Research Papers: Energy Systems Analysis

Study of Heat and Mass Transfer in MgCl2/NH3 Thermochemical Batteries

[+] Author and Article Information
Seyyed Ali Hedayat Mofidi

Sustainable Energy Laboratory,
Department of Mechanical Engineering,
University of Utah,
Salt Lake City, UT 84112
e-mail: Ali.Hedayat@Utah.edu

Kent S. Udell

Department of Mechanical Engineering,
University of Utah,
Salt Lake City, UT 84112
e-mail: Udell@mech.Utah.edu

1Corresponding author.

Contributed by the Advanced Energy Systems Division of ASME for publication in the JOURNAL OF ENERGY RESOURCES TECHNOLOGY. Manuscript received August 12, 2016; final manuscript received January 11, 2017; published online February 14, 2017. Assoc. Editor: Antonio J. Bula.

J. Energy Resour. Technol 139(3), 032005 (Feb 14, 2017) (10 pages) Paper No: JERT-16-1339; doi: 10.1115/1.4035750 History: Received August 12, 2016; Revised January 11, 2017

Intermittency of sustainable energy or waste heat availability calls for energy storage systems such as thermal batteries. Thermochemical batteries based on a reversible solid–gas (MgCl2–NH3) reactions and NH3 liquid–gas phase change are of specific interest since the kinetics of absorption are fast and the heat transfer rates for liquid–vapor phase change are high. Thus, a thermochemical battery based on reversible reaction between magnesium chloride and ammonia was studied. Two-dimensional experimental studies were conducted on a reactor in which temperature profiles within the solid matrix and pressure and flow rates of gas were obtained during discharging processes. A numerical model based on heat and mass transfer within the salt and salt–gas reactions was developed to simulate the NH3 absorption processes within the solid matrix, and the results were compared with experimental data to determine dominant heat and mass transfer processes within the salt. It is shown that for high permeability salt beds, the reactor uniformly adsorbs gaseous ammonia until the bed reaches the equilibrium temperature, then adsorbs gas near the cooled boundaries as the reaction front moves inward. In that mode, the heat transfer is the dominant factor in determining reaction rates.

