Session: 06-03 Novel Reactors and Processes

Paper Number: 117923

117923 - Solar Hydrogen Production With a Membrane Reactor: Process Description and Reactor Design. 

Hydrogen plays a key role in the energy transition towards a decarbonised economy. According to the 2030 Net Zero Scenario[1], global H₂ demand is expected to reach about 180 Mt, since this fuel will be used by important sectors of our economy such as heavy-duty transport, shipping, aviation, as well as heavy industry. To cover the expected hydrogen demand, improvement of existing technologies as well as development of new systems is needed. Solar thermal energy is an attractive option to power membrane-supported steam thermolysis for hydrogen production. Compared to two-steps Solar Thermochemical Water Splitting (STWS) cycles, solar membrane reactors are inherently operated under isothermal conditions and also don’t require a pressure swing. The isothermal process avoids the need for heat recovery between the oxidation and reduction steps, which is one of the main challenges of two steps STWS cycles. In the scope of the MESOWAS[2] project, a membrane reactor for the production of hydrogen from steam is being developed and analysed. The ceramic membrane reactor is based on the Jülich design concept of a F10 stack of solid oxide cells [3]. The steam flow is supplied to one side of the oxygen-permeable membrane, while the oxygen is continuously removed on the other side. Two approaches to guarantee a constant low oxygen partial pressure on the permeate side of the membrane are considered: Sweep gas or the partial oxidation of biomethane. The chosen flat membrane geometry allows the combination of multiple membrane layers in a single stack, which can facilitate the upscaling of this design. The coupling of the membrane reactor with solar thermal energy is analysed regarding a required homogeneous temperature distribution for the membrane stack, and a strategy for the planned experimental demonstration is developed. Using the model presented by Bulfin[4], the thermodynamic limit of an ideal countercurrent membrane reactor is identified, and an operating strategy to produce hydrogen is determined.

Key words: hydrogen production, solar thermal energy, membrane reactor.

[1] IEA (2022), Hydrogen, IEA, Paris https://www.iea.org/reports/hydrogen, License: CC BY 4.0

[2] MESOWAS: Membrane-basierte solar-thermische Kreisläufe für die Synthese von grünem Wasserstoff, Bundesministerium für Bildung und Forschung (BMBF.722), 03SF0648A.

[3] Q. Fang et al., “Performance and degradation of Solid Oxide Electrolysis Cells in Stack”, Journal of The Electrochemical society, 2015, 162.

[4] B. Bulfin, “Thermodynamic limits of countercurrent reactor systems, with examples in membrane reactors and the ceria redox cycle”, Phys. Chem. Phys., 2019, 21.

Presenting Author: Juan Pablo Rincon Duarte German Aerospace Center (DLR) - Institute of Future Fuels

Presenting Author Biography: M. Sc. Juan Pablo Rincon Duarte is a mechanical engineer with a master in renewable energy systems from the TU-Berlin. He has been working on solar thermochemical processes using solar thermal energy at the German Aerospace Center (DLR) since Sep. 2018. He is currently a PhD candidate from the RWTH University at the chair for Solar Fuel Production - Faculty of Mechanical Engineering in Germany. Main topics of his research is decarbonisation of industry as well as design of solar reactors.