The membrane-assisted chemical looping reforming concept for efficient H2 production with inherent CO2 capture: Experimental demonstration and model validation. (1st April 2018)

• Record Type: Journal Article
• Authors: Medrano, J.A.; Potdar, I.; Melendez, J.; Spallina, V.; Pacheco-Tanaka, D.A.; van Sint Annaland, M.; Gallucci, F.
• Is Part Of: Applied energy. Volume 215(2018)
• Page Start: 75
• Page End: 86
• Publication Date: 2018-04-01
• Subjects: Membrane reactor -- H2 production -- Chemical Looping -- Steam methane reforming; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2018.01.087
• Languages: English
• ISSNs: 0306-2619

Abstract

Graphical abstract: Highlights: A new reactor concept has been experimentally demonstrated at lab-scale. A phenomenological model has been developed and validated with experimental data. Methane conversions above 90% at intermediate temperatures. Hydrogen recoveries above 30% at low pressure operation. Abstract: In 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 CO2 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 H2 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% O2 ). The complete demonstration has been carried out feeding up to 1 L/min of CH4 (corresponding to 0.6 kW of thermal input) while up to 1.15 L/min of H2 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, H2 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.