Solar hydrogen production by thermochemical reaction Development of a packed-bed reactor

Abstract

Keywords: Hydrogen; Packed Bed; CFD; Balls

Introduction

Hydrogen is actually considered as the most promising green fuel vector for the future as it has prodigious capability of reducing greenhouse gas and other environmental pollutants (Cn Hm ,NOx , heavy metals, radioactivity) emitted by fossil energy systems. It is considered that engines operating with hydrogen [1-3] can tremendously reduce dependence on nonrenewable fuel sources [4]. Thus, the use of hydrogen as an alternative fuel vector unlocks potential means of converting energy from solar radiation to storable chemical energy. It is envisaged that the hydrogen will replace smoothly fossil energy resources in automotive industry through fuel cell technology. It would be more efficient as fuel for internal combustion engines with comparable performance, emitting just water vapour [4, 5]. Historically, it is observed that there have been tendency toward the decarbonization of energy sources from solid to liquid to gaseous fuels. From coal to oil back to natural gas again, the ratio of carbon to hydrogen in the molecule of each successive source of energy has decreased [6], which confirms the global tendency towards using hydrogen as a future source of energy. Currently a growth in demand for hydrogen is observed, with major applications in Ammonia production, petroleum processing, petrochemical production, oil and fat hydrogenation, fertilizer production, metallurgical applications and electronics industry [7], it is also anticipated that interest in using hydrogen as fuel for automotive industry will further enhance the demand of the green fuel. Hence, it is necessary to expand the existing hydrogen production capacity by using renewable energy resources, in order to meet the worlthe d increasing demand. Consumption of hydrogen in different applications is shown in the following Figure [4]. There are basically three major pathways for Hydrogen production: electrochemical, thermochemical and biological methods. One of the most attractive methods for the acquisition of hydrogen could be water thermochemically splitting.

This paper was recommended for publication in revised form by Regional Editor Prof. Dr. Jaap Hoffman Hoffman 1 Département de Génie mécanique / Laboratoire Energétique et Thermique Appliquée ETAP, Abou-Bekr BELKAÏD University, B.P 119, 13000 Tlemcen, Algeria 2 Centre de Développement des Satellites CDS/ Algerian Space Agency ASAL / BP 4065, Ibn Rochd USTO 31130 Oran, Algeria 3 Institute for Technology and Resources Management in the Tropics and Subtropics (ITT) / Technische Hochschule Köln /University of Applied Sciences Betzdorfer Strasse 2 /50679 Cologne, Germany E-mail address: seladji@yahoo.fr, ddarfilal@cds.asal.dz, ramchandra.bhandari@th-koeln.de Orcid id: https://orcid.org/0000-0001-8538-2439, https://orcid.org/0000-0002-3940-1704, https://orcid.org/0000-0002-4892-0397 https://orcid.org/0000-0001-8538-2439 Manuscript Received 13 June 2018, Accepted 07 August 2018

Journal of Thermal Engineering, Research Article, Vol. 6, No. 2, Special Issue 11, pp. 152-169, March,2020

Figure 1. Hydrogen consumption by industry sector Thermochemical hydrogen production process necessitates only water as a material input and heat as an energy source (rather than electricity for electrolysis process). The output of the process is H2 and O2 . The process itself comprises a set of chemical reactions, which sum the splitting of H2 O molecule [8].

In the following section, the thermochemical Hydrogen production methods coupled with solar energy source are briefly described. The exploitation of the massive amount of solar radiation and its conversion to chemical storable energy such as hydrogen is a subject of primary technological interest [9]. There are basically three methods and their combinations for producing hydrogen using solar radiations namely photochemical, electrochemical and thermochemical [10, 11]. The latter is based on the use of concentrated solar radiations as the driving force that produce hydrogen from transformation of its feedstock [4]. There are different thermochemical hydrogen production pathways, namely steam reforming [12-15], gas cracking [16, 17] and water splitting [9, 18-20]. There have been several papers in literature that have reviewed existing thermochemical cycles for hydrogen production [21-24]. The investigations for thermochemical cycles which could be made efficient hydrogen production from water was started worldwide in the late 1960s by James E. Funk and RM Reinstrom [8, 25]. James E. Funk [21] was the first to evaluate the energy requirements for the production of hydrogen from water and the possibility of using two-step thermochemical processes. Thermocemical cycles evaluation in [22] by Sandia National Laboratories have been investigated last decades by several researchers . From over 350 multistep thermochemical cycles initially selected [22], 14 cycles are found suitable for solar application. The most thermochemical cycles promising candidates are based on Ferrite-based metal oxides, Zinc oxide, tin oxide as well as sulfates iodine. An attractive cycle for solar hydrogen production is the two-step solar thermochemical water-splitting using redox pair metal oxides, since it implicates less complex reactions, non-corrosive and nontoxic materials.

