Effective syngas cleanup and reforming using Ni/γ-Al2O3 catalyst

This work reports the performance of a selective Ni-based catalyst in tar removal and syngas reforming. Benzene was used as the model tar to optimize catalytic reaction conditions. Parameters investigated were reaction temperature (700°C to 900°C), gas residence time (0.1 s to 1.1 s), and catalyst loadings (3% to 21% of the weight of y-Al2O3 support). On the basis of the benzene test, a reaction temperature of 800°C, catalyst loading of 15wt%, and residence time of 0.3 s were chosen as optimum reaction conditions. Testing of these conditions showed that the Ni/y-Al2O3 catalyst removed more than 99% of tars in syngas in the downdraft gasifier and 98% in the updraft gasifier. Concentrations of combustible compounds of syngas also increased significantly. H2 concentration increased from 19.96% to 51.78% in the downdraft gasifier and from 23.97% to 37.39% in the updraft gasifier; CO concentration increased from 16.26% to 21.10% in the downdraft gasifier and from 22.95% to 25.64% in the updraft gasifier. The results indicate that the Ni/y-Al2O3 catalyst and associated catalytic conditions could not only effectively eliminate tars but also improve the quality of syngas in biomass gasification. Key words: gasification, Ni/y-Al2O3 catalyst, syngas reforming, tar removal