This work reports on the development of a transient heat transfer model of a solar receiver–reactor designed for thermochemical redox cycling by temperature and pressure swing of pure cerium dioxide in the form of a reticulated porous ceramic (RPC). In the first, endothermal step, the cerium dioxide RPC is directly heated with concentrated solar radiation to 1500 °C while under vacuum pressure of less than 10 mbar, thereby releasing oxygen from its crystal lattice. In the subsequent, exothermic step, the reactor is repressurized with carbon dioxide as it cools, and at temperatures below 1000 °C, the partially reduced cerium dioxide is re-oxidized with a flow of carbon dioxide. To analyze the performance of the solar reactor and to gain insight into improved design and operational conditions, a transient heat transfer model of the solar reactor for a solar radiative input power of 50 kW during the reduction step was developed and implemented in ANSYS cfx. The numerical model couples the incoming concentrated solar radiation using Monte Carlo ray tracing, incorporates the reduction chemistry by assuming thermodynamic equilibrium, and accounts for internal radiation heat transfer inside the porous ceria by applying effective heat transfer properties. The model was experimentally validated using data acquired in a high-flux solar simulator (HFSS), where temperature evolution and oxygen production results from model and experiment agreed well. The numerical results indicate the prominent influence of solar radiative input power, where increasing it substantially reduces reduction time of the cerium dioxide structure. Consequently, the model predicts a solar-to-fuel energy conversion efficiency of >6% at a solar radiative power input of 50 kW; efficiency >10% can be obtained provided the RPC macroporosity is substantially increased, and better volumetric absorption and uniform heating is achieved. Managing the ceria surface temperature during reduction to avoid sublimation is a critical design consideration for direct absorption solar receiver–reactors.

References

References
1.
Romero
,
M.
, and
Steinfeld
,
A.
,
2012
, “
Concentrating Solar Thermal Power and Thermochemical Fuels
,”
Energy Environ. Sci.
,
5
(
11
), pp.
9234
9245
.
2.
Kodama
,
T.
, and
Gokon
,
N.
,
2007
, “
Thermochemical Cycles for High-Temperature Solar Hydrogen Production
,”
Chem. Rev.
,
107
(
10
), pp.
4048
4077
.
3.
Abanades
,
S.
,
Charvin
,
P.
,
Flamant
,
G.
, and
Neveu
,
P.
,
2006
, “
Screening of Water-Splitting Thermochemical Cycles Potentially Attractive for Hydrogen Production by Concentrated Solar Energy
,”
Energy
,
31
(
14
), pp.
2805
2822
.
4.
Marxer
,
D.
,
Furler
,
P.
,
Scheffe
,
J.
,
Geerlings
,
H.
,
Falter
,
C.
,
Batteiger
,
V.
,
Sizmann
,
A.
, and
Steinfeld
,
A.
,
2015
, “
Demonstration of the Entire Production Chain to Renewable Kerosene Via Solar Thermochemical Splitting of H2O and CO2
,”
Energy Fuels
,
29
(
5
), pp.
3241
3250
.
5.
Scheffe
,
J. R.
, and
Steinfeld
,
A.
,
2014
, “
Oxygen Exchange Materials for Solar Thermochemical Splitting of H2O and CO2: A Review
,”
Mater. Today
,
17
(
7
), pp.
341
348
.
6.
Chueh
,
W. C.
, and
Haile
,
S. M.
,
2009
, “
Ceria as a Thermochemical Reaction Medium for Selectively Generating Syngas or Methane From H2O and CO2
,”
ChemSusChem: Chem. Sustainability Energy Mater.
,
2
(
8
), pp.
735
739
.
7.
Chueh
,
W. C.
, and
Haile
,
S. M.
,
2010
, “
A Thermochemical Study of Ceria: Exploiting an Old Material for New Modes of Energy Conversion and CO2 Mitigation
,”
Philos. Trans. R. Soc. London A: Math., Phys. Eng. Sci.
