摘要:
为研究CaO对不同变质程度煤在催化热解过程中的作用规律,以锡林郭勒褐煤和宁夏石嘴山无烟煤为研究对象,利用实验室小型固定床反应器,研究了CaO对褐煤和无烟煤热解特性及煤焦结构的影响,运用X射线衍射(XRD)及傅里叶红外光谱(FT-IR)对比研究了不同温度下褐煤、无烟煤添加CaO前后热解半焦微晶结构以及脂肪结构、芳构化、富氧程度等红外结构参数的变化规律。试验结果表明:在900℃时,添加质量分数2%Ca O的褐煤煤样H2累积产率最大,达39.11 m L/g;添加CaO后煤样在高温热解阶段生成CO的累积产率大于未添加CaO煤样的量。与加入CaO相比,温度对芳香层片间距和芳香层片直径影响更大;热解温度为900℃时,随着CaO的加入,褐煤半焦芳香层片堆积高度和晶层数逐渐增大;而对于无烟煤半焦来说,则与之相反;加入CaO的褐煤和无烟煤热解半焦的微晶结构偏离石墨化程度大于未加入Ca O的热解半焦。褐煤半焦的脂肪结构、芳构化、富氧程度等红外结构参数普遍高于无烟煤半焦。高温时,缩合反应程度增大,CaO促进半焦的转化率提高,导致芳构化参数变大;原煤中C O基团很少,高温下通过CaO促进芳环裂解和CO2反应生成C=O基团,进而导致半焦中富氧程度呈升高趋势。
Abstract:
in order to explore the effect of calcium oxide on the catalytic pyrolysis characterstics of dfferent rank coas.the changes of the pyolysispreducts ditobution and the char structre were analzed based on Inmner Mongo ia Xilinguoe linte and Ningia Shizuis han anthracte were cariedout with a fived bed reaco.B)means of X.ray difiraction( XRD) and Fourier ranstom infrared specroscopy( FTIR).the variance of mcvocrytallinestructre aihatic stroctre,aromatizaion and oxygen-eniched eficiency of char prepared by pyrolysis oflignie and anthraiie under different temperatures before and afer addtion of cactum oxide were investigatedThe reseach resuts showed that the h2 cumulative yield of 2%CcaO added in ingnite at soo '℃ was the lagestreaching 39.11 m L/g. The Co cunmulatve yield of coasample with cacium oxide was greater than that of without calciun oxide in igh temperature pyrolysis stage.compared ith the adition of cactomn oxc e.the te mperture had a greater ifuence on the aromatic layer spacing and the diamer of the aromaticlayer.The value of ignte char aromatic layer stack height and the layer number increased gradcually with the adding of calciun oxide at $oo ℃C.but anthracite char was on the contrary.The stuctural devaion degre of graptitizaton ofthe miecocrytalline structure of char prepared by pyrolysisof lignte and anthracie with the aditon of calcum oxide was higher than that of the char without the adtion of calcun oxide. The alighatic structure,aromatzation and oxygen-enrched eficiency infrared stucture parameterso lgntecharwas geneall highe than that of anthractchar.At high temperature,the degree of the condensation reaction was increased, and the conversion rate of the char was enhancedwith the adition of CaO, which led o the aromatzation parameters increased.The CO groups conmtent in raw oal was rare, and the Co groups wvas generated through reacion between the cacumn oxidepromoted aromatic ring cracking under high temperature and CO2, which led to oxygen-enriched effiency in char increased gradually
百度学术
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