THERMODYNAMIC EVALUATION OF THE USING OF CARBONATE SORBENTS IN DRY METHODS OF FLUE GAS DESULPHURIZATION

Abstract

In the article the comparative analysis of energy consumption in the process of combustion of solid fuel containing sulfur compounds, while simultaneously feeding directly into the fire space of the boiler of carbonate sorbents (CaCO3, Ca(OH)2, CaO) for the absorption of formed sulfur dioxide, as is the case in dry methods of flue gas desulphurization, was presented. The calculations were made when supplying sorbents in a stoichiometric ratio and with a triple excess sorbent. It was shown that the energy costs for decomposition and heating of CaCO3 and Ca(OH)2 or only the heating of CaO when applied in the dry method desulphurization are practically compensated by the secondary reactions of the sequestration of sulfur dioxide. A simple and practical method for determining the temperature of a stationary state with simultaneous flow of coal combustion processes and sulfur dioxide chemisorption by carbonate sorbents was proposed, which is essential for choosing a temperature range in which sulfur is actively absorbed without decomposition of CaSO4 formed. Bibl. 6, Fig. 3, Tab. 1.