Protic ionic liquids mono, di, triethanolamine laurate as green phase change materials: thermal energy storage capacity and conversion to electricity.

A promising solution for challenges in thermal energy storage (TES) and its management is the use of phase change materials (PCMs). The ionic liquids (ILs) offer a unique properties that make them proper candidates for a number of energy related applications. The IL based PCMs are an important category of novel materials that significantly contribute to the efficient use and conservation of solar energy and wasted heat. This work presents a new family of ionic liquids (ILs) 2-hydroxyethylammonium, bis (2-hydroxyethyl) ammonium, and tris (2-hydroxyethyl) ammonium laurate as PCMs for the first time operating in the temperature range of 50–150 °C, and offer a safe and inexpensive capacity. The latent heat of fusion values were 147.13, 131.95 and 113.54 kJ·kg−1 for the [HEA]Lau, [DHEA]Lau and [THEA]Lau, respectively. Also, the thermal stability was obtained to be 99% for the [HEA]Lau. Finally, the thermal-to-electric energy conversion is performed using a homemade electronic data gathering and processing instrument with a PCMs (synthesized ILs) container cell and a commercial thermoelectric generator (TEG) device to record the real-time generated electric energy. The recorded output voltage (open circuit case) of TEG device versus time was measured that demonstrated that after turning off the thermal energy source, the proposed system provides the electric energy for a while (more than 2 h). [ABSTRACT FROM AUTHOR]