The increasing demand for energy, coupled with the negative environmental impact of fossil fuels, has led researchers to explore alternative, sustainable energy sources. Concentrated Solar Power (CSP), integrated with Thermochemical Energy Storage (TCES), emerges as a promising solution for meeting energy demands efficiently. Unlike other TCES systems, the CaCO₃/CaO pair stands out for its affordability, abundance, and safety.
Scientists Azhar Abbas Khosa and Xinyue Han from Jiangsu University, led by C.Y. Zhao at Shanghai Jiao Tong University have conducted groundbreaking large-scale experiments on the CaCO₃/CaO thermochemical energy storage (TCES) system.
This system has drawn attention for its potential application in Concentrated Solar Power (CSP) plants. The extensive laboratory studies address the critical need for large-scale experiments to provide a detailed analysis for real-time applications.
Key Findings:
- Packed Bed Reactor Development: The researchers constructed a packed bed reactor capable of high-temperature and high-pressure operation, specifically designed for the carbonation and decarbonation reactions of the CaCO₃/CaO pair.
- Decarbonation Temperature Optimisation: The study focused on understanding the heat storage process concerning different decarbonation temperatures. Results revealed that the heat storage rate and efficiency significantly improve at temperatures above 925 °C, highlighting the necessity of high-temperature operation for optimal performance.
- Sample Size Impact: The research explored the influence of sample sises on both decarbonation and carbonation processes. Findings suggest that the heat storage and release processes are affected by the amount of sample in grams, providing insights to optimise the system.
- Pure vs. Composite Samples: A comparison was made between the heat storage performance of pure and composite samples. The study indicated that composite samples exhibit promising results, potentially enhancing the overall efficiency of the CaCO₃/CaO TCES system.
- CO₂ Concentration Influence: The heat release process was examined by varying the concentration of CO₂. Results demonstrated that a higher concentration of CO₂ in the reactor leads to a smooth and efficient release of heat, emphasising the system’s potential as a heat pump.
- CaCO₃/CaO TCES System as a Heat Pump: The study affirms that the CaCO₃/CaO TCES system has the capability to function as a heat pump, effectively upgrading the temperature of released heat from lower to higher values.
This research provides crucial insights into the performance of the CaCO₃/CaO TCES system, shedding light on key parameters such as temperature, sample size, and composite materials. The use of a packed bed reactor in large-scale experiments opens avenues for industrial applications, offering guidelines for the design and optimisation of CaCO₃/CaO-based thermochemical energy storage systems. The study marks a significant step towards the practical implementation of this system in CSP plants, contributing to the global transition to cleaner and sustainable energy sources.
Source
Experimental investigation of CaCO₃/CaO reaction pair in a fixed bed reactor for CSP application, Renewable Energy, Elsevier, via ScienceDirect, 2024-02
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