增加，表明钾有利于羧基（COOH）和羰基（CO）基团的断裂和重排。此外，钾对纤维素和木聚糖热解的影响强于对木质素热解的影响。这种影响还导致生物质组分分解的活化能增加，尤其是在高温区间。而且，添加的钾含量越高，活化能的增加越大。
