Multimetallic Anionic Clays and Derived Products for SOx Removal in the Fluid Catalytic Cracking Process

摘要

The present invention relates to the preparation of Multimetallic Anionic Clays (MACs) through a simple method, which are then shaped by spray-drying into microspheres with adequate mechanical properties, suitable to be fluidized. The microspheres are appropriate for application as additives in the Fluid Catalytic Cracking (FCC) process, i.e. blended with the conventional catalyst, to in situ remove sulfur oxides (SOx) from the combustion gases produced in the regeneration stage of the FCC process, when cracking sulfur-containing hydrocarbon feeds. An oxidation promoter is added to the MACs in order to promote the oxidation of SO2 to SO3, a key step in SOx removal, providing more efficient and versatile materials, which are apt to be used in atmospheres with variable oxygen concentration.

主权项

1. A composition for removing sulfur oxides from combustion gases in a catalytic hydrocarbon cracking process, wherein said composition comprises particles of multimetallic anionic clays (MACs) having the formula:
[MgxAlyFez(OH)2](An−(y+z)/n)[CeO2]p.mH2O wherein Mg, Al and Fe are metals forming layers of the multimetallic anionic clay and wherein Ce is present in an amount effective as an oxidant promoter, and wherein Ce is present as cerium oxide highly dispersed on the inside of said MAC particles; An− denotes an anion located between the layers formed by the metal cations; n represents the interlaminar anion's negative electronic charge from −1 to −8; m is the molecules of water present as hydration water or as water present in the interlaminar region and is from 0 to 2; where x=0.667 to 0.833, y=0.001 to 0.275, z=0.055 to 0.256, p=0.029 to 0.110; and wherein said multimetallic anionic clay is obtained by a process including the steps of mixing MgO in an acidified aqueous media to obtain a suspension containing a layered structure of Mg(OH)2; dissolving CeNO3 and Fe(NO3)2 in an aqueous media to form a mixture, adding beohmite to said mixture and mixing for a time sufficient to form a gel; combining said suspension containing the Mg(OH)2 and said gel and mixing to form a slurry of said multimetallic anionic clay; and spray drying said slurry to obtain microspheroidal particles of said multimetallic anionic clay.