Abstract
This paper reports on the numerical analysis of a volumetric solar receiver-reactor for hydrogen production, using the 2-step reduction–oxidation cycle. A detailed parametric sweep covering hundreds of various parameter combinations is performed for a large solar reactor, using a transient physical model. We generate performance maps which are currently cost prohibitive via experimental or high–fidelity simulation studies. The following performance metrics are evaluated: solar to fuel efficiency, hydrogen yield, conversion extent and specific hydrogen yield. We show that the relations between the different performance metrics are complex, leading to different optimal points depending on the metric pursued. The daily hydrogen yield for a single reactor varied between 0.89 kg for an absorber thickness of 30 mm, and up to 1.04 kg for a 60 mm thick receiver, with solar to fuel efficiency values of 3.84% and 3.81% respectively. For a case with 45 mm thick receiver, an intermediate hydrogen yield of 0.94 kg is calculated, while exhibiting the highest efficiency (4.05%). The efficiency can be further increased to 5.86% by using a simple heat recovery system, and reach an upper limit of 21.16% with a more sophisticated heat recovery method.
Highlights
Hydrogen is a critically important energy carrier used for many applications in the chemical industry, transportation, and energy sectors
This paper reports on the numerical analysis of a volumetric solar receiver-reactor for hydrogen production, using the 2-step reductioneoxidation cycle
We have investigated various advanced concepts in the design and operation of a solar receiverereactor for hydrogen production by the 2-step redox cycle, operated with a sweep gas
Summary
Hydrogen is a critically important energy carrier used for many applications in the chemical industry, transportation, and energy sectors. The solaredriven thermochemical process for hydrogen production is a twoestep reductioneoxidation cycle, used for splitting water into hydrogen and oxygen. The high temperature heat required for the endothermic reduction reaction is achieved by using concentrated sunlight, where a metal oxide is reduced and oxygen is released. Following this step, an exothermic oxidation reaction occurs when water reacts with the reduced oxide, whereupon the water molecules split into hydrogen and oxygen, and the oxygen is absorbed back in the oxide. Families of reductioneoxidation (redox) materials have been developed and tested over the years, non-stoichiometric cerium oxide remains one of the most promising candidates for the water splitting reaction [4e7].
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call