Processing Fly Ash from the Thermal Power Stations for Gas Emissions Purification from Sulfur Dioxide

The aim of the work is development of technology of adsorptive, catalytical- chemisorptive purification of gas emissions from sulfur dioxide with simultaneous separation of sulfonic acids and sulfoxides as reaction products. For this research, the fractions of non-perforated cenospheres from the combustion of coal of Ekibastuz field (Kazakhstan) at the Almaty TPP-2 (Kazakhstan) have been applied. The method of microspherical sorbent obtaining from technogenic aluminosilicate raw material – energetic ash of Almaty TPP-2 has been elaborated. The aluminosilicate composite was studied after modification in the process of SO2 oxidation by the oxygen in stationary conditions in aqueous solution, in the kinetic mode and in the temperature range of 40-60°C. The conditions of selective oxidation of SO2 (100 %) to give the sulfuric acid as a product were optimized. The catalysts elaborated were tested in the process of treatment of gases from SO2 at a pilot vortex stirrer on the model gas mixtures SO2–Ar with a content of SO2up to 1.0 % vol. The results obtained have demonstrated that degree of SO2 removal reached 87-95%. The structure and composition of the obtained microspherical composite is studied. The iron nanostructural distribution in aluminosilicate is proved with the help of different research methods: IR- and EPR-spectroscopy, X-ray diffraction, SEM, elemental and Chemical analysis.