Novel catalyst for cracking of biomass tar

Cracking of biomass tar was investigated over Ni/dolomite catalyst prepared by the incipient wetness method using modified dolomite as precursor. Modified dolomite was prepared by mixing Fe₂O ₃ powders with natural dolomite powders to increase Fe ₂O₃ content for higher activity of tar cracking. Four other catalysts (natural dolomite, modified dolomite, ICI-46-1, and Z409) were tested and compared with Ni/dolomite catalyst. The effects of temperature, steam-to-carbon, and space velocity on tar conversion were explored. Ni/dolomite is shown to be very active and useful for tar removal. A 97% tar removal is easily obtained at catalyst temperature of 750 °C and space velocities of 12 000 h^-1. The minimum S/C ratio for Ni/dolomite was 2.5 at a catalyst temperature of 750 °C to prevent the formation of the coke on the catalyst. No obvious deactivation of catalyst was observed in 60 h on-stream tests. Compared with the Ni-based catalysts (ICI-46-1, Z409), Ni/dolomite catalyst is cheap and has also excellent activity and anticoke ability.