Synthetic natural gas production through CO2 methanation process

2019 edition

Andreina Alexandra Alarcón Avellán

The chemical energy storage as the power-to-gas (PtG) technology is called to play an important role in the future energy system, especially in countries where there is already a significant investment in renewable energy. This technology proves to be efficient because besides taking advantage of electricity excess, it also incorporates CO2 as a source of carbon for the production of synthetic natural gas (methane (CH4)).

The CO2 methanation is a thermochemical process carried out through the Sabatier reaction, in which CO2 is combined with H2 over a suitable catalyst to form CH4 and H2O. This reaction is highly exothermic and has an important volume decreasing. In order to obtain efficient syngas production, a compromise between thermodynamics, control temperature in the reactor, linked to the kinetics of the catalyst and hydrodynamic conditions, is essential to minimize “hot spot” that promote other secondary reactions that limits the conversion of carbon dioxide or the formation of coke causing a deactivation of the catalyst.

In this context, the design of active methanation catalyst, the working conditions, operation procedures and optimal design of a tubular fixed-bed exchanger reactor are investigated for CO2 methanation.