,
368
(
1923
), pp.
3269
3294
.
8.
Chueh
,
W. C.
,
Falter
,
C.
,
Abbott
,
M.
,
Scipio
,
D.
,
Furler
,
P.
,
Haile
,
S. M.
, and
Steinfeld
,
A.
,
2010
, “
High-Flux Solar-Driven Thermochemical Dissociation of CO2 and H2O Using Nonstoichiometric Ceria
,”
Science
,
330
(
6012
), pp.
1797
1801
.
9.
Ackermann
,
S.
,
Scheffe
,
J. R.
, and
Steinfeld
,
A.
,
2014
, “
Diffusion of Oxygen in Ceria at Elevated Temperatures and Its Application to H2O/CO2 Splitting Thermochemical Redox Cycles
,”
J. Phys. Chem. C
,
118
(
10
), pp.
5216
5225
.
10.
Knoblauch
,
N.
,
Dörrer
,
L.
,
Fielitz
,
P.
,
Schmücker
,
M.
, and
Borchardt
,
G.
,
2015
, “
Surface Controlled Reduction Kinetics of Nominally Undoped Polycrystalline CeO2
,”
Phys. Chem. Chem. Phys.
,
17
(
8
), pp.
5849
5860
.
11.
Ackermann
,
S.
,
Sauvin
,
L.
,
Castiglioni
,
R.
,
Rupp
,
J. L.
,
Scheffe
,
J. R.
, and
Steinfeld
,
A.
,
2015
, “
Kinetics of CO2 Reduction Over Nonstoichiometric Ceria
,”
J. Phys. Chem. C
,
119
(
29
), pp.
16452
16461
.
12.
Kaneko
,
H.
,
Miura
,
T.
,
Fuse
,
A.
,
Ishihara
,
H.
,
Taku
,
S.
,
Fukuzumi
,
H.
,
Naganuma
,
Y.
, and
Tamaura
,
Y.
,
2007
, “
Rotary-Type Solar Reactor for Solar Hydrogen Production With Two-Step Water Splitting Process
,”
Energy Fuels
,
21
(
4
), pp.
2287
2293
.
13.
Diver
,
R. B.
,
Miller
,
J. E.
,
Allendorf
,
M. D.
,
Siegel
,
N. P.
, and
Hogan
,
R. E.
,
2008
, “
Solar Thermochemical Water-Splitting Ferrite-Cycle Heat Engines
,”
ASME J. Sol. Energy Eng.
,
130
(
4
), p.
041001
.
14.
Koepf
,
E.
,
Villasmil
,
W.
, and
Meier
,
A.
,
2016
, “
Pilot-Scale Solar Reactor Operation and Characterization for Fuel Production Via the Zn/ZnO Thermochemical Cycle
,”
Appl. Energy
,
165
, pp.
1004
1023
.
15.
Bader
,
R.
,
Chandran
,
R. B.
,
Venstrom
,
L. J.
,
Sedler
,
S. J.
,
Krenzke
,
P. T.
,
De Smith
,
R. M.
,
Banerjee
,
A.
,
Chase
,
T. R.
,
Davidson
,
J. H.
, and
Lipiński
,
W.
,
2015
, “
Design of a Solar Reactor to Split CO2 Via Isothermal Redox Cycling of Ceria
,”
ASME J. Sol. Energy Eng.
,
137
(
3
), p.
031007
.
16.
Ermanoski
,
I.
,
Siegel
,
N. P.
, and
Stechel
,
E. B.
,
2013
, “
A New Reactor Concept for Efficient Solar-Thermochemical Fuel Production
,”
ASME J. Sol. Energy Eng.
,
135
(
3
), p.
031002
.
17.
Koepf
,
E.
,
Advani
,
S. G.
,
Steinfeld
,
A.
