Synthesis and characterization of vanadium species coated on alumina, magnesium oxide and hydrotalcite supports to SOx removal

Authors: Thiago Crispim da Silva, Evandro Brum Pereira, Rafael Pereira dos Santos, Benoit Louis, Jean-Philippe Tessonnier, Marcelo Maciel Pereira

Abstract:
Vanadium oxide catalysts coated on MgO, Al₂O₃ and mixed oxide (obtained by thermal treatment of hydrotalcite) were synthesized and thoroughly characterized by X-ray fluorescence, textural analysis, temperature-programmed reduction (TPR), UV–vis with diffuse reflectance (DRS), XRD, SEM-EDX and XANES. The V₂O₅ loading was kept around 5 wt.% for all catalysts. The existence of vanadium preferential location in the vicinity of magnesium was ascertained for the mixed oxide. It has been proposed that the vanadium location and its dispersion are governed by the basic magnesium. The DeSOx tests were carried out gravimetrically in a TGA/MS system at similar temperature conditions of those used in FCC units. The vanadium addition to MgO and MgO + MgAl₂O₄ supports led to an increase of SO₃ pick-up efficiency (the absorption rate was multiplied by two to all supports in presence of vanadium) and the amount of SO3 was largely increased upon vanadium addition to both pristine MgO and mixed oxide. The reduction step of sulfate to H₂S and water at lower temperature was also largely improved in presence of vanadium; this value increased five and four times for V/MgO and V/MgO + MgAl2O4 catalysts, respectively.

Keywords:
Hydrotalcite
Vanadium
Magnesium
XANES
DeSOx

Published in: Applied catalysis A: General  (Volumes 462–463, Pages 1-310, 10 July 2013)

Publisher: Elsevier      

ISSN Information: 0926-860X

Synthesis and characterization of vanadium species coated on alumina, magnesium oxide and hydrotalcite supports to SOx removal

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