Study On Catalytic Steam Reforming Of Acetic Acid For Hydrogen Production

Biomass pyrolysis is one of the efficient technologies of biomass conversion in the world. The bio-oil produced from biomass pyrolysis can be used for hydrogen production by catalytic steam reforming process, which is an economical and promising method for hydrogen production. In this paper, kinetics analysis of bio-oil combustion characteristics was carried out. Thermodynamic analysis with Gibbs free energy minimization was performed for aqueous phase reforming of acetic acid as a model compounds for hydrogen production from bio-oil. Ni-based catalysts were prepared and studied in catalytic steam reforming of acetic acid for hydrogen production, optimizing preparation of catalysts and process condition of steam reforming for acetic acid.The characteristics of combustion of bio-oil with air atmosphere were preformed by using thermogravimetric analyzer. The kinetic mechanism model was also established, and the kinetic parameters of the various stages such as pre-exponential factor and activation energy were calculated with Coats-Redfern method.Thermodynamic analysis was carried out based on steam reforming of acetic acid via Gibbs free energy minimization method. The optimal reaction conditions can be concluded as:temperature 600～800℃, S/B>6, pressure 0.1MPa.Nickel-based catalysts load on PG, γ-Al2O3 or SiO2-γ-Al2O3 support were prepared with impregnation method for catalytic steam reforming of acetic acid. The results showed that:the catalyst Ni/SiO2-γ-Al2O3 existed higher catalytic activity and stability when the reaction temperature exceeded 500 ℃. The yield of H2 as index, the optimal preparation conditions for the catalyst can be concluded as:Ni content of 15%, calcination temperature of 700 ℃, and calcination duration of 6h.Ni/SiO2-γ-Al2O3 catalysts adding additives La, were prepared with impregnation method for catalytic steam reforming of acetic acid. The results showed that adding additives La increased H2 selectivity and catalyst stability, and La content of 6%, yield of H2 was maximized. The optimal reaction conditions as follows:temperature was 700℃, S/C was 8, WHSV was 2h-1. Compared experimental values with thermodynamic calculation values, the yield of H2 trends with temperature and S/C are basically similar.