, and
Prasad
,
A. K.
,
2012
, “
A Novel Beam-Down, Gravity-Fed, Solar Thermochemical Receiver/Reactor for Direct Solid Particle Decomposition: Design, Modeling, and Experimentation
,”
Int. J. Hydrogen Energy
,
37
(
22
), pp.
16871
16887
.
18.
Wei
,
B.
,
Fakhrai
,
R.
, and
Saadatfar
,
B.
,
2014
, “
Catalytic CO2 Conversion Via Solar-Driven Fluidized Bed Reactors
,”
Int. J. Low-Carbon Technol.
,
9
(
2
), pp.
127
134
.
19.
Welte
,
M.
,
Barhoumi
,
R.
,
Zbinden
,
A.
,
Scheffe
,
J. R.
, and
Steinfeld
,
A.
,
2016
, “
Experimental Demonstration of the Thermochemical Reduction of Ceria in a Solar Aerosol Reactor
,”
Ind. Eng. Chem. Res.
,
55
(
40
), pp.
10618
10625
.
20.
Brkic
,
M.
,
Koepf
,
E.
, and
Meier
,
A.
,
2016
, “
Continuous Solar Carbothermal Reduction of Aerosolized ZnO Particles Under Vacuum in a Directly Irradiated Vertical-Tube Reactor
,”
ASME J. Sol. Energy Eng.
,
138
(
2
), p.
021010
.
21.
Furler
,
P.
,
Scheffe
,
J.
,
Marxer
,
D.
,
Gorbar
,
M.
,
Bonk
,
A.
,
Vogt
,
U.
, and
Steinfeld
,
A.
,
2014
, “
Thermochemical CO2 Splitting Via Redox Cycling of Ceria Reticulated Foam Structures With Dual-Scale Porosities
,”
Phys. Chem. Chem. Phys.
,
16
(
22
), pp.
10503
10511
.
22.
Furler
,
P.
, and
Steinfeld
,
A.
,
2015
, “
Heat Transfer and Fluid Flow Analysis of a 4 kW Solar Thermochemical Reactor for Ceria Redox Cycling
,”
Chem. Eng. Sci.
,
137
, pp.
373
383
.
23.
Marxer
,
D.
,
Furler
,
P.
,
Takacs
,
M.
, and
Steinfeld
,
A.
,
2017
, “
Solar Thermochemical Splitting of CO2 Into Separate Streams of CO and O2 With High Selectivity, Stability, Conversion, and Efficiency
,”
Energy Environ. Sci.
, 10, pp. 1142–1149.
24.
Batteiger
,
V.
,
Brendelberger
,
S.
,
Dufour
,
J.
,
Falter
,
C.
,
Galvez
,
J.-L.
,
González-Aguilar
,
J.
,
Iribarren
,
D.
,
Koepf
,
E.
,
Kyrimis
,
S.
,
Le Clercq
,
P.
,
Lieftink
,
D.
,
Luque
,
S.
,
Pitz-Paal
,
R.
,
Prieto
,
C.
,
Roeb
,
M.
,
Rodriguez
,
A.
,
Romero
,
M.
,
Ruiz
,
F.
,
Sizmann
,
A.
,
Steinfeld
,
A.
,
von Storch
,
H.
,
de Wit
,
E.
, and
Zoller
,
S.
,
2019
, “
Sun-to-Liquid: Solar Fuels From H2O, CO2 and Concentrated Sunlight
,”
Solar Power And Chemical Energy Systems (SolarPACES), Casablanca, Morocco
, Oct. 2–5.
25.
Petrasch
,
J.
,
Coray
,
P.
,
Meier
,
A.
,
Brack
,
M.
,
Häberling
,
P.
,
Wuillemin
,
D.
, and
Steinfeld
,
A.
,
2007
, “
A Novel 50 kW 11,000 Suns High-Flux Solar Simulator Based on an Array of Xenon Arc Lamps
,”
ASME J. Sol. Energy Eng.
,
129
(
4
), pp.
