Demineralization and Desulfurization of Subbituminous Coal with Hydrogen Peroxide

The effect of hydrogen peroxide solution alone and in the presence of dilute sulfuric acid on desulfurization and demineralization of coal collected from the Makum coalfield situated at North-Eastern region, India, was investigated and the process conditions (temperature, time, and hydrogen peroxide and sulfuric acid concentrations) were optimized. Hydrogen peroxide (15%) alone leads to removal of over 76% pyritic sulfur and 70% sulfate sulfur and around 5% organic sulfur and 14% ash at 25 °C, which increases to almost complete removal of pyritic and sulfate sulfur and over 26% organic sulfur and 43% ash in the presence of 0.1 N H2SO4. The oxidation rate was found to increase significantly with increasing temperature (15 to 40 °C) and hydrogen peroxide concentration (2.5 to 15%). The rate of reaction was found to be well represented by a continuous reaction model that was second order with respect to pyritic sulfur. The activation energy for pyritic conversion in Boragolai and Ledo coal are, respectively,...

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