Development of Pilot-Scale CO2 Methanation Using Pellet-Type Catalysts for CO2 Recycling in Sewage Treatment Plants and Its Validation through Computational Fluid Dynamics (CFD) Modeling

In this study, a pilot-scale reactor was designed and compared using computational fluid dynamics (CFD) for a high-efficiency CO2 methanation reaction. The trends of the CO2 methanation catalyst efficiency at a pilot or industrial scale could be lower than those measured at the laboratory scale, owing to the flow of fluid characteristics. Therefore, the CO2 methanation reactor was designed based on the results of the CFD analysis to minimize the above phenomenon. Ni–Ce–Zr was used to manufacture a CO2 methanation catalyst in the form of pellets. The catalyst successfully produced about 43.3 Nm3/d of methane from the reactor. This result shows that CO2 methanation, which is known as an exothermic reaction, was stable at the pilot scale. It is believed that the self-supply of energy will be possible when this CO2 methanation technology is applied to industrial processes generating large amounts of CO2 and H2 from by-product gases.

In situ synthesis of methane using Ag–GDC composite electrodes in a tubular solid oxide electrolytic cell: new insight into the role of oxide ion removal

In situ synthesis of methane in a single-temperature zone SOEC in the absence of any methanation catalyst is a completely electrochemical phenomenon governed by the thermodynamic equilibrium of various reactions.

Study on syngas methanation mechanism over Ni4/MCM-41 catalyst based on density functional theory

The density functional theory method is employed to systematically explore the mechanism of syngas methanation on the Ni4/MCM-41 catalyst surface. The calculation results show that the optimal pathway of CH4 formation is CO + H → CHO + H → CH2O + H → CH3O → CH3 + H → CH4 with the rate-determining step of CH3O direct dissociation. Because the activation energy for the direct dissociation of CH3O species is much lower than that for the CH3OH formation (198.6 vs 264.8 kJ mol−1), there is almost no by-product CH3OH that appeared in the products of the syngas methanation over the Ni4/MCM-41 catalyst. Compared with other conventional nickel-based methanation catalysts, Ni4/MCM-41 catalyst is an excellent methanation catalyst with high selectivity of CH4.

Screening of Additives to Ni-Based Methanation Catalyst for Enhanced Anti-Sintering Performance

The resistance to sintering of Ni/Al2O3 catalysts with different additives for methanation reaction was modeled and predicted by data mining. In the screening, the resistance to sintering of Na, Ca, Ce, Mg, La, Cu, Zn, Zr, In, Mo, and Ti promoted Ni/Al2O3 catalyst were measured in terms of the increased rate of the size of the metallic nickel particles. The resistance to sintering of catalysts, described by the increased rate of Ni particle size as well as basic physicochemical properties of the 11 selected elements, was adopted for optimization model construction by data mining. Through regression model prediction and experimental verification, Cs was found to be an additive, and promotes the resistance to sintering mostly for Ni/Al2O3 catalysts. This result provides further evidence that data mining techniques can be employed as a highly efficient tool for the discovery of new catalysts in comparison with the traditional experimental method.