Power cycles integration in concentrated solar power plants with energy storage based on calcium looping

• Published in: Energy conversion and management 2017-10, Vol.149, p.815-829
• Main Authors: Ortiz, C., Chacartegui, R., Valverde, J.M., Alovisio, A., Becerra, J.A.
• Format: Article
• Language: English
• Subjects: Brayton cycle; Calcium; Calcium carbonate; Calcium Looping (CaL); Calcium oxide; Carbon cycle; Carbon dioxide; Carbonation; Concentrated Solar Power (CSP); Electricity generation; Energy efficiency; Energy storage; Exothermic reactions; Global warming; High temperature; Integration; Internal energy; Lime; Power cycles; Power plants; Rankine cycle; Renewable energies; Roasting; Solar energy; Solar power; Steam electric power generation; Stored products; Studies; Supercritical CO2 power cycle; Thermal energy; Thermochemical Energy Storage (TCES)
• ISSN: 0196-8904; 1879-2227
• DOI: 10.1016/j.enconman.2017.03.029

•The use of Calcium-Looping for storage of concentrated solar energy is studied.•Diverse power cycles coupled to the Calcium-Looping process are analysed.•High solar plant efficiency can be achieved using a closed carbon dioxide Brayton cycle. Efficient, low-cost and environmentally friendly storage of thermal energy stands as a main challenge for large scale deployment of solar energy. This work explores the integration into concentrated solar power plants of the calcium looping process based upon the reversible carbonation/calcination of calcium oxide for thermochemical energy storage. An efficient concentrated solar power-calcium looping integration would allow storing energy in the long term by calcination of calcium carbonate thus overcoming the hurdle of variable power generation from solar. After calcination, the stored products of the reaction (calcium oxide and carbon dioxide) are brought together in a carbonator reactor whereby the high temperature exothermic reaction releases the stored energy for efficient power production when needed. This work analyses several power cycle configurations with the main goal of optimizing the performance of the overall system integration. Possible integration schemes are proposed in which power production is carried out directly (using a closed carbon dioxide Brayton power cycle) or indirectly (by means of a steam reheat Rankine cycle or a supercritical carbon dioxide Brayton cycle). The results obtained show that the highest plant efficiencies (up to 45–46%) are achievable using a closed carbon dioxide Brayton power cycle.