Characteristic analysis for the lignite before and after oxidized

doi:10.16085/j.issn.1000-6613.2017-0294

Abstract

Abstract: Lignite has been regarded as inferior fuel because of its low calorific value and poor thermal stability.In recent years, more and more attention has been paid to the bioconversion and utilization of lignite.However, very complex organic structure of lignite is rather resistive to direct actions of microorganisms, which resulted in low conversion efficiency.The researchers used a variety of oxidation methods to improve the structure of lignite and microbial actions in lignite.In this study, the lignite sample was oxidized and pretreated with NaClO, HNO₃, H₂O₂ and microwave, respectively.The oxidized lignite samples were bioliquefied by a white-rot fungus under the same condition.Through the experiment, the oxidization of HNO₃ is the most optimal.The characteristic of the lignite before and after oxidized with HNO₃ was analyzed using a scanning electron microscope (SEM), X-ray diffraction (XRD), element analyzer, specific surface area analyzer (BET) and fourier transform infrared (FTIR) spectrometer.Results show that the aromatic ring structures were destroyed and oxygen-containing groups were oxidized by HNO₃.The complexity of lignite structure was reduced and the oxidation degree of lignite was increased.Therefore, the lignite after oxidation could be depolymerized easily by microorganism.

Key words: lignite, oxidation pretreatment, bio-liquefaction, characteristic analysis

摘要： 褐煤由于热值低、热稳定性差等性质，一直以来被视为劣质燃料，近年来褐煤的生物转化和利用越来越受到重视。但褐煤化学结构复杂，微生物直接利用效率低，研究者们运用了多种氧化方法改善褐煤的结构，以期提高微生物对煤的作用。本文即分别采用NaClO、HNO₃和H₂O₂溶液氧化及微波4种方法处理褐煤，利用白腐菌在相同条件下对氧化处理后的褐煤进行生物液化，通过液化效果确定：HNO₃氧化是最优的处理方法；利用扫描电镜（SEM）、元素分析、X射线衍射（XRD）、比表面积测定和傅里叶红外光谱（FTIR）对氧化处理前后褐煤的特性进行分析。结果表明：HNO₃氧化破坏了部分芳环结构，以及氧化了大量酮基、碳氧键等含氧官能团，使褐煤的结构复杂度降低、氧化程度增高，从而易于被微生物所降解。

关键词: 褐煤, 氧化处理, 生物液化, 特性分析

CLC Number:

TQ536.9
Q819

YU Qiaoni, ZHANG Yue, YANG Fan, ZHAO Shangming, XIAO Lei, YAO Jinghua, CUI Zhuoyi. Characteristic analysis for the lignite before and after oxidized[J]. Chemical Industry and Engineering Progress, 2017, 36(S1): 175-179.

俞乔尼, 张越, 杨帆, 赵尚明, 肖雷, 姚菁华, 崔卓异. 褐煤氧化前后的特性分析[J]. 化工进展, 2017, 36(S1): 175-179.

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