Abstract: In order to improve the utilization rate of quinoa straw, this paper studied the effects of low-intensity steam explosion (0.5 MPa, 1.0 MPa, 1.5 MPa, 5 min) on chemical composition of quinoa straw, and analyzed the straw fiber structure characteristics by scanning electron microscopy, X-ray diffractometer, infrared spectroscopy and thermogravimetry. The results indicated that the effect of steam explosion treatment on straw hemicellulose was the most significant, followed by lignin, and the effect on cellulose was the least. Among them, the degradation rates of hemicellulose and lignin were the highest under 1.0 MPa pressure, and soluble sugar content of straw was the highest, reaching 20.30%. Simultaneously, after the steam explosion, the fiber surface of quinoa straw was damaged to various extents, including superficial area increasing, holes producing, absolute crystallinity of cellulose decreasing, thermal decomposition temperature decreasing and pyrolysis rate accelerating. All these indicated that steam explosion was an effective method for treating wood fiber.

Key words: quinoa straw, steam explosion, chemical composition, fiber structure

摘要： 为了提高藜麦秸秆资源利用率，研究了低强度蒸汽爆破技术（0.5 MPa、1.0 MPa、1.5 MPa，5 min）对藜麦秸秆化学组成变化的影响，并采用扫描电镜、X射线衍射仪、红外光谱及热重法对秸秆纤维结构特性进行分析。结果表明：汽爆处理对秸秆半纤维素影响最为显著，木质素次之，纤维素影响不显著，其中在1.0 MPa压力下半纤维素、木质素的降解率最大，且秸秆可溶性糖含量最高，达20.30%；汽爆后藜麦秸秆纤维表面受到不同程度的破坏，表面积增加，产生孔洞，纤维素的绝对结晶度降低，且热分解温度降低，热解速率加快。由此说明蒸汽爆破是一种有效的木质纤维处理方法。

关键词: 藜麦秸秆, 蒸汽爆破, 化学组成, 纤维结构