作为一种典型的生物质废弃物，棉杆经水热处理后热压成型可有效解决其结构松散、热值低和能量密度低等问题。以新疆棉杆为研究对象，使用高压反应釜完成180～280 ℃水热处理实验后制备成型颗粒，利用电子万能材料试验机与扫描电镜仪等手段分析了不同水热处理温度下棉杆成型颗粒的物理性能，使用傅里叶红外分析仪、X-射线衍射仪等手段分析了棉杆中主要化学组分(纤维素、半纤维素与木质素)的衍变，探究了生物质三组分衍变行为对其成型颗粒物理性能的影响规律，确定了影响棉杆成型性能的关键作用组分。结果表明：随着水热处理温度的升高，棉杆成型颗粒的抗压强度和表观密度均呈先上升后下降的趋势，并在230 ℃水热处理时达到最大值(抗压强度9.3 MPa，表观密度1 478.46 kg/m³)；在水热处理过程中，半纤维素于200 ℃前几乎完全分解，无定形纤维素和结晶纤维素分别在230 ℃及280 ℃前分解完毕，而木质素则是在280 ℃下水热后棉杆中存在的主要组分；结晶纤维素在棉杆成型颗粒中起到骨架支撑作用，是保证棉杆成型颗粒机械强度至关重要的组分，而木质素在棉杆成型过程中主要起黏结剂作用，且有利于增加棉杆颗粒间的结合程度。

The cotton stalk is a typical biomass waste. Its problems such as the loose structure, low calorific value and low energy density can be effectively solved by hydrothermal treatment and hot pressing forming. In this study, the Xinjiang cotton stalk was taken as the research object, and the molded particles were prepared after completing the 180−280 ℃ hydrothermal treatment experiment using a high-pressure reactor. The diffraction of the main chemical components (cellulose, hemicellulose and lignin) in the cotton stalk was analyzed by means of Fourier infrared analyzer and X-ray diffractometer. The influence of the three-component diffraction behavior of biomass on the physical properties of the molding particles was explored. The influence of the evolution of the main chemical components (cellulose, hemicellulose, lignin) in the cotton stalk on the physical properties of its pellets and the key components were investigated. The results show that with the increase of hydrothermal temperature, the compress strength and apparent density of cotton stalk pellets increased first and then decreased, and reached the highest value at 230 ℃ (The compress strength was 9.3 MPa, the apparent density was 1 478.46 kg/m³). In the hydrothermal treatment process, the hemicellulose was completely decomposed before 200 ℃, the amorphous cellulose and crystalline cellulose were completely decomposed before 230 ℃ and 280 ℃, respectively, while the lignin still existed at 280 ℃. Finally, based on the variation trend of the physical properties of the pellets, it was found that the crystalline cellulose played a skeleton supporting role in the cotton stalk pellets, which was an important component to provide mechanical strength and also an important source of apparent density. Lignin, as a binder in the pellets, could strengthen the degree of bonding between surrounding particles during the densification process.