INVESTIGADORES
SEDRAN Ulises Anselmo
congresos y reuniones científicas
Título:
Novel synthesis of FCC catalyst matrix materials
Autor/es:
ULISES SEDRAN; MARISA G. FALCO; JAIME RETUERT; ALEXIS HIDROBO; CRISTIAN COVARRUBIAS; PAULO ARAYA
Lugar:
Cancún, México
Reunión:
Congreso; 1. XVIII International Materials Research Congress, New Catalytic Materials Symposium; 2009
Institución organizadora:
Sociedad Mexicana de Materiales A.C.
Resumen:
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The
catalytic cracking of hydrocarbons (FCC) develops new trends in response to
increasing demands to process heavier crudes and residual feedstocks, to
control contaminants in products and emissions, and to maximize the yields of
petrochemical materials. Consequently, the formulation of FCC catalysts is
shifting to high accessibility, resid or bottoms upgrading catalysts with
active matrices. Active matrices are either silica-aluminas or aluminas. Within
the growing interest in mesoporous materials with controlled morphology, with
pore sizes between 20 and 200 Å, one of the approaches is the production of
composites between inorganic networks, such as silica, and organic polymers. The
removal of the organic component by calcination these composites develops
porosity. Mesoporous silica-aluminas were synthesised with standard aluminium
and silicon sources by means of inorganic organic composites with the
addition of chitosan biopolymer, and compared to conventional analogous
catalysts. Some catalysts were subjected to hydrothermal treatment. The surface
areas were from 480 to 573 m2/g in the untreated samples and 300 to
430 m2/g in the hydrotreated catalysts, average pore sizes ranging
from 32 to 100 Å with sharp, unimodal distributions. The chitosan materials
showed higher surface areas and larger pore sizes than those of their non
chitosan counterparts. The most important differences in the acidic properties
were in the relationships between tetrahedral and octahedral aluminium atoms,
the chitosan materials having higher relative amounts of tetrahedral aluminium
than the conventional silica-aluminas. Evidences of stabilization in the
physical and chemical properties were observed in the chitosan-containing
catalysts. The catalytic performance was evaluated with tri-isopropylbenzene at
400 ºC,
to assess activity and accessibility, and cyclohexene at 300 ºC, to assess hydrogen
transfer properties. The highest activity and accessibility was observed in the
hydrotreated, chitosan-containing catalyst, while hydrogen transfer
capabilities were similar to those of medium unit cell sizes, equilibrium
commercial FCC catalysts.