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Gardie, P. , and Goetz, V. , 1995, “ Thermal Energy Storage System by Solid Absorption for Electric Automobile Heating and Air-Conditioning,” SAE Technical Paper No. 950017.
Li, T. X. , Wang, R. Z. , Oliveira, R. G. , Kiplagat, J. K. , and Wang, L. W. , 2009, “ A Combined Double-Way Chemisorption Refrigeration Cycle Based on Adsorption and Resorption Processes,” Int. J. Refrig., 32(1), pp. 47–57. [CrossRef]
Neveu, P. , and Castaing, J. , 1993, “ Solid-Gas Chemical Heat Pumps: Field of Application and Performance of the Internal Heat of Reaction Recovery Process,” Heat Recovery Syst. CHP, 13(3), pp. 233–251. [CrossRef]
Li, J. , Fan, P. , Zak Fang, Z. , and Zhou, C. , 2014, “ Kinetics of Isothermal Hydrogenation of Magnesium With TiH2 Additives,” Int. J. Hydrogen Energy, 39(14), pp. 7373–7381. [CrossRef]
McClaine, A. W. , Brown, K. , and Bowen, D. D. G. , 2015, “ Magnesium Hydride Slurry: A Better Answer to Hydrogen Storage,” J. Energy Resour. Technol., 137(6), p. 061201. [CrossRef]
van der Pal, M. , de Boer, R. , and Veldhuis, J. , 2013, “ Experimental Setup for Determining Ammonia-Salt Adsorption and Desorption Behavior Under Typical Heat Pump Conditions: Experimental Results,” ECN Biomass and Energy Efficiency, Paper No. IMPRES2013-084.
Haije, W. G. , Veldhuis, J. B. J. , Smeding, S. F. , and Grisel, R. J. H. , 2007, “ Solid/Vapour Sorption Heat Transformer: Design and Performance,” Appl. Therm. Eng., 27(8–9), pp. 1371–1376. [CrossRef]
Bao, H. , Wang, Y. , and Roskilly, A. P. , 2014, “ Modelling of a Chemisorption Refrigeration and Power Cogeneration System,” Appl. Energy, 119, pp. 351–362. [CrossRef]
Udell, K. S. , Kekelia, B. , Fan, P. , Zhou, C. , and Fang, Z. , 2015, “ Performance of a Multi-Cell MgCl2/NH3 Thermo-Chemical Battery During Recharge and Operation,” ASME Paper No. ES2015-49508.
Klerke, A. , Christensen, C. H. , Nørskov, J. K. , and Vegge, T. , 2008, “ Ammonia for Hydrogen Storage: Challenges and Opportunities,” J. Mater. Chem., 18(20), pp. 2304–2310. [CrossRef]
Sørensen, R. Z. , Hummelshøj, J. S. , Klerke, A. , Reves, J. B. , Vegge, T. , Nørskov, J. K. , and Christensen, C. H. , 2008, “ Indirect, Reversible High-Density Hydrogen Storage in Compact Metal Ammine Salts,” J. Am. Chem. Soc., 130(27), pp. 8660–8668. [CrossRef] [PubMed]
Christensen, C. H. , Sørensen, R. Z. , Johannessen, T. , Quaade, U. J. , Honkala, K. , Elmøe, T. D. , Køhler, R. , and Nørskov, J. K. , 2005, “ Metal Ammine Complexes for Hydrogen Storage,” J. Mater. Chem., 15(38), pp. 4106–4108. [CrossRef]
Hong, H. , Liu, Q. , and Jin, H. , 2009, “ Solar Hydrogen Production Integrating Low-Grade Solar Thermal Energy and Methanol Steam Reforming,” J. Energy Resour. Technol., 131(1), p. 012601. [CrossRef]
Berry, G. D. , and Aceves, S. M. , 2005, “ The Case for Hydrogen in a Carbon Constrained World,” J. Energy Resour. Technol., 127(2), pp. 89–94. [CrossRef]
Lu, H. , and Mazet, N. , 1999, “ Mass-Transfer Parameters in Gas-Solid Reactive Media to Identify Permeability of IMPEX,” AIChE J., 45(11), pp. 2444–2453. [CrossRef]
Huang, H. , Wu, G. , Yang, J. , Dai, Y. , Yuan, W. , and Lu, H. , 2004, “ Modeling of Gas–Solid Chemisorption in Chemical Heat Pumps,” Sep. Purif. Technol., 34(1–3), pp. 191–200. [CrossRef]
Lu, H. , Mazet, N. , and Spinner, B. , 1996, “ Modelling of Gas-Solid Reaction—Coupling of Heat and Mass Transfer With Chemical Reaction,” Chem. Eng. Sci., 51(15), pp. 3829–3845. [CrossRef]
Han, J. H. , Lee, K. , Kim, D. H. , and Kim, H. , 2000, “ Transformation Analysis of Thermochemical Reactor Based on Thermophysical Properties of Graphite–MnCl2 Complex,” Ind. Eng. Chem. Res., 39(11), pp. 4127–4139. [CrossRef]
Dutour, S. , Mazet, N. , Joly, J. L. , and Platel, V. , 2005, “ Modeling of Heat and Mass Transfer Coupling With Gas–Solid Reaction in a Sorption Heat Pump Cooled by a Two-Phase Closed Thermosyphon,” Chem. Eng. Sci., 60(15), pp. 4093–4104. [CrossRef]
Kekelia, B. , 2013, “ Heat Transfer to and From a Reversible Thermosiphon Placed in Porous Media,” Ph.D. dissertation, University of Utah, Salt Lake City, UT.
Elmøe, T. D. , Sørensen, R. Z. , Quaade, U. , Christensen, C. H. , Nørskov, J. K. , and Johannessen, T. , 2006, “ A High-Density Ammonia Storage/Delivery System Based on Mg(NH3)6Cl2 for SCR–DeNOx in Vehicles,” Chem. Eng. Sci., 61(8), pp. 2618–2625. [CrossRef]
Leineweber, A. , Friedriszik, M. W. , and Jacobs, H. , 1999, “ Preparation and Crystal Structures of Mg(NH3)2Cl2, Mg(NH3)2Br2, and Mg(NH3)2I2,” J. Solid State Chem., 147(1), pp. 229–234. [CrossRef]
Quintero, L. R. , 1981, “ On the Thermodynamic Properties of Hydrates and Ammines of Magnesium Chloride,” Master's thesis, McGill University, Montreal, QC.
Goetz, V. , and Marty, A. , 1992, “ A Model for Reversible Solid-Gas Reactions Submitted to Temperature and Pressure Constraints: Simulation of the Rate of Reaction in Solid-Gas Reactor Used as Chemical Heat Pump,” Chem. Eng. Sci., 47(17–18), pp. 4445–4454. [CrossRef]
Weller, H. G. , Tabor, G. , Jasak, H. , and Fureby, C. , 1998, “ A Tensorial Approach to Computational Continuum Mechanics Using Object-Oriented Techniques,” Comput. Phys., 12(6), pp. 620–631.
Song, X. F. , Wang, J. , Wang, X. T. , and Yu, J. G. , 2005, “Preparation of Anhydrous Magnesium Chloride From MgCl2·6H2O—II: Thermal Decomposition Mechanism of the Intermediate Product,” Mater. Sci. Forum, 488–489, pp. 61–64. [CrossRef]
Zhang, Q. , Pan, L. , Zhou, H. , Yuan, J. , Li, B. , Sun, Y. , and Zhou, B. , 2009, “ Investigation of Thermal Decomposition of Hexammoniate Magnesium Chloride by TG-DTA and DSC,” J. Salt Chem. Ind., 38(5), pp. 20–25.
Bevers, E. R. T. , Oonk, H. A. J. , Haije, W. G. , and van Ekeren, P. J. , 2007, “ Investigation of Thermodynamic Properties of Magnesium Chloride Amines by HPDSC and TG,” J. Therm. Anal. Calorim., 90(3), pp. 923–929. [CrossRef]
Long, G. , Ma, P. , Wu, Z. , Li, M. , and Chu, M. , 2004, “ Investigation of Thermal Decomposition of MgCl2 Hexammoniate and MgCl2 Biglycollate Biammoniate by DTA–TG, XRD and Chemical Analysis,” Thermochim. Acta, 412(1–2), pp. 149–153.
Zhu, H. , Gu, X. , Yao, K. , Gao, L. , and Chen, J. , 2009, “ Large-Scale Synthesis of MgCl2·6NH3 as an Ammonia Storage Material,” Ind. Eng. Chem. Res., 48(11), pp. 5317–5320. [CrossRef]
Kubota, M. , Matsuo, K. , Yamanouchi, R. , and Matsuda, H. , 2014, “ Absorption and Desorption Characteristics of NH3 With Metal Chlorides for Ammonia Storage,” J. Chem. Eng. Jpn., 47(7), pp. 542–548. [CrossRef]


