Dehydration performance improvement of calcium hydroxide/calcium oxide system based on horizontal biaxial stirred reactor

The calcium hydroxide/calcium oxide (Ca(OH)2/CaO) system, with low cost, high energy density, and a reaction temperature range of 300–600 °C, makes it an ideal candidate for thermochemical heat storage. However, the low thermal conductivity of the material leads to poor heat transfer and low reaction efficiency. In this work, a novel reactor of horizontal biaxial stirred reactor (HBSR) was developed, the multi-physics field coupling mechanism in the reactor was revealed, and its feasibility in dehydration process enhancement was demonstrated. The results showed that the HBSR enhanced the solid fluidity and had good dehydration performance. Numerical simulations explored the effect of different reaction conditions, and it was found that the wall temperature was the key parameter affecting the dehydration process. Experimental tests further verified the excellent dehydration performance of the HBSR, with an increase of more than 2.65 times in the reaction rate and a 93.5 % increase in the bed temperature uniformity compared with the fixed bed reactor (FBR). Additionally, the powder behaviors of agglomeration and elutriation were identified, emphasizing the need for optimization of the reactor structure. Overall, this work provides a fascinating option for the design and performance improvement of future heat storage reactors.