Catalytic reforming of biomass pyrolysis gas over Ni catalysts: Alumina, spent fluid catalytic cracking catalyst and char as supports

Abstract

The potential replaceability of a Ni catalyst supported on commercial α-Al₂O₃ (Ni/Al₂O₃) by Ni on biomass-derived char (Ni/Char), and Ni on spent fluid catalytic cracking catalyst (Ni/FCC) for steam reforming of biomass pyrolysis gas was investigated (14 h at 850°C, steam/carbon ratio = 5). The catalysts reformed 60–80 % of C₂-C₅ hydrocarbons, producing 2.7–4.1 mg min⁻¹ of H₂. The reforming activity of Ni/Al₂O₃ and Ni/FCC was higher compared to Ni/Char, indicating the beneficial role of metal oxide supports. The use of Al₂O₃ and FCC resulted in a lower thermo-oxidative stability of coke formed on Ni/Al₂O₃ and Ni/FCC compared to Ni/Char. Furthermore, the deposited Ni showed higher stability towards oxidation by steam into NiO in case of Al₂O₃ and FCC compared to char. According to reforming activity, H₂ production rate, coking, and Ni oxidation of the catalysts, FCC has better prospects as an alternative support in a reforming catalyst than char.