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Fig. 2

Schematic of the experiment setup

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Fig. 1

Equilibrium line for magnesium chloride–ammonium reaction. Numbers after / indicate the number of ammonia molecules absorbed by the salt. Constants are reported from Ref.[3].

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Fig. 3

The method used to measure thermal conductivity: (a) central heater is on for short period of time and (b) slope of the curve at the left can be used to measure thermal conductivity

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Fig. 6

Pressure of reactor inlet and exit during absorption process

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Fig. 10

Temperature profiles of absorption process of case 1: (a), (c), (e), (g), and (i) obtained from experiment and (b), (d), (f), (h), and (j) obtained from numerical model

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Fig. 5

Mass flow rate of ammonia during absorption process in case 1

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Fig. 7

Variation of temperatures within salt–graphite complex during absorption process at location 6

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Fig. 8

Comparison of global reaction rate obtained by numerical simulation and experiment

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Fig. 9

Comparison of global reaction progress (based on mass of ammonia absorbed obtained by integration of flow rate of ammonia)

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Fig. 4

Geometry and boundary conditions used in numerical simulations

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Fig. 11

Radial profiles of reaction progress and temperature from numerical simulations

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Fig. 12

Contours of propagation of reaction. Each line shows Xm = 0.95 at different values for Xg. Note: R scale is different than x scale.



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