Thibaut Esence
Hadrien Benoit
Damien Poncin
Michael Tessonneaud
Gilles Flamant
2019-12-21
<p>A laboratory-scale solar reactor prototype dedicated to calcination processes of non-metallic mineral particles is<br>
tested and characterized. The prototype consists of an indirect heating shallow cross-flow fluidized-bed reactorreceiver.<br>
It is composed of 4 compartments in series in which the particles are thermally treated with solar power<br>
in order to drive the endothermic calcination reaction. The particles are fluidized in the reactor with preheated<br>
air and are heated up to 800 °C through the front wall of the reactor receiving the concentrated solar flux (about<br>
200 kW/m2). The tests are carried out at the 1-MW Odeillo’s solar furnace (France). The thermal decomposition<br>
of a continuous stream of 9.4 kg/h of dolomite (CaMg(CO3)2) is investigated in this paper. The half decomposition<br>
of dolomite (CaMg(CO3)2 → CaCO3 + MgO + CO2) is performed with a degree of conversion of 100%.<br>
The complete decomposition of dolomite (CaMg(CO3)2 → CaO + MgO + 2CO2) is not reached because, with<br>
respect to the CO2 partial pressure in the reactor, the temperature of particles is not high enough to decompose<br>
the calcium carbonate. The calculated thermochemical efficiency (i.e. the energy absorbed by the endothermic<br>
calcination reaction compared to the solar energy provided to the system) is 6.6%. This low efficiency is neither<br>
surprising nor critical since the reactor design was not optimised with respect to energy efficiency but designed<br>
to the control of particle flow and front wall solar flux distribution. A numerical model considering the 4<br>
compartments of the reactor as 4 ideal continuous stirred tank reactors in series is developed. The model accounts<br>
for the mass and the energy balances, as well as the reaction kinetics of the half decomposition of<br>
dolomite. The model gives consistent results compared to the experimental data. These results are a proof of<br>
concept of continuous calcination reaction using concentrated solar energy in a cross-flow fluidized-bed reactor.</p>
https://doi.org/10.1016/j.solener.2019.12.029
oai:zenodo.org:3703370
eng
Zenodo
https://zenodo.org/communities/solpart
https://zenodo.org/communities/eu
info:eu-repo/semantics/openAccess
Creative Commons Attribution 4.0 International
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Solar heat in industrial process
Calcination
Cross-flow fluidized bed
Experiment
Modelling
A shallow cross-flow fluidized-bed solar reactor for continuous calcination processes
info:eu-repo/semantics/article