Abstract
MCM-36 materials containing mixed oxide pillars (MgO Al 2O 3-MCM-36, BaO Al 2O 3-MCM-36, MgO Al 2O 3 SiO 2-MCM-36, BaO Al 2O 3 SiO 2-MCM-36) were investigated as additives for the in situ reduction of NO x formed during the regeneration of coked cracking catalysts in FCC units. The additives were investigated under reaction conditions similar to the oxygen-depleted and the oxygen-enriched zone of the FCC regenerator. MCM-36-type materials with basic mixed oxide clusters in the interlayer galleries showed high NO conversions ( ∼ 85 % ) and high N 2 yields ( ∼ 80 % ) under oxygen-deficient reaction conditions. The catalytic activity of MCM-36 with alkaline earth metal aluminum oxide pillars incorporated between the zeolitic layers was higher (MgO Al 2O 3-MCM-36: 77% N 2 yield at 650 °C) compared to the nonpillared parent material MCM-22 (22%). The materials have been added in regeneration experiments to industrial (coked) FCC catalysts in a fluidized-bed reactor. The materials led to a reduction of NO emissions also in the presence of Pt-based CO combustion promoters ( ∼ 30 % NO reduction). It is speculated that Brønsted acid sites in the zeolite layers of the composite materials catalyze the reduction of NO with NH 3, which is an intermediate in the regeneration of nitrogen-containing carbonaceous deposits on deactivated FCC catalysts.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
