Bio-based sustainable organic eutectic PCMs for thermal energy systems: Comprehensive assessment

The integration of phase change materials (PCM) in thermal energy systems (TES) has enhanced thermal management efficiency. Eutectic PCMs are gaining attention for their sharp melting points and high volumetric heat storage. Incorporating bio-based components into eutectic PCMs not only improves sustainability and thermal performance but also promotes localized, eco-friendly production of advanced energy storage materials. To the best of the authors' knowledge, a comprehensive assessment specifically addressing the role of bio-based materials as substitute PCMs in organic eutectic formulations, with a detailed focus on their thermo-physical characteristics, performance enhancement strategies for enhancing thermal conductivity, super cooling suppression, anti-leak tendency, energy density, corrosion resistance, and their applicability in TES has not been reported. This comprehensive assessment, structured into six phases and based on recent and relevant research studies, focuses exclusively on the contribution of bio-materials as substitution media in organic eutectic PCM formulations. Furthermore, for each examined study, limitations and implications are discussed in order to identify research gaps for further improvements. Reviewed studies show those pure and derivative sustainable organic eutectic PCMs (SOEP) exhibit melting points from −24.6 °C to 66.05 °C and energy densities between 34 and 367.6 J/g, indicating strong potential for low to medium temperature TES applications. Challenges, environmental impact of SOEP, and their applications in TES systems are summarized. The evolving prospects in this field offer significant potential for advancing thermally efficient and cost-effective TES systems, supporting to a sustainable energy transition and aligning with key sustainable development goals, particularly SDGs 7 and 13.