Gelation elimination in eco-friendly preparation of double-layered calcium alginate-coconut oil latent heat energy storing microcapsules

Latent heat storage by phase change materials (PCMs) has become an important research area due to the need of energy saving especially in the building sector. Environmental considerations require the intensified use of bio-originated materials instead of agents gained from mineral oil. Due to its melting point in the range of room temperature, the coconut oil is an available bio-originated PCM with low cost and high heat capacity. In this study, the main process parameters of coconut oil PCM-loaded calcium alginate microcapsules with double -layered shell were optimised. Viscosity of alginate solution, contact time, concentrations of alginate and cal-cium ions played important role in the process optimisation and waste reduction. In a thermal cycling test, it was confirmed that the microcapsules did not leak the PCM after 200 heating and cooling cycles.