Modelling of sorption-enhanced steam methane reforming in a fixed bed reactor network integrated with fuel cell

In this study sorption-enhanced steam methane reforming (SE-SMR) in fixed beds is investigated by means of 1D numerical modelling, and the model is validated with the data reported in the literature. Isothermal conditions (973 K) are considered, and the equilibrium between the carbonation and calcination stages is shifted by a pressure swing: 3.5 · 10⁶ Pa and 1013 Pa, respectively. The results showed that under these operating conditions at least 8 reactors in parallel are required to continuously produce a high-purity stream of H₂, and a separated stream of concentrated CO₂. The average H₂ purity is 0.92, whilst the average H₂ yield and selectivity are 2.9 mol_H2 mol_CH4⁻¹ and 90%, respectively. A thermodynamic analysis was performed, which highlighted that, by using a portion of the produced H₂ (about 0.4 mol_H2 mol_CH4⁻¹), it is possible to fully cover heat and power demands of the process, making it completely energy self-sufficient. In the case when the proposed SE-SMR is integrated with a solid oxide fuel cell, net power generation at the scale of ∼950 kW_el can be achieved with a net efficiency of the entire system of 51%, with the important feature that CO₂ is concentrated.