煤中活性基团的氧化及自反应过程  

Oxidation and self-reaction of active groups in coal

作　　者：戚绪尧[1,2] 

机构地区：[1]中国矿业大学安全工程学院,江苏徐州221116 [2]中国矿业大学煤炭资源与安全开采国家重点实验室,江苏徐州221008

出　　处：《煤炭学报》2011年第12期2133-2134,共2页Journal of China Coal Society

基　　金：国家自然科学基金专项基金资助项目(50927403);国家自然科学基金资助项目(50674088);江苏省创新学者攀登资助项目(BK2009004);煤炭资源与安全开采国家重点实验室自主课题资助(SKLCRSM08x06)

摘　　要：现有的煤自燃反应模式中,煤直接氧化和煤氧吸附分解两个序列已得到证实,但其能否全面反映煤自燃过程仍存在质疑。基于这一现状,对煤中活性基团的氧化与自反应过程进行了研究。采用傅里叶变换红外光谱技术分析了不同变质程度原始煤样中基团的基本情况,从含氧基团、烷基侧链、含硫基团等类别分别对煤中原生和次生活性基团进行了分析,明确了煤中基团的分布情况。系统测试了活性基团在不同条件下的实时变化情况,从微观上论证了活性基团的自反应。采用红外光谱原位测试技术,以内置反应池为煤样载体,通过外置供气系统和控温装置模拟不同的反应条件,实时测试了供氧、无氧和无氧反应后供氧等条件下煤反应升温过程30～220℃范围内的红外光谱。研究表明:供氧反应过程中,低阶煤中活性基团在初始阶段存在先减后增现象,不同基团的拐点温度差别较大,其中,较低者40～50℃,较高者130～140℃;无氧反应过程的变化趋势与供氧反应类似,但基团数量减小25%～80%,拐点温度约降低10℃;无氧反应后煤样的供氧反应过程中,活性基团的初期减小现象基本消失。上述变化规律表明部分活性基团可在无氧条件下自发反应。供氧和无氧反应过程初期,煤中原生活性基团因反应被消耗,而次生活性基团的生成又存在滞后性,导致活性基团总量的暂时性减小;而在无氧反应后的供氧反应过程中,大部分原生活性基团已在无氧反应中被消耗,后续供氧反应过程的原生活性基团自反应较弱,基团总量随次生基团产生而逐渐增多,初期减小现象消失。为了进一步证实煤中活性基团的自反应,采用色谱分析技术对供氧、无氧、无氧反应后供氧等3种条件下活性基团反应过程的产物进行了研究。结果表明:3种条件下煤中活性基团的反应过程均能产生不同种类的产物;供氧条件下The direct burn-off of coal and sorption reaction sequences between coal and oxygen had been confirmed to occur in this phenomenon.However,whether the two squences can comprehensively reflect spontaneous combustion of coal is still being suspected.The dissertation focused on the oxidation and self-reaction of active groups in coal.Firstly,the active groups in coal were analyzed.According to the formed time,the active groups in coal were separated to initial ones and secondary ones.The groups in initial coal samples were tested by FTIR.The real-time changes of active groups were obtained using an in-situ FTIR.An in-situ testing system of infared spectrogram was designed based on traditional FTIR.In the in-situ testing system,a chamber was used to load coal sample;a gas providing system and an electronical heater was used to simulate different conditions.Using the in-situ testing system,the real-time changes of active groups under different conditions were tested.Under oxygen atmosphere,some active groups decreases at initial stage and then increases with the rise of temperature later.The break points of different active groups are also different.Under oxygen-free atmosphere,the change trends of active groups are similar to oxygen atmosphere.In contrast with oxygen atmosphere,the quantity of active groups under oxygen-free atmosphere is smaller and the temperatures at break points are lower.Under oxygen atmosphere after oxygen-free atmosphere,the decrease at initial stage almost disappears.The analysis on real-time change of active groups indicates some types of active groups can react at low temperatures under oxygen-free atmoshphere.At the initial stage of coal reactions under oxygen and oxygen-free atmospheres,initial active groups in coal are consumed but the same types of secondary active groups cannot form very much until a high enough temperature.So the quantity of active groups decreases at the initial stage.During the reaction under oxygen atmosphere of coal samples which had reacted under oxygen-free atmo

关 键 词：煤自燃 活性基团 氧化 自反应 三序列 

分 类 号：TQ03[化学工程]