Gasification of Coal–Water Compositions by Laser Pulses of Various Intensity

Abstract

The paper analyzes the processes occurring on the interaction of high-power nanosecond laser pulses with a coal–water mixture prepared from gas-coal waste. It was found that the rate of production of a mixture of CO and H2 sharply increased at a laser radiation intensity higher than 8 J/cm2. This was expressed in a sharp increase in the concentration of the combustible components of synthesis gas (CO, up to 0.57 vol %) and in a noticeable acceleration of the growth of the mass of a gas–aerosol fuel mixture upon the absorption of laser pulses (by 40%). At low pulse energy densities, the generation of a finely dispersed (particle size, 30–70 μm) fuel aerosol was a predominant process. Gasification came into play above the effective ablation threshold when the weight ratio between synthesis gas and the sprayed aerosol reached 1 : 3. Thus, the action of laser pulses makes it possible to convert coal preparation wastes into a highly flammable gas–aerosol fuel mixture.