Journal of Thermal Engineering, Research Article, Vol. 6, No. 2, Special Issue 11, pp. 152-169, March,2020 Table 1. Investigations in solar thermochemical cycles Thermochemical cycle Ferrite-based cycles;

EU-FP5 project HYDROSOL, EU-FP6 project HYDROSOL 2 DOE project

EU-FP5 project SOLZINC DOE project DOE project EU-FP6 project HYTHEC EU-FP7 project HYCYCLES

Cerium-based cycles; UT3-cycle; 𝐒𝐧𝐎𝟐 /𝐒𝐧𝐎 cycle ; Hybrid sulfuric acid cycle;

APTL (GR), DLR (D), Johnson Matthey (UK), StobbeTech (DK), CIEMAT (E) CNRS-PROMES (F) Sandia, NREL , U. of Colorado, Pinnacle West (USA) Tokyo Institute / Niigata U. (Japan) PSI/ETH (CH), U. of Minnesota (USA) PSI/ETH (CH), CNRS-PROMES (F), ScanArc (S) CNRS-PROMES (F) Sandia, NREL, U. of Colorado, Pinnacle West (USA) Sandia, NREL,U. of Colorado, Pinnacle West (USA) CEA (F), DLR (D), ProSim (F), U. of Sheffield (UK), DIMI (I), Empresarios Agrupados (E) DLR (D), CEA (France), ETH (CH), U. of Sheffield (UK), BoosTec (F), Empresarios Agrupados (E), APTL (GR), JRC (EU), ENEA (I), General Atomics (USA), Westinghouse (USA), JAEA (Japan), CSIRO (Australia) CNRS-PROMES (F) ENEA (I) CNRS-PROMES (F) CEA (F), DLR (D), ProSim (F), U. of Sheffield (UK), DIMI (I), Empresarios Agrupados (E)

Recently, enormous efforts has been made in developing concentration systems that exceed 5000 suns solar concentration ratios, capable of achieving temperatures above 1400°C, which are needed to release two-step thermochemical reactions using metal oxide. Ferrite-based thermochemical cycle has been the most explored cycle [23], it was demonstrated at 3;100;750 kW level within the project HYDROSOL, HYDROSOL 2, HYDROSOL-PLANT successively. The SiC-based monolith reactor model, was similar to the catalytic converter used for automobiles exhaust gas treatment catalytic converter. The reactor is constructed from ceramic multichanneled monoliths that absorbs the solar radiation flux [24]. The Ferrite-based cycle has been extensively studied in the solar furnace of Tokyo Institute of Technology [25] and Sandia National Laboratories [22, 26] with locally developed solar reactor prototypes.

Figure 2. Solar reactors: (A) HYDROSOL 2 reactor, (B) CR5 reactor, (C) SOLARJET reactor

Journal of Thermal Engineering, Research Article, Vol. 6, No. 2, Special Issue 11, pp. 152-169, March,2020 ZnO/Zn cycle is one of the most researched thermochemical cycles, the 𝑍𝑛𝑂 reduction to Zn and 𝑂2 at high temperatures have been experimentally demonstrated mainly at PSI, CNRS-PROMES and UD FCRL USA. Reduction step

𝑍𝑛 + 𝐻2 𝑂 → 𝑍𝑛𝑂 + 𝐻2 For this chemical process, several solar reactors were developed and tested at PSI’s solar furnace, ZIRRUS and ROCA reactors were demonstrated at 10 kW solar radiation. Temperature reached a value >1900 K for both reactors.

