不同粒度的煤样等温吸附研究

Isotherm Adsorption of Coal Samples with Different Grain Size

根据不同粒度的干燥煤样、含平衡水煤样的等温吸附实验,结合压汞法对煤样孔隙结构的测试实验,分析了粒度变化对孔隙结构的影响,探讨了粒度和孔隙结构变化对干燥煤样和含平衡水煤样吸附甲烷的影响及其作用机理.研究结果表明:实验范围内的粒度对干燥煤样吸附甲烷气体的影响只是在吸附时间上,而对含平衡水煤样的同等压力下吸附的甲烷量、Langmuir压力参数(pL)和吸附时间都有明显影响,但对Langmuir体积参数(VL)影响不大.并根据实验中出现的到了某一压力之后随着压力增大煤样吸附量下降的现象,研究认为Langmuir等温吸附模型已不适用,需要建立一种新的等温吸附理论模型.

Based on the study of isotherm adsorption of dry coal samples and equilibrium-water-bearing ones and the analysis of pore structure of coal sample with different sizes,the influence of variation in granularity of coal samples on pore structure is analyzed. The influence mechanism of CH_4 adsorption of dry and equilibrium-water-bearing coal samples by the change of granularity and the pore structure is discussed. The result shows that the size influences only on adsorption time for dry coal samples; However, it influences on adsorption capacity under the same pressure, Langmuir pressure parameter (p_L), and adsorption time for the sample containing equilibrium-water, of which the influence on Langmuir volume parameter (V_L)is not significant. According to the phenomenon that adsorption capacity decreases with the increase of pressure when the sample reaches a certain pressure, the authors hold that the Langmuir Isotherm-Adsorption Model can not explain this phenomenon any more and so should be replaced by a new model.