先锋褐煤热溶残煤的过氧化氢氧化及产物分析

H_2O_2 Oxidation of Xianfeng Lignite Treated by Thermal Extraction and Products Analysis

先锋褐煤经四氢萘高温热溶得到热溶残煤,在40℃温和条件下用过氧化氢水溶液氧化热溶残煤,计算氧化残煤和气体产物CO2的收率。结果表明,该条件下热溶残煤氧化反应性很高,产生了大量的水溶性产物;结合元素分析和FTIR等分析手段对热溶和氧解产物进行结构表征,结果表明,热溶过程中脂肪烃易被抽提,得到芳香度更高的热溶残煤,且氧化过程引入了含氧官能团,水溶性产物中含有大量有机羧酸;采用阴离子交换树脂对氧解水溶液进行富集分离,三氟化硼/甲醇衍生化,并进行GC/MS分析,发现水溶性氧解产物中含有大量短链二元羧酸,同时还发现相当含量的N-甲基吡咯烷酮和苯甲酸。

The oxidation of the residue from thermal extraction of Xianfeng lignite by tetralin was carried out at 40℃ using 5％ H2O2 aqueous solution.The yields of the oxidized residue and CO2 were calculated.The results suggeste that the thermal residue performed high activity in H2O2 oxidation and there are large amounts of water-soluble products during the oxidation.The products from extraction and oxidation were characterized by FTIR and element analysis.The results indicate that aliphatic hydrocarbons are likely to be released during thermal extraction and the extraction residue with higher aromaticity is obtained.Many carboxyl groups are introduced into the oxidized residue during H2O2 mild oxidation,resulting in large amounts of organic acids dissolved in the reaction solution.The reaction solution is subsequently extracted and adsorbed on an anion exchange macroreticular resin （D301） and esterified with methanol and borontrifluoride-methanol mixed solution.GC-MS analysis of the derivatives from water soluble fraction demonstrates that the organic acids consistes chiefly of short-chain fatty acids.In addition,large amounts of N-methyl-2-pyrrolidone and benzoic acid are detected in the water soluble fraction.