The aim of this thesis is to validate the suitability of a clinoptilolite-calcium chloride composite material for its use in thermochemical energy storage applications. The practical part of this thesis involves two subtasks, one of which was that an existing experimental setup was optimised. The biggest improvement is the possibility to accurately adjust the relative humidity of the used synthetic air. Subsequently, pure clinoptilolite, the synthetic zeolite 13XBF as well as composites with different mass fractions of salt and hydrophobicity treatment were studied in the same desorption-adsorption cycle. With the help of thorough literature research, the results are ascribed to the complex process in the sorption reactor. It shows that the salt impregnation is able to improve the thermal properties of the pure zeolite. The hydrophobicity treatment turns out to be a suitable way of stabilising the salt on the zeolite surface. Problems, which make the applicability of the composite materials unviable at this time, are explained and analysed in order to lead the way for future research.