Solar thermochemical hydrogen production:Experimental analysis and modelling of a solar reactor for decomposition of sulphuric acidThe Hybrid-Sulphur-Cycle is a promising thermochemical cycle to produce hydrogen – as a future energy carrier – at high efficiency. For a technical realisation of this process, DLR developed a test reactor for solar decomposition of sulphuric acid during the European project HycycleS. The second reaction chamber for catalytic dissociation of SO3 was modelled using the software package Dymola®/Modelica®. Validation was successfully performed by comparing the simulation results with experimental data available from systematic testing series in DLR’s solar furnace in Cologne. As a result, the model can now be used to simulate the reactor’s behaviour for operating points not analysed experimentally and gain an in-depth understanding of the process.

Institute ofSolar Research

Dennis Thomey*, Lamark de Oliveira,

Daniel Schöllgen, Martin Roeb,

Christian Sattler

* Tel.: +49 2203 601-2936, Fax: +49 2203 601-4141,E-Mail: dennis.thomey@dlr.de

The authors thank the European Commission for co-funding the projectHycycleS in the seventh framework program (contract number 212470)and the solar furnace team in Cologne for their support.

Heat800–1200°C

OxygenWater

Hydrogen

electrolysis

H2SO4

SO3 + H2O

SO2 + O2 + H2OSolar radiation(focus 2)

Solar radiation(focus 1)

1 2 3 4 5 6 7700

750

800

850

900

Experiment Simulation

hone

ycom

b te

mpe

ratu

re [

°C]

Volume flow rate of sulfuric acid [ml/min]

1 2 3 4 5 6 70

20

40

60

80

100

SO

3 c

onve

rsio

n [%

]

Volume flow rate of sulfuric acid [ml/min]

Experiment Simulation Equilibrium