制备生物炭的结构特征及炭化机理的XRD光谱分析

XRD光谱分析是研究物质内部结晶结构物质的重要手段。利用X射线技术分析了不同物料来源和制备方式对生物炭结晶结构特征及其炭化机理。结果表明：生物炭均含有d₁₀₁和d₀₀₂晶面衍射峰类石墨微晶纤维素炭，但炭化后析出的盐分随不同物料，差异较大，如牛粪、蓖麻粕以及糠醛渣的CaCO₃含量要高于其他生物炭，而仅牛粪与蓖麻粕含有CaMg(CO₃)₂。随温度升高，玉米秸秆炭中半纤维素优先分解，然后为纤维素石墨微晶化，结晶度提高，向更稳定的碳化合物转化。其中的矿物盐分随着炭化裂解温度升高，由稀土类氧化物→醋酸盐类物质→碳酸盐类物质逐步析出，CaCO₃的含量也随之增多。不同炭化方法的炭化机理不同，先干燥后炭化可促进半纤维素的分解，高温微波处理则是强烈震荡，主要促进物质多键断裂分解，碳酸盐类物质析出相对较少。通过X射线衍射分析可以很好研究生物炭内部结构结晶特征，可有效反映其炭化过程裂解机理。

Analysis of XRD Spectral Structure and Carbonization of the Biochar Preparation

XRD spectroscopy is an important means of research material inside the crystalline structure of the material.In this study it was analyzed with X-ray sources in terms of manner of preparation of different materials carbon crystal structure of bio-logical characteristics and charring mechanism.The results showed that:Biochar contain d101 and d002 crystal face diffraction peak of carbon graphite-like microcrystalline cellulose,but after charring precipitated salt with different materials,and have a big difference,such as ox dung,castor dregs and furfural dregs of CaCO3 carbon content than other organisms,but only ox dung and castor dregs containing CaMg (CO3 )2 .Corn stover charcoal preferentially decompose hemicelluloses and cellulose microcrys-talline graphite with increasing temperature so with the degree of crystallinity which becomes more stable conversion of carbon compounds.Wherein the mineral salt as a pyrolysis carbonization temperature,gradually precipitated by metals oxides→Acetales→carbonate,and with increasing temperature the content of CaCO3 also increase.After different methods of carbonization,char-ring its mechanism is different from the first dry charring can promote the decomposition of hemicellulose,high temperature mi-crowave treatment is highly volatile,mainly promoting substances multiple bond rupture decomposed substance carbonate precip-itates relatively small.Comprehensive illustrated by X-ray diffraction study biochar may well feature the internal structure of the crystalline,can effectively reflect the cracking mechanism of carbonization process.