Estudo da utilização de processo contínuo em coluna de leito fixo para adsorção de compostos sulfurados e nitrogenados presentes em combustível diesel

Abstract

In a brief history of oil consumption and, more specifically, the consumption of diesel oil, one can observe a growing trend due to urbanization and transport demand. While facilitating the logistical issue, this increase in consumption is linked to environmental fuel and damage to the population's health due to the release of pollutants. With a view to solving this problem, new – and more rigorous – legislation standards were created and, to follow the requirements, contaminant removal processes are employed. As sulfur (S) and nitrogen compounds are the main ones, desulphurization, and denitrogenation of diesel fuel are areas for improvement. The main process is hydrotreatment, which involves the hydrogenation of the aromatic rings, through their intervention in the contaminants present in the petroleum fractions. There are factors that resulted in the efficiency of this process such as temperature, pressure, technology, and catalyst used. Other finishing processes (complementary to hydrotreatment to reach the required content) are used, with adsorption in fixed bed columns being the main focus of this work. In this physical process of separation, adsorbents are employed that adhere to a surface or interface, retaining another material, called adsorbate, in its vicinity. In order to predict the adsorption behavior, adsorption models are used. Research shows that this is an efficient process and that the choice of adsorbents is an important factor when analyzing the viability of the process, due to the need to pay attention to the characteristics of the hydrocarbon to be treated, the operating temperature, and pressure, the desired process efficiency, in addition to the cost and availability of selective adsorbents. In this line, there are opportunities for the use of new adsorbent materials for nitrogen and sulfur removal in fixed bed adsorption columns, such as transition metals of specific periods, such as period 4, studied in a recent work presented in 2022, which proved that their use is efficient.