摘要
为进一步揭示煤层瓦斯吸附特性,选择典型矿井煤样进行不同温度(40,50,60,70,80℃)下煤样瓦斯等温吸附实验,采用准一级、准二级、颗粒内扩散以及Elovich等吸附动力学模型分析瓦斯等温吸附规律及机理,进而探讨温度对煤吸附瓦斯动力学特性的影响。研究表明:温度升高,瓦斯吸附量、吸附饱和平衡时间减小;相同温度条件下,吸附速率与时间呈负相关关系;4种吸附动力学模型中,准一级动力学模型拟合效果最好,准二级动力学模型次之,颗粒内扩散模型最差,准一级动力学模型得到的平衡时吸附量与实验结果最为吻合;温度与准一级吸附速率常数k1,准二级吸附速率常数k2,Elovich吸附速率常数β呈正线性相关,与颗粒内扩散速率常数kp,准一级及准二级动力学平衡吸附量Qe1,Qe2均呈负幂函数关系,与Elovich吸附常数α呈负线性关系。温度影响煤体吸附瓦斯分子体系的反应速率,相同条件下,温度升高,瓦斯分子脱附速率增大,煤体瓦斯吸附量减小。
To further reveal gas adsorption characteristics of coal seam,typical coal samples were chosen to conduct adsorption experiment at different temperatures(40,50,60,70 and 80℃).The pseudo-first-order adsorption kinetic model,the pseudo-second-order adsorption kinetic model,the intra-particle diffusion model and the Elovich kinetic model were used to analyze gas isothermal adsorption rules and mechanism.Then the influence of temperature on gas dynamic characteristics of coal adsorption was discussed.Results show that with the increasing temperature,the adsorption capacity of gas and the time of adsorption saturation are reduced.At the same temperature,the adsorption rate is negatively correlated with time.Among the four adsorption kinetic models,the pseudo-first-order kinetic model has the best fitting effect,followed by the pseudo-second-order kinetic model,and the intra-particle diffusion model is the worst.Adsorption capacity Q e1 of the pseudo-first-order kinetic model is consistent with the experimental results.There is a positive linear correlation between the temperature and pseudo-first-order adsorption rate constant k 1,pseudo-secondary adsorption rate constant k 2,and Elovich adsorption rate constantβ.There is a negative power function relationship between temperature and the diffusion rate constant k p,adsorption capacity Q e1 and Q e2.The temperature has a negative linear correlation with Elovich adsorption constantα.Temperature affects the reaction rate of coal-gas adsorption system.Under the same conditions,with the increase of temperature,the rate of gas desorption increases and the gas adsorption capacity of coal decreases.
作者
李树刚
白杨
林海飞
严敏
刘静波
LI Shu-gang;BAI Yang;LIN Hai-fei;YAN Min;LIU Jing-bo(College of Safety Science and Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;Key Laboratory of Western Mine Exploitation and Hazard Prevention,Ministry of Education, Xi’an University of Science and Technology,Xi’an 710054,China)
出处
《西安科技大学学报》
CAS
北大核心
2018年第2期181-186,272,共7页
Journal of Xi’an University of Science and Technology
基金
国家自然科学基金重点项目(51734007)
国家自然科学基金(51674192
51604220)
关键词
温度
瓦斯吸附
动力学模型
吸附速率
temperature
gas adsorption
kinetic model
adsorption rate
