Preparation of NiO-Fe₂O₃/PG-γ-Al₂O₃ catalysts and its application in pyrolysis of biomass straw

The supported NiO-Fe₂O₃/Palygorskite and Gamma Alumina(NiO-Fe₂O₃/PG-γ-Al₂O₃) catalysts were prepared by deposition-precipitation and homogeneous-precipitation methods using PG-γ-Al₂O₃ as a carrier, and different approaches including EDX, XRD, SEM and N₂ isothermal adsorption-desorption were used to characterize the synthetic catalysts. Meanwhile, the catalytic pyrolysis of biomass straw was conducted to test the catalytic activity, the regenerative service life and the anti-carbon capacity of NiO-Fe₂O₃/PG-γ-Al₂O₃ catalyst in a tube furnace, and to compare with the catalytic properties of single carrier catalysts. The results indicate that the prepared PG-γ-Al₂O₃ carriers have a high specific surface area of 134.21 m²/g and the average pore size is 39.65 nm. The active components are loaded uniformly and in a good dispersion over NiO-Fe₂O₃/PG-γ-Al₂O₃ catalyst, meanwhile, the Ni-Fe alloy and the nickel-aluminum spinel structure exist simultaneously in the catalyst. The catalytic activity testing shows that the NiO-Fe₂O₃/PG-γ-Al₂O₃ catalysts have a very high catalytic activity in pyrolysis of biomass straw. It could obviously improve the quality of the gas such as the content of H₂ and CO and the calorific value. The catalytic activity, regeneration effect and anti-carbon deposition ability of NiO-Fe₂O₃/PG catalyst are better than that with single carrier catalyst.