Shaanxi Huangling No. 2 Coal Mine Co., Ltd.

为研究不同温度下煤样瓦斯等温吸附规律,利用PCTPro全自动高压气体吸附解吸仪,对黄陵二号矿井煤样开展不同温度(30℃、35℃、40℃、45℃、50℃)作用下煤样瓦斯等温吸附实验。采用Langmuir模型、Freundlich模型、BET模型、D-R模型对实验结果进行拟合分析,探讨温度影响下煤样瓦斯吸附机理。结果表明,煤样瓦斯吸附量随温度升高而降低。温度变化在30~50℃之间时,瓦斯吸附量由13.6409cm3/g降低为9.8017cm3/g。4种吸附模型拟合度均在0.9以上,拟合效果依次为:Langmuir模型>D-R模型>BET模型>Freundlich模型,表明相比于其他3种模型,用Langmuir模型描述煤样瓦斯等温吸附过程最为贴切,且Langmuir模型计算得到的饱和吸附量均大于其他3种模型。吸附常数a、b值与温度呈线性关系且均为负相关,即升高温度,气体分子动能随之增大,削弱了煤基质对气体分子的束缚能力,进而抑制煤中瓦斯吸附。从吸附热力学研究温度效应对瓦斯吸附特性的影响,为黄陵二号矿工程实践提供一定的理论支撑。

In order to study the isothermal adsorption law of coal sample gas at different temperatures, the isothermal adsorption experiment of coal sample gas at different temperatures ( 30 ℃ , 35 ℃ , 40 ℃ , 45 ℃ , 50 ℃ ) was carried out by PCTPro automatic high-pressure gas adsorption desorption apparatus. Langmuir model, Freundlich model, BET model and D-Rmodel were used to fit the experimental results and discuss the mechanism of coal gas adsorption under the influence of temperature. The results show that the gas adsorption capacity of coal samples decreases with the increase of temperature. Whenthe temperature changes between 30 ℃ and 50 ℃ , the gas adsorption capacity decreases from 13. 640 9 cm3 / g to 9. 801 7cm3 / g. The fitting degrees of the four adsorption models were all above 0. 9, and the fitting effects were as follows: Langmuirmodel > D-R model > BET model > Freundlich model, indicating that compared with the other three models, Langmuir modelis the most suitable to describe the isothermal adsorption process of coal gas, and the saturated adsorption amount calculatedby Langmuir model is greater than the other three models. The adsorption constants A and B are linearly and negatively correlated with temperature. In other words, the kinetic energy of gas molecules increases with the increase of temperature,which weakens the binding ability of coal matrix to gas molecules and further inhibits the adsorption of gas in coal. The influence of temperature effect on gas adsorption characteristics is studied using adsorption thermodynamics, which providessome basic theoretical support for engineering practice of Huangling No. 2 mine.