Start-and-Stop Operation of Fixed-Bed Methanation Reactors - Results from Modeling and Simulation

The production of synthetic natural gas (SNG) from renewable sources in cases requires a dynamic and intermitted operation of the methanation reactors. This may lead to catalyst damage. Therefore, the present work is aiming at identifying restrictions and optimization approaches of the start-and-stop operation of fixed-bed methanation reactors. 2D modeling and simulation work is conducted and the warm-start behavior of a fixed-bed reactor after one to four hours operation intermittence is analyzed. The result reveals the possibility for an operation interruption of up to four hours without high adaptation effort to restart the reactor. After approximately four hours, the catalyst bed at the inlet part of the reactor reaches a temperature that provokes problems for a subsequent warm start.