Figure 2. Solar reactors : (A) ZIRRUS reactor ; (B)2G-RC5 reactor; (C) GRAFSTRR reactor Another promising two-step thermochemical cycle is 𝑆𝑛𝑂2 /𝑆𝑛𝑂 cycle. Experiments showed that the 𝑆𝑛𝑂2 reduction can be performed efficiently at 1773 K. A 1 kW solar reactor prototype was successfully developed and tested at CNRS-PROMES. The leading candidate for the multi-step thermochemical cycles is actually the three-step SI cycle (sulfur iodine) based on the thermal decomposition of sulfuric acid at 1123 K. 155

Journal of Thermal Engineering, Research Article, Vol. 6, No. 2, Special Issue 11, pp. 152-169, March,2020 Bunsen reaction

𝐼2 + 𝑆𝑂2 + 2𝐻2 O → 2𝐻𝐼 + 𝐻2 𝑆𝑂4 (120 °C); Distillation

𝐻2 𝑆𝑂4 → 2 𝑆𝑂2 + 2𝐻2 O + 𝑂2 (830 °C) 𝐻𝐼 → 𝐼2 + 𝐻2 (450 °C) The SI cycle was demonstrated within the USA DOE project, EU-FP6 HYTHEC and EU-FP7 HYCYCLES projects. Table 2. Summary of experimental solar reactors developments. Test facility DLR solar furnace [27-30] SNL solar furnace [31] PSI solar furnace Switzerland [32]

Hydrosol-Plant

Ferrite-based cycles Ferrite-based cycles Ferrite-based cycles 𝐶𝑜3 𝑂4 /𝐶𝑜𝑂 cycles Cerium-based cycles Cerium-based cycles

Zirrus Solref

𝑍𝑛𝑂/𝑍𝑛 𝑐𝑦𝑐𝑙𝑒 ZnO/Zn cycle Steam gasification of petcoke 𝑀𝑛𝑂2 , 𝐹𝑒2 𝑂3 and 𝐹𝑒3 𝑂4 reduction 𝑍𝑛𝑂/𝑍𝑛 cycle 𝑍𝑛𝑂/𝑍𝑛 cycle

UD FCRL USA

𝑀𝑛3 𝑂4 reduction 𝑀𝑛2 𝑂3 , 𝑀𝑛3 𝑂4 and 𝐶𝑒 𝑂2 reduction

Journal of Thermal Engineering, Research Article, Vol. 6, No. 2, Special Issue 11, pp. 152-169, March,2020 In order to build a low cost feasible solar reactor, a packed bed based on ceramic is proposed. The body of this reactor/ receiver consists of spherical balls made of silicon carbide coated with the reactive ferrites material. The idea of studying the packed bed solar receiver/reactor is interesting because: - The spheres/ beads are inexpensive compared to the monolithic or foam structured media, and can fill the space of the cavity without issues of peripheral support/packing. - The wash-coating procedures are much easier and homogeneous than other porous structure previously used geometry. Packed bed based on particles may be designed in many cases as a set of identical spheres occupying a determined space.

Figure 3. Reactor packing arrangement When this space is limited to a predetermined space , such as cylindrical channels of a nanostructured porous structure filled by atoms or molecules of a substance, the geometric & thermophysical properties (Thermal conductivity , porosity ..) of the resulting porous matrix strongly depend on the arrangement (Porosity as example in [37-39]. Table 3. Effect of the arrangement on the porosity Structure Cubic Hexagonal Rhombohedral Orthorhombic Tetragonal Triclinic

Packed beds are used in a large industrial thermal-fluid systems applications, such as nuclear reactors [40, 41], catalysts [42], and in cryogenics [43, 44]. A number of exploratory studies investigated solar thermochemical reaction in packed bed reactor [45-48]. In Figure 4 a 5 kW solar reactor, subjected to solar radiation up to 2953 suns and operated at temperatures up to 1490 K was demonstrated at PSI [49].

Journal of Thermal Engineering, Research Article, Vol. 6, No. 2, Special Issue 11, pp. 152-169, March,2020 The aim of the present paper is to study the feasibility of using this kind of porous structure as a receiver/reactor for direct thermal water splitting. It is important to mention that this specific design of directly irradiated reactor using ceramic balls, has not been studied extensively before, and could be very interesting technically.

