Lin Li, E Yang, Sun Qiang, Chen Yixuan, Dai Wanning, Bao Zhengrong, Niu Weisheng, Meng Jun
Biochar Engineering & Technology Research Center of Liaoning Province, College of Agronomy, Shenyang Agricultural University, Shenyang 110866, China.
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Biotechnology in Plant Protection of Ministry of Agriculture and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo 315211, China.
Molecules. 2024 Dec 24;30(1):10. doi: 10.3390/molecules30010010.
This study employed thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) to characterize and provide insights into the pyrolysis behaviors and by-products of rice husk (RH) and rice straw (RS). The primary pyrolysis range is partitioned into three stages, designated as pseudo-hemicellulose, pseudo-cellulose, and pseudo-lignin pyrolysis, by an asymmetric bi-Gaussian function. The average activation energies of the three pseudo-components of RH were estimated by the Flynn-Wall-Ozawa and Starink methods to be 179.1 kJ/mol, 187.4 kJ/mol, and 239.3 kJ/mol, respectively. The corresponding values for RS were 171.8 kJ/mol, 185.8 kJ/mol, and 203.2 kJ/mol. The results of the model-fitting method indicated that the diffusion model is the most appropriate for describing the pseudo-hemicellulose reaction. The reaction of pseudo-cellulose and pseudo-lignin is most accurately described by a nucleation mechanism. An accelerated heating rate resulted in enhanced pyrolysis performance, with RS exhibiting superior performance to that of RH. RH produces 107 condensable pyrolysis by-products, with ketones, acids, and phenols representing the largest proportion; RS produces 135 species, with ketones, phenols, and alcohols as the main condensable by-products. These high-value added by-products have the potential to be utilized in a variety of applications within the agricultural, bioenergy, and chemical industries.
本研究采用热重分析（TGA）、傅里叶变换红外光谱（FTIR）和热解气相色谱/质谱联用（Py-GC/MS）对稻壳（RH）和稻草（RS）的热解行为及副产物进行表征并提供深入见解。通过非对称双高斯函数将一次热解范围划分为三个阶段，分别称为准半纤维素热解、准纤维素热解和准木质素热解。采用Flynn-Wall-Ozawa法和Starink法估算出RH三个准组分的平均活化能分别为179.1 kJ/mol、187.4 kJ/mol和239.3 kJ/mol。RS的相应值分别为171.8 kJ/mol、185.8 kJ/mol和203.2 kJ/mol。模型拟合方法的结果表明，扩散模型最适合描述准半纤维素反应。准纤维素和准木质素的反应最准确地由成核机理描述。加热速率加快导致热解性能增强，RS的性能优于RH。RH产生107种可冷凝热解副产物，其中酮类、酸类和酚类占比最大；RS产生135种，酮类、酚类和醇类是主要的可冷凝副产物。这些高附加值副产物有潜力应用于农业、生物能源和化学工业的多种领域。
