Aluminosilicates supported La-containing sulfur reduction additives for FCC catalyst: Correlation between activity, support structure and acidity

Mesoporous silica oxides MCM-41, SBA-15 and SBA-16 were synthesized and modified to form aluminosilicates with Al/Si atomic ratio of 1/400. In order to improve thermal and mechanical stability the alumina phase was intercalated. The resulted Al-MCM-41/Al2O3, Al-SBA-15/Al2O3, Al-SBA-16/Al2O3 supports were impregnated with 5% lanthanum and tested as sulfur reduction additives to equilibrium microspherical zeolite-containing cracking catalyst (e-cat). The well-ordered pore arrangement and incorporation of alumina atoms into mesoporous framework were confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and Al-27 solid-state magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy. To compare the sulfur reduction activity with respect to the nature of the support, the textural properties and acidity were studied by low-temperature nitrogen adsorption/desorption (N-2 adsorption/desorption) and temperature programmed desorption of ammonia (NH3-TPD) techniques. Catalytic cracking of vacuum gas oil (VGO) over e-cat mixed with mesoporous supported La additives (10 wt%) synthesized was carried out on a micro activity testing (MAT) laboratory unit at 500 degrees C and catalyst/feedstock weight ratio of 3.4 to compare the morphology of mesoporous structure and sulfur reduction activity. In order to assess the support effect on catalytic performance a comparative study of La/Al2O3 and mesoporous La supported additives was carried out. Hydrothermal stability of additives was also studied by means of steaming procedure at the temperature of 700 degrees C (100% steam) for 2 h.