Simulação e análise termodinâmica de uma planta de produção de ácido sulfúrico por duplo contato

Abstract

With the increasing demand for energy in the world, it is becoming more and more important to adopt practices that use energy resources more efficiently. In this sense, the techniques based on the first and second law of thermodynamics play a fundamental role in the industrial sector, which is the world's largest energy consumer. In this context, this study aims to investigate how it is possible to optimize the use of energy resources in a sulfuric acid production plant through thermodynamic analysis. This analysis allowed us to identify the thermodynamic efficiency of the plant and pinpoint the equipment responsible for the greatest loss of work. The simulation of the double contact sulfuric acid production process was carried out using the UniSim Design process simulator, and Aspen Plus was used to determine the enthalpy and entropy of each process stream, variables that are used in thermodynamic analysis. The results of the analysis showed that the furnace is the main contributor to the plant's work loss, accounting for 59% of the total. This result is consistent with previous studies conducted by other authors. The thermodynamic efficiency of the plant was identified as low, also in agreement with the literature, reaching only 17.05%. Based on these results, a simulation of a new plant was carried out with temperature adjustments in some of the process streams, aimed at increasing thermodynamic efficiency. The new plant showed a significant reduction in work loss in the intermediate absorption tower by 32.52% and saved nearly 6,000 kW of energy compared to the original plant. Additionally, the thermodynamic efficiency of the new plant increased to 18.59%, representing an improvement over the original plant. These results are important for the industry, as they show how thermodynamic techniques can be applied to improve energy efficiency in industrial processes, contributing to a more sustainable economy and the preservation of the environment.