Catalytic Removal of Sulfur Compounds From Petroleum Streams

Abstract

Sulfur removal aiming at attending environmental legislation standards has been the focus of many studies. The use of Fluid Catalytic Cracking, FCC, in the removal of gasoline-fraction sulfur contaminants is regarded as advantageous when compared to desulfurization processes downstream of the FCC process. This paper evaluates the effect of Mg addition to the Beta zeolite over n-hexane and thiophene cracking. The catalysts were characterized by X-ray diffraction (XRD), X-ray with dispersive energy fluorescence analysis (EDXRF), Fourier transform infrared spectroscopy (FTIR), ammonia temperature programmed desorption (NH 3-TPD), and Brunauer-Emmett-Teller method (BET). The magnesium incorporation into the zeolite increased the number of Brønsted active sites and total acidity in the catalyst, favoring an increase in selectivity for catalytic cracking reactions and a decrease of isomerization reactions in the n-hexane conversion step. In thiophene conversion, the greater selectivity for hydrogen transfer promoted the formation of H 2 S, and adsorptive capacity is a key factor in alkylated product formation due to the presence of Lewis active sites, which are more predominant in magnesium incorporated catalysts.