利用核磁共振（NMR）技术测试了CH4与CO2,N2在煤样中相互作用过程的NMR信号,并通过T2谱形态和谱面积对各气体间相互作用的整个过程进行了描述和分析。测试结果表明:CH4在煤中吸附过程的T2谱呈双峰结构,弛豫时间较小的为吸附峰,另一个为游离峰。随着吸附时间和注入压力的增加,吸附总量逐渐增加,但吸附速率逐渐降低。强吸附性气体能置换煤中已吸附的弱吸附性气体,反之效果不明显;置换过程中,大孔隙内的气体比小孔隙内的更容易置换。将弱吸附性气体注入已吸附强吸附性气体的煤中,一定程度上能促使原气体由吸附态向游离态转化;同时,少量的弱吸附性气体也能被吸附,气压越大越明显。NMR测试结果直观反映了CH4与各气体间的相互作用关系。

Nuclear magnetic resonance (NMR) technique is used to characterize the different states of CH4 in coal. By testing the NMR signal of interaction between CH4 and CO2 and N2 in coal samples,the whole process of the interac- tion between each gas are described and analyzed by the T2 spectrum morphology and spectral area. The test results show that the T2 spectrum of CH4 adsorption process in coal is double peaks structure,and the smaller relaxation time is the adsorption peak and the other is free peak. With the increase of adsorption time and injection pressure,the total amount of adsorption increased gradually,but the adsorption rate decreased. Strong adsorption gas can displace the weakly adsorbed gas adsorbed in coal,but on the contrary,the effect is not obvious. In the replacement process,the gas in the macropores is easier to replace than the small pores. When the weakly adsorbed gas is injected into the coal, which has been adsorbed strongly adsorbed gas,the primary gas can be transformed from the adsorbed state to the free state. At the same time,a small amount of weakly adsorbed gas can also be adsorbed,and the greater the pressure,the more obvious. The results of NMR test have directly reflected the interaction between CH4 and other gas.