Experimental Study on Methane Desorption from Lumpy Coal under the Action of Hydraulic and Thermal

Table 3

Raw data of the two coal samples at gas adsorption pressure around 0.50 MPa.

Experimental stage	Sample number	ΔP (MPa)	P1 (MPa)	V1 (L)	P2 (MPa)	m1 (g)	m2 (g)	ω (%)	V2 (L)	V3 (L)	V4 (L)	dV5 (mL/g)	ηmax
Natural desorption	1	0.2	0.459	3349	—	1101	—	0	93.64	424.32	7545.67	6.85	0.3875
	2	0.22	0.506	4432	—	1074	—	0	101.73	508.15	8258.84	7.68	0.4751
1 time of adsorption pressure (about 0.25 MPa)	1	0.18	0.535	1702.8	0.53	1101	—	1.303	93.86	495.71	6677.28	6.06	0.1807
	12	0.18	0.535	4420	0.53	1101	1115.3	1.303	93.86	495.71	6677.28	6.06	0.5878
	2	0.2	0.505	2354.4	0.52	1074	1090.2	1.512	102.02	508.63	7461.36	6.94	0.2473
2.5 times of adsorption pressure (about 0.625 MPa)	1	0.185	0.528	1129.8	1.32	1101	—	1.265	93.86	489.22	6883.02	6.25	0.0930
	12	0.185	0.528	4855	1.32	1101	1114.9	1.265	93.86	489.22	6883.02	6.25	0.7984
	2	0.2	0.486	1281.2	1.23	1074	1090.6	1.553	102.02	489.49	7480.50	6.96	0.1058
6.25 times of adsorption pressure (about 1.56 MPa)	1	0.185	0.611	1007.9	3.82	1101	—	1.362	93.86	566.13	6606.86	6.00	0.0668
	12	0.185	0.611	3596	3.82	1101	1116	1.362	93.86	566.13	6606.86	6.00	0.6111
	2	0.2	0.5	979	3.12	1074	1092.6	1.732	84.73	418.23	7551.76	7.03	0.0742
16 times of adsorption pressure (about 4.00 MPa)	1	0.185	0.495	700.31	8	1101	—	1.306	93.86	458.65	6714.34	6.09	0.0474
	12	0.185	0.495	3617.3	8	1101	1115.3	1.306	93.86	458.65	6714.34	6.09	0.47
	2	0.2	0.488	944.65	8	1074	1092.5	1.723	102.02	491.51	7478.48	6.96	0.0556