Solar hydrogen from a manganese oxide based thermochemical cycle

A novel system composed by an aqueous slurry prepared by MnO and NaOH mixture was tested for the hydrogen production in the sodium manganese oxide thermochemical cycle. The hydrogen evolution occurs at lower temperature than conventional mixtures utilized in the cycle. Experiments performed in a Temperature Programmed Desorption/Reaction apparatus (TPD/TPR) have evidenced hydrogen production around 500°C. The hydrolysis step of α-NaMnO2 has been studied and the importance to conduct hydrolysis reaction under inert gas is discussed. A manganese disproportion mechanism is hypothesized to explain the appearance of manganese (II) and manganese (IV) containing phases.

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Techno-Economic Assessment of Solar Hydrogen Production by Means of Thermo-Chemical Cycles

Energies ◽

10.3390/en12030352 ◽

2019 ◽

Vol 12 (3) ◽

pp. 352 ◽

Cited By ~ 9

Author(s):

Massimo Moser ◽

Matteo Pecchi ◽

Thomas Fend

Keyword(s):

Hydrogen Production ◽

Nickel Ferrite ◽

System Analysis ◽

Meteorological Data ◽

Economic Assessment ◽

Base Case ◽

Thermochemical Cycle ◽

Case Scenario ◽

Solar Hydrogen ◽

Solar Hydrogen Production

This paper presents the system analysis and the techno-economic assessment of selected solar hydrogen production paths based on thermochemical cycles. The analyzed solar technology is Concentrated Solar Power (CSP). Solar energy is used in order to run a two-step thermochemical cycle based on two different red-ox materials, namely nickel-ferrite and cerium dioxide (ceria). Firstly, a flexible mathematical model has been implemented to design and to operate the system. The tool is able to perform annual yield calculations based on hourly meteorological data. Secondly, a sensitivity analysis over key-design and operational techno-economic parameters has been carried out. The main outcomes are presented and critically discussed. The technical comparison of nickel-ferrite and ceria cycles showed that the integration of a large number of reactors can be optimized by considering a suitable time displacement among the activation of the single reactors working in parallel. In addition the comparison demonstrated that ceria achieves higher efficiency than nickel-ferrite (13.4% instead 6.4%), mainly because of the different kinetics. This difference leads to a lower LCOH for ceria (13.06 €/kg and 6.68 €/kg in the base case and in the best case scenario, respectively).

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Manganese oxide films with controlled oxidation state for water splitting devices through a combination of atomic layer deposition and post-deposition annealing

RSC Advances ◽

10.1039/c6ra19188f ◽

2016 ◽

Vol 6 (100) ◽

pp. 98337-98343 ◽

Cited By ~ 27

Author(s):

Felix Mattelaer ◽

Tom Bosserez ◽

Jan Rongé ◽

Johan A. Martens ◽

Jolien Dendooven ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Atomic Layer Deposition ◽

Manganese Oxide ◽

Atomic Layer ◽

Post Deposition Annealing ◽

Solar Hydrogen ◽

Layer Deposition ◽

Thin Film Catalysts ◽

Post Deposition

Manganese oxide thin films were obtained by a combination of atomic layer deposition and post-deposition annealing, and the viability of these thin films as thin film catalysts for solar hydrogen devices has been demonstrated.

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