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Vanadium oxide-porous phosphate heterostructure catalysts for the selective oxidation of H2S to sulphur.
|Marta León 2, Jose Jimenez Jimenez 2, Antonio Jimenez-Lopez 2, Enrique Rodriguez Castellon 2, María Dolores Soriano 1, José Manuel Lopéz Nieto 1|
1. Instituto de Tecnología Química UPV-CSIC (ITQ), avda. de los Naranjos s/n, Valencia 46022, Spain
Current stringent environmental regulations oblige to treat hydrogen sulphide (H2S) emissions originated in petroleum refineries and gas plants. Claus and Super Claus processes are the most common used, but due to thermodynamic limitations a relevant percentage of H2S is not converted to sulphur in the Claus process, and high concentration of H2S (2% vol) cannot be treated with the Super Claus technology. Vanadium oxide catalysts supported on mesoporous materials, based on a surfactant expanded zirconium phosphate with silica galleries into the interlayer space, named porous phosphate heterostructure (PPH), were prepared by using TEOS and vanadium oxitripropoxide in n-propanol as sources of Si and V, respectively; with different Si/V molar ratios of 1, 2, 5 and 25; and calcining at 550 ºC for 6 hours. Using this method, vanadium is incorporated to the structure of the gallery, but the surface area strongly decreases with the increase of the vanadium content. The solids obtained were denoted V-yPPH, where y is the Si/V molar ratio added. The catalysts were characterised before and after catalysis by XRD, XPS, TEM, FT-IR and Raman, and tested in the selective catalytic reduction of H2S using a fixed bed reactor, at atmospheric pressure, at 180-260 ºC. The catalysts with high contents of vanadium, samples V-1PPH and V-2PPH are very active at 200 ºC, showing H2S conversions of 85-99%, with a high selectivity to elemental sulphur and with a low formation of SO2.
Presentation: Oral at E-MRS Fall Meeting 2008, Symposium D, by José Manuel Lopéz Nieto
See On-line Journal of E-MRS Fall Meeting 2008
Submitted: 2008-05-12 18:22 Revised: 2009-06-07 00:48