Portal de Periódicos da CAPES

High Surface Area Mn,Mg,Al-Spinels as Catalyst Additives for SO x Abatement in Fluid Catalytic Cracking Units

2009; American Chemical Society; Volume: 49; Issue: 3 Linguagem: Inglês

10.1021/ie900931t

1520-5045

Carla Maria Salerno Polato, Alexandre Carlos Camacho Rodrigues, José Luiz Fontes Monteiro, Cristiane A. Henriques,

Layered Double Hydroxides Synthesis and Applications

Mn,Mg,Al-spinels derived from hydrotalcite-like compounds with different Al/(M2+ + Al) molar ratios (0.25 and 0.50) and Mn/Mg of 0.30 were evaluated as catalysts for SOx removal under conditions similar to those found in fluid catalytic cracking (FCC) units. For both samples, the maximum rate of SOx pickup took place in the first 5 min of reaction, which is an interesting feature since the contact time inside the FCC regenerator is about 5−10 min. As to the regeneration step, propane seems to be a less effective reducing agent than hydrogen since it favored the release of SO2 as reduction product and shifted the reduction profile to higher temperatures. The results from XRD indicate that SO2 was mainly fixed as MgSO4, although the formation of MnSO4 has been indirectly evidenced. The performance of both samples for SOx uptake and sulfur release was also evaluated in the presence of CO and NO and no adverse effect was observed. The obtained results suggest that Mn-containing spinels are promising additives for SOx removal.