Fosfato de alumínio como matriz em catalisadores de craqueamento catalítico em leito fluidizado

Abstract

The objective of this Thesis is to investigate aluminum phosphates (AlPO4) as matrix of fluid catalytic cracking (FCC) catalysts in terms of catalytic activity for feedstock pre-cracking and binding effect. The study comprises the characterization of aluminum phosphates by varying reagent sources, pH and Al/P molar ratio; the characterization of composites to investigate the effect of aluminum phosphates on the hydrothermal stability of Y zeolite; catalytic evaluation of catalysts containing AlPO4 by vacuum gasoil cracking. Although it does not act as a binding agent, amorphous AlPO4 with Al/P molar ratio 1,0 is an effective active matrix, providing the gasoil pre-cracking. The interaction between AlPO4 and Y zeolite inhibits AlPO4 crystallization under steaming, which preserves their mesopores and favors the effective transport of reagents and products to and from the zeolite active sites. The second remarkable consequence of such interaction is an increase of the rate of hydrogen transfer reactions, in comparison with an alumina-containing reference catalyst, providing a significant increase in aromatics yields, with no reduction of liquid products yields.