An innovative method for directly converting brown coal to synthesis gas (hydrogen and carbon monoxide) in a single step was developed. 2.45GHz of microwaves with the desired power level controlled by a waveguide tuner were irradiated into the upperside of the packed bed under successive supply of gases (helium, oxygen/helium, hydrogen or methane), and the effects of irradiation time on coal conversion and the quantifies of hydrogen and carbon monoxide were discussed.
