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 SO2; 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 LiNO3-CaCO3 and LiNO3-CaO systems with sulphur dioxide have been established. Scientific novelty. It has been established for the first time that lithium nitrate (LiNO3) is the powerful activator of the interaction processes of SO2 with CaCO3 and CaO. The activation effect is provided by the small size of Li+ ion and its high mobility. The Li+ diffusion into CaCO3 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 CaCO3 and CaO with SO2 manifests itself at the temperatures of ~ 200…450 °С and it is determined by N+5 nitrate ion atom stability in LiNO3 to the recovery by S+4 sulphur compounds in SO2 compounds at the same temperature. At the temperature over 450 оС SO2 recovers in the activator: the nitrate ion into the nitrite ion at the first stage and further on it is the recovery up to N2 and lithium oxide (Li2О) which extricates the activator out of the active form. Practical value. The data on activating capability of lithium compounds in the interaction processes of CaCO3 and CaO with SO2 may serve as a basis for development of a new class of sorbents based on calcium compounds activated by alkali salts.