Intracrystalline mesoporosity over Y zeolites. Processing of VGO and resid-VGO mixtures in FCC

J.R. GARCIA; M. FALCO; U. SEDRAN

CATALYSIS TODAY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2017 vol. 296 p. 247 - 253

0920-5861

Prototypesof FCC catalysts containing 30 %wt. Y zeolite with different intracrystallinemesoporosity generated by alkaline desilication, on an inert silica matrix,were tested in cracking a conventional vacuum gasoil (VGO) feedstock, alone and mixed with anatmospheric tower residue (ATR). The experiments were performed in a fluidized bed CREC Riser Simulatorreactor (reaction time: 5-30 s, temperature: 550 °C, catalyst/feedstock: 4.5).Independently of thecatalyst, the conversions of the ATR-VGO mixture were higher than those of theVGO at the same conditions. With both feedstocks, the catalyst including thezeolite with increased intracrystalline mesoporosityand higher acidity showed a higher observed activity than the catalyst with theparent zeolite. In addition, the catalyst with the modified zeolite showedhigher selectivity to LCO, which is an intermediate product in FCC and a contributor to the diesel pool, especiallywith the ATR-VGO mixture. This effect was the consequence of the enhanced diffusion transport ofprimary product molecules in the zeolite pore system which, in diffusingfaster, have fewer chances to be further cracked. The catalyst with highermesoporosity showed higher coke selectivity, coke being less condensed, due to the higher free volume in the porous systemallowing accommodate precursors of coke.