The membrane-assisted chemical looping reforming concept for efficient H\u3csub\u3e2\u3c/sub\u3e production with inherent CO\u3csub\u3e2\u3c/sub\u3e capture:Experimental demonstration and model validation

\u3cp\u3eIn this work a novel reactor concept referred to as Membrane-Assisted Chemical Looping Reforming (MA-CLR) has been demonstrated at lab scale under different operating conditions for a total working time of about 100 h. This reactor combines the advantages of Chemical Looping, such as CO\u3csub\u3e2\u3c/sub\u3e capture and good thermal integration, with membrane technology for a better process integration and direct product separation in a single unit, which in its turn leads to increased efficiencies and important benefits compared to conventional technologies for H\u3csub\u3e2\u3c/sub\u3e production. The effect of different operating conditions (i.e. temperature, steam-to-carbon ratio or oxygen feed in the reactor) has been evaluated in a continuous chemical looping reactor, and methane conversions above 90% have been measured with (ultra-pure) hydrogen recovery from the membranes. For all the cases a maximum recovery factor of around 30% has been measured, which could be increased by operating the concept at higher pressures and with more membranes. The optimum conditions have been found at temperatures around 600 °C for a steam-to-carbon ratio of 3 and diluted air in the air reactor (5% O\u3csub\u3e2\u3c/sub\u3e). The complete demonstration has been carried out feeding up to 1 L/min of CH\u3csub\u3e4\u3c/sub\u3e (corresponding to 0.6 kW of thermal input) while up to 1.15 L/min of H\u3csub\u3e2\u3c/sub\u3e was recovered. Simultaneously, a phenomenological model has been developed and validated with the experimental results. In general, good agreement is observed, with overall deviations below 10% in terms of methane conversion, H\u3csub\u3e2\u3c/sub\u3e recovery and separation factor. The model allows better understanding of the behavior of the MA-CLR concept and the optimization and design of scaled-up versions of the concept.\u3c/p\u3