Dynamic methanation of carbon oxides

Dynamic methanation of carbon oxides

The hydrogenation of carbon oxides (CO, CO2) with hydrogen, produced by renewable energies, to synthetic natural gas (SNG) is gaining increasing interest for energy storage applications. This is also denoted as the "Power-to-Gas" process. Due to the fluctuating supply of hydrogen, based on the renewable power source, a dynamic operation of the methanation reactor can be possible. However, chemical reactors are usually designed for and operated in a steady-state mode. This imposes new requirements on the reactor and the catalyst. Designing the reactor for the dynamic operation demands profound knowledge of the transient behavior of the reaction on the catalyst scale, especially the kinetics. The aim of this project is the experimental investigation of the methanation kinetics on Ni catalysts during dynamic operation and the determination of approaches to thoroughly describe the processes on the catalyst and in the reactor.

The kinetics of the CO2 methanation on Ni is experimentally studied with a laboratory unit equipped with a fixed-bed reactor and a Berty reactor whereby steady-state as well as dynamic methods are applied. The kinetic measurements are assisted by detailed adsorption and desorption investigations. Microkinetic models are generated with a "Reaction Mechanism Generator" (RMG), for which density functional theory (DFT) calculations are required to determine the thermochemistry of the adsorbates and transition states of elementary steps. The combination of transient experiments with microkinetic modeling allows sophisticated insights into the mechanism of the methanation reaction, which enables the derivation of suitable kinetic approaches for the dynamic methanation.

More information:
https://rmg.mit.edu/