Modeling of sorption enhanced steam methane reforming in an adiabatic fixed bed reactor

Sorption enhanced methane reforming (SER), employing a CaO-based solid as a high temperature CO2 sorbent, is generally considered to be a promising route for H-2 production. In this paper we present a dynamic pseudo-homogeneous model to describe the operation of a packed bedreactor in which the SER reaction is carried out under adiabatic conditions. This reactor can be implemented according to several process schemes, including a novel Ca/Cu looping process for hydrogen generation with inherent CO2 capture. The proposed SER model is based on the well-established principles of gassolid contact and heat transfer in fixed-bedreactors and on the kinetic expressions published in the literature that describe the main reactions involved in the process. The resulting model describes the transient performance of the SER reaction and confirms the theoretical viability of this critical reaction stage in a large scale H-2 production facility. It is demonstrated that the SER process can yield a CH4 conversion and H-2 purity of up to 85% and 95%, respectively, under operating conditions of 923 K, 3.5 MPa, a steam/carbon ratio of 5 and a space velocity of 3.5 kg/m(2) s.