Syngas production from gasification of brown coal in a microwave torch plasma

Atmospheric-pressure pure steam torch plasma was generated by making use of 2.45 GHz microwave energy and was used in a coal gasification investigation. The steam torch plasma contains also highly active species, enhancing the chemical reaction rate and eliminating the need for catalysts in material processing. Fine coal powders with an average particle size of 70 mu m were delivered through a feeder and used in the experiment. The brown coal from Indonesia with ash and moisture content of 38.12% was injected to the steam torch with microwave power of 4 kW. From the experimental data showing the relative concentrations of synthesized gas species versus the ratio of coal to steam for brown coal at the microwave power of 4 kW, the relative concentrations of synthesized gases at a ratio of 136 of coal to steam was 48% of hydrogen, 23% of carbon monoxide, 25% of carbon dioxide and 4% of methane. The further increase of coal to steam ratio did not much reduce carbon dioxide concentration. We note that a low-grade coal can also be well gasified in steam plasma torch. (C) 2012 Elsevier Ltd. All rights reserved.