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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-421-2

International Heat Transfer Conference 15
August, 10-15, 2014, Kyoto, Japan

Non-Isothermal Kinetics of Zeolite Water Vapor Adsorption Into a Packed Bed Lab Scale Thermochemical Reactor

Get access (open in a dialog) DOI: 10.1615/IHTC15.tst.009169
pages 9053-9063

Abstract

Replacing fossil fuels by solar energy is of high interest to reduce climate change and depletion of fossil fuel resources. However, to reach high solar fractions, storage of solar energy is necessary. A reliable method for long term solar heat storage is to use thermochemical materials, TCMs. The process is based on a reversible adsorption-desorption reaction, which is exothermic in one direction (hydration) and endothermic in the reverse direction (dehydration). In this research, a lab-scale prototype thermochemical heat storage system was tested. In the experimental setup, moist air enters a reactor vessel filled with dehydrated zeolite 13X. The temperature profile is measured as a function of time both along the flow direction and perpendicular to the flow. Input and output temperatures, pressures and humidity are measured. In addition, a thermal model is developed for the packed bed during the hydration of the zeolite. The model includes mass and heat transfer in the gas, the packed bed and the reactor wall, as well as the adsorption reaction of water vapor on the zeolite which is described by a Linear Driving Force model. Equilibrium constants are modeled as a function of temperature. By comparing the temperatures of the experimental investigation with the results of the numerical simulation model, the kinetic parameters for the adsorption in non-isothermal and non-adiabatic conditions are found. In the near future, the developed numerical model will be used to simulate the heat and vapor transport processes in a large-scale reactor system.