Chinese Journal of Chemical Engineering, Vol.28, No.6, 1628-1636, 2020
Promotion effect of Re additive on the bifunctional Ni catalysts for methanation coupling with water gas shift of biogas: Insights from activation energy
The cheap manganese sand was first modified by H2O2 and was further creatively utilized as Ni-based catalyst support. In order to enhance the catalytic performance, Re was added into the Ni-based catalyst and the promotion effect of Re on the methanation coupling with water gas shift of biogas was investigated from the perspective of activation energy. It was found that CH4 and CO2 formation rates, which separately represented the reaction rate of methanation and water gas shift, were both enhanced after Re addition compared to non-added catalyst. Two kinetics models including empirical model and K-model were employed and from the results of calculation. it showed that Re selectively decreased the activation energy of methanation reaction and had little impact on the activation energy of water gas shift. The increased CO2 formation rate was owing to the assistance of accelerated H2O production from methanation rather than the activation energy change in water gas shift. (C) 2020 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co.. Ltd. All rights reserved.