Air-stable, earth-abundant molten chlorides and corrosion-resistant containment for chemically-robust, high-temperature thermal energy storage for concentrated solar power

MATERIALS TODAY

卷:46

Article

Caldwell, Adam S.¹  Itskos, Grigorios¹  Sandhage, Kenneth H.¹ 

[1] Purdue Univ, Sch Mat Engn, W Lafayette, IN 47907 USA

关键词: Thermal energy storage;    Molten chlorides;    Air stable;    Concentrated solar power;    High-temperature corrosion calculations;    Thermodynamic calculations;   

DOI  :  10.1016/j.mattod.2021.02.015

来源: Elsevier

【 摘 要 】

A dramatic reduction in man-made CO2 emissions could be achieved if the cost of electricity generated from concentrated solar power (CSP) plants could become competitive with fossil-fuel-derived electricity. The solar heat-to-electricity conversion efficiency of CSP plants may be significantly increased (and the associated electricity cost decreased) by operating CSP turbines with inlet temperatures >= 750 degrees C instead of <= 550 degrees C, and by using thermal energy storage (TES) at >750 degrees C to allow for rapidly dispatchable and/or continuous electricity production. Unfortunately, earth -abundant MgCl2-KCl-based liquids currently being considered as low-cost media for large-scale, high-temperature TES are susceptible to oxidation in ambient air, with associated undesired changes in liquid composition and enhanced corrosion of metal alloys in pipes and tanks containing such liquids. In this paper, alternative high-temperature, earth-abundant molten chlorides that are resistant to oxidation in ambient air are identified via thermodynamic calculations. The oxidation resistance, and corrosion-resistant containment, of such molten chlorides at 750 degrees C are then demonstrated. Such an air-tolerant strategy, involving chemically-robust, low-cost TES media paired with effective contain-ment materials, provides a critical advance towards the higher-temperature operation of, and lower-cost electricity generation from, CSP plants.

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