چكيده به لاتين
Dry reforming of methane is an endothermic reaction to produce synthesis gas with a H2/CO ratio close to unity that can be preferentially used for the production of liquid hydrocarbons in the Fischer Tropcsh synthesis.
In this study, firstly Ni/Al2O3 catalyst promoted by K and Cu promoters with different metal content which are synthesized with impregnation method, was investigated. Reactor tests showed that the K as a promoter with different metal content reduced methane conversion greatly. So, K was eliminated from this study. Then, the effects of nickel (5, 7.5, 10 wt.%) and copper (0, 1, 2 wt.%) contents and reaction temperature (650, 700, 750 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, H2/CO ratio and deactivation. Different catalysts were prepared by impregnation method and characterized by XRD, BET, H2-TPR, FESEM and TGA/DTA analysis. The results revealed that Ni dispersion and reduction were improved through Ni-Cu alloy formation. So the methane conversion and stability of the catalyst promoted significantly by Cu addition up to 1 wt. %.However catalysts with higher Cu loading were less active and less stable during reaction time (7 hours) due to the aggregation of Cu rich phase over Ni active sites. The optimal conditions were determined as 10 wt. % of Ni, 0.83 wt.% of Cu and 750 C.CH4 conversion of 95.1%, H2/CO ratio of 1, deactivation of 1.4% and CO2 conversion of 95.73 % obtained experimentally under optimum conditions were in close agreement with the values predicted by the developed model.
