In order to comprehend the applicability of microwave irradiation for recovering coalbed methane

it is necessary to evaluate the microwave irradiation-induced alterations in coals with varying levels of metamorphism. In this work

the carbon molecular sieve combined with KMnO

4

oxidation was selected to fabricate carbon molecular sieve with diverse oxidation degrees

which can serve as model substances toward coals. Afterwards

the microwave irradiation dependences of pores

functional groups

and high-pressure methane adsorption characteristics of model substances were studied. The results indicated that microwave irradiation causes rearrangement of oxygen-containing functional groups

which could block the micropores with a size of 0.40-0.60 nm in carbon molecular sieve; meanwhile

naphthalene and phenanthrene generated by macro-molecular structure pyrolysis due to microwave irradiation could block the micropores with a size of 0.70-0.90 nm. These alterations in micropore structure weaken the saturated methane adsorption capacity of oxidized carbon molecular sieve by 2.91%-23.28%

suggesting that microwave irradiation could promote methane desorption. Moreover

the increased mesopores found for oxidized carbon molecular sieve after microwave irradiation could benefit CH

4

diffusion. In summary

the oxidized carbon molecular sieve can act as model substances toward coals with different ranks. Add

itionally

microwave irradiation is a promising technology to enhance coalbed methane recovery.