Fisher-Tropsch Synthesis on Alumina Supported Iron-Nickel Catalysts: Effect of Preparation Methods

Two 40 % Fe/60 % Ni/Al2O3 catalysts were prepared using incipient wetness (catalyst A) and co-precipitation (catalyst B), and the activity and selectivity to light olefins in Fischer-Tropsch Synthesis (FTS) has been studied in a fixed-bed reactor under different operating conditions. These conditions were: temperature 220–270 °C, Pressure 1–15 bar, H2/CO molar ratio 1–3 and gas hourly space velocity (GHSV) 1600–5600 h–1. The optimum operating conditions were found for each catalyst and were used to study catalytic performance after stabilization. The results showed that these catalysts were highly stable and retained activity and selectivity for 240 h. The results also showed that the incipient wetness catalyst had a higher activity, higher selectivity to light olefin and C5+ products and lower selectivity to methane and water-gas shift (WGS) activity after stabilization. Also, it was found that higher iron dispersion enhances the negative effects of water such as low CO conversion, low olefin selectivity and higher methane and CO2 selectivity