Reactor Description

The receiver/reactor body (Figure 6) consists of a cylindrical chamber (0.05 m internal diameter and 0.05 m long) that contains the ceramic spherical balls. The front of the receiver/reactor is directly irradiated by concentrated solar energy (maximal power of 2 kW constant solar flux density distribution).

Figure 7. Reactor design The chamber of the reactor is surrounded by an insulator. A glass window is proposed to separate the system from the ambient to provide a controlled environment inside the chamber.

Mathematical And Numerical Modelling

The study presents an approach to the computational modelling of a volumetric solar receiver/reactor consisting of an absorption cavity that is filled by a packed bed of ceramic spheres and irradiated from the flow inlet face. The variation of cavity thermal response is examined for a different sphere packing arrangements while a comparison against third party experimental results is shown. The model of the bed of packed spheres is based on a two-dimensional scalar transport in a homogeneous porous medium for which distinct solid and fluid temperature fields are retained. The model approach used in this model is macroscopic, which is based on the averaging of fundamental flow equations such as continuity, momentum and energy as well as turbulence over a representative volume of the porous media [51]. The most research efforts in computation of turbulent flow in porous media [52-54] have

Journal of Thermal Engineering, Research Article, Vol. 6, No. 2, Special Issue 11, pp. 152-169, March,2020 been focused on developing macroscopic equations through the averaging volume techniques of the k-ε turbulence model. The governing equation assumptions are the following: - Uniform porosity through the porous structure. - The flow field is steady and turbulent - Effect of Buoyancy, Hydrodynamic dispersion, viscous dissipation are negligible. - Thermal expansion is negligible.

Continuity and momentum equation According to the cited assumptions, the averaged continuity and momentum equation for the proposed model are:

Where α is the permeability of the porous media, C_2 is the inertial coefficient. The first and the second term on the right hand side are the momentum source terms. The equation neglects the convective term as the flow is fully developed. The turbulence model are obtained by averaging the standard turbulence kinetic energy and the dissipation rate equation.

Energy equations In LTNE energy model approach, the solid and fluid phases are spatially coincident and interact between them with regard to heat transfer (source term), two equation are solved separately for the fluid and solid phases in this proposed model. The Fluid phase equation under steady state conditions is:

Solid phase energy equation under steady state condition is the following:

S_(conv ) Present the source term of the convective heat exchange between the solid and the fluid phases.

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Where hfs present the coefficient of the convective volumetric heat transfer and Afs is the exchange area between the solid matrix and the fluid.

Convective volumetric heat transfer coefficient According to the following references [55] and [56] the volumetric heat transfer coefficient is constant over the length of the reactor. Table 4 gives an overview of some models existing in the literatue. Table 4. Different models for the volumetric heat transfer coefficient 𝐡𝐟𝐬 = ̅̅̅̅ 𝐡𝐟𝐬

[𝟐, 𝟎𝟗𝟔𝜺𝒑 𝟎,𝟑𝟖 𝝀𝒇 . 𝑹𝒆𝟎,𝟒𝟑𝟖 . (−𝟖. 𝟐𝟕𝟖 𝜺𝒑 𝟎,𝟑𝟖 + 𝟓𝟕, 𝟑𝟖𝟒𝜺𝒑 𝟏,𝟑𝟖 − 𝟏𝟎𝟔, 𝟔𝟑 𝜺𝒑 𝟐,𝟑𝟖 + 𝟗𝟓, 𝟕𝟓𝟔𝜺𝒑 𝟑,𝟑𝟖 − 𝟑𝟕, 𝟐𝟒𝜺𝒑 𝟒,𝟑𝟖 )]/𝒅𝟐𝒔 For (0.66<𝜺𝒑 <0.93) & (0.66<Re<0.93) 𝟏

((𝟏. 𝟏𝟖 𝐑𝐞𝟎.𝟓𝟖 ) + (𝟎. 𝟐𝟑𝐑𝐞𝟎.𝟕𝟓 𝐡 ) ) /(𝒅𝒑 𝒌𝒇 ) Where 𝐑𝐞𝐡 =

The model used to find the heat transfer correlation and the interfacial area density is a general correlation, which can be used for all Particle Reynolds Number [62] 1

𝑘𝑓 (2 + 1,1 . 𝑃𝑟 3 . 𝑅𝑒 0.6 ) ℎ𝑓𝑠 = 𝑑𝑝 The area correlation for this model is given by:

