低温环境下煤表面吸附的均匀性试验

 等量吸附热是表征固体表面吸附非均匀性的重要参数.采用高低温吸附仿真实验装置,对九里山无烟煤、新元贫煤、潘北气肥煤进行瓦斯吸附测试,通过计算等量吸附热与吸附量的关系,探讨从常温(30、20℃)降至低温(-10、-20、-30℃)对煤表面不均匀性的影响.结果表明,不同变质程度煤的瓦斯吸附量都随温度降低而增大;在常温时(30、20℃)煤的等量吸附热随吸附量的增大而减小,表明煤表面能量是不均匀的.降温至-10、-20、-30℃时煤的等量吸附热几乎和吸附量无关,表明煤表面是均匀的.煤吸附瓦斯理论Langmuir 方程在低温环境(0℃以下)更加适用.

Experimental Study of Coal Surface Adsorption Uniformity in Low Temperature Environment

The isosteric adsorption heat is an important parameter to measure the solid surface inhomogeneity during its adsorption. In this paper a high/low temperature adsorption experiment device is utilized to test the gas adsorption of anthracite coal of Jiulishan coal mine, lean coal of Xinyuan coal mine and gas-fat coal of Panbei coal mine at different temperatures ranging from 30 to -30℃. Then according to the relationship of isosteric adsorption heat and adsorption capacity, the influence of coal surface inhomogeneity is discussed at ordinary temperatures (30, 20℃) and low temperatures (-10, -20, -30℃). The analytical results show that the gas adsorption capacities of different coal ranks all increase with the decrease of environmental temperature. In an ordinary temperature environment (30, 20℃ ) the isosteric adsorption heat of coal decreases as the gas adsorption capacity increases, which indicates that the coal surface energy of adsorption is heterogeneous. But when cooling to -10, -20, or -30℃, the isosteric adsorption heat is almost irrelevant to the adsorption capacity of coal, which indicates that the coal surface energy of adsorption is uniform. So the Langmuir equation of the coal gas adsorption theory is more suitable to a low temperature environment (below 0℃).