Simulation of Biogas Conversion Using Porous Solid Oxide Electrochemical Cells: Virtual Prototyping

Abstract

The computer-aided engineering approach has made it possible to achieve virtual prototypes and to describe expected performances of new apparatuses. In this study, a direct production of syngas with biogas using the configuration of the cascade conversion cell in the supply feed direction of the system was exhibited. Momentum, heat, mass and charge balances were solved using COMSOL Multiphysics® commercial software. These simulations allowed calculation of distributions of partial pressures for all gas species within the anode (CH4, H2, CO, CO2, H2O, N2), as well as velocity field and temperature. The conversion process included methane reforming (steam and dry) associated with the water–gas shift reaction. The computing results showed that the configuration of three porous oxide solid cells based on a solid oxide fuel cell (SOFC) system conferred a larger active surface area and limited thermal stress in oxide materials. In addition, depending on the production process of the biogas, feeding composition strongly influences the conversion rate of CO2 and CH4. We observed that production of syngas was optimal for a CO2/CH4 ratio = 1.

Keywords

• biogas conversion
• dry methane reforming
• steam methane reforming
• syngas production
• solid oxide electrochemical cell
• multiphysics modeling