Snižování emisí rtuti ze spalování fosilních paliv

Abstract

The presented dissertation deals with the reduction of mercury emissions from the fossil fuel combustion in large combustion plants. In the first part, attention was paid to the impact of mercury on human health and the environment, legislation, measurement of mercury emissions and the possibility of reducing mercury emissions from coal combustion in large combustion plants. Based on this information, a large combustion plant with a classic configuration (boiler, electrostatic precipitator, wet flue gas desulphurisation) was selected. A mercury balance was done, which mapped the current state of the selected facility and which identified two potential options for meeting the emission limits. In both cases, there was an intensification of mercury capture, either in an electrostatic precipitator and/or in a wet flue gas desulphurisation. In the theoretical part, both possibilities were analyzed in detail and analyzes of samples taken from individual devices were performed. Wet flue gas desulphurisation was chosen for the next procedure, where the ability to intensify the mercury capture is greatest. The theoretical part describes in detail the process of adsorption, which is crucial for the capture of mercury in wet desulfurization, using the Langmuir model of adsorption on the surface of the sorbent in the liquid. For this case, an experiment was designed and performed with a gypsum slurry and fly ash (sorbent). The findings obtained from the experimental part confirm the perspective of intensification of mercury capture in the wet desulphurisation method. The results suggest a possible solution to achieve mercury capture for a given case, due to the final product energy gypsum, which is a valuable material.