405
411
.
26.
Furler
,
P.
,
Scheffe
,
J.
,
Gorbar
,
M.
,
Moes
,
L.
,
Vogt
,
U.
, and
Steinfeld
,
A.
,
2012
, “
Solar Thermochemical CO2 Splitting Utilizing a Reticulated Porous Ceria Redox System
,”
Energy Fuels
,
26
(
11
), pp.
7051
7059
.
27.
Ackermann
,
S.
,
Takacs
,
M.
,
Scheffe
,
J.
, and
Steinfeld
,
A.
,
2017
, “
Reticulated Porous Ceria Undergoing Thermochemical Reduction With High-Flux Irradiation
,”
Int. J. Heat Mass Transfer
,
107
, pp.
439
449
.
28.
Panlener
,
R. J.
,
Blumenthal
,
R. N.
, and
Garnier
,
J. E.
,
1975
, “
A Thermodynamic Study of Nonstoichiometric Cerium Dioxide
,”
J. Phys. Chem. Solids
,
36
(
11
), pp.
1213
1222
.
29.
Ackermann
,
S.
, and
Steinfeld
,
A.
,
2017
, “
Spectral Hemispherical Reflectivity of Nonstoichiometric Cerium Dioxide
,”
Sol. Energy Mater. Sol. Cells
,
159
, pp.
167
171
.
30.
Mogensen
,
M.
,
Sammes
,
N. M.
, and
Tompsett
,
G. A.
,
2000
, “
Physical, Chemical and Electrochemical Properties of Pure and Doped Ceria
,”
Solid State Ionics
,
129
(
1–4
), pp.
63
94
.
31.
Meija
,
J.
,
Coplen
,
T. B.
,
Berglund
,
M.
,
Brand
,
W. A.
,
De Bievre
,
P.
,
Groning
,
M.
,
Holden
,
N. E.
,
Irrgeher
,
J.
,
Loss
,
R. D.
,
Walczyk
,
T.
, and
Prohaska
,
T.
,
2016
, “
Atomic Weights of the Elements 2013 (IUPAC Technical Report)
,”
Pure Appl. Chem.
,
88
(
3
), pp.
265
291
.
32.
Riess
,
I.
,
Ricken
,
M.
, and
No
,
J.
,
1985
, “
On the Specific Heat of Nonstoichiometric Ceria
,”
J. Solid State Chem.
,
57
(
3
), pp.
314
322
.
33.
Touloukian
,
Y. S.
,
1967
, Thermophysical Properties of High Temperature Solid Materials. Volume 4: Oxides and Their Solutions and Mixtures. Part 1: Simple Oxygen Compounds and Their Mixtures, Macmillan, New York.
34.
Ackermann
,
S.
,
Scheffe
,
J. R.
,
Duss
,
J.
, and
Steinfeld
,
A.
,
2014
, “
Morphological Characterization and Effective Thermal Conductivity of Dual-Scale Reticulated Porous Structures
,”
Materials
,
7
(
11
), pp.
7173
7195
.
35.
Rath USA
,
2018
, “
Altra KVS High Temperature Vacuum Formed Boards and Shapes
,” Rath Inc., Newark, DE, accessed Dec. 10, 2018, http://www.rath-usa.com/datasheets/KVS-CERAMIC-FIBER-BOARDS-AND-SHAPES-FULL-LINE.pdf
36.
Archer
,
D. G.
,
1993
, “
Thermodynamic Properties of Synthetic Sapphire (α‐Al2O3), Standard Reference Material 720 and the Effect of Temperature‐Scale Differences on Thermodynamic Properties
,”
J. Phys. Chem. Reference Data
,
22
(
6
), pp.
1441
1453
.
37.
Pankratz
,
L. B.
, and
Mrazek
,
R. V.
,
1982
,
Thermodynamic Properties of Elements and Oxides
,
U.S. Bureau of Mines Bulletin
,
Washington, DC
.
