Characterization of Permeability Changes in Coal of High Rank during the CH₄-CO₂ Replacement Process

Table 1

Results of vitrinite reflectance and proximate analysis.

Coal specimen	Length (mm)	Diameter (mm)	RO, ran (%)	Mad	Aad	Vad
Sihe	98.63	49.16	3.07	1.76	14.74	5.63
Tunliu	102.12	49.22	1.96	5.02	14.85	11.97

^aM_ad = moisture content (wt.%, air dry basis), A_ad = ash yield (wt.%, air dry basis), and V_ad = volatile matter (wt.%, air dry basis).