Blends of varying ratios of castor and soybean oils were used to produce biodiesel by alkaline transesterification using the methylic route. To increase the yield of esters, an experimental study using a full 2 4 factorial design was performed to evaluate the influence of methanol:oil molar ratio, KOH concentration, temperature, and reaction time on the biodiesel produced from each blend. Yields exceeding 95% were obtained, and the highest conversion was 99.05% at 25°C with a reaction time of 20 min using 2% KOH as a catalyst and a methanol:oil molar ratio of 12:1. To reduce process costs based on the amount of methanol used without limiting the conversion to esters, a second set of process conditions was identified, in which a 98.59% conversion to esters was obtained using the same temperature, reaction time, and catalyst concentration but a different methanol:oil molar ratio (6:1).

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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.

The development of additives for FCC catalysts aiming at a greater sulfur removal in the gasoline fraction has been a priority with tougher environmental legislation demands. In this context, this study has evaluated the effect of magnesium modified beta zeolite on n-hexane cracking, and the catalytic conversion of thiophene added as contaminant. Catalytic tests’ results, performed at low conversion at 400 ºC with a WHSV of 0.83 s-1 indicate that magnesium addition increased n-hexane cracking from 37.7 to 53.6% in mols, but favored the formation of alkylated sulfur compounds over H2S production.