38.
Touloukian
,
Y. S.
, and
DeWitt
,
D. P.
,
1972
,
Thermal Radiative Properties: Nonmetallic Solids
, Vol.
8
, Plenum Press, New York.
39.
Steels
,
A.
,
2011
, “
Grade Data Sheet 316 316 L 316H
,” accessed Dec. 10, 2018, http://atlas.strategyonline.com/documents/Atlas_Grade_datasheet_316_rev_Jan_2011.pdf
40.
Valencia
,
J. J.
, and
Quested
,
P. N.
,
2008
, “
Thermophysical Properties
,” ASM Handbook, Vol. 15: Casting, ASM International, Materials Park, OH, pp.
468
481
.
41.
Modest
,
M. F.
,
2013
,
Radiative Heat Transfer
,
Academic Press
,
Oxford, UK
.
42.
Flumroc AG,
2018
, “
Flumroc-Brandschutzmatte FMI 500
,” Flumroc AG, Flums, St. Gallen, Switzerland, accessed Dec. 10, 2018, https://www.flumroc.ch/produkte/technische-daemmung/detail/product/detail/flumroc-brandschutzmatte-fmi-500/
43.
Potter
,
D. F.
,
Karl
,
S.
,
Lambert
,
M.
, and
Hannemann
,
K.
, 2013, “
Computation of Radiative and Convective Contributions to Viking Afterbody Heating
,”
AIAA
Paper No. 2013-2895.
44.
Martienssen
,
W.
, and
Warlimont
,
H.
,
2006
,
Springer Handbook of Condensed Matter and Materials Data
,
Springer
,
Berlin
.
45.
Mills
,
K. C.
,
2002
,
Recommended Values of Thermophysical Properties for Selected Commercial Alloys
,
Woodhead Publishing
, Oxford, UK.
46.
Villasmil
,
W.
,
Cooper
,
T.
,
Koepf
,
E.
,
Meier
,
A.
, and
Steinfeld
,
A.
,
2017
, “
Coupled Concentrating Optics, Heat Transfer, and Thermochemical Modeling of a 100-kW(th) High-Temperature Solar Reactor for the Thermal Dissociation of ZnO
,”
ASME J. Sol. Energy Eng.
,
139
(
2
), p.
021015
.
47.
Shackelford
,
J. F.
, and
Alexander
,
W.
,
2001
,
Thermal Properties of Materials
,
CRC Press
,
Boca Raton, FL
.
48.
Petrasch
,
J. R.
, “
A Free and Open Source Monte Carlo Ray Tracing Program for Concentrating Solar Energy Research
,”
ASME
Paper No. ES2010-90206.
49.
Koepf
,
E.
,
Zoller
,
S.
,
Luque
,
S.
,
Thelen
,
M.
,
Brendelberger
,
S.
,
González-Aguilar
,
J.
,
Romero
,
M.
, and
Steinfeld
,
A.
,
2019
, “
Liquid Fuels From Concentrated Sunlight: An Overview on Development and Integration of a 50 kW Solar Thermochemical Reactor and High Concentration Solar Field for the Sun-to-Liquid Project
,”
Solar Power And Chemical Energy Systems (SolarPACES)
, Casablanca, Morocco, Oct. 2–5.
50.
Scheffe
,
J. R.
,
Jacot
,
R.
,
Patzke
,
G. R.
, and
Steinfeld
,
A.
,
2013
, “
Synthesis, characterization, and Thermochemical Redox Performance of Hf4+, Zr4+, and Sc3+ Doped Ceria for Splitting CO2
,”
J. Phys. Chem. C
,
117
(
46
), pp.
24104
24114
.
51.
Takacs
,
M.
,
Scheffe
,
J. R.
, and
Steinfeld
,
A.
,
2015
, “
Oxygen Nonstoichiometry and Thermodynamic Characterization of Zr Doped Ceria in the 1573–1773 K Temperature Range
,”
Phys. Chem. Chem. Phys.
