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The Use of Ammonium Carbamate as a High Energy Density Thermal Energy Storage Material

  • Joel E. Schmidt (a1) (a2), Douglas S. Dudis (a1) and Douglas J. Miller (a3)

Phase change materials (PCMs) often have higher specific energy storage capacities at elevated temperatures. Thermal management (TM) systems capable of handling high heat fluxes in the temperature range from 20–100°C are necessary but lacking. State of the art PCMs in this temperature range are usually paraffin waxes with energy densities on the order of a few hundred kJ/kg or ice slurries with energy densities of the same magnitude. However, for applications where system weight and size are limited, it is necessary to improve this energy density by at least an order of magnitude. The compound ammonium carbamate, [NH4][H2NCOO], is a solid formed from the reaction of ammonia and carbon dioxide which endothermically decomposes back to CO2 and NH3 in the temperature range 20-100°C with an enthalpy of decomposition of ∼2,000 kJ/kg. Various methods to use this material for TM of low-grade, high-flux heat have been evaluated including: bare powder, thermally conductive carbon foams, thermally conductive metal foams, hydrocarbon based slurries, and a slurry in ethylene glycol or propylene glycol. A slurry in glycol is a promising system medium for enhancing heat and mass transfer for TM. Progress on material and system characterization is reported.

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1.Lafdi, K., Mesalhy, O., and Elgafy, A., “Graphite foams infiltrated with phase change materials as alternative materials for space and terrestrial thermal energy storage applications,” Carbon 46[1] 159– 68 (2008).
2.Zhong, Y., Li, S., Wei, X., Liu, Z., Guo, Q., Shi, J., and Liu, L., “Heat transfer enhancement of paraffin wax using compressed expanded natural graphite for thermal energy storage,” Carbon 48 300304 (2009).
3.Leong, K.C. and Jin, L.W., “Study of highly conductive graphite foams in thermal management applications,” Adv. Eng. Mater. 10[4] 338–45 (2008).
4.Mesalhy, O., Lafdi, K. and Elgafy, A., “Carbon foam matrices saturated with PCM for thermal protection purposes,” Carbon 44[10] 2080–8(2006).
5.Py, X., Olives, R. and Mauran, S., “Paraffin/porous-graphite-matrix composite as a high and constant power thermal storage material,” Int. J. Heat Mass Transfer 44[14] 2727–37 (2001).
6.Klett, J.W. and Burchell, T.D., “Pitch-based carbon foam heat sink with phase change material,” U.S. Pat. 7,166,237, January 2007.
7.Park, C., Vallury, A. and Perez, J., “Advanced hybrid cooling loop technology for high performance thermal management,” Proc. 4th Intl. Energy Convers. Eng. Conf., San Diego, CA, 2006.
8.Klatt, N.D., “On-Board Thermal Management of Waste Heat from a High-Energy Device,” M.S. Thesis. Air Force Institute of Technology, Wright-Patterson AFB, OH, 2008.
9.Meessen, J.H. and Petersen, H., Urea. Wiley-VCH, 2000.
10.LeFrois, R.T., “Solar Energy Heat Utilization,” U.S. Pat. 4,169,499, 1979.
11.Koutinas, A.A., Yianoulis, P. and Lycourghiotis, A., “Industrial scale modelling of the thermochemical energy storage system based on CO2 + 2NH3<–> NH2COONH4 equilibrium,” Energy Convers. Manage. 23[1] 5563 (1983).
12.Briggs, T. R. and Migrdichian, V., “The Ammonium Carbamate Equilibrium,” J. Phys. Chem. 28[11] 1121–35 (1924).
13.Egan, E.P., Potts, J.E. and Potts, G.D., “Dissociation Pressure of Ammonium Carbamate,” Ind. Eng. Chem. 38[4] 454–6 (1946).
14.Bennett, R.N., Ritchie, P.D., Roxburgh, D. and Thomson, J., “The system ammonia carbon dioxide ammonium carbamate. Part I-The equilibrium of thermal dissociation of ammonium carbamate,” Trans. Faraday Soc. 49 925–9 (1953).
15.Joncich, M.J., Solka, B.H. and Bower, J.E., “The thermodynamic properties of ammonium carbamate: An experiment in heterogeneous equilibrium,” J. Chem. Educ. 44[10] 598 (1967).
16.Schmidt, J.E., Dudis, D.S., Miller, D.J. and Susoreny, J., Proceedings of the 42nd AIAA Thermophysics Conference, Honolulu, HI, 2011.
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