Primary reactions of lignite-water slurry gasification under the supercritical pressure in the electric field

Abstract Lignite-water suspension supercritical gasification was carried out in an electric field with an intensity of 0.5 V/cm in the presence of additives under the pressure of 24 MPa in two temperature ranges: 330–360 and 390–450 °C. From 50 to 78% of hydrogen and oxygen of gas products were of water origin. The application of the electric field switched carbon oxidation over to hydrocracking in the range of the subcritical temperature. At the subcritical temperature, the electric field had moderated the lignite hydrolysis and intensified its hydrocracking. The gasification of lignite-water suspension under the supercritical pressure in the electric field had at least five types of interactions: electrolysis of water, thermal decomposition of coal, carbon oxidation by oxygen of water as well as hydrolysis and hydrocracking of coal. Electrolysis and hydrocracking were dominant for the process at the subcritical temperature on water. Hydrolysis and hydrocracking of C C bonds of coal were the main at the supercritical parameters of water.