Comparison of low-field NMR and mercury intrusion porosimetry in characterizing pore size distributions of coals

► NMR is compared with pressure- and rate-controlled mercury intrusion porosimetries. ► NMR is efficient for nondestructively quantifying coal pore size distribution (PSD). ► PSD determined by mercury porosimetry may inaccurate due to coal compressibility. ► PSD determined by mercury porosimetry may inaccurate due to pore-shielding-effects. ► Rate-controlled mercury porosimetry is limited to study PSD of coal macropores.