Estudo de possibilidade de aproveitamento de passivo ambiental oriundo de processos de dessulfurição

Abstract

The demand for food has been growing at a high rate after the end of the 20th century and to maintain the food supply it is necessary to use fertilizers with a product to produce more food per square meter of land, however the production of fertilizers involves natural resource explorations included, among them elemental sulfur. Currently, Brazil does not have sources of fertilizers, since almost the entire national market is served by the foreign market and is subject to variations in external requirements, this ends up generating a great weakness in the Brazilian economy, since its largest economic niche is linked to agribusiness. One way to minimize the impact generated by this fragility is to invest in technology for the production of inputs used in the fertilizer industries. It proposes an interesting route for the production of elemental sulfur from gypsum, in the proposed route first converting gypsum (CaSO4) into calcium sulfate (CaS), after conversion using calcium sulfide to generate elemental sulfur. In the present study, we sought to prove the proposal using residues from thermoelectric plants in the region for the formation of calcium sulfide. Waste generated by thermoelectric plants was sought, as the region has good availability of environmental liabilities. During the study, it was possible to prove the reduction reaction, but with low conversion values (4.53% without control material, 3.23% for material from plant A and 3.79% for material from of plant B) if compared to the reference that shows values close to 95% of conversion, the low conversion originates from some limitations in the reaction environment, such as the reactor operating temperature and the time available for reaction. The current study aims as a continuation of the improvement of the reaction environment and the continuation of the proposal that aims to use calcium sulfide in the cyclic route for the production of elemental sulfur.