Thermochemical energy storage (TCES) is a novel heat storage technology with high heat storage density and capability of large-scale energy storage for a long time. This work describes a composite material which has improved mechanical and reaction properties based on Ca(OH)2/CaO heat storage system. Heavy tar was used as a binder of CaO particles. The mechanical and heat transfer properties of the composite are enhanced due to the matrix carbon structure produced by tar calcination. The most suitable material (tar content of 15 wt%, calcinated in N2 at 850 °C) was tested for 30 dehydration/ hydration cycles. The cyclic test shows that the composite has good mechanical and reaction properties with a crushing strength value of > 11 N and molar hydration conversion of > 90 % after 30 cycles.
Keywords Thermochemical Energy Storage, Calcium oxide, Composite material, Heavy tar