Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
688135 | Chemical Engineering and Processing: Process Intensification | 2008 | 6 Pages |
Catalytic elimination of tars contained in the produced gas is crucial to improve the process of biomass gasification in circulating fluidized bed gasifier—permitting gas cleanup and increasing syngas (CO + H2) yield. Natural olivine, often used as primary catalyst, was previously improved by Ni addition. The catalyst Ni/olivine developed and tested in pilot scale showed very good performances in tar reduction and increasing H2 content in the produced gas. To understand the tar decrease, a model study in laboratory scale fixed bed reactor of toluene steam reforming is presented here. The toluene conversion obtained with Ni/olivine at 560 °C is the same as with olivine at 850 °C. Moreover, with Ni/olivine only CO, CO2 and H2 are produced but with olivine ∼20% of benzene, polyaromatics and methane are formed additionally to the previous gases. Carbon deposit characterised by TEM and TPO is negligible at 800 °C due to the specific Ni–olivine interactions. A kinetic model established, taking into consideration a zero order for water and first order for toluene gives the kinetic parameters (Ea = 196 kJ mol−1 and A(k′) = 3.14 × 1013 m3 (kgcat h)−1) comparable to those reported for steam reforming of benzene or tars on commercial nickel catalysts.