Modeling and optimization of methane dry reforming over Ni-Cu/Al2O3 catalyst using Box-Behnken design

In this work the effects of the contents of nickel (5, 7.5, 10 wt%) and copper (0, 1, 2 wt%) and reaction temperature (650, 700, 750 degrees C) on the catalytic performance of Ni-Cu/Al2O3 catalyst in methane dry reforming were evaluated using Box-Behnken design in order to optimize methane conversion, H-2/CO ratio and the catalyst deactivation. Different catalysts were prepared by co-impregnation method and characterized by XRD, BET, H-2-TPR, FESEM and TG/DTA analyses. The results revealed that copper addition improved the catalyst reducibility. Promoted catalyst with low amounts of Cu gave higher activity and stability with high resistance to coke deposition and agglomeration of active phase especially during the reaction. However catalysts with high amounts of Cu were less active and rather deactivated due to the active sites sintering as well as Ni covering by Cu-enriched phase. The optimal conditions were determined by desirability function approach as 10 wt% of Ni, 0.83 wt% of Cu at 750 degrees C. CH4 conversion of 95.1%, H-2/CO ratio of 1 and deactivation of 1.4% were obtained experimentally under optimum conditions, which were in close agreement with the values predicted by the developed model. (c) 2017 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.