Thermodynamic analysis of different methanation reactors for biogas upgrading

Abstract

Biomethane production from biogas can be increased by methanation of carbon dioxide with hydrogen through the Sabatier reaction. In this work, the performance of the methanation process is investigated under isothermal and adiabatic conditions for different temperature and pressure levels. The processes were modelled assuming equilibrium conditions, minimizing the Gibbs free energy. The results indicate that the exergy of heat removed from the process, and thereby the integration potential, increases with increasing temperature. The internal irreversibility is smaller and the heat integration potential larger for adiabatic reactors than for isothermal reactors.