Sorption-Enhanced Methanation Using CaO- and Ni-Based Catalysts as Functional Materials.

Area of Science:

• Chemical Engineering
• Catalysis
• Gas Conversion

Background:

• Synthetic natural gas (SNG) production is crucial for energy storage and utilization.
• Sorption-enhanced methanation (SEM) offers a promising route for high-purity SNG production by in-situ CO2 removal.
• Optimizing SEM operational parameters is key to maximizing methane yield and purity.

Purpose of the Study:

• To conduct a detailed parametric study of sorption-enhanced methanation (SEM).
• To identify optimal operational conditions for producing high-purity synthetic natural gas.
• To evaluate the performance and stability of functional materials under various conditions.

Main Methods:

• Parametric study of SEM using a commercial Ni-based catalyst and CaO sorbent.
• Investigation of reaction temperature, H2/CO ratio, CO space velocity, and CaO/catalyst mass ratio.
• Cycle stability testing and analysis of sintered CaO sorbent performance.

Main Results:

• Achieved high methane (CH4) purity (~90%) at 275 °C with H2/CO = 3, 0.8 kgCO/kgcat h, and CaO/catalyst ratio of 1.
• Demonstrated good cycle stability and reproducibility over 14 cycles.
• Sintered CaO sorbent showed comparable effectiveness to calcined CaO after reactivation.
• Attained 80% CH4 purity using a H2/CO/CO2 feed mixture.

Conclusions:

• Optimal operational parameters were identified for high-purity synthetic natural gas production via SEM.
• The SEM process exhibits robust stability and reproducibility with the chosen materials.
• Reactivation of sorbent materials is effective, maintaining process efficiency.
• SEM is a viable technology for producing methane from gas mixtures containing CO2.