,
17
(
12
), pp.
7813
7822
.
52.
Bader
,
R.
,
Venstrom
,
L. J.
,
Davidson
,
J. H.
, and
Lipiński
,
W.
,
2013
, “
Thermodynamic Analysis of Isothermal Redox Cycling of Ceria for Solar Fuel Production
,”
Energy Fuels
,
27
(
9
), pp.
5533
5544
. (pp.
53.
Hao
,
Y.
,
Yang
,
C.-K.
, and
Haile
,
S. M.
,
2013
, “
High-Temperature Isothermal Chemical Cycling for Solar-Driven Fuel Production
,”
Phys. Chem. Chem. Phys.
,
15
(
40
), pp.
17084
17092
.
54.
Hoes
,
M.
,
Ackermann
,
S.
,
Theiler
,
D.
,
Furler
,
P.
, and
Steinfeld
,
A.
,
2019
, “
Additive-Manufactured Ordered Porous Structures Made of Ceria for Solar Thermochemical Redox Splitting of H2O and CO2
,”
Adv. Mater. Technol.
(in press).
55.
Hoes
,
M.
,
Koepf
,
E.
,
Davenport
,
P.
, and
Steinfeld
,
A.
,
2019
, “
Reticulated Porous Ceramic Ceria Structures With Modified Surface Geometry for Solar Thermochemical Splitting of Water and Carbon Dioxide
,”
Solar Power And Chemical Energy Systems (SolarPACES)
, Casablanca, Morocco, Oct. 2–5.
56.
Levenspiel
,
O.
,
1999
,
Chemical Reaction Engineering
,
Wiley
,
New York
.
57.
Hathaway
,
B. J.
,
Bala Chandran
,
R.
,
Gladen
,
A. C.
,
Chase
,
T. R.
, and
Davidson
,
J. H.
,
2016
, “
Demonstration of a Solar Reactor for Carbon Dioxide Splitting Via the Isothermal Ceria Redox Cycle and Practical Implications
,”
Energy Fuels
,
30
(
8
), pp.
6654
6661
.
58.
Lapp
,
J.
,
Davidson
,
J. H.
, and
Lipiński
,
W.
,
2012
, “
Efficiency of Two-Step Solar Thermochemical Non-Stoichiometric Redox Cycles With Heat Recovery
,”
Energy
,
37
(
1
), pp.
591
600
.
59.
Siegel
,
N. P.
,
Miller
,
J. E.
,
Ermanoski
,
I.
,
Diver
,
R. B.
, and
Stechel
,
E. B.
,
2013
, “
Factors Affecting the Efficiency of Solar Driven Metal Oxide Thermochemical Cycles
,”
Ind. Eng. Chem. Res.
,
52
(
9
), pp.
3276
3286
.
60.
Brendelberger
,
S.
,
Holzemer-Zerhusen
,
P.
,
von Storch
,
H.
, and
Sattler
,
C.
,
2019
, “
Performance Assessment of a Heat Recovery System for Monolithic Receiver-Reactors
,”
ASME J. Sol. Energy Eng.
(in press).
61.
Muhich
,
C.
, and
Steinfeld
,
A.
,
2017
, “
Principles of Doping Ceria for the Solar Thermochemical Redox Splitting of H2O and CO2
,”
J. Mater. Chem. A
,
5
(
30
), pp.
15578
15590
.
62.
Hoes
,
M.
,
Muhich
,
C. L.
,
Jacot
,
R.
,
Patzke
,
G. R.
, and
Steinfeld
,
A.
,
2017
, “
Thermodynamics of Paired Charge-Compensating Doped Ceria With Superior Redox Performance for Solar Thermochemical Splitting of H2O and CO2
,”
J. Mater. Chem. A
,
5
(
36
), pp.
19476
19484
.
You do not currently have access to this content.