Modeling sorption-enhanced methane synthesis for system control and operation

To address energy transition in the immediate future, synthetic energy carriers are among the most promising options for decarbonization due to their capability to store renewable energy in the long term and rely on existing infrastructure. Methane, as a substitute for natural gas, can be produced at high purity through sorption-enhanced processes. These processes are discontinuous, they require sorbent regeneration once saturation is reached. Therefore, optimal operation of these complex systems requires the control of many time-dependent variables. In this framework, the rapid analyses that can be carried out via dynamic mathematical models could be greatly beneficial in lowering costs at the design stage. In this study, a model of a sorption-enhanced methanation system was developed and validated with experimental data. The proposed model allows the dynamic behavior of the process to be captured during production and sorbent regeneration. Insights into the process show the behavior of the sorbent bed while retaining water, demonstrating how the bed saturation occurs and how to effectively exploit it. The model potential was assessed by analyzing the alternating operation of two reactors for continuous production. The importance of bed drying was underlined to ensure the enhancement of the reaction and maximize the conversion.