The liquefaction of low-rank coal with supercritical water has been studied at 400°C and 25.3 MPa using a semi-batch microreactor. Liquid yield up to 41wt% is attained in less than 7 min. Subsequent gasification of residue takes place. 2D-n. m. r. spectral analysis of liquids products in supercritical and the results of mass balance suggests that both hydrolysis and condensation reactions contribute to oxygen removal during supercritical water liquefaction of coal.
