Abstract
Theoretical analysis of an alternative process for hydrogen production through steam methane reforming (SMR), based on the concept of adsorption-enhanced reaction, is presented. This approach can improve reactant conversion and establish a more favourable reaction equilibrium than that of a conventional reactor. As a result, relatively low operating temperatures are possible for a given conversion. In the proposed process, mobile (pneumatically conveyed) adsorbent particles are passed through a stationary SMR catalyst monolith. Adsorbent regeneration is carried out in an external regeneration unit, thus decoupling the reaction and adsorbent regeneration steps. Heat for reaction is also supplied via the regeneration unit (i.e. via the thermal capacitance of the adsorbent), and thus effective energy integration is possible between the reactor and regenerator units. A mathematical model accounting for non-isothermal reaction and adsorption, mass transfer limited adsorption kinetics and non-linear (Langmuirian) adsorption equilibria, has been developed. The performance of the adsorptive reactor in terms of conversion enhancement is presented in this paper. Simulation results indicate considerable reaction enhancement through the use of a flowing adsorbent medium. The importance of the correct selection of operating parameters on the process feasibility is also highlighted.