SORBENTS OF SULPHUR DIOXIDE BASED ON CaO AND CaCO<sub>3</sub> ACTIVATED BY LITHIUM NITRATE
Purpose. Generation of the highly active sulphur dioxide chemisorbents based on calcium oxide and calcium carbonate. Methods. Differential thermal analysis for detecting the temperatures of interaction of an activator with the calcium compounds and interaction of the systems with SO<sub>2</sub>; infrared spectroscopy for identifying the quality profile of reaction products. Results. There has been detected the sulphur dioxide effective sorption by calcium oxide and calcium carbonate impregnated by lithium nitrate acting as the activator. The temperatures of the interaction onset of LiNO<sub>3</sub>-CaCO<sub>3</sub> and LiNO<sub>3</sub>-CaO systems with sulphur dioxide have been established. Scientific novelty. It has been established for the first time that lithium nitrate (LiNO<sub>3</sub>) is the powerful activator of the interaction processes of SO<sub>2 </sub>with CaCO<sub>3</sub> and CaO. The activation effect is provided by the small size of Li<sup>+</sup> ion and its high mobility. The Li<sup>+</sup> diffusion into CaCO<sub>3</sub> and CaO crystal lattices causes their disorder and increase in the reactivity. It has been registered for the first time that the lithium nitrate activating effect in reactions of CaCO<sub>3</sub> and CaO with SO<sub>2</sub> manifests itself at the temperatures of ~ 200…450 °С and it is determined by N<sup>+5</sup> nitrate ion atom stability in LiNO<sub>3 </sub>to the recovery by S<sup>+4</sup> sulphur compounds in SO<sub>2 </sub>compounds at the same temperature. At the temperature over 450 <sup>о</sup>С SO<sub>2</sub> recovers in the activator: the nitrate ion into the nitrite ion at the first stage and further on it is the recovery up to N<sub>2</sub> and lithium oxide (Li<sub>2</sub>О) which extricates the activator out of the active form. Practical value. The data on activating capability of lithium compounds in the interaction processes of CaCO<sub>3</sub> and CaO with SO<sub>2</sub> may serve as a basis for development of a new class of sorbents based on calcium compounds activated by alkali salts.