Dynamic biogas upgrading based on the Sabatier process: thermodynamic and dynamic process simulation.

Area of Science:

• Chemical Engineering
• Renewable Energy Systems
• Biotechnology

Background:

• Biogas from anaerobic digestion is a renewable resource.
• Hydrogen from renewable energy systems offers a clean energy carrier.
• Integrating these sources for substitute natural gas (SNG) production is a key area for sustainable energy.

Purpose of the Study:

• To investigate the feasibility of SNG generation using biogas and renewable hydrogen.
• To develop and verify an integrated approach for a biogas-based Sabatier process.
• To assess the controllability of SNG quality for gas grid standards.

Main Methods:

• Thermodynamic equilibrium analysis.
• Kinetic reactor modeling and transient simulation.
• Experimental verification using a lab-scale heterogeneous methanation reactor.

Main Results:

• A single reactor setup can produce SNG meeting gas grid standards.
• SNG quality (Wobbe index, CO2 content, calorific value) is controllable via the H2/CO2 ratio.
• An optimal H2/CO2 ratio of 3.45-3.7 yields high calorific value and Wobbe index.
• Dynamic simulations confirmed rapid process start-up (minutes) for utilizing surplus renewable electricity.

Conclusions:

• The biogas-based Sabatier process is a feasible method for SNG production.
• The process is controllable and can meet gas grid specifications.
• The system efficiently integrates renewable energy sources for gas production.