Differences in ignition and combustion characteristics of waste-derived oil-water emulsions and coal-water slurries containing petrochemicals

The creation of general-purpose combustion chambers and drafting of regulations (unified technologies) which would secure efficient combustion of complex fuel compositions necessitates reliable experimental data concerning the main ignition and combustion characteristics of high-potential oil-water emulsions, coal-water slurries and coal-water slurries containing petrochemicals. In the conducted experiments, we varied the main factors of heating, ignition and combustion processes: properties and concentrations of solid and liquid fuels, the temperature in the model combustion chamber, and initial sizes of fuel droplets. It was established that ignition delay times of oil-water emulsions and coal-water slurries containing petrochemicals based on typical industrial waste can differ 3-4 times. The combustion heat of typical waste industrial oil (collected from power plants after use) makes up 50-90% of the total combustion heat of oil-water emulsions and coal-water slurries containing petrochemicals. The main anthropogenic emission concentrations (sulfur and nitrogen oxides) are 5-6 times higher from burning oil-water emulsions than from burning coal-water slurries containing petrochemicals. We have defined thermal conditions providing close values of the main combustion parameters for oil-water emulsions and fuel slurries. Using two approaches, we have calculated relative efficiency indicators (criteria) of burning high-potential oil-water emulsions, coal-water slurries, and coal-water slurries containing petrochemicals versus coal. These criteria take into account environmental, economic and energy performance. Environmental and energy performance indicators of coal-water slurries containing petrochemicals are 35-90 times higher than those of oil-water emulsions, and 6-16 times higher than those of coal dust fuel.