Avaliação da cinética, equilíbrio e termodinâmica na dessulfurização adsortiva do dibenzotiofeno utilizando o carvão ativado da casca do coco de dendê

Abstract

The Petroleum-derived fuels are widely used worldwide and contain contaminants such as sulfur compounds (SO2, H2S, SO4 2-, H2SO4, S2-, SO3 2-) that can harm human health and the environment. Environmental legislation has helped establish standards and guidelines for reducing sulfur emissions, opening the way for the study of alternative methods for the removal of these compounds. The objective of this work was to evaluate the adsorptive desulfurization of thiophenic compounds and the efficiency of activated carbon from dendê coconut shell (CACD) with aluminum impregnation using the incipient method and oxidative treatment. Adsorption experiments (kinetics and equilibrium) with the removal of dibenzothiophene (DBT) as a single-component system, were conducted in a closed and batch system. The adsorption experiments (kinetics and equilibrium), for removal of the compound dibenzothiophene (DBT) in a single-component system, were carried out in a closed and batch system. To describe the adsorption equilibrium, isotherm models such as BET, SIPS, Freundlich, Langmuir, Tóth, and Radke-Praunitz models were used, with the SIPS model showing the best fit for the phenomenological parameters. In the equilibrium isotherm, the SIPS model had a maximum adsorption capacity (qmax) at a temperature of 30 °C of 0.6626 mmol g-1, showing a significant interference in thermodynamic models; the higher the temperature, the lower the affinity of the adsorbent to the adsorbate, and the lower the adsorption. For the kinetic data, the SIPS HSDM model was used, demonstrating that all limiting steps were completed, with the adsorption molecule having difficulty in inserting into the adsorbent, as it has micropores. The results of kinetics, equilibrium isotherms, and thermodynamics show that activated carbon from dendê coconut shell (CACD) proved to be efficient in the adsorptive desulfurization of dibenzothiophene (DBT).