"Estudo de caso da preparação da peneira molecular mesoporosa AI-MCM-41."

Abstract

The hydrorefining became a process of great importance in the petroleum industry due to the need of increasingly heavy oils treatment. In this context, the refineries are betting on the use of mesoporous molecular sieves, such as MCM-41 with Aluminum metal embedded (Al-MCM-41). This material has been widely used in refineries as a support for catalysts, particularly in the treatment of petroleum fractions contaminated by sulfur compounds, nitrogen, aromatics, olefins and oxygenates, due this one be characterized by high thermal and hydrothermal stability, surface area around 1000 m² / g, high acidity (Bronsted and Lewis), among other properties. In this context, the aim of this study was to synthesis and characterization the Al-MCM-41, assessing their viability in main hydrorefining operations. The Al-MCM-41 was synthesized hydrothermally following the of Poladi et. al., (2002) methodology, with Saha et. al,. (2008) adaptations using the SiO2/Al2O3 ratio of 32, source of aluminum and aluminum sulfate TEOS as a silica source and driver structure. The synthesized Al- MCM-41 was characterized by the techniques of XRD, FTIR, EMV and XRD at first. The synthesized product was calcined and again subjected to the same characterization techniques. The results of the presented analysis XRD and FTIR confirmed the synthesis of solid Al-MCM-41, with the formation of characteristic phase hexagonal mesoporous material. Quantitative analysis EDX showed that the chemical composition of Al-MCM-41 was essentially synthesized of silicon dioxide and aluminum trioxide, which was expected. The EMV analysis showed a material with the morphology characteristic of Al-MCM-41, with rounded and thin particles, sometimes overlapping sometimes crowded. Through the TGA curves / DTG uncalcined material was observed four regions mass loss attributed to desorption of water and drivers used, while in the calcined material were two mass loss. The analysis of physical adsorption using the BET method showed a material having low values of surface area and pore volume relative to Saha et al. al. (2008), which was the reference literature, probably due to the heat treatment was carried out in a short period of time.