Solomon Assefa Wassie (PhD)
Membrane reactors have recently emerged as one of the most promising technologies for pure hydrogen production as these reactors integrate the catalytic reactions, mostly reforming and water-gas shift reactions for hydrogen generation, and separation through membranes in a single unit. This combination of process units brings a high degree of process intensification with additional benefits in terms of increased process efficiencies.
Recently, a novel membrane assisted fluidized bed reactor concept has been proposed for ultra-pure hydrogen production with integrated CO2 capture from steam methane reforming. The so called Chemical Switching Reforming reactor (CSR) (Figure 1) utilizes an oxygen carrier (Ni-based) which acts both as catalyst and heat carrier to the endothermic reforming reaction and is periodically exposed to fuel/steam and air streams; when air is fed to the reactor, the oxygen carrier is heated by the exothermic solids oxidation reaction, this heat is then utilized in the fuel stage where endothermic reduction and catalytic reactions regenerate the oxygen carrier and produce syngas.
This novel concept also utilizes hydrogen perm-selective membrane (Pd-membrane) to directly recover pure hydrogen produced during steam-methane reforming while simultaneously shifting steam reforming and water-gas shift reactions equilibria towards complete conversion at lower temperatures.
CSR concept brings large benefits in design simplification, scale up and ease of operation at elevated pressures. The main aim of this research is to demonstrate the technical feasibility of the novel reactor concept of CSR through dedicated experimental and modelling studies.
The development of the proposed project requires the combination of several important points that have to be studied in great detail: studies of membranes and hydrodynamics of the proposed fluidized bed reactor, studies of different oxygen carriers (catalysts), development of a phenomenological model, design of the novel reactor and finally experimental evaluation.
The objective of the project is to give a proof of principle of the CSR operated at high temperature with different oxygen carriers. The effect of membranes on the overall performance will also be investigated.