咪唑类离子液体抑制煤氧化热动力学参数的研究  

Research on imidazolium ionic liquid inhibiting coal oxidation thermo-kinetics parameters

作　　者：肖旸 李达江 吕慧菲 邓军 XIAO Yang;LI Dajiang;L Huifei;DENG Jun(School of Safety Science and Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;Shaanxi Key Laboratory of Prevention and Control of Coal Fire,Xi’an University of Science and Technology,Xi’an 710054,China)

机构地区：[1]西安科技大学安全科学与工程学院,陕西西安710054 [2]陕西省煤火灾害防治重点实验室,陕西西安710054

出　　处：《煤炭学报》2019年第S01期187-194,共8页Journal of China Coal Society

基　　金：国家重点研发计划资助项目(2018YFC0807900);国家自然科学基金资助项目(51704226);陕西省博士后科研资助项目(2016BSHEDZZ28)。

摘　　要：煤自燃灾害是威胁我国煤炭资源保护与利用的主要灾害之一,不仅造成巨大的经济损失,而且释放大量有毒有害气体,引发严重的生态问题。阻化技术在防治煤自燃方面取得了很好的效果,而离子液体以其优良的物理化学特性以及绿色环保等优点,在煤自燃防治领域受到广泛关注。煤自燃的发生是由于煤和氧的反应,通过自活化等因素提供反应动力。为了考察咪唑类离子液体对煤氧化动力学的影响,开展热分析实验测试,采用Flynn Wall Ozawa,FWO方法计算煤氧化表观活化能(E a)和指前因子(A),用Popescu法计算机理函数。结果表明:转化率(α)一定时,随着升温速率的增加,达到相同程度的氧化温度出现一定的滞后性。离子液体处理煤样均改变了其反应机理函数,增大了煤氧化反应路径,使煤反应路径从一维扩散向多维扩散转变。煤达到着火点之前,随着α的增加,E a,A值也随之增加,但发生自燃以后,随着α的增加,E a,A值开始逐渐降低。离子液体增加了煤分子成为活化分子的门槛,降低了活化分子反应速度,不同程度上均起到抑制煤自燃反应的作用;同时,发现[BMIM][BF 4]对煤自燃抑制效果较好。α在0.2~0.6,IL-untc的E a值最低,说明离子液体对煤在不同程度上起到一定的抑制作用。研究结果可为离子液体抑制煤自燃领域提供基础,对煤自燃防治工作起着指导性的作用。In China,coal spontaneous combustion(CSC)is one of the major disasters which threaten the protection and utilization of coal resource.When coal fire happens,numerous coal resources would be depleted,resulting in enormous economic loss.Meanwhile,toxic and harmful gases produced by the coal oxidation and combustion would damage the ecosystem.The inhibition technology has achieved favorite results in CSC prevention.Ionic liquid(IL)has excellent physical and chemical properties and environmental protection advantages.Therefore,it has received extensive attention in the field of CSC prevention.CSC is caused by the reaction of coal and oxygen,and the reaction energy is provided by self-activation.To investigate the effect of imidazolium-based IL on the oxidation thermo-kinetics of coal,a thermal analysis experiment was conducted.The Flynn-Wall-Ozawa(FWO)method was used to calculate the apparent activation energy(E a)and pre-exponential factor(A)of coal oxidation.Using the Popescu method,the mechanism function was calculated.The results showed that when the conversion(α)is constant,as the heating rate increases,a certain degree of hysteresis occurs,at the same degree of oxidation temperature.The IL treatment of coal samples(IL-tc)changes their reaction mechanism function,which increases coal oxidation reaction path.It is transformed from one-dimensional diffusion to multi-dimensional diffusion.Before coal ignition,asαincreases,the values of E a and A increase.However,after coal ignition,as theαincreases,the values of E a and A begin to decrease gradually.The IL increases the threshold of the coal molecules to become activated molecules,reduces the reaction speed of the activated molecules,and plays a role in inhibiting CSC varying degrees.Whenα=0.2-0.6,the E a value of IL-untc is the lowest,indicating that IL has a certain degree inhibiting effect on coal.This study has a guiding role in the prevention and control on CSC.

关 键 词：煤 离子液体 动力学 表观活化能 机理函数 

分 类 号：TD752.2[矿业工程—矿井通风与安全]