Journal of Thermal Engineering, Research Article, Vol. 6, No. 2, Special Issue 11, pp. 152-169, March,2020

Effective conductivity The Effective thermal conductivity is the thermal conductivity used in porous media, it is calculated generally through correlations. The most accurate formula [63] is used in this study. (The default model used in ANSYS FLUENT) (10) 𝑘𝑓 = (𝜀 𝑘𝑓 )

Permeability and inertial loss coefficients Ergun Equation is a semi empirical correlation applicable over a vast range of Reynold numbers and it is applicable for many type of packing:

From Ergun correlation, the permeability and inertial loss coefficients are identified as:

Results & Discussions

To verify the model developed, the model was validated with experimental and numerical results obtained by [68] using the same thermophysical properties of the cited model . Figure 8 presents the variation of temperature through the position. The results are showed good agreement with [68] experimental and numerical studies. In order to optimise the performances of the packed bed solar receiver, we conducted a series of sensitivity study of the inlet velocity, the balls arrangement and the inlet solar flux.

Figure 8. model validation Left hand side: fluid phase Right hand side: Solid phase

Journal of Thermal Engineering, Research Article, Vol. 6, No. 2, Special Issue 11, pp. 152-169, March,2020

Figure 9. Temperature distribution, Left hand side: fluid phase Right hand side: Solid phase The impact of the incident solar flux on the temperature distributions of solid and fluid phases is studied in order to select the optimum solar power flux (Figure 10. Temperature distributions along the symmetry axis under several heat flux power, Left hand side Fluid phase Right hand side: Solid phase). As a result, the optimal solar power value for the reaction at the working temperature of 1200 K is at least 2 KW and it must not exceed

Conclusion

In the present study, CFD analysis of a water splitting solar reactor is given. The local thermal nonequilibrium model was used to investigate the temperature distributions. Numerical study was conducted to study the effect of the inlet velocity, solar radiation, ball arrangement and the reaction. The simulations were also compared with experimental data. The results shows that the temperature distribution depend strongly with the working conditions and the porous media properties. The results shows that the ideal temperature distribution with the maximum solid porous structure temperature located inside the absorber. It is remarkable that the packed balls arrangement has an interesting effect on the temperature distributions inside the reactor. Regarding reactive flow simulations, the impact of the reaction on the temperature distributions was analyzed, a temperature decrease reaching about 60 K was evidenced due to the endothermic reaction. In this study, pulsatile flow in an intracranial aneurysm is numerically investigated under the combined effect of the aneurysm size, the curvature of the artery and the flow rates. The aim of this study is to evaluate the flow field and the wall shear stress distribution along the saccular cavity wall during a cardiac cycle and use these findings to have a better understanding of the mechanism leading to the rupture of the vessel.

Nomeclature

Afs 𝐂𝟏 , 𝐂𝟐 𝐶𝑜𝑛𝑣 𝐶𝑝 𝐷𝑖,𝑚 𝑑𝑝 𝑒𝑓𝑓 𝑓 𝐺𝑖 GHG ℎ𝑓𝑠 𝑘𝑡 𝑘 𝑀𝑖

Exchange area between the solid matrix and the fluid k-ε model Inertial coefficient [m] Convection Thermal capacity [𝐽𝑘𝑔−1 𝐾 −1 ] Mass diffusion coefficient for the species i Mean Particle diameter [m] Effective Fluid

Generation rate of the intrinsic average of 𝑘𝑡 Greenhouse gazes Convective volumetric heat transfer coefficient [𝑊𝑚−3 𝐾 −1 ] Turbulance kinetic energy [𝑚2 𝑠 −2 ] Thermal Conductivity [𝑊𝑚−1 𝐾 −1 ] Molecular weight Pressure [Pa] Prandtl Number 166

Journal of Thermal Engineering, Research Article, Vol. 6, No. 2, Special Issue 11, pp. 152-169, March,2020 𝑅𝑐ℎ𝑒𝑚,𝑖

chemical source terme relates to the net rate of production of the species i Reynolds number Volumetric heat source term [ 𝑊 𝑚−3 ]

