STUDY OF BIOLOGICAL SABATIER REACTION WITH FLUID DYNAMICS SIMULATIONS

An alternative to catalytic Sabatier reaction is the biological Sabatier reaction that may be a suitable option for the future energy storage. In this paper a computational fluid dynamics analysis is carried out to study the mixing inside the anaerobic digester, to evaluate the gas to liquid mass transfer and the efficiency of this biological reaction. A detailed modeling about hydrodynamics and mixing is developed. The standard k-ε mixture turbulence model and the Eulerian-Eulerian approach are used to simulate the flow inside the anaerobic digestion. External sludge re-circulating pumps are present as system mixing. Results of simulations show that with higher liquid velocity there are the higher mass to transfer from gas to liquid and turbulent dissipation rate. A sensitivity analysis is carried out to evaluate the influence of reactor pressure on methane evolution rate and methane content in the off gas: the effect is positive for the two responses. The future construction of the anaerobic digester will provide the obtained results.