Amghar, Nabil , Perejon, Antonio , ORTIZ DOMÍNGUEZ, CARLOS, Maqueda, Luis A. Perez , Sanchez-Jimenez, Pedro E.
No
Energy Fuels
Article
Científica
5.2
1.018
20/10/2023
001092709500001
2-s2.0-85177077575
Long-term storage capability is often claimed as one of the distinct advantages of the calcium looping process as a potential thermochemical energy storage system for integration into solar power plants. However, the influence of storage conditions on the looping performance has seldom been evaluated experimentally. The storage conditions must be carefully considered as any potential carbonation at the CaO storage tank would reduce the energy released during the subsequent carbonation, thereby penalizing the round-trip efficiency. From lab-scale to conceptual process engineering, this work considers the effects of storing solids at low temperatures (50-200 degrees C) in a CO2 atmosphere or at high temperatures (800 degrees C) in N-2. Experimental results show that carbonation at temperatures below 200 degrees C is limited; thus, the solids could be stored during long times even in CO2. It is also demonstrated at the lab scale that the multicycle performance is not substantially altered by storing the solids at low temperatures (under CO2) or high temperatures (N-2 atmosphere). From an overall process perspective, keeping solids at high temperatures leads to easier heat integration, a better plant efficiency (+2-4%), and a significantly higher energy density (+40-62%) than considering low-temperature storage. The smooth difference in the overall plant efficiency with the temperature suggests a proper long-term energy storage performance if adequate energy integration is carried out.
Atmospheric temperature; Calcium; Carbonation; Energy storage; Integration; Solar energy; Solar power plants; Calcium looping; Highest temperature; Long-term storage; Lows-temperatures; Performance; Plant efficiency; Storage capability; Storage condition; Thermochemical energy storage; Thermochemicals; Carbon dioxide