An Open Sorption Heat Storage Concept and Materials for Building Heat Supply

The potential of an open sorption storage process for space heating and hot water was evaluated using sorptive material namely zeolite 4A (low grade) and salt-based composite. Sorptive material beds of about 55 kg to 74 kg were able to generate an adsorption heat between 3 and 5 kWh and temperature shifts of the process air between 20 K and 25 K depending on the material type, the inlet air water content, and the state of dehydration of the storage materials. The evaluation of the composite material based on LiCl/MgSO4 and MgCl2/MgSO4 impregnated clinoptilolite (using max. desorption temperature of 110 °C) in a rotating heat drum showed that not agglomeration due to sticking of the grains happens, good controllability of the process was possible, and sufficient high temperature shifts for room heating applications were achieved.