Thermochemical energy storage and conversion: A-state-of-the-art review of the experimental research under practical conditions

Application of Chemical Heat Pumps for Temperature

“…An extensive literature exists on the ChHPs, which have been typically used for thermal energy storage, space heating and cooling (including refrigeration), drying, and thermoamplification (Wongsuwan et al 2001). In general, the ChHPs can be classified into those based on sorption processes and those based on chemical reactions (Cot-Gores et al 2012). The following figure (Figure 3) summarizes the various inorganic ChHPs systems that have been experimentally investigated.…”

“…The hydration/dehydration and carbonation/decarbonation ChHPs systems are typified through the following reactions involving Ca (Cot-Gores et al 2012 (Guo and Huai 2012).…”

Long-Term Durability and Reactivation of Thermochemical Heat Storage Driven by the CaO/Ca(OH)<sub>2</sub> Reversible Reaction

“…Thermochemical heat storage systems have a high potential for energy saving owing to their high heat storing capacity and low heat loss [1] [2]. The chemical system explored in this study is based on the CaO/Ca(OH) 2 reversible reaction, as shown in Equation (1), which involves low cost and environmentally friendly materials.…”

“…Although 1000 -10,000 stable charging/discharging operations are generally considered suitable for practical applications, reactant deactivation by sintering remains a concern for reactions requiring high charging temperatures, such as MgO/Mg(OH) 2 , [3] CaO/Ca(OH) 2 , and CaO/CaCO 3 , [4] as sintering leads to the formation of granulated and densified reactant particles and the disappearance of surface structures.…”

“…Compared with MgO/Mg(OH) 2 and CaO/CaCO 3 , the CaO/Ca(OH) 2 reaction exhibits superior repetitive durability, as constant reaction rates and final conversions have been confirmed over 50 -100 repetitions using small-scale thermogravimetric analysis [5] [6] [7]. However, durability remains problematic, as various factors affect the sintering rate, including the state of the packed bed and the charging/discharging conditions, such as packing density, particle size, temperature, atmospheric gas species, gas pressure, and reaction time.…”