Temperature Superficial Velocity [𝑚 𝑠 −1 ] Velocity fluctution [𝑚 𝑠 −1 ] local mass fraction of species i Permeability Dynamic viscosity [𝑘𝑔 𝑚−1 𝑠 −1 ] Density [𝑘𝑔 𝑚−3 ] Dissipation rate [𝑚2 𝑠 −3 ] Porosity

References

1. White, C., R. Steeper, and A. Lutz. The hydrogen-fueled internal combustion engine: a technical review. International journal of hydrogen energy, 2006; 31(10), 1292-1305.
2. Antunes, J.M.G. The use of hydrogen as a fuel for compression ignition engines.;2011.
3. Antunes, J.G., R. Mikalsen, and A. Roskilly. An investigation of hydrogen-fuelled HCCI engine performance and operation. International journal of hydrogen energy, 2008; 33(20), 5823-5828.
4. Chaubey, R., et al. A review on development of industrial processes and emerging techniques for production of hydrogen from renewable and sustainable sources. Renewable and Sustainable Energy Reviews, 2013; 23, 443- 462.
5. Blok, K., et al. Hydrogen production from natural gas, sequestration of recovered CO2 in depleted gas wells and enhanced natural gas recovery. Energy, 1997; 22(2-3), 161-168.
6. Dunn, S. .Hydrogen futures: toward a sustainable energy system. International journal of hydrogen energy, 2002; 27(3), 235-264.
7. Ramachandran, R. and R.K. Menon..An overview of industrial uses of hydrogen. International journal of hydrogen energy, 1998; 23(7), 593-598.
8. Funk, J.E..Thermochemical hydrogen production: past and present. International journal of hydrogen energy, 2001; 26(3), 185-190.
9. Agrafiotis, C., et al. Solar water splitting for hydrogen production with monolithic reactors. Solar Energy, 79(4), 2005; 409-421.
10. Xiao, L., S.-Y. Wu, and Y.-R. Li..Advances in solar hydrogen production via two-step water-splitting thermochemical cycles based on metal redox reactions. Renewable Energy, 2012; 41, 1-12.
11. BIČÁKOVÁ, O. and P. Straka.The resources and methods of hydrogen production. Acta Geodyn. Geomater,2010; 7(158), 175.
12. Epstein, M. Solar thermal reforming of methane. SFERA Winter School. Switzerland. Zürich, 2011.
13. Giaconia, A., et al. Multi-fuelled solar steam reforming for pure hydrogen production using solar salts as heat transfer fluid. Energy Procedia,2015; 69, 1750-1758.
14. Simakov, D.S., et al. Solar thermal catalytic reforming of natural gas: a review on chemistry, catalysis and system design. Catalysis Science & Technology,2015; 5(4), 1991-2016.
15. Dahl, J.K., et al. Solar-thermal processing of methane to produce hydrogen and syngas. Energy & fuels, 2001; 15(5), 1227-1232.
16. Abanades, S. and G. Flamant. High-temperature solar chemical reactors for hydrogen production from natural gas cracking. Chemical Engineering Communications,2008; 195(9), 1159-1175.
17. Abánades, A., et al. Experimental analysis of direct thermal methane cracking. International journal of hydrogen energy, 2011; 36(20), 12877-12886.
18. Steinfeld, A. Solar hydrogen production via a two-step water-splitting thermochemical cycle based on Zn/ZnO redox reactions. International journal of hydrogen energy,2002; 27(6), 611-619.
19. Abanades, S. and G. Flamant. Thermochemical hydrogen production from a two-step solar-driven water- splitting cycle based on cerium oxides. Solar Energy,2006; 80(12), 1611-1623. 167 Journal of Thermal Engineering, Research Article, Vol. 6, No. 2, Special Issue 11, pp. 152-169, March,2020
20. Tamaura, Y., et al. Production of solar hydrogen by a novel, 2-step, water-splitting thermochemical cycle. Energy, 1995; 20(4), 325-330.
21. Funk, J.E. and R.M. Reinstrom. Energy requirements in production of hydrogen from water. Industrial & Engineering Chemistry Process Design and Development, 1966; 5(3), 336-342.
22. Perret, R. Solar Thermochemical hydrogen production research (STCH), Sandia National Lab.(SNL-CA), Livermore, CA (United States),2011.
23. Yadav, D. and R. Banerjee A review of solar thermochemical processes. Renewable and Sustainable Energy Reviews, 2016; 54, 497-532.
24. Konstandopoulos, A.G. and S. Lorentzou. Novel Monolithic Reactors for Solar Thermochemical Water Splitting. On Solar Hydrogen & Nanotechnology,2009; 621-639.
25. Kaneko, H., et al..Simulation study of Tokyo Tech rotary-type solar reactor on solar field test at CSIRO in Australia. in Proceedings of the ASME 2011 5th International Conference on Energy Sustainability (ES2011), ESFuelCell2011-54568,2011; Washington, DC.
26. ADMIN. High-Efficiency Solar Thermochemical Reactor for Hydrogen Production. 2014 [cited 2017 22 august]; Available from: http://energy.sandia.gov/high-efficiency-solar-thermochemical-reactor-for-hydrogen- production/.
27. Neises, M., et al. Solar-heated rotary kiln for thermochemical energy storage. Solar Energy, 2012; 86(10), 3040-3048.
28. Roeb, M., et al. Technologies and trends in solar power and fuels. Energy & Environmental Science,2011; 4(7), 2503-2511.
29. Pagliaro, M., et al. Solar hydrogen: fuel of the near future. Energy & Environmental Science,2010; 3(3), 279- 287.
30. EnergyBusinessEurope. HYDROSOL Plant Project – Hydrogen power for zero CO2 emissions. 2016 [cited 2017 21/08]; Available from: http://www.energybusinesseurope.com/hydrogen-power-for-zero-co2-emissions- and-energy-security/.
31. OTERO, A. Concentrating on Sunshine to Advance the Hydrogen Economy. 2013 [cited 2017 22 August]; Available from: http://crf.sandia.gov/concentrating-on-sunshine-to-advance-the-hydrogen-economy/.
32. Alonso, E. and M. Romero..Review of experimental investigation on directly irradiated particles solar reactors. Renewable and Sustainable Energy Reviews,2015; 41, 53-67.
33. CHAMBON, M. Thermochemical cycles based on the ZnO/Zn or SnO2/SnO redox couples : Kinetic characterizations and study of solar reactors, SFERA Winter School Solar Fuels & Materials: ETH Zürich, 13; 2011.
34. Lichty, P.R., et al. Solar thermal reactor materials characterization, National Renewable Energy Laboratory (NREL), Golden, CO.2008.
35. TRANSPORT, E.F.-A.a.A. The SOLAR-JET Project, ILA BERLIN.2014.
36. E.E., K. Solar-Thermochemical Hydrogen. 2010 [cited 2017 22 August]; Available from: http://www.me.udel.edu/research_groups/prasad/research/solartherm.html.
37. Tingate, G.Some geometrical properties of packings of equal spheres in cylindrical vessels. Nuclear Engineering and design, 1973; 24(2), 153-179.
38. Burtseva, L., et al. Modeling of Monosized Sphere Packings into Cylinders: Univ., Fak. für Mathematik.;2015.
39. Van Antwerpen, W., C. Du Toit, and P. Rousseau. A review of correlations to model the packing structure and effective thermal conductivity in packed beds of mono-sized spherical particles. Nuclear Engineering and design, 2010; 240(7), 1803-1818.
40. Fumizawa, M., Y. Kaneko, and M. Izumi. Porosity Effect in the Core Thermal Hydraulics for Ultra High Temperature Gas-Cooled Reactor. Journal of Systemics, Cybernetics and Informatics, 2008; 6(6), 86-92.
41. Oktajianto, H., E. Setiawati, and V. Richardina. Modelling of HTR (High Temperature Reactor) Pebble-Bed 10 MW to Determine Criticality as A Variations of Enrichment and Radius of the Fuel (Kernel) With the Monte Carlo Code MCNP4C. International Journal of Science and Engineering, 2015; 8(1), 42-46.
42. Cervone, A., et al. Development of hydrogen peroxide monopropellant rockets. AIAA paper, 5239, 2006.
43. Tuinier, M., et al. Cryogenic CO2 capture using dynamically operated packed beds. Chemical Engineering Science, 2010; 65(1), 114-119.
44. Ali, A.H., S. Ganguly, and A.B.M. Shariff. Simulation of cryogenic packed bed using 1-dimensional pseudo homogeneous model. J. Appl. Sci.,2014; 14, 3118-3121. 168 Journal of Thermal Engineering, Research Article, Vol. 6, No. 2, Special Issue 11, pp. 152-169, March,2020
45. Wieckert, C., et al. Syngas production by thermochemical gasification of carbonaceous waste materials in a 150 kWth packed-bed solar reactor. Energy & fuels, 2013; 27(8), 4770-4776.
46. Reich, L., et al. Heat and mass transfer model of a packed-bed reactor for solar thermochemical CO2 capture. in Proc. of 15th Int. Heat Trans. Conf. 2014.
47. Piatkowski, N., C. Wieckert, and A. Steinfeld. Experimental investigation of a packed-bed solar reactor for the steam-gasification of carbonaceous feedstocks. Fuel processing technology, 2009; 90(3), 360-366.
48. Bellouard, Q., et al.A high temperature drop-tube and packed-bed solar reactor for continuous biomass gasification. in AIP Conference Proceedings, AIP Publishing.2017.
49. Wieckert, C. Solar Carbothermic Production of Zinc, SFERA Winter School Solar Fuels & Materials,2011; 32.
50. Pvt.Ltd, D.I. Inert Ceramic Balls [cited 2016 07/09]; Available from: http://devsongroup.com/site/index.php?pid=0009.0001.
51. Lopez-Hernandez, H.D. Experimental analysis and macroscopic and pore-level flow simulations to compare non-Darcy flow models in porous media. 2007.
52. Getachew, D., W. Minkowycz, and J. Lage. A modified form of the κ–ε model for turbulent flows of an incompressible fluid in porous media. International Journal of Heat and Mass Transfer, 2000; 43(16), 2909-2915.
53. Pedras, M.H. and M.J. de Lemos. Computation of Turbulent Flow in Porous Media Using a Low-Reynolds K-ε Modeland AN Infinite Array of Transversally Displaced Elliptic Rods. Numerical Heat Transfer: Part A: Applications, 2003; 43(6), 585-602.
54. Xu, C., Z. Song, and Y. Zhen. Numerical investigation on porous media heat transfer in a solar tower receiver. Renewable Energy,2011; 36(3), 1138-1144.
55. Alazmi, B. and K. Vafai. Analysis of variants within the porous media transport models. Journal of Heat Transfer, 2000; 122(2), 303-326.
56. Villafán-Vidales, H., et al. Heat transfer simulation in a thermochemical solar reactor based on a volumetric porous receiver. Applied Thermal Engineering,2011; 31(16), 3377-3386.
57. Vafai, K.a.A., A. Non-Darcian Effects in a confined Forced convective Flows,. Chemical Engineering Sciences,1998; 2523-2532.
58. Hwang, G.J.C.C.H. Heat Transfer Measurment and Analysis for Sintred Porous Channels ASME Journal Of Heat Transfer,1994; 456-464
59. Dixon, A.G.C., D. L. Theoretical Prediction of effective Heat Transfer Parameters in Pached Bed AIChE Journal,1979; 663-676.
60. Abenbach, E. Heat and flow charactaristics of packed beds. Experimental Thermal and fluid Science, 1995; 17-27.
61. Vafai, K. and A. Amiri. Non-Darcian effects in confined forced convective flows. Transport phenomena in porous media, 1998; 1, 313-329.
62. Nelson, A.T., et al. Thermal expansion, heat capacity, and thermal conductivity of Nickel Ferrite (NiFe2O4). Journal of the American Ceramic Society, 2014; 97(5), 1559-1565.
63. Massot, M., et al. Critical behavior of CoO and NiO from specific heat, thermal conductivity, and thermal diffusivity measurements. Physical Review B, 2008; 77(13), 134438.
64. Schrettle, F., et al. Wüstite: electric, thermodynamic and optical properties of FeO. The European Physical Journal B-Condensed Matter and Complex Systems,2012; 85(5): p. 1-12.
65. Lewis, F. and N. Saunders. The thermal conductivity of NiO and CoO at the Neel temperature. Journal of Physics C: Solid State Physics, 1973; 6(15), 2525.
66. Wu, Z., et al. Coupled radiation and flow modeling in ceramic foam volumetric solar air receivers. Solar Energy,2011; 85(9),2374-2385. 169

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