465019 Modeling Catalyst Deactivation in a Packed Bed Reactor for Thermo-Catalytic Hydrogenation of CO2
Modeling catalyst deactivation in a packed bed reactor for thermo-catalytic hydrogenation of CO2
Duo Sun and David Simakov
Department of Chemical Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
Converting CO2 into synthetic fuels and chemicals is an attractive route to reduce CO2 emissions and, at the same time, fossil fuels consumption. There are several pathways, including thermocatalytic conversion via Sabatier reaction (CO2 + 4H2 = CH4 + 2H2O) to produce synthetic natural gas [1-4]. Some technological issues are yet to be resolved in order to make this process truly viable economically, including catalyst deactivation by sintering and carbon formation. Sabatier reaction is highly exothermic which can lead to reactor overheating, catalyst sintering and accelerated methane cracking producing large amounts of coke. We developed a transient numerical model to study the effects of catalyst deactivation on the performance of the heat-exchanger type packed bed CO2 hydrogenation reactor. Our results show that catalyst deactivation can significantly limit CO2 conversion under certain operating conditions, changing also products distribution. On the other hand, the presence of H2 in the reaction mixture and the generation of H2O lead to in situ catalyst reactivation. Our model predicts that, with a proper design, it is possible to operate the reactor at reasonably high CO2 conversions (e.g. 80% CO2 conversion after 1,000 h on stream) even using Ni-based catalysts which are prone to coking.
References
[1] Rönsch, S. et al. Review on methanation From fundamentals to current projects. Fuel 2016, 166, 276-296.
[2] Schaaf, T. et al. Methanation of CO2 storage of renewable energy in a gas distribution system. Energy Sustain. Soc. 2014, 4, 29.
[3] Götz, M et al. Renewable Power-to-Gas: A technological and economic review. Renew. Energ. 2016, 85, 1371-1390.
[4] Gahleitner, G. Hydrogen from renewable electricity: An international review of power-to-gas pilot plants for stationary applications. Int. J. Hydrogen Energ. 2013, 38, 2039-2061.
See more of this Group/Topical: Catalysis and Reaction Engineering Division