Low-Rank Coal Supported Ni Catalysts for CO2 Methanation

As renewable energy source integration increases, P2G technology that can store surplus renewable power as methane is expected to expand. The development of a CO2 methanation catalyst, one of the core processes of the P2G concept, is being actively conducted. In this work, low-rank coal (LRC) was used as a catalyst support for CO2 methanation, as it can potentially enhance the diffusion and adsorption behavior by easily controlling the pore structure and composition. It can also improve the process efficiency owing to its simplicity (no pre-reduction step) and high thermal conductivity, compared to conventional metal oxide-supported catalysts. A screening of single metals (Ni, Co, Ru, Rh, and Pd) on LRC was performed, which showed that Ni was the most active. When Ni on the LRC catalyst was doped with a promoter (Ce and Mg), the CO2 conversion percentage increased by >10% compared to that of the single Ni catalyst. When the CO2 methanation activity was compared at 250-500 degrees C, the Ce-doped Ni/Eco and Mg-doped Ni/Eco catalysts showed similar or better activity than the commercial metal oxide-supported catalyst. In addition, the catalytic performance remained stable even after the test for an extended time (similar to 200 h). The results of XRD, TEM, and TPR showed that highly efficient LRC-based CO2 methanation catalysts can be made when the metal dispersion and composition are modified.

Automated summary

The use of low-rank coal as a catalyst support for CO2 methanation can enhance diffusion and adsorption behavior, leading to improved process efficiency. Nickel showed to be the most active metal when supported on low-rank coal, and doping with promoters like Cerium and Magnesium further increased CO2 conversion percentage. The modified LRC-based catalysts exhibited similar or higher activity than commercial metal oxide-supported catalysts, with stable performance over extended periods.