Micro-explosive droplet fragmentation of environmentally promising coal-water slurries containing petrochemicals

Abstract

The findings of experimental research into the environmental and energy performance indicators characterizing the combustion of promising coal-water slurries based on the coal processing waste (filter cake), rapeseed oil, and water are presented. The relative environmental, economic, and energy characteristics of their combustion are compared with those of coal. The most promising composition in terms of environmental characteristics and relative indicators is based on 90% of filter cake N (wet) and 10% of rapeseed oil. A composition is also identified that sustainably undergoes the intense micro-explosive fragmentation: it is based on 9% of filter cake N (dry), 10% of water, and 81% of rapeseed oil. The micro-explosive fragmentation of the parent drop provides a significant increase in the slurry surface area. This increases the heat release per unit time due to fuel burnout. We establish the regimes, threshold conditions, and outcomes of droplet micro-dispersion with varying temperature in a wide range (200–1100 °C) typical of the so-called low-temperature fuel combustion. This regime is generally considered the most environmentally friendly, i.e., producing the least anthropogenic emissions. Using the research findings, we calculate the size distributions of child droplets, the ratios of their average size to the original size of the parent droplet, the evaporation surface areas, and the external surface area of the resulting aerosol cloud. The combustion of coal-water slurries containing petrochemicals can produce less anthropogenic emissions due to the presence of water in the component composition and through the micro-explosive fragmentation of droplets.