What about greener phase change materials? A review on biobased phase change materials for thermal energy storage applications

The increasing energy demand in conjunction with greater environmental concern has lifted the development of sustainable energy sources, including materials for energy storage. The use of phase change materials (PCM) for thermal energy storage (TES) has become one of the emerging research fields. Paraffins are currently the most studied organic PCMs for TES applications due to their favorable physical and thermal properties. However, they are produced from non-renewable sources and their carbon footprint and associated environmental impact cannot be overlooked. A green alternative are the biobased PCMs such as fatty acid esters andfatty acids. The present paper reviews the current research status of biobased PCMs with focus on various limitations and drawbacks, and on strategies adopted for improving their TES characteristics. The paper also discusses the use of waste biomaterials such as waste cooking oil and non-edible plant oils as potential alternatives to edible oil based PCMs. Novel strategies which could serve as a cornerstone for further research on new biobased PCMs for the future, are also discussed.