Avaliação do coprocessamento na indústria de cimento em relação às emissões atmosféricas de NOx

Abstract

The cement industry is described as one of the sectors with high pollutant potential, as well as a significant demand for thermal and electrical energy. In the last two decades, the cement sector has experienced technological advances focusing on sustainable and more economical alternatives for fuel use, aiming to reduce production costs. Therefore, co-processing has emerged as one of the significant advancements for the cement industry. In general, waste co-processing has gained prominence in the industry and represents a fuel alternative for the partial replacement of more precious fuels in the cement sector, such as coke. It is worth emphasizing that this technique is a sustainable method for disposing of various polluting residues, providing a more environmentally suitable disposal method. This is because rotary kilns operate at extremely high temperatures, ensuring the complete destruction of the residues. Thus, the objective of this study is to evaluate the influence of waste co-processing, focusing on NOx emissions (nitrogen oxides). The gases after combustion in the furnace chimney were analyzed, using the continuous combustion gas monitoring and analysis system to determine the NOx content. Both traditional and alternative fuels were considered in the evaluation of combustion gases. With the obtained results, it was possible to assess the application of co-processing, i.e., the use of alternative fuels, and their influence on the content of NOx atmospheric emissions at the chimney outlet, comparing them with the limits recommended by CONAMA/MMA Resolution No. 499 of October 2020. The results of this research were favorable to the use of alternative fuels present in co-processing regarding NOx atmospheric emissions.