Remoção de H2S por absorção química com solução contendo íons de ferro

Abstract

The large amount of waste generated in the agro-industrial production can serve as raw material for the generation of biogas from the anaerobic digestion of waste. Can emphasize the diversification of the Brazilian energy matrix when compared to previous years. The twenty-first century is becoming the era of gases, especially biogas, changing our current growth model to a decentralized model. Investing in biogas means being connected to the future. But however that biogas has a high calorific value, from methane (CH4), hydrogen sulfide (H2S) becomes a halt to their use, because at concentrations ranging up to 3%, causes serious problems to the materials (corrosion) and also to living beings. So we need a biogas purification process. Thus, this study aims to evaluate the efficiency in the removal of H2S by means of a solution containing iron ions (Fe2+ and Fe3+). To prepare this solution we used the methodology of electrolysis, in which a certain electrical conductivity is required for the process to occur. Thus, the sodium salts were analyzed nitrite (NaNO2), sodium nitrate (NaNO3), sodium chloride (NaCl) and sodium phosphate dibasic (Na2HPO4) for electrolysis to occur. The tests were conducted in a module, bench scale, fueled with biogas from the refrigerator. The biogas composition analyzes before and after purification, were performed on a Gas Chromatograph with Thermal Conductivity Detector (GC-TCD). The results showed that the solution of iron ions, prepared with Na2HPO4 salt was the most suitable for use in the module. It was observed by tests that may have been an effective removal of H2S occurred or a dilution of biogas in the void volume of the module, it is not possible to obtain a quantitative value for its removal.