Simulação de colunas de destilação para produção de etanol hidratado: avaliação do impacto de parâmetros de processo nas perdas de etanol nas correntes de resíduos

Abstract

In response to the growing demand for mitigating environmental impacts, ethanol has emerged as a promising alternative in the transition to a more sustainable energy matrix. In the conventional process adopted by Brazilian distilleries for obtaining hydrated ethanol, two distillation columns, referred to as columns A and B, are used. In these columns, the wine resulting from fermentation, with an alcohol content of 8 to 12% v/v, is processed to produce hydrated ethanol with an alcohol content of 92.5 to 94.6% w/w. Vinasse and phlegmasse residues are by-products generated during ethanol production, with vinasse being the bottom stream of column A and phlegmasse the bottom stream of column B. The efficiency of the distillation process is evaluated by the ratio between the amount of ethanol recovered and the amount of ethanol initially present in the wine feed. To ensure adequate ethanol recovery efficiency, alcohol losses in the vinasse and phlegmasse streams must be maintained below 0.02% v/v. This study aims to simulate a real distillation apparatus to produce hydrated ethanol fuel using Aspen Plus® software, developed by Aspen Tech. The simulation enables the construction of a model to be used for future evaluations, as well as the analysis of the impact of fluctuations in process parameters, such as steam flow rate, on ethanol losses in the vinasse and phlegmasse streams. The steam consumption obtained in the simulation was 2.28 kg/L of ethanol, and an inverse proportionality was observed between steam consumption and ethanol losses in the residue streams. The simulated temperatures showed a good correlation with the operational conditions of the real equipment, reinforcing the representativeness of the developed model.