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2023
Conference Paper
Title
Preliminary testing and evaluation of two zeolites for integration of a sorption system into industrial tumble dryers
Abstract
Open sorption systems based on the adsorption and desorption of water on zeolites promise energy savings by leveraging either the heat pump effect or the storage effect, or even both. The challenge consists in transferring these potential energy savings to matching applications. An application with high potential are industrial tumble dryers where high humidity and temperature requirements necessitate in-depth material characterisation and testing. It was investigated, if it is possible to acquire equilibrium data with an existing self-built hydrothermal test setup to determine the characteristic curves of zeolites CWK 13XBFK and CWK NaYBFK. The characteristic curve relates the adsorbed water volume to the adsorption potential They were determined for an adsorption potential (F) between 81 kJ kg-1 ≤ F ≤ 2192 kJ kg-1. The obtained characteristic curves are in good agreement with existing ones from other sources. Evaluating CWK 13XBFK and CWK NaYBFK under desorption and adsorption conditions identified for the industrial tumble dryer, similar binding enthalpies of around 180 kJ kg-1 and 181 kJ kg-1, respectively, were calculated with the experimentally determined equilibrium data. The equilibrium data also served as input for the method of the characteristic temperature difference. With this method, the driving temperature differences as measures for the potential sorption dynamics in adsorption and desorption under temperature boundary conditions of the application can be assessed. Results show that under the given application conditions, 13XBFK would be the superior choice. Furthermore, preliminary ageing tests were carried out on both zeolites with desorption conditions of 300 °C temperature and 60 °C dew point temperature in a self-built cycling device. After 140 cycles, a decrease of 36.5% in the water uptake of 13XBFK was determined, while the decrease was only 3.3% for NaYBFK. Therefore, these preliminary measurements already allow eliminating 13XBFK as zeolite for application in industrial tumble dryers.
Author(s)
Conference
Rights